refactor(transcoding): update default command handling and add codec support for transcoding

Signed-off-by: Deluan <deluan@navidrome.org>

adapters/deezer/client_auth_test.go

@@ -252,7 +252,7 @@ var _ = Describe("JWT Authentication", func() {
 
 			// Writer goroutine
 			wg.Go(func() {
-				for i := 0; i < 100; i++ {
+				for i := range 100 {
 					cache.set(fmt.Sprintf("token-%d", i), 1*time.Hour)
 					time.Sleep(1 * time.Millisecond)
 				}
@@ -260,7 +260,7 @@ var _ = Describe("JWT Authentication", func() {
 
 			// Reader goroutine
 			wg.Go(func() {
-				for i := 0; i < 100; i++ {
+				for range 100 {
 					cache.get()
 					time.Sleep(1 * time.Millisecond)
 				}

adapters/gotaglib/gotaglib.go

@@ -49,6 +49,7 @@ func (e extractor) Version() string {
 func (e extractor) extractMetadata(filePath string) (*metadata.Info, error) {
 	f, close, err := e.openFile(filePath)
 	if err != nil {
+		log.Warn("gotaglib: Error reading metadata from file. Skipping", "filePath", filePath, err)
 		return nil, err
 	}
 	defer close()
@@ -64,6 +65,7 @@ func (e extractor) extractMetadata(filePath string) (*metadata.Info, error) {
 		Channels:   int(props.Channels),
 		SampleRate: int(props.SampleRate),
 		BitDepth:   int(props.BitsPerSample),
+		Codec:      props.Codec,
 	}
 
 	// Convert normalized tags to lowercase keys (go-taglib returns UPPERCASE keys)
@@ -254,7 +256,7 @@ func parseTIPL(tags map[string][]string) {
 	}
 	var currentRole string
 	var currentValue []string
-	for _, part := range strings.Split(tipl[0], " ") {
+	for part := range strings.SplitSeq(tipl[0], " ") {
 		if _, ok := tiplMapping[part]; ok {
 			addRole(currentRole, currentValue)
 			currentRole = part

adapters/lastfm/auth_router.go

@@ -65,7 +65,7 @@ func (s *Router) routes() http.Handler {
 }
 
 func (s *Router) getLinkStatus(w http.ResponseWriter, r *http.Request) {
-	resp := map[string]interface{}{
+	resp := map[string]any{
 		"apiKey": s.apiKey,
 	}
 	u, _ := request.UserFrom(r.Context())

adapters/listenbrainz/auth_router.go

@@ -60,7 +60,7 @@ func (s *Router) routes() http.Handler {
 }
 
 func (s *Router) getLinkStatus(w http.ResponseWriter, r *http.Request) {
-	resp := map[string]interface{}{}
+	resp := map[string]any{}
 	u, _ := request.UserFrom(r.Context())
 	key, err := s.sessionKeys.Get(r.Context(), u.ID)
 	if err != nil && !errors.Is(err, model.ErrNotFound) {
@@ -107,7 +107,7 @@ func (s *Router) link(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	_ = rest.RespondWithJSON(w, http.StatusOK, map[string]interface{}{"status": resp.Valid, "user": resp.UserName})
+	_ = rest.RespondWithJSON(w, http.StatusOK, map[string]any{"status": resp.Valid, "user": resp.UserName})
 }
 
 func (s *Router) unlink(w http.ResponseWriter, r *http.Request) {

adapters/listenbrainz/auth_router_test.go

@@ -37,7 +37,7 @@ var _ = Describe("ListenBrainz Auth Router", func() {
 			req = httptest.NewRequest("GET", "/listenbrainz/link", nil)
 			r.getLinkStatus(resp, req)
 			Expect(resp.Code).To(Equal(http.StatusOK))
-			var parsed map[string]interface{}
+			var parsed map[string]any
 			Expect(json.Unmarshal(resp.Body.Bytes(), &parsed)).To(BeNil())
 			Expect(parsed["status"]).To(Equal(false))
 		})
@@ -47,7 +47,7 @@ var _ = Describe("ListenBrainz Auth Router", func() {
 			req = httptest.NewRequest("GET", "/listenbrainz/link", nil)
 			r.getLinkStatus(resp, req)
 			Expect(resp.Code).To(Equal(http.StatusOK))
-			var parsed map[string]interface{}
+			var parsed map[string]any
 			Expect(json.Unmarshal(resp.Body.Bytes(), &parsed)).To(BeNil())
 			Expect(parsed["status"]).To(Equal(true))
 		})
@@ -80,7 +80,7 @@ var _ = Describe("ListenBrainz Auth Router", func() {
 			req = httptest.NewRequest("PUT", "/listenbrainz/link", strings.NewReader(`{"token": "tok-1"}`))
 			r.link(resp, req)
 			Expect(resp.Code).To(Equal(http.StatusOK))
-			var parsed map[string]interface{}
+			var parsed map[string]any
 			Expect(json.Unmarshal(resp.Body.Bytes(), &parsed)).To(BeNil())
 			Expect(parsed["status"]).To(Equal(true))
 			Expect(parsed["user"]).To(Equal("ListenBrainzUser"))

adapters/listenbrainz/client.go

@@ -75,14 +75,14 @@ const (
 
 type listenInfo struct {
 	ListenedAt    int           `json:"listened_at,omitempty"`
-	TrackMetadata trackMetadata `json:"track_metadata,omitempty"`
+	TrackMetadata trackMetadata `json:"track_metadata"`
 }
 
 type trackMetadata struct {
 	ArtistName     string         `json:"artist_name,omitempty"`
 	TrackName      string         `json:"track_name,omitempty"`
 	ReleaseName    string         `json:"release_name,omitempty"`
-	AdditionalInfo additionalInfo `json:"additional_info,omitempty"`
+	AdditionalInfo additionalInfo `json:"additional_info"`
 }
 
 type additionalInfo struct {

adapters/spotify/client.go

@@ -73,7 +73,7 @@ func (c *client) authorize(ctx context.Context) (string, error) {
 	auth := c.id + ":" + c.secret
 	req.Header.Add("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(auth)))
 
-	response := map[string]interface{}{}
+	response := map[string]any{}
 	err := c.makeRequest(req, &response)
 	if err != nil {
 		return "", err
@@ -86,7 +86,7 @@ func (c *client) authorize(ctx context.Context) (string, error) {
 	return "", errors.New("invalid response")
 }
 
-func (c *client) makeRequest(req *http.Request, response interface{}) error {
+func (c *client) makeRequest(req *http.Request, response any) error {
 	log.Trace(req.Context(), fmt.Sprintf("Sending Spotify %s request", req.Method), "url", req.URL)
 	resp, err := c.hc.Do(req)
 	if err != nil {

cmd/wire_gen.go

@@ -19,6 +19,7 @@ import (
 	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/playback"
 	"github.com/navidrome/navidrome/core/scrobbler"
+	"github.com/navidrome/navidrome/core/transcode"
 	"github.com/navidrome/navidrome/db"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/persistence"
@@ -102,7 +103,8 @@ func CreateSubsonicAPIRouter(ctx context.Context) *subsonic.Router {
 	modelScanner := scanner.New(ctx, dataStore, cacheWarmer, broker, playlists, metricsMetrics)
 	playTracker := scrobbler.GetPlayTracker(dataStore, broker, manager)
 	playbackServer := playback.GetInstance(dataStore)
-	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, modelScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics)
+	decider := transcode.NewDecider(dataStore)
+	router := subsonic.New(dataStore, artworkArtwork, mediaStreamer, archiver, players, provider, modelScanner, broker, playlists, playTracker, share, playbackServer, metricsMetrics, decider)
 	return router
 }
 

conf/configuration.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"strings"
 	"time"
 
@@ -433,7 +434,7 @@ func mapDeprecatedOption(legacyName, newName string) {
 func parseIniFileConfiguration() {
 	cfgFile := viper.ConfigFileUsed()
 	if strings.ToLower(filepath.Ext(cfgFile)) == ".ini" {
-		var iniConfig map[string]interface{}
+		var iniConfig map[string]any
 		err := viper.Unmarshal(&iniConfig)
 		if err != nil {
 			_, _ = fmt.Fprintln(os.Stderr, "FATAL: Error parsing config:", err)
@@ -466,7 +467,7 @@ func disableExternalServices() {
 }
 
 func validatePlaylistsPath() error {
-	for _, path := range strings.Split(Server.PlaylistsPath, string(filepath.ListSeparator)) {
+	for path := range strings.SplitSeq(Server.PlaylistsPath, string(filepath.ListSeparator)) {
 		_, err := doublestar.Match(path, "")
 		if err != nil {
 			log.Error("Invalid PlaylistsPath", "path", path, err)
@@ -480,7 +481,7 @@ func validatePlaylistsPath() error {
 // It trims whitespace from each entry and ensures at least [DefaultInfoLanguage] is returned.
 func parseLanguages(lang string) []string {
 	var languages []string
-	for _, l := range strings.Split(lang, ",") {
+	for l := range strings.SplitSeq(lang, ",") {
 		l = strings.TrimSpace(l)
 		if l != "" {
 			languages = append(languages, l)
@@ -494,13 +495,7 @@ func parseLanguages(lang string) []string {
 
 func validatePurgeMissingOption() error {
 	allowedValues := []string{consts.PurgeMissingNever, consts.PurgeMissingAlways, consts.PurgeMissingFull}
-	valid := false
-	for _, v := range allowedValues {
-		if v == Server.Scanner.PurgeMissing {
-			valid = true
-			break
-		}
-	}
+	valid := slices.Contains(allowedValues, Server.Scanner.PurgeMissing)
 	if !valid {
 		err := fmt.Errorf("invalid Scanner.PurgeMissing value: '%s'. Must be one of: %v", Server.Scanner.PurgeMissing, allowedValues)
 		log.Error(err.Error())

consts/consts.go

@@ -151,7 +151,13 @@ var (
 			Name:           "aac audio",
 			TargetFormat:   "aac",
 			DefaultBitRate: 256,
-			Command:        "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f adts -",
+			Command:        "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -",
+		},
+		{
+			Name:           "flac audio",
+			TargetFormat:   "flac",
+			DefaultBitRate: 0,
+			Command:        "ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -",
 		},
 	}
 )

core/agents/agents_test.go

@@ -365,7 +365,7 @@ var _ = Describe("Agents", func() {
 })
 
 type mockAgent struct {
-	Args []interface{}
+	Args []any
 	Err  error
 }
 
@@ -374,7 +374,7 @@ func (a *mockAgent) AgentName() string {
 }
 
 func (a *mockAgent) GetArtistMBID(_ context.Context, id string, name string) (string, error) {
-	a.Args = []interface{}{id, name}
+	a.Args = []any{id, name}
 	if a.Err != nil {
 		return "", a.Err
 	}
@@ -382,7 +382,7 @@ func (a *mockAgent) GetArtistMBID(_ context.Context, id string, name string) (st
 }
 
 func (a *mockAgent) GetArtistURL(_ context.Context, id, name, mbid string) (string, error) {
-	a.Args = []interface{}{id, name, mbid}
+	a.Args = []any{id, name, mbid}
 	if a.Err != nil {
 		return "", a.Err
 	}
@@ -390,7 +390,7 @@ func (a *mockAgent) GetArtistURL(_ context.Context, id, name, mbid string) (stri
 }
 
 func (a *mockAgent) GetArtistBiography(_ context.Context, id, name, mbid string) (string, error) {
-	a.Args = []interface{}{id, name, mbid}
+	a.Args = []any{id, name, mbid}
 	if a.Err != nil {
 		return "", a.Err
 	}
@@ -398,7 +398,7 @@ func (a *mockAgent) GetArtistBiography(_ context.Context, id, name, mbid string)
 }
 
 func (a *mockAgent) GetArtistImages(_ context.Context, id, name, mbid string) ([]ExternalImage, error) {
-	a.Args = []interface{}{id, name, mbid}
+	a.Args = []any{id, name, mbid}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -409,7 +409,7 @@ func (a *mockAgent) GetArtistImages(_ context.Context, id, name, mbid string) ([
 }
 
 func (a *mockAgent) GetSimilarArtists(_ context.Context, id, name, mbid string, limit int) ([]Artist, error) {
-	a.Args = []interface{}{id, name, mbid, limit}
+	a.Args = []any{id, name, mbid, limit}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -420,7 +420,7 @@ func (a *mockAgent) GetSimilarArtists(_ context.Context, id, name, mbid string,
 }
 
 func (a *mockAgent) GetArtistTopSongs(_ context.Context, id, artistName, mbid string, count int) ([]Song, error) {
-	a.Args = []interface{}{id, artistName, mbid, count}
+	a.Args = []any{id, artistName, mbid, count}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -431,7 +431,7 @@ func (a *mockAgent) GetArtistTopSongs(_ context.Context, id, artistName, mbid st
 }
 
 func (a *mockAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*AlbumInfo, error) {
-	a.Args = []interface{}{name, artist, mbid}
+	a.Args = []any{name, artist, mbid}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -444,7 +444,7 @@ func (a *mockAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string)
 }
 
 func (a *mockAgent) GetSimilarSongsByTrack(_ context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
-	a.Args = []interface{}{id, name, artist, mbid, count}
+	a.Args = []any{id, name, artist, mbid, count}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -455,7 +455,7 @@ func (a *mockAgent) GetSimilarSongsByTrack(_ context.Context, id, name, artist,
 }
 
 func (a *mockAgent) GetSimilarSongsByAlbum(_ context.Context, id, name, artist, mbid string, count int) ([]Song, error) {
-	a.Args = []interface{}{id, name, artist, mbid, count}
+	a.Args = []any{id, name, artist, mbid, count}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -466,7 +466,7 @@ func (a *mockAgent) GetSimilarSongsByAlbum(_ context.Context, id, name, artist,
 }
 
 func (a *mockAgent) GetSimilarSongsByArtist(_ context.Context, id, name, mbid string, count int) ([]Song, error) {
-	a.Args = []interface{}{id, name, mbid, count}
+	a.Args = []any{id, name, mbid, count}
 	if a.Err != nil {
 		return nil, a.Err
 	}
@@ -488,12 +488,12 @@ type testImageAgent struct {
 	Name   string
 	Images []ExternalImage
 	Err    error
-	Args   []interface{}
+	Args   []any
 }
 
 func (t *testImageAgent) AgentName() string { return t.Name }
 
 func (t *testImageAgent) GetArtistImages(_ context.Context, id, name, mbid string) ([]ExternalImage, error) {
-	t.Args = []interface{}{id, name, mbid}
+	t.Args = []any{id, name, mbid}
 	return t.Images, t.Err
 }

core/archiver.go

@@ -176,7 +176,7 @@ func (a *archiver) addFileToZip(ctx context.Context, z *zip.Writer, mf model.Med
 
 	var r io.ReadCloser
 	if format != "raw" && format != "" {
-		r, err = a.ms.DoStream(ctx, &mf, format, bitrate, 0)
+		r, err = a.ms.DoStream(ctx, &mf, StreamRequest{Format: format, BitRate: bitrate})
 	} else {
 		r, err = os.Open(path)
 	}

core/archiver_test.go

@@ -44,7 +44,7 @@ var _ = Describe("Archiver", func() {
 			}}).Return(mfs, nil)
 
 			ds.On("MediaFile", mock.Anything).Return(mfRepo)
-			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(3)
+			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0, 0, 0, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(3)
 
 			out := new(bytes.Buffer)
 			err := arch.ZipAlbum(context.Background(), "1", "mp3", 128, out)
@@ -73,7 +73,7 @@ var _ = Describe("Archiver", func() {
 			}}).Return(mfs, nil)
 
 			ds.On("MediaFile", mock.Anything).Return(mfRepo)
-			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
+			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0, 0, 0, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
 
 			out := new(bytes.Buffer)
 			err := arch.ZipArtist(context.Background(), "1", "mp3", 128, out)
@@ -104,7 +104,7 @@ var _ = Describe("Archiver", func() {
 			}
 
 			sh.On("Load", mock.Anything, "1").Return(share, nil)
-			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
+			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0, 0, 0, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
 
 			out := new(bytes.Buffer)
 			err := arch.ZipShare(context.Background(), "1", out)
@@ -136,7 +136,7 @@ var _ = Describe("Archiver", func() {
 			plRepo := &mockPlaylistRepository{}
 			plRepo.On("GetWithTracks", "1", true, false).Return(pls, nil)
 			ds.On("Playlist", mock.Anything).Return(plRepo)
-			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
+			ms.On("DoStream", mock.Anything, mock.Anything, "mp3", 128, 0, 0, 0, 0).Return(io.NopCloser(strings.NewReader("test")), nil).Times(2)
 
 			out := new(bytes.Buffer)
 			err := arch.ZipPlaylist(context.Background(), "1", "mp3", 128, out)
@@ -217,8 +217,8 @@ type mockMediaStreamer struct {
 	core.MediaStreamer
 }
 
-func (m *mockMediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqFormat string, reqBitRate int, reqOffset int) (*core.Stream, error) {
-	args := m.Called(ctx, mf, reqFormat, reqBitRate, reqOffset)
+func (m *mockMediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, req core.StreamRequest) (*core.Stream, error) {
+	args := m.Called(ctx, mf, req.Format, req.BitRate, req.SampleRate, req.BitDepth, req.Channels, req.Offset)
 	if args.Error(1) != nil {
 		return nil, args.Error(1)
 	}

core/artwork/cache_warmer_test.go

@@ -143,7 +143,7 @@ var _ = Describe("CacheWarmer", func() {
 
 		It("processes items in batches", func() {
 			cw := NewCacheWarmer(aw, fc).(*cacheWarmer)
-			for i := 0; i < 5; i++ {
+			for i := range 5 {
 				cw.PreCache(model.MustParseArtworkID(fmt.Sprintf("al-%d", i)))
 			}
 

core/artwork/reader_album.go

@@ -79,7 +79,7 @@ func (a *albumArtworkReader) Reader(ctx context.Context) (io.ReadCloser, string,
 
 func (a *albumArtworkReader) fromCoverArtPriority(ctx context.Context, ffmpeg ffmpeg.FFmpeg, priority string) []sourceFunc {
 	var ff []sourceFunc
-	for _, pattern := range strings.Split(strings.ToLower(priority), ",") {
+	for pattern := range strings.SplitSeq(strings.ToLower(priority), ",") {
 		pattern = strings.TrimSpace(pattern)
 		switch {
 		case pattern == "embedded":

core/artwork/reader_artist.go

@@ -99,7 +99,7 @@ func (a *artistReader) Reader(ctx context.Context) (io.ReadCloser, string, error
 
 func (a *artistReader) fromArtistArtPriority(ctx context.Context, priority string) []sourceFunc {
 	var ff []sourceFunc
-	for _, pattern := range strings.Split(strings.ToLower(priority), ",") {
+	for pattern := range strings.SplitSeq(strings.ToLower(priority), ",") {
 		pattern = strings.TrimSpace(pattern)
 		switch {
 		case pattern == "external":
@@ -116,7 +116,7 @@ func (a *artistReader) fromArtistArtPriority(ctx context.Context, priority strin
 func fromArtistFolder(ctx context.Context, artistFolder string, pattern string) sourceFunc {
 	return func() (io.ReadCloser, string, error) {
 		current := artistFolder
-		for i := 0; i < maxArtistFolderTraversalDepth; i++ {
+		for range maxArtistFolderTraversalDepth {
 			if reader, path, err := findImageInFolder(ctx, current, pattern); err == nil {
 				return reader, path, nil
 			}

core/auth/auth.go

@@ -4,6 +4,7 @@ import (
 	"cmp"
 	"context"
 	"crypto/sha256"
+	"maps"
 	"sync"
 	"time"
 
@@ -53,9 +54,7 @@ func createBaseClaims() map[string]any {
 
 func CreatePublicToken(claims map[string]any) (string, error) {
 	tokenClaims := createBaseClaims()
-	for k, v := range claims {
-		tokenClaims[k] = v
-	}
+	maps.Copy(tokenClaims, claims)
 	_, token, err := TokenAuth.Encode(tokenClaims)
 
 	return token, err
@@ -66,9 +65,7 @@ func CreateExpiringPublicToken(exp time.Time, claims map[string]any) (string, er
 	if !exp.IsZero() {
 		tokenClaims[jwt.ExpirationKey] = exp.UTC().Unix()
 	}
-	for k, v := range claims {
-		tokenClaims[k] = v
-	}
+	maps.Copy(tokenClaims, claims)
 	_, token, err := TokenAuth.Encode(tokenClaims)
 
 	return token, err
@@ -100,7 +97,7 @@ func TouchToken(token jwt.Token) (string, error) {
 	return newToken, err
 }
 
-func Validate(tokenStr string) (map[string]interface{}, error) {
+func Validate(tokenStr string) (map[string]any, error) {
 	token, err := jwtauth.VerifyToken(TokenAuth, tokenStr)
 	if err != nil {
 		return nil, err

core/auth/auth_test.go

@@ -45,7 +45,7 @@ var _ = Describe("Auth", func() {
 		})
 
 		It("returns the claims from a valid JWT token", func() {
-			claims := map[string]interface{}{}
+			claims := map[string]any{}
 			claims["iss"] = "issuer"
 			claims["iat"] = time.Now().Unix()
 			claims["exp"] = time.Now().Add(1 * time.Minute).Unix()
@@ -58,7 +58,7 @@ var _ = Describe("Auth", func() {
 		})
 
 		It("returns ErrExpired if the `exp` field is in the past", func() {
-			claims := map[string]interface{}{}
+			claims := map[string]any{}
 			claims["iss"] = "issuer"
 			claims["exp"] = time.Now().Add(-1 * time.Minute).Unix()
 			_, tokenStr, err := auth.TokenAuth.Encode(claims)
@@ -93,7 +93,7 @@ var _ = Describe("Auth", func() {
 	Describe("TouchToken", func() {
 		It("updates the expiration time", func() {
 			yesterday := time.Now().Add(-oneDay)
-			claims := map[string]interface{}{}
+			claims := map[string]any{}
 			claims["iss"] = "issuer"
 			claims["exp"] = yesterday.Unix()
 			token, _, err := auth.TokenAuth.Encode(claims)

core/external/extdata_helper_test.go

@@ -40,7 +40,7 @@ func (m *mockArtistRepo) Get(id string) (*model.Artist, error) {
 
 // GetAll implements model.ArtistRepository.
 func (m *mockArtistRepo) GetAll(options ...model.QueryOptions) (model.Artists, error) {
-	argsSlice := make([]interface{}, len(options))
+	argsSlice := make([]any, len(options))
 	for i, v := range options {
 		argsSlice[i] = v
 	}
@@ -99,7 +99,7 @@ func (m *mockMediaFileRepo) GetAllByTags(_ model.TagName, _ []string, options ..
 
 // GetAll implements model.MediaFileRepository.
 func (m *mockMediaFileRepo) GetAll(options ...model.QueryOptions) (model.MediaFiles, error) {
-	argsSlice := make([]interface{}, len(options))
+	argsSlice := make([]any, len(options))
 	for i, v := range options {
 		argsSlice[i] = v
 	}
@@ -152,7 +152,7 @@ func (m *mockAlbumRepo) Get(id string) (*model.Album, error) {
 
 // GetAll implements model.AlbumRepository.
 func (m *mockAlbumRepo) GetAll(options ...model.QueryOptions) (model.Albums, error) {
-	argsSlice := make([]interface{}, len(options))
+	argsSlice := make([]any, len(options))
 	for i, v := range options {
 		argsSlice[i] = v
 	}

core/external/provider.go

@@ -93,7 +93,7 @@ func NewProvider(ds model.DataStore, agents Agents) Provider {
 }
 
 func (e *provider) getAlbum(ctx context.Context, id string) (auxAlbum, error) {
-	var entity interface{}
+	var entity any
 	entity, err := model.GetEntityByID(ctx, e.ds, id)
 	if err != nil {
 		return auxAlbum{}, err
@@ -187,7 +187,7 @@ func (e *provider) populateAlbumInfo(ctx context.Context, album auxAlbum) (auxAl
 }
 
 func (e *provider) getArtist(ctx context.Context, id string) (auxArtist, error) {
-	var entity interface{}
+	var entity any
 	entity, err := model.GetEntityByID(ctx, e.ds, id)
 	if err != nil {
 		return auxArtist{}, err

core/ffmpeg/ffmpeg.go

@@ -12,11 +12,24 @@ import (
 	"sync"
 
 	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/log"
 )
 
+// TranscodeOptions contains all parameters for a transcoding operation.
+type TranscodeOptions struct {
+	Command    string // DB command template (used to detect custom vs default)
+	Format     string // Target format (mp3, opus, aac, flac)
+	FilePath   string
+	BitRate    int // kbps, 0 = codec default
+	SampleRate int // 0 = no constraint
+	Channels   int // 0 = no constraint
+	BitDepth   int // 0 = no constraint; valid values: 16, 24, 32
+	Offset     int // seconds
+}
+
 type FFmpeg interface {
-	Transcode(ctx context.Context, command, path string, maxBitRate, offset int) (io.ReadCloser, error)
+	Transcode(ctx context.Context, opts TranscodeOptions) (io.ReadCloser, error)
 	ExtractImage(ctx context.Context, path string) (io.ReadCloser, error)
 	Probe(ctx context.Context, files []string) (string, error)
 	CmdPath() (string, error)
@@ -35,15 +48,19 @@ const (
 
 type ffmpeg struct{}
 
-func (e *ffmpeg) Transcode(ctx context.Context, command, path string, maxBitRate, offset int) (io.ReadCloser, error) {
+func (e *ffmpeg) Transcode(ctx context.Context, opts TranscodeOptions) (io.ReadCloser, error) {
 	if _, err := ffmpegCmd(); err != nil {
 		return nil, err
 	}
-	// First make sure the file exists
-	if err := fileExists(path); err != nil {
+	if err := fileExists(opts.FilePath); err != nil {
 		return nil, err
 	}
-	args := createFFmpegCommand(command, path, maxBitRate, offset)
+	var args []string
+	if isDefaultCommand(opts.Format, opts.Command) {
+		args = buildDynamicArgs(opts)
+	} else {
+		args = buildTemplateArgs(opts)
+	}
 	return e.start(ctx, args)
 }
 
@@ -51,7 +68,6 @@ func (e *ffmpeg) ExtractImage(ctx context.Context, path string) (io.ReadCloser,
 	if _, err := ffmpegCmd(); err != nil {
 		return nil, err
 	}
-	// First make sure the file exists
 	if err := fileExists(path); err != nil {
 		return nil, err
 	}
@@ -156,6 +172,139 @@ func (j *ffCmd) wait() {
 	_ = j.out.Close()
 }
 
+// formatCodecMap maps target format to ffmpeg codec flag.
+var formatCodecMap = map[string]string{
+	"mp3":  "libmp3lame",
+	"opus": "libopus",
+	"aac":  "aac",
+	"flac": "flac",
+}
+
+// formatOutputMap maps target format to ffmpeg output format flag (-f).
+var formatOutputMap = map[string]string{
+	"mp3":  "mp3",
+	"opus": "opus",
+	"aac":  "ipod",
+	"flac": "flac",
+}
+
+// defaultCommands is used to detect whether a user has customized their transcoding command.
+var defaultCommands = func() map[string]string {
+	m := make(map[string]string, len(consts.DefaultTranscodings))
+	for _, t := range consts.DefaultTranscodings {
+		m[t.TargetFormat] = t.Command
+	}
+	return m
+}()
+
+// isDefaultCommand returns true if the command matches the known default for this format.
+func isDefaultCommand(format, command string) bool {
+	return defaultCommands[format] == command
+}
+
+// buildDynamicArgs programmatically constructs ffmpeg arguments for known formats,
+// including all transcoding parameters (bitrate, sample rate, channels).
+func buildDynamicArgs(opts TranscodeOptions) []string {
+	cmdPath, _ := ffmpegCmd()
+	args := []string{cmdPath, "-i", opts.FilePath}
+
+	if opts.Offset > 0 {
+		args = append(args, "-ss", strconv.Itoa(opts.Offset))
+	}
+
+	args = append(args, "-map", "0:a:0")
+
+	if codec, ok := formatCodecMap[opts.Format]; ok {
+		args = append(args, "-c:a", codec)
+	}
+
+	if opts.BitRate > 0 {
+		args = append(args, "-b:a", strconv.Itoa(opts.BitRate)+"k")
+	}
+	if opts.SampleRate > 0 {
+		args = append(args, "-ar", strconv.Itoa(opts.SampleRate))
+	}
+	if opts.Channels > 0 {
+		args = append(args, "-ac", strconv.Itoa(opts.Channels))
+	}
+	// Only pass -sample_fmt for lossless output formats where bit depth matters.
+	// Lossy codecs (mp3, aac, opus) handle sample format conversion internally,
+	// and passing interleaved formats like "s16" causes silent failures.
+	if opts.BitDepth >= 16 && isLosslessOutputFormat(opts.Format) {
+		args = append(args, "-sample_fmt", bitDepthToSampleFmt(opts.BitDepth))
+	}
+
+	args = append(args, "-v", "0")
+
+	if outputFmt, ok := formatOutputMap[opts.Format]; ok {
+		args = append(args, "-f", outputFmt)
+	}
+
+	// For AAC in MP4 container, enable fragmented MP4 for pipe-safe streaming
+	if opts.Format == "aac" {
+		args = append(args, "-movflags", "frag_keyframe+empty_moov")
+	}
+
+	args = append(args, "-")
+	return args
+}
+
+// buildTemplateArgs handles user-customized command templates, with dynamic injection
+// of sample rate and channels when the template doesn't already include them.
+func buildTemplateArgs(opts TranscodeOptions) []string {
+	args := createFFmpegCommand(opts.Command, opts.FilePath, opts.BitRate, opts.Offset)
+
+	// Dynamically inject -ar, -ac, and -sample_fmt for custom templates that don't include them
+	if opts.SampleRate > 0 {
+		args = injectBeforeOutput(args, "-ar", strconv.Itoa(opts.SampleRate))
+	}
+	if opts.Channels > 0 {
+		args = injectBeforeOutput(args, "-ac", strconv.Itoa(opts.Channels))
+	}
+	if opts.BitDepth >= 16 && isLosslessOutputFormat(opts.Format) {
+		args = injectBeforeOutput(args, "-sample_fmt", bitDepthToSampleFmt(opts.BitDepth))
+	}
+	return args
+}
+
+// injectBeforeOutput inserts a flag and value before the trailing "-" (stdout output).
+func injectBeforeOutput(args []string, flag, value string) []string {
+	if len(args) > 0 && args[len(args)-1] == "-" {
+		result := make([]string, 0, len(args)+2)
+		result = append(result, args[:len(args)-1]...)
+		result = append(result, flag, value, "-")
+		return result
+	}
+	return append(args, flag, value)
+}
+
+// isLosslessOutputFormat returns true if the format is a lossless audio format
+// where preserving bit depth via -sample_fmt is meaningful.
+// Note: this covers only formats ffmpeg can produce as output. For the full set of
+// lossless formats used in transcoding decisions, see core/transcode/codec.go:isLosslessFormat.
+func isLosslessOutputFormat(format string) bool {
+	switch strings.ToLower(format) {
+	case "flac", "alac", "wav", "aiff":
+		return true
+	}
+	return false
+}
+
+// bitDepthToSampleFmt converts a bit depth value to the ffmpeg sample_fmt string.
+// FLAC only supports s16 and s32; for 24-bit sources, s32 is the correct format
+// (ffmpeg packs 24-bit samples into 32-bit containers).
+func bitDepthToSampleFmt(bitDepth int) string {
+	switch bitDepth {
+	case 16:
+		return "s16"
+	case 32:
+		return "s32"
+	default:
+		// 24-bit and other depths: use s32 (the next valid container size)
+		return "s32"
+	}
+}
+
 // Path will always be an absolute path
 func createFFmpegCommand(cmd, path string, maxBitRate, offset int) []string {
 	var args []string

core/ffmpeg/ffmpeg_test.go

@@ -2,19 +2,27 @@ package ffmpeg
 
 import (
 	"context"
+	"os"
+	"path/filepath"
 	"runtime"
 	sync "sync"
 	"testing"
 	"time"
 
+	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/log"
-	"github.com/navidrome/navidrome/tests"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
 
 func TestFFmpeg(t *testing.T) {
-	tests.Init(t, false)
+	// Inline test init to avoid import cycle with tests package
+	//nolint:dogsled
+	_, file, _, _ := runtime.Caller(0)
+	appPath, _ := filepath.Abs(filepath.Join(filepath.Dir(file), "..", ".."))
+	confPath := filepath.Join(appPath, "tests", "navidrome-test.toml")
+	_ = os.Chdir(appPath)
+	conf.LoadFromFile(confPath)
 	log.SetLevel(log.LevelFatal)
 	RegisterFailHandler(Fail)
 	RunSpecs(t, "FFmpeg Suite")
@@ -70,6 +78,286 @@ var _ = Describe("ffmpeg", func() {
 		})
 	})
 
+	Describe("isDefaultCommand", func() {
+		It("returns true for known default mp3 command", func() {
+			Expect(isDefaultCommand("mp3", "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -f mp3 -")).To(BeTrue())
+		})
+		It("returns true for known default opus command", func() {
+			Expect(isDefaultCommand("opus", "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a libopus -f opus -")).To(BeTrue())
+		})
+		It("returns true for known default aac command", func() {
+			Expect(isDefaultCommand("aac", "ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -")).To(BeTrue())
+		})
+		It("returns true for known default flac command", func() {
+			Expect(isDefaultCommand("flac", "ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -")).To(BeTrue())
+		})
+		It("returns false for a custom command", func() {
+			Expect(isDefaultCommand("mp3", "ffmpeg -i %s -b:a %bk -custom-flag -f mp3 -")).To(BeFalse())
+		})
+		It("returns false for unknown format", func() {
+			Expect(isDefaultCommand("wav", "ffmpeg -i %s -f wav -")).To(BeFalse())
+		})
+	})
+
+	Describe("buildDynamicArgs", func() {
+		It("builds mp3 args with bitrate, samplerate, and channels", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:     "mp3",
+				FilePath:   "/music/file.flac",
+				BitRate:    256,
+				SampleRate: 48000,
+				Channels:   2,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-map", "0:a:0",
+				"-c:a", "libmp3lame",
+				"-b:a", "256k",
+				"-ar", "48000",
+				"-ac", "2",
+				"-v", "0",
+				"-f", "mp3",
+				"-",
+			}))
+		})
+
+		It("builds flac args without bitrate", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:     "flac",
+				FilePath:   "/music/file.dsf",
+				SampleRate: 48000,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.dsf",
+				"-map", "0:a:0",
+				"-c:a", "flac",
+				"-ar", "48000",
+				"-v", "0",
+				"-f", "flac",
+				"-",
+			}))
+		})
+
+		It("builds opus args with bitrate only", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "opus",
+				FilePath: "/music/file.flac",
+				BitRate:  128,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-map", "0:a:0",
+				"-c:a", "libopus",
+				"-b:a", "128k",
+				"-v", "0",
+				"-f", "opus",
+				"-",
+			}))
+		})
+
+		It("includes offset when specified", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "mp3",
+				FilePath: "/music/file.mp3",
+				BitRate:  192,
+				Offset:   30,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.mp3",
+				"-ss", "30",
+				"-map", "0:a:0",
+				"-c:a", "libmp3lame",
+				"-b:a", "192k",
+				"-v", "0",
+				"-f", "mp3",
+				"-",
+			}))
+		})
+
+		It("builds aac args with fragmented MP4 container", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "aac",
+				FilePath: "/music/file.flac",
+				BitRate:  256,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-map", "0:a:0",
+				"-c:a", "aac",
+				"-b:a", "256k",
+				"-v", "0",
+				"-f", "ipod",
+				"-movflags", "frag_keyframe+empty_moov",
+				"-",
+			}))
+		})
+
+		It("builds flac args with bit depth", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "flac",
+				FilePath: "/music/file.dsf",
+				BitDepth: 24,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.dsf",
+				"-map", "0:a:0",
+				"-c:a", "flac",
+				"-sample_fmt", "s32",
+				"-v", "0",
+				"-f", "flac",
+				"-",
+			}))
+		})
+
+		It("omits -sample_fmt when bit depth is 0", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "flac",
+				FilePath: "/music/file.flac",
+				BitDepth: 0,
+			})
+			Expect(args).ToNot(ContainElement("-sample_fmt"))
+		})
+
+		It("omits -sample_fmt when bit depth is too low (DSD)", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "flac",
+				FilePath: "/music/file.dsf",
+				BitDepth: 1,
+			})
+			Expect(args).ToNot(ContainElement("-sample_fmt"))
+		})
+
+		It("omits -sample_fmt for mp3 even when bit depth >= 16", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "mp3",
+				FilePath: "/music/file.flac",
+				BitRate:  256,
+				BitDepth: 16,
+			})
+			Expect(args).ToNot(ContainElement("-sample_fmt"))
+		})
+
+		It("omits -sample_fmt for aac even when bit depth >= 16", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "aac",
+				FilePath: "/music/file.flac",
+				BitRate:  256,
+				BitDepth: 16,
+			})
+			Expect(args).ToNot(ContainElement("-sample_fmt"))
+		})
+
+		It("omits -sample_fmt for opus even when bit depth >= 16", func() {
+			args := buildDynamicArgs(TranscodeOptions{
+				Format:   "opus",
+				FilePath: "/music/file.flac",
+				BitRate:  128,
+				BitDepth: 16,
+			})
+			Expect(args).ToNot(ContainElement("-sample_fmt"))
+		})
+	})
+
+	Describe("bitDepthToSampleFmt", func() {
+		It("converts 16-bit", func() {
+			Expect(bitDepthToSampleFmt(16)).To(Equal("s16"))
+		})
+		It("converts 24-bit to s32 (FLAC only supports s16/s32)", func() {
+			Expect(bitDepthToSampleFmt(24)).To(Equal("s32"))
+		})
+		It("converts 32-bit", func() {
+			Expect(bitDepthToSampleFmt(32)).To(Equal("s32"))
+		})
+	})
+
+	Describe("buildTemplateArgs", func() {
+		It("injects -ar and -ac into custom template", func() {
+			args := buildTemplateArgs(TranscodeOptions{
+				Command:    "ffmpeg -i %s -b:a %bk -v 0 -f mp3 -",
+				FilePath:   "/music/file.flac",
+				BitRate:    192,
+				SampleRate: 44100,
+				Channels:   2,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-b:a", "192k", "-v", "0", "-f", "mp3",
+				"-ar", "44100", "-ac", "2",
+				"-",
+			}))
+		})
+
+		It("injects only -ar when channels is 0", func() {
+			args := buildTemplateArgs(TranscodeOptions{
+				Command:    "ffmpeg -i %s -b:a %bk -v 0 -f mp3 -",
+				FilePath:   "/music/file.flac",
+				BitRate:    192,
+				SampleRate: 48000,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-b:a", "192k", "-v", "0", "-f", "mp3",
+				"-ar", "48000",
+				"-",
+			}))
+		})
+
+		It("does not inject anything when sample rate and channels are 0", func() {
+			args := buildTemplateArgs(TranscodeOptions{
+				Command:  "ffmpeg -i %s -b:a %bk -v 0 -f mp3 -",
+				FilePath: "/music/file.flac",
+				BitRate:  192,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-b:a", "192k", "-v", "0", "-f", "mp3",
+				"-",
+			}))
+		})
+
+		It("injects -sample_fmt for lossless output format with bit depth", func() {
+			args := buildTemplateArgs(TranscodeOptions{
+				Command:  "ffmpeg -i %s -v 0 -c:a flac -f flac -",
+				Format:   "flac",
+				FilePath: "/music/file.dsf",
+				BitDepth: 24,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.dsf",
+				"-v", "0", "-c:a", "flac", "-f", "flac",
+				"-sample_fmt", "s32",
+				"-",
+			}))
+		})
+
+		It("does not inject -sample_fmt for lossy output format even with bit depth", func() {
+			args := buildTemplateArgs(TranscodeOptions{
+				Command:  "ffmpeg -i %s -b:a %bk -v 0 -f mp3 -",
+				Format:   "mp3",
+				FilePath: "/music/file.flac",
+				BitRate:  192,
+				BitDepth: 16,
+			})
+			Expect(args).To(Equal([]string{
+				"ffmpeg", "-i", "/music/file.flac",
+				"-b:a", "192k", "-v", "0", "-f", "mp3",
+				"-",
+			}))
+		})
+	})
+
+	Describe("injectBeforeOutput", func() {
+		It("inserts flag before trailing dash", func() {
+			args := injectBeforeOutput([]string{"ffmpeg", "-i", "file.mp3", "-f", "mp3", "-"}, "-ar", "48000")
+			Expect(args).To(Equal([]string{"ffmpeg", "-i", "file.mp3", "-f", "mp3", "-ar", "48000", "-"}))
+		})
+
+		It("appends when no trailing dash", func() {
+			args := injectBeforeOutput([]string{"ffmpeg", "-i", "file.mp3"}, "-ar", "48000")
+			Expect(args).To(Equal([]string{"ffmpeg", "-i", "file.mp3", "-ar", "48000"}))
+		})
+	})
+
 	Describe("FFmpeg", func() {
 		Context("when FFmpeg is available", func() {
 			var ff FFmpeg
@@ -93,7 +381,12 @@ var _ = Describe("ffmpeg", func() {
 				command := "ffmpeg -f lavfi -i sine=frequency=1000:duration=0 -f mp3 -"
 
 				// The input file is not used here, but we need to provide a valid path to the Transcode function
-				stream, err := ff.Transcode(ctx, command, "tests/fixtures/test.mp3", 128, 0)
+				stream, err := ff.Transcode(ctx, TranscodeOptions{
+					Command:  command,
+					Format:   "mp3",
+					FilePath: "tests/fixtures/test.mp3",
+					BitRate:  128,
+				})
 				Expect(err).ToNot(HaveOccurred())
 				defer stream.Close()
 
@@ -115,7 +408,12 @@ var _ = Describe("ffmpeg", func() {
 				cancel() // Cancel immediately
 
 				// This should fail immediately
-				_, err := ff.Transcode(ctx, "ffmpeg -i %s -f mp3 -", "tests/fixtures/test.mp3", 128, 0)
+				_, err := ff.Transcode(ctx, TranscodeOptions{
+					Command:  "ffmpeg -i %s -f mp3 -",
+					Format:   "mp3",
+					FilePath: "tests/fixtures/test.mp3",
+					BitRate:  128,
+				})
 				Expect(err).To(MatchError(context.Canceled))
 			})
 		})
@@ -142,7 +440,10 @@ var _ = Describe("ffmpeg", func() {
 				defer cancel()
 
 				// Start a process that will run for a while
-				stream, err := ff.Transcode(ctx, longRunningCmd, "tests/fixtures/test.mp3", 0, 0)
+				stream, err := ff.Transcode(ctx, TranscodeOptions{
+					Command:  longRunningCmd,
+					FilePath: "tests/fixtures/test.mp3",
+				})
 				Expect(err).ToNot(HaveOccurred())
 				defer stream.Close()
 

core/library.go

@@ -159,7 +159,7 @@ type libraryRepositoryWrapper struct {
 	pluginManager PluginUnloader
 }
 
-func (r *libraryRepositoryWrapper) Save(entity interface{}) (string, error) {
+func (r *libraryRepositoryWrapper) Save(entity any) (string, error) {
 	lib := entity.(*model.Library)
 	if err := r.validateLibrary(lib); err != nil {
 		return "", err
@@ -191,7 +191,7 @@ func (r *libraryRepositoryWrapper) Save(entity interface{}) (string, error) {
 	return strconv.Itoa(lib.ID), nil
 }
 
-func (r *libraryRepositoryWrapper) Update(id string, entity interface{}, _ ...string) error {
+func (r *libraryRepositoryWrapper) Update(id string, entity any, _ ...string) error {
 	lib := entity.(*model.Library)
 	libID, err := strconv.Atoi(id)
 	if err != nil {

core/maintenance.go

@@ -196,9 +196,7 @@ func (s *maintenanceService) getAffectedAlbumIDs(ctx context.Context, ids []stri
 // refreshStatsAsync refreshes artist and album statistics in background goroutines
 func (s *maintenanceService) refreshStatsAsync(ctx context.Context, affectedAlbumIDs []string) {
 	// Refresh artist stats in background
-	s.wg.Add(1)
-	go func() {
-		defer s.wg.Done()
+	s.wg.Go(func() {
 		bgCtx := request.AddValues(context.Background(), ctx)
 		if _, err := s.ds.Artist(bgCtx).RefreshStats(true); err != nil {
 			log.Error(bgCtx, "Error refreshing artist stats after deleting missing files", err)
@@ -214,7 +212,7 @@ func (s *maintenanceService) refreshStatsAsync(ctx context.Context, affectedAlbu
 				log.Debug(bgCtx, "Successfully refreshed album stats after deleting missing files", "count", len(affectedAlbumIDs))
 			}
 		}
-	}()
+	})
 }
 
 // Wait waits for all background goroutines to complete.

core/media_streamer.go

@@ -18,9 +18,20 @@ import (
 	"github.com/navidrome/navidrome/utils/cache"
 )
 
+// StreamRequest contains all parameters for creating a media stream.
+type StreamRequest struct {
+	ID         string
+	Format     string
+	BitRate    int // kbps
+	SampleRate int
+	BitDepth   int
+	Channels   int
+	Offset     int // seconds
+}
+
 type MediaStreamer interface {
-	NewStream(ctx context.Context, id string, reqFormat string, reqBitRate int, offset int) (*Stream, error)
-	DoStream(ctx context.Context, mf *model.MediaFile, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error)
+	NewStream(ctx context.Context, req StreamRequest) (*Stream, error)
+	DoStream(ctx context.Context, mf *model.MediaFile, req StreamRequest) (*Stream, error)
 }
 
 type TranscodingCache cache.FileCache
@@ -36,28 +47,31 @@ type mediaStreamer struct {
 }
 
 type streamJob struct {
-	ms       *mediaStreamer
-	mf       *model.MediaFile
-	filePath string
-	format   string
-	bitRate  int
-	offset   int
+	ms         *mediaStreamer
+	mf         *model.MediaFile
+	filePath   string
+	format     string
+	bitRate    int
+	sampleRate int
+	bitDepth   int
+	channels   int
+	offset     int
 }
 
 func (j *streamJob) Key() string {
-	return fmt.Sprintf("%s.%s.%d.%s.%d", j.mf.ID, j.mf.UpdatedAt.Format(time.RFC3339Nano), j.bitRate, j.format, j.offset)
+	return fmt.Sprintf("%s.%s.%d.%d.%d.%d.%s.%d", j.mf.ID, j.mf.UpdatedAt.Format(time.RFC3339Nano), j.bitRate, j.sampleRate, j.bitDepth, j.channels, j.format, j.offset)
 }
 
-func (ms *mediaStreamer) NewStream(ctx context.Context, id string, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error) {
-	mf, err := ms.ds.MediaFile(ctx).Get(id)
+func (ms *mediaStreamer) NewStream(ctx context.Context, req StreamRequest) (*Stream, error) {
+	mf, err := ms.ds.MediaFile(ctx).Get(req.ID)
 	if err != nil {
 		return nil, err
 	}
 
-	return ms.DoStream(ctx, mf, reqFormat, reqBitRate, reqOffset)
+	return ms.DoStream(ctx, mf, req)
 }
 
-func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqFormat string, reqBitRate int, reqOffset int) (*Stream, error) {
+func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, req StreamRequest) (*Stream, error) {
 	var format string
 	var bitRate int
 	var cached bool
@@ -67,13 +81,13 @@ func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqF
 			"originalFormat", mf.Suffix, "originalBitRate", mf.BitRate)
 	}()
 
-	format, bitRate = selectTranscodingOptions(ctx, ms.ds, mf, reqFormat, reqBitRate)
+	format, bitRate = selectTranscodingOptions(ctx, ms.ds, mf, req.Format, req.BitRate, req.SampleRate)
 	s := &Stream{ctx: ctx, mf: mf, format: format, bitRate: bitRate}
 	filePath := mf.AbsolutePath()
 
 	if format == "raw" {
 		log.Debug(ctx, "Streaming RAW file", "id", mf.ID, "path", filePath,
-			"requestBitrate", reqBitRate, "requestFormat", reqFormat, "requestOffset", reqOffset,
+			"requestBitrate", req.BitRate, "requestFormat", req.Format, "requestOffset", req.Offset,
 			"originalBitrate", mf.BitRate, "originalFormat", mf.Suffix,
 			"selectedBitrate", bitRate, "selectedFormat", format)
 		f, err := os.Open(filePath)
@@ -87,12 +101,15 @@ func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqF
 	}
 
 	job := &streamJob{
-		ms:       ms,
-		mf:       mf,
-		filePath: filePath,
-		format:   format,
-		bitRate:  bitRate,
-		offset:   reqOffset,
+		ms:         ms,
+		mf:         mf,
+		filePath:   filePath,
+		format:     format,
+		bitRate:    bitRate,
+		sampleRate: req.SampleRate,
+		bitDepth:   req.BitDepth,
+		channels:   req.Channels,
+		offset:     req.Offset,
 	}
 	r, err := ms.cache.Get(ctx, job)
 	if err != nil {
@@ -105,7 +122,7 @@ func (ms *mediaStreamer) DoStream(ctx context.Context, mf *model.MediaFile, reqF
 	s.Seeker = r.Seeker
 
 	log.Debug(ctx, "Streaming TRANSCODED file", "id", mf.ID, "path", filePath,
-		"requestBitrate", reqBitRate, "requestFormat", reqFormat, "requestOffset", reqOffset,
+		"requestBitrate", req.BitRate, "requestFormat", req.Format, "requestOffset", req.Offset,
 		"originalBitrate", mf.BitRate, "originalFormat", mf.Suffix,
 		"selectedBitrate", bitRate, "selectedFormat", format, "cached", cached, "seekable", s.Seekable())
 
@@ -131,12 +148,13 @@ func (s *Stream) EstimatedContentLength() int {
 }
 
 // TODO This function deserves some love (refactoring)
-func selectTranscodingOptions(ctx context.Context, ds model.DataStore, mf *model.MediaFile, reqFormat string, reqBitRate int) (format string, bitRate int) {
+func selectTranscodingOptions(ctx context.Context, ds model.DataStore, mf *model.MediaFile, reqFormat string, reqBitRate int, reqSampleRate int) (format string, bitRate int) {
 	format = "raw"
 	if reqFormat == "raw" {
 		return format, 0
 	}
-	if reqFormat == mf.Suffix && reqBitRate == 0 {
+	needsResample := reqSampleRate > 0 && reqSampleRate < mf.SampleRate
+	if reqFormat == mf.Suffix && reqBitRate == 0 && !needsResample {
 		bitRate = mf.BitRate
 		return format, bitRate
 	}
@@ -175,7 +193,7 @@ func selectTranscodingOptions(ctx context.Context, ds model.DataStore, mf *model
 			bitRate = t.DefaultBitRate
 		}
 	}
-	if format == mf.Suffix && bitRate >= mf.BitRate {
+	if format == mf.Suffix && bitRate >= mf.BitRate && !needsResample {
 		format = "raw"
 		bitRate = 0
 	}
@@ -217,7 +235,16 @@ func NewTranscodingCache() TranscodingCache {
 				transcodingCtx = request.AddValues(context.Background(), ctx)
 			}
 
-			out, err := job.ms.transcoder.Transcode(transcodingCtx, t.Command, job.filePath, job.bitRate, job.offset)
+			out, err := job.ms.transcoder.Transcode(transcodingCtx, ffmpeg.TranscodeOptions{
+				Command:    t.Command,
+				Format:     job.format,
+				FilePath:   job.filePath,
+				BitRate:    job.bitRate,
+				SampleRate: job.sampleRate,
+				BitDepth:   job.bitDepth,
+				Channels:   job.channels,
+				Offset:     job.offset,
+			})
 			if err != nil {
 				log.Error(ctx, "Error starting transcoder", "id", job.mf.ID, err)
 				return nil, os.ErrInvalid

core/media_streamer_Internal_test.go

@@ -26,42 +26,64 @@ var _ = Describe("MediaStreamer", func() {
 			It("returns raw if raw is requested", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0)
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0, 0)
 				Expect(format).To(Equal("raw"))
 			})
 			It("returns raw if a transcoder does not exists", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, _ := selectTranscodingOptions(ctx, ds, mf, "m4a", 0)
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "m4a", 0, 0)
 				Expect(format).To(Equal("raw"))
 			})
 			It("returns the requested format if a transcoder exists", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0, 0)
 				Expect(format).To(Equal("mp3"))
 				Expect(bitRate).To(Equal(160)) // Default Bit Rate
 			})
 			It("returns raw if requested format is the same as the original and it is not necessary to downsample", func() {
 				mf.Suffix = "mp3"
 				mf.BitRate = 112
-				format, _ := selectTranscodingOptions(ctx, ds, mf, "mp3", 128)
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "mp3", 128, 0)
 				Expect(format).To(Equal("raw"))
 			})
 			It("returns the requested format if requested BitRate is lower than original", func() {
 				mf.Suffix = "mp3"
 				mf.BitRate = 320
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 192)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 192, 0)
 				Expect(format).To(Equal("mp3"))
 				Expect(bitRate).To(Equal(192))
 			})
 			It("returns raw if requested format is the same as the original, but requested BitRate is 0", func() {
 				mf.Suffix = "mp3"
 				mf.BitRate = 320
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0, 0)
 				Expect(format).To(Equal("raw"))
 				Expect(bitRate).To(Equal(320))
 			})
+			It("returns the format when same format is requested but with a lower sample rate", func() {
+				mf.Suffix = "flac"
+				mf.BitRate = 2118
+				mf.SampleRate = 96000
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "flac", 0, 48000)
+				Expect(format).To(Equal("flac"))
+				Expect(bitRate).To(Equal(0))
+			})
+			It("returns raw when same format is requested with same sample rate", func() {
+				mf.Suffix = "flac"
+				mf.BitRate = 1000
+				mf.SampleRate = 48000
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "flac", 0, 48000)
+				Expect(format).To(Equal("raw"))
+			})
+			It("returns raw when same format is requested with no sample rate constraint", func() {
+				mf.Suffix = "flac"
+				mf.BitRate = 1000
+				mf.SampleRate = 96000
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "flac", 0, 0)
+				Expect(format).To(Equal("raw"))
+			})
 			Context("Downsampling", func() {
 				BeforeEach(func() {
 					conf.Server.DefaultDownsamplingFormat = "opus"
@@ -69,13 +91,13 @@ var _ = Describe("MediaStreamer", func() {
 					mf.BitRate = 960
 				})
 				It("returns the DefaultDownsamplingFormat if a maxBitrate is requested but not the format", func() {
-					format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 128)
+					format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 128, 0)
 					Expect(format).To(Equal("opus"))
 					Expect(bitRate).To(Equal(128))
 				})
 				It("returns raw if maxBitrate is equal or greater than original", func() {
 					// This happens with DSub (and maybe other clients?). See https://github.com/navidrome/navidrome/issues/2066
-					format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 960)
+					format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 960, 0)
 					Expect(format).To(Equal("raw"))
 					Expect(bitRate).To(Equal(0))
 				})
@@ -90,34 +112,34 @@ var _ = Describe("MediaStreamer", func() {
 			It("returns raw if raw is requested", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0)
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0, 0)
 				Expect(format).To(Equal("raw"))
 			})
 			It("returns configured format/bitrate as default", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 0, 0)
 				Expect(format).To(Equal("oga"))
 				Expect(bitRate).To(Equal(96))
 			})
 			It("returns requested format", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0, 0)
 				Expect(format).To(Equal("mp3"))
 				Expect(bitRate).To(Equal(160)) // Default Bit Rate
 			})
 			It("returns requested bitrate", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 80)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 80, 0)
 				Expect(format).To(Equal("oga"))
 				Expect(bitRate).To(Equal(80))
 			})
 			It("returns raw if selected bitrate and format is the same as original", func() {
 				mf.Suffix = "mp3"
 				mf.BitRate = 192
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 192)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 192, 0)
 				Expect(format).To(Equal("raw"))
 				Expect(bitRate).To(Equal(0))
 			})
@@ -133,27 +155,27 @@ var _ = Describe("MediaStreamer", func() {
 			It("returns raw if raw is requested", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0)
+				format, _ := selectTranscodingOptions(ctx, ds, mf, "raw", 0, 0)
 				Expect(format).To(Equal("raw"))
 			})
 			It("returns configured format/bitrate as default", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 0, 0)
 				Expect(format).To(Equal("oga"))
 				Expect(bitRate).To(Equal(192))
 			})
 			It("returns requested format", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "mp3", 0, 0)
 				Expect(format).To(Equal("mp3"))
 				Expect(bitRate).To(Equal(160)) // Default Bit Rate
 			})
 			It("returns requested bitrate", func() {
 				mf.Suffix = "flac"
 				mf.BitRate = 1000
-				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 160)
+				format, bitRate := selectTranscodingOptions(ctx, ds, mf, "", 160, 0)
 				Expect(format).To(Equal("oga"))
 				Expect(bitRate).To(Equal(160))
 			})

core/media_streamer_test.go

@@ -39,34 +39,34 @@ var _ = Describe("MediaStreamer", func() {
 
 	Context("NewStream", func() {
 		It("returns a seekable stream if format is 'raw'", func() {
-			s, err := streamer.NewStream(ctx, "123", "raw", 0, 0)
+			s, err := streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "raw"})
 			Expect(err).ToNot(HaveOccurred())
 			Expect(s.Seekable()).To(BeTrue())
 		})
 		It("returns a seekable stream if maxBitRate is 0", func() {
-			s, err := streamer.NewStream(ctx, "123", "mp3", 0, 0)
+			s, err := streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "mp3"})
 			Expect(err).ToNot(HaveOccurred())
 			Expect(s.Seekable()).To(BeTrue())
 		})
 		It("returns a seekable stream if maxBitRate is higher than file bitRate", func() {
-			s, err := streamer.NewStream(ctx, "123", "mp3", 320, 0)
+			s, err := streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "mp3", BitRate: 320})
 			Expect(err).ToNot(HaveOccurred())
 			Expect(s.Seekable()).To(BeTrue())
 		})
 		It("returns a NON seekable stream if transcode is required", func() {
-			s, err := streamer.NewStream(ctx, "123", "mp3", 64, 0)
+			s, err := streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "mp3", BitRate: 64})
 			Expect(err).To(BeNil())
 			Expect(s.Seekable()).To(BeFalse())
 			Expect(s.Duration()).To(Equal(float32(257.0)))
 		})
 		It("returns a seekable stream if the file is complete in the cache", func() {
-			s, err := streamer.NewStream(ctx, "123", "mp3", 32, 0)
+			s, err := streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "mp3", BitRate: 32})
 			Expect(err).To(BeNil())
 			_, _ = io.ReadAll(s)
 			_ = s.Close()
 			Eventually(func() bool { return ffmpeg.IsClosed() }, "3s").Should(BeTrue())
 
-			s, err = streamer.NewStream(ctx, "123", "mp3", 32, 0)
+			s, err = streamer.NewStream(ctx, core.StreamRequest{ID: "123", Format: "mp3", BitRate: 32})
 			Expect(err).To(BeNil())
 			Expect(s.Seekable()).To(BeTrue())
 		})

core/playback/queue.go

@@ -3,6 +3,7 @@ package playback
 import (
 	"fmt"
 	"math/rand"
+	"strings"
 
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
@@ -21,11 +22,11 @@ func NewQueue() *Queue {
 }
 
 func (pd *Queue) String() string {
-	filenames := ""
+	var filenames strings.Builder
 	for idx, item := range pd.Items {
-		filenames += fmt.Sprint(idx) + ":" + item.Path + " "
+		filenames.WriteString(fmt.Sprint(idx) + ":" + item.Path + " ")
 	}
-	return fmt.Sprintf("#Items: %d, idx: %d, files: %s", len(pd.Items), pd.Index, filenames)
+	return fmt.Sprintf("#Items: %d, idx: %d, files: %s", len(pd.Items), pd.Index, filenames.String())
 }
 
 // returns the current mediafile or nil

core/playlists.go

@@ -45,7 +45,7 @@ func InPlaylistsPath(folder model.Folder) bool {
 		return true
 	}
 	rel, _ := filepath.Rel(folder.LibraryPath, folder.AbsolutePath())
-	for _, path := range strings.Split(conf.Server.PlaylistsPath, string(filepath.ListSeparator)) {
+	for path := range strings.SplitSeq(conf.Server.PlaylistsPath, string(filepath.ListSeparator)) {
 		if match, _ := doublestar.Match(path, rel); match {
 			return true
 		}
@@ -193,8 +193,8 @@ func (s *playlists) parseM3U(ctx context.Context, pls *model.Playlist, folder *m
 			if line == "" || strings.HasPrefix(line, "#") {
 				continue
 			}
-			if strings.HasPrefix(line, "file://") {
-				line = strings.TrimPrefix(line, "file://")
+			if after, ok := strings.CutPrefix(line, "file://"); ok {
+				line = after
 				line, _ = url.QueryUnescape(line)
 			}
 			if !model.IsAudioFile(line) {
@@ -533,7 +533,7 @@ type nspFile struct {
 }
 
 func (i *nspFile) UnmarshalJSON(data []byte) error {
-	m := map[string]interface{}{}
+	m := map[string]any{}
 	err := json.Unmarshal(data, &m)
 	if err != nil {
 		return err

core/scrobbler/play_tracker.go

@@ -212,10 +212,7 @@ func (p *playTracker) NowPlaying(ctx context.Context, playerId string, playerNam
 
 	// Calculate TTL based on remaining track duration. If position exceeds track duration,
 	// remaining is set to 0 to avoid negative TTL.
-	remaining := int(mf.Duration) - position
-	if remaining < 0 {
-		remaining = 0
-	}
+	remaining := max(int(mf.Duration)-position, 0)
 	// Add 5 seconds buffer to ensure the NowPlaying info is available slightly longer than the track duration.
 	ttl := time.Duration(remaining+5) * time.Second
 	_ = p.playMap.AddWithTTL(playerId, info, ttl)

core/share.go

@@ -87,7 +87,7 @@ func (r *shareRepositoryWrapper) newId() (string, error) {
 	}
 }
 
-func (r *shareRepositoryWrapper) Save(entity interface{}) (string, error) {
+func (r *shareRepositoryWrapper) Save(entity any) (string, error) {
 	s := entity.(*model.Share)
 	id, err := r.newId()
 	if err != nil {
@@ -127,7 +127,7 @@ func (r *shareRepositoryWrapper) Save(entity interface{}) (string, error) {
 	return id, err
 }
 
-func (r *shareRepositoryWrapper) Update(id string, entity interface{}, _ ...string) error {
+func (r *shareRepositoryWrapper) Update(id string, entity any, _ ...string) error {
 	cols := []string{"description", "downloadable"}
 
 	// TODO Better handling of Share expiration

core/storage/storagetest/fake_storage.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"maps"
 	"net/url"
 	"path"
 	"testing/fstest"
@@ -135,9 +136,7 @@ func (ffs *FakeFS) UpdateTags(filePath string, newTags map[string]any, when ...t
 	if err != nil {
 		panic(err)
 	}
-	for k, v := range newTags {
-		tags[k] = v
-	}
+	maps.Copy(tags, newTags)
 	data, _ := json.Marshal(tags)
 	f.Data = data
 	ffs.Touch(filePath, when...)
@@ -180,9 +179,7 @@ func Track(num int, title string, tags ...map[string]any) map[string]any {
 	ts["title"] = title
 	ts["track"] = num
 	for _, t := range tags {
-		for k, v := range t {
-			ts[k] = v
-		}
+		maps.Copy(ts, t)
 	}
 	return ts
 }
@@ -200,9 +197,7 @@ func MP3(tags ...map[string]any) *fstest.MapFile {
 func File(tags ...map[string]any) *fstest.MapFile {
 	ts := map[string]any{}
 	for _, t := range tags {
-		for k, v := range t {
-			ts[k] = v
-		}
+		maps.Copy(ts, t)
 	}
 	modTime := time.Now()
 	if mt, ok := ts[fakeFileInfoModTime]; !ok {

core/transcode/aliases.go

@@ -0,0 +1,87 @@
+package transcode
+
+import (
+	"slices"
+	"strings"
+)
+
+// containerAliasGroups maps each container alias to a canonical group name.
+var containerAliasGroups = func() map[string]string {
+	groups := [][]string{
+		{"aac", "adts", "m4a", "mp4", "m4b", "m4p"},
+		{"mpeg", "mp3", "mp2"},
+		{"ogg", "oga"},
+		{"aif", "aiff"},
+		{"asf", "wma"},
+		{"mpc", "mpp"},
+		{"wv"},
+	}
+	m := make(map[string]string)
+	for _, g := range groups {
+		canonical := g[0]
+		for _, name := range g {
+			m[name] = canonical
+		}
+	}
+	return m
+}()
+
+// codecAliasGroups maps each codec alias to a canonical group name.
+// Codecs within the same group are considered equivalent.
+var codecAliasGroups = func() map[string]string {
+	groups := [][]string{
+		{"aac", "adts"},
+		{"ac3", "ac-3"},
+		{"eac3", "e-ac3", "e-ac-3", "eac-3"},
+		{"mpc7", "musepack7"},
+		{"mpc8", "musepack8"},
+		{"wma1", "wmav1"},
+		{"wma2", "wmav2"},
+		{"wmalossless", "wma9lossless"},
+		{"wmapro", "wma9pro"},
+		{"shn", "shorten"},
+		{"mp4als", "als"},
+	}
+	m := make(map[string]string)
+	for _, g := range groups {
+		for _, name := range g {
+			m[name] = g[0] // canonical = first entry
+		}
+	}
+	return m
+}()
+
+// matchesWithAliases checks if a value matches any entry in candidates,
+// consulting the alias map for equivalent names.
+func matchesWithAliases(value string, candidates []string, aliases map[string]string) bool {
+	value = strings.ToLower(value)
+	canonical := aliases[value]
+	for _, c := range candidates {
+		c = strings.ToLower(c)
+		if c == value {
+			return true
+		}
+		if canonical != "" && aliases[c] == canonical {
+			return true
+		}
+	}
+	return false
+}
+
+// matchesContainer checks if a file suffix matches any of the container names,
+// including common aliases.
+func matchesContainer(suffix string, containers []string) bool {
+	return matchesWithAliases(suffix, containers, containerAliasGroups)
+}
+
+// matchesCodec checks if a codec matches any of the codec names,
+// including common aliases.
+func matchesCodec(codec string, codecs []string) bool {
+	return matchesWithAliases(codec, codecs, codecAliasGroups)
+}
+
+func containsIgnoreCase(slice []string, s string) bool {
+	return slices.ContainsFunc(slice, func(item string) bool {
+		return strings.EqualFold(item, s)
+	})
+}

core/transcode/codec.go

@@ -0,0 +1,59 @@
+package transcode
+
+import "strings"
+
+// isLosslessFormat returns true if the format is a lossless audio codec/format.
+// Note: core/ffmpeg has a separate isLosslessOutputFormat that covers only formats
+// ffmpeg can produce as output (a smaller set). This function covers all known lossless formats
+// for transcoding decision purposes.
+func isLosslessFormat(format string) bool {
+	switch strings.ToLower(format) {
+	case "flac", "alac", "wav", "aiff", "ape", "wv", "tta", "tak", "shn", "dsd":
+		return true
+	}
+	return false
+}
+
+// normalizeSourceSampleRate adjusts the source sample rate for codecs that store
+// it differently than PCM. Currently handles DSD (÷8):
+// DSD64=2822400→352800, DSD128=5644800→705600, etc.
+// For other codecs, returns the rate unchanged.
+func normalizeSourceSampleRate(sampleRate int, codec string) int {
+	if strings.EqualFold(codec, "dsd") && sampleRate > 0 {
+		return sampleRate / 8
+	}
+	return sampleRate
+}
+
+// normalizeSourceBitDepth adjusts the source bit depth for codecs that use
+// non-standard bit depths. Currently handles DSD (1-bit → 24-bit PCM, which is
+// what ffmpeg produces). For other codecs, returns the depth unchanged.
+func normalizeSourceBitDepth(bitDepth int, codec string) int {
+	if strings.EqualFold(codec, "dsd") && bitDepth == 1 {
+		return 24
+	}
+	return bitDepth
+}
+
+// codecFixedOutputSampleRate returns the mandatory output sample rate for codecs
+// that always resample regardless of input (e.g., Opus always outputs 48000Hz).
+// Returns 0 if the codec has no fixed output rate.
+func codecFixedOutputSampleRate(codec string) int {
+	switch strings.ToLower(codec) {
+	case "opus":
+		return 48000
+	}
+	return 0
+}
+
+// codecMaxSampleRate returns the hard maximum output sample rate for a codec.
+// Returns 0 if the codec has no hard limit.
+func codecMaxSampleRate(codec string) int {
+	switch strings.ToLower(codec) {
+	case "mp3":
+		return 48000
+	case "aac":
+		return 96000
+	}
+	return 0
+}

core/transcode/limitations.go

@@ -0,0 +1,206 @@
+package transcode
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/navidrome/navidrome/model"
+)
+
+// adjustResult represents the outcome of applying a limitation to a transcoded stream value
+type adjustResult int
+
+const (
+	adjustNone      adjustResult = iota // Value already satisfies the limitation
+	adjustAdjusted                      // Value was changed to fit the limitation
+	adjustCannotFit                     // Cannot satisfy the limitation (reject this profile)
+)
+
+// checkLimitations checks codec profile limitations against source media.
+// Returns "" if all limitations pass, or a typed reason string for the first failure.
+func checkLimitations(mf *model.MediaFile, sourceBitrate int, limitations []Limitation) string {
+	for _, lim := range limitations {
+		var ok bool
+		var reason string
+
+		switch lim.Name {
+		case LimitationAudioChannels:
+			ok = checkIntLimitation(mf.Channels, lim.Comparison, lim.Values)
+			reason = "audio channels not supported"
+		case LimitationAudioSamplerate:
+			ok = checkIntLimitation(mf.SampleRate, lim.Comparison, lim.Values)
+			reason = "audio samplerate not supported"
+		case LimitationAudioBitrate:
+			ok = checkIntLimitation(sourceBitrate, lim.Comparison, lim.Values)
+			reason = "audio bitrate not supported"
+		case LimitationAudioBitdepth:
+			ok = checkIntLimitation(mf.BitDepth, lim.Comparison, lim.Values)
+			reason = "audio bitdepth not supported"
+		case LimitationAudioProfile:
+			// TODO: populate source profile when MediaFile has audio profile info
+			ok = checkStringLimitation("", lim.Comparison, lim.Values)
+			reason = "audio profile not supported"
+		default:
+			continue
+		}
+
+		if !ok && lim.Required {
+			return reason
+		}
+	}
+	return ""
+}
+
+// applyLimitation adjusts a transcoded stream parameter to satisfy the limitation.
+// Returns the adjustment result.
+func applyLimitation(sourceBitrate int, lim *Limitation, ts *StreamDetails) adjustResult {
+	switch lim.Name {
+	case LimitationAudioChannels:
+		return applyIntLimitation(lim.Comparison, lim.Values, ts.Channels, func(v int) { ts.Channels = v })
+	case LimitationAudioBitrate:
+		current := ts.Bitrate
+		if current == 0 {
+			current = sourceBitrate
+		}
+		return applyIntLimitation(lim.Comparison, lim.Values, current, func(v int) { ts.Bitrate = v })
+	case LimitationAudioSamplerate:
+		return applyIntLimitation(lim.Comparison, lim.Values, ts.SampleRate, func(v int) { ts.SampleRate = v })
+	case LimitationAudioBitdepth:
+		if ts.BitDepth > 0 {
+			return applyIntLimitation(lim.Comparison, lim.Values, ts.BitDepth, func(v int) { ts.BitDepth = v })
+		}
+	case LimitationAudioProfile:
+		// TODO: implement when audio profile data is available
+	}
+	return adjustNone
+}
+
+// applyIntLimitation applies a limitation comparison to a value.
+// If the value needs adjusting, calls the setter and returns the result.
+func applyIntLimitation(comparison string, values []string, current int, setter func(int)) adjustResult {
+	if len(values) == 0 {
+		return adjustNone
+	}
+
+	switch comparison {
+	case ComparisonLessThanEqual:
+		limit, ok := parseInt(values[0])
+		if !ok {
+			return adjustNone
+		}
+		if current <= limit {
+			return adjustNone
+		}
+		setter(limit)
+		return adjustAdjusted
+	case ComparisonGreaterThanEqual:
+		limit, ok := parseInt(values[0])
+		if !ok {
+			return adjustNone
+		}
+		if current >= limit {
+			return adjustNone
+		}
+		// Cannot upscale
+		return adjustCannotFit
+	case ComparisonEquals:
+		// Check if current value matches any allowed value
+		for _, v := range values {
+			if limit, ok := parseInt(v); ok && current == limit {
+				return adjustNone
+			}
+		}
+		// Find the closest allowed value below current (don't upscale)
+		var closest int
+		found := false
+		for _, v := range values {
+			if limit, ok := parseInt(v); ok && limit < current {
+				if !found || limit > closest {
+					closest = limit
+					found = true
+				}
+			}
+		}
+		if found {
+			setter(closest)
+			return adjustAdjusted
+		}
+		return adjustCannotFit
+	case ComparisonNotEquals:
+		for _, v := range values {
+			if limit, ok := parseInt(v); ok && current == limit {
+				return adjustCannotFit
+			}
+		}
+		return adjustNone
+	}
+
+	return adjustNone
+}
+
+func checkIntLimitation(value int, comparison string, values []string) bool {
+	if len(values) == 0 {
+		return true
+	}
+
+	switch comparison {
+	case ComparisonLessThanEqual:
+		limit, ok := parseInt(values[0])
+		if !ok {
+			return true
+		}
+		return value <= limit
+	case ComparisonGreaterThanEqual:
+		limit, ok := parseInt(values[0])
+		if !ok {
+			return true
+		}
+		return value >= limit
+	case ComparisonEquals:
+		for _, v := range values {
+			if limit, ok := parseInt(v); ok && value == limit {
+				return true
+			}
+		}
+		return false
+	case ComparisonNotEquals:
+		for _, v := range values {
+			if limit, ok := parseInt(v); ok && value == limit {
+				return false
+			}
+		}
+		return true
+	}
+	return true
+}
+
+// checkStringLimitation checks a string value against a limitation.
+// Only Equals and NotEquals comparisons are meaningful for strings.
+// LessThanEqual/GreaterThanEqual are not applicable and always pass.
+func checkStringLimitation(value string, comparison string, values []string) bool {
+	switch comparison {
+	case ComparisonEquals:
+		for _, v := range values {
+			if strings.EqualFold(value, v) {
+				return true
+			}
+		}
+		return false
+	case ComparisonNotEquals:
+		for _, v := range values {
+			if strings.EqualFold(value, v) {
+				return false
+			}
+		}
+		return true
+	}
+	return true
+}
+
+func parseInt(s string) (int, bool) {
+	v, err := strconv.Atoi(s)
+	if err != nil || v < 0 {
+		return 0, false
+	}
+	return v, true
+}

core/transcode/transcode.go

@@ -0,0 +1,359 @@
+package transcode
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+)
+
+const (
+	tokenTTL       = 12 * time.Hour
+	defaultBitrate = 256 // kbps
+)
+
+func NewDecider(ds model.DataStore) Decider {
+	return &deciderService{
+		ds: ds,
+	}
+}
+
+type deciderService struct {
+	ds model.DataStore
+}
+
+func (s *deciderService) MakeDecision(ctx context.Context, mf *model.MediaFile, clientInfo *ClientInfo) (*Decision, error) {
+	decision := &Decision{
+		MediaID: mf.ID,
+	}
+
+	sourceBitrate := mf.BitRate // kbps
+
+	log.Trace(ctx, "Making transcode decision", "mediaID", mf.ID, "container", mf.Suffix,
+		"codec", mf.AudioCodec(), "bitrate", sourceBitrate, "channels", mf.Channels,
+		"sampleRate", mf.SampleRate, "lossless", mf.IsLossless(), "client", clientInfo.Name)
+
+	// Build source stream details
+	decision.SourceStream = buildSourceStream(mf)
+
+	// Check global bitrate constraint first.
+	if clientInfo.MaxAudioBitrate > 0 && sourceBitrate > clientInfo.MaxAudioBitrate {
+		log.Trace(ctx, "Global bitrate constraint exceeded, skipping direct play",
+			"sourceBitrate", sourceBitrate, "maxAudioBitrate", clientInfo.MaxAudioBitrate)
+		decision.TranscodeReasons = append(decision.TranscodeReasons, "audio bitrate not supported")
+		// Skip direct play profiles entirely — global constraint fails
+	} else {
+		// Try direct play profiles, collecting reasons for each failure
+		for _, profile := range clientInfo.DirectPlayProfiles {
+			if reason := s.checkDirectPlayProfile(mf, sourceBitrate, &profile, clientInfo); reason == "" {
+				decision.CanDirectPlay = true
+				decision.TranscodeReasons = nil // Clear any previously collected reasons
+				break
+			} else {
+				decision.TranscodeReasons = append(decision.TranscodeReasons, reason)
+			}
+		}
+	}
+
+	// If direct play is possible, we're done
+	if decision.CanDirectPlay {
+		log.Debug(ctx, "Transcode decision: direct play", "mediaID", mf.ID, "container", mf.Suffix, "codec", mf.AudioCodec())
+		return decision, nil
+	}
+
+	// Try transcoding profiles (in order of preference)
+	for _, profile := range clientInfo.TranscodingProfiles {
+		if ts, transcodeFormat := s.computeTranscodedStream(ctx, mf, sourceBitrate, &profile, clientInfo); ts != nil {
+			decision.CanTranscode = true
+			decision.TargetFormat = transcodeFormat
+			decision.TargetBitrate = ts.Bitrate
+			decision.TargetChannels = ts.Channels
+			decision.TargetSampleRate = ts.SampleRate
+			decision.TargetBitDepth = ts.BitDepth
+			decision.TranscodeStream = ts
+			break
+		}
+	}
+
+	if decision.CanTranscode {
+		log.Debug(ctx, "Transcode decision: transcode", "mediaID", mf.ID,
+			"targetFormat", decision.TargetFormat, "targetBitrate", decision.TargetBitrate,
+			"targetChannels", decision.TargetChannels, "reasons", decision.TranscodeReasons)
+	}
+
+	// If neither direct play nor transcode is possible
+	if !decision.CanDirectPlay && !decision.CanTranscode {
+		decision.ErrorReason = "no compatible playback profile found"
+		log.Warn(ctx, "Transcode decision: no compatible profile", "mediaID", mf.ID,
+			"container", mf.Suffix, "codec", mf.AudioCodec(), "reasons", decision.TranscodeReasons)
+	}
+
+	return decision, nil
+}
+
+func buildSourceStream(mf *model.MediaFile) StreamDetails {
+	return StreamDetails{
+		Container:  mf.Suffix,
+		Codec:      mf.AudioCodec(),
+		Bitrate:    mf.BitRate,
+		SampleRate: mf.SampleRate,
+		BitDepth:   mf.BitDepth,
+		Channels:   mf.Channels,
+		Duration:   mf.Duration,
+		Size:       mf.Size,
+		IsLossless: mf.IsLossless(),
+	}
+}
+
+// checkDirectPlayProfile returns "" if the profile matches (direct play OK),
+// or a typed reason string if it doesn't match.
+func (s *deciderService) checkDirectPlayProfile(mf *model.MediaFile, sourceBitrate int, profile *DirectPlayProfile, clientInfo *ClientInfo) string {
+	// Check protocol (only http for now)
+	if len(profile.Protocols) > 0 && !containsIgnoreCase(profile.Protocols, ProtocolHTTP) {
+		return "protocol not supported"
+	}
+
+	// Check container
+	if len(profile.Containers) > 0 && !matchesContainer(mf.Suffix, profile.Containers) {
+		return "container not supported"
+	}
+
+	// Check codec
+	if len(profile.AudioCodecs) > 0 && !matchesCodec(mf.AudioCodec(), profile.AudioCodecs) {
+		return "audio codec not supported"
+	}
+
+	// Check channels
+	if profile.MaxAudioChannels > 0 && mf.Channels > profile.MaxAudioChannels {
+		return "audio channels not supported"
+	}
+
+	// Check codec-specific limitations
+	for _, codecProfile := range clientInfo.CodecProfiles {
+		if strings.EqualFold(codecProfile.Type, CodecProfileTypeAudio) && matchesCodec(mf.AudioCodec(), []string{codecProfile.Name}) {
+			if reason := checkLimitations(mf, sourceBitrate, codecProfile.Limitations); reason != "" {
+				return reason
+			}
+		}
+	}
+
+	return ""
+}
+
+// computeTranscodedStream attempts to build a valid transcoded stream for the given profile.
+// Returns the stream details and the internal transcoding format (which may differ from the
+// response container when a codec fallback occurs, e.g., "mp4"→"aac").
+// Returns nil, "" if the profile cannot produce a valid output.
+func (s *deciderService) computeTranscodedStream(ctx context.Context, mf *model.MediaFile, sourceBitrate int, profile *Profile, clientInfo *ClientInfo) (*StreamDetails, string) {
+	// Check protocol (only http for now)
+	if profile.Protocol != "" && !strings.EqualFold(profile.Protocol, ProtocolHTTP) {
+		log.Trace(ctx, "Skipping transcoding profile: unsupported protocol", "protocol", profile.Protocol)
+		return nil, ""
+	}
+
+	responseContainer, targetFormat := s.resolveTargetFormat(ctx, profile)
+	if targetFormat == "" {
+		return nil, ""
+	}
+
+	targetIsLossless := isLosslessFormat(targetFormat)
+
+	// Reject lossy to lossless conversion
+	if !mf.IsLossless() && targetIsLossless {
+		log.Trace(ctx, "Skipping transcoding profile: lossy to lossless not allowed", "targetFormat", targetFormat)
+		return nil, ""
+	}
+
+	ts := &StreamDetails{
+		Container:  responseContainer,
+		Codec:      strings.ToLower(profile.AudioCodec),
+		SampleRate: normalizeSourceSampleRate(mf.SampleRate, mf.AudioCodec()),
+		Channels:   mf.Channels,
+		BitDepth:   normalizeSourceBitDepth(mf.BitDepth, mf.AudioCodec()),
+		IsLossless: targetIsLossless,
+	}
+	if ts.Codec == "" {
+		ts.Codec = targetFormat
+	}
+
+	// Apply codec-intrinsic sample rate adjustments before codec profile limitations
+	if fixedRate := codecFixedOutputSampleRate(ts.Codec); fixedRate > 0 {
+		ts.SampleRate = fixedRate
+	}
+	if maxRate := codecMaxSampleRate(ts.Codec); maxRate > 0 && ts.SampleRate > maxRate {
+		ts.SampleRate = maxRate
+	}
+
+	// Determine target bitrate (all in kbps)
+	if ok := s.computeBitrate(ctx, mf, sourceBitrate, targetFormat, targetIsLossless, clientInfo, ts); !ok {
+		return nil, ""
+	}
+
+	// Apply MaxAudioChannels from the transcoding profile
+	if profile.MaxAudioChannels > 0 && mf.Channels > profile.MaxAudioChannels {
+		ts.Channels = profile.MaxAudioChannels
+	}
+
+	// Apply codec profile limitations to the TARGET codec
+	if ok := s.applyCodecLimitations(ctx, sourceBitrate, targetFormat, targetIsLossless, clientInfo, ts); !ok {
+		return nil, ""
+	}
+
+	return ts, targetFormat
+}
+
+// resolveTargetFormat determines the response container and internal target format
+// by looking up transcoding configs. Returns ("", "") if no config found.
+func (s *deciderService) resolveTargetFormat(ctx context.Context, profile *Profile) (responseContainer, targetFormat string) {
+	responseContainer = strings.ToLower(profile.Container)
+	targetFormat = responseContainer
+	if targetFormat == "" {
+		targetFormat = strings.ToLower(profile.AudioCodec)
+		responseContainer = targetFormat
+	}
+
+	// Try the container first, then fall back to the audioCodec (e.g. "ogg" → "opus", "mp4" → "aac").
+	_, err := s.ds.Transcoding(ctx).FindByFormat(targetFormat)
+	if errors.Is(err, model.ErrNotFound) && profile.AudioCodec != "" && !strings.EqualFold(targetFormat, profile.AudioCodec) {
+		codec := strings.ToLower(profile.AudioCodec)
+		log.Trace(ctx, "No transcoding config for container, trying audioCodec", "container", targetFormat, "audioCodec", codec)
+		_, err = s.ds.Transcoding(ctx).FindByFormat(codec)
+		if err == nil {
+			targetFormat = codec
+		}
+	}
+	if err != nil {
+		if !errors.Is(err, model.ErrNotFound) {
+			log.Error(ctx, "Error looking up transcoding config", "format", targetFormat, err)
+		} else {
+			log.Trace(ctx, "Skipping transcoding profile: no transcoding config", "targetFormat", targetFormat)
+		}
+		return "", ""
+	}
+	return responseContainer, targetFormat
+}
+
+// computeBitrate determines the target bitrate for the transcoded stream.
+// Returns false if the profile should be rejected.
+func (s *deciderService) computeBitrate(ctx context.Context, mf *model.MediaFile, sourceBitrate int, targetFormat string, targetIsLossless bool, clientInfo *ClientInfo, ts *StreamDetails) bool {
+	if mf.IsLossless() {
+		if !targetIsLossless {
+			if clientInfo.MaxTranscodingAudioBitrate > 0 {
+				ts.Bitrate = clientInfo.MaxTranscodingAudioBitrate
+			} else {
+				ts.Bitrate = defaultBitrate
+			}
+		} else {
+			if clientInfo.MaxAudioBitrate > 0 && sourceBitrate > clientInfo.MaxAudioBitrate {
+				log.Trace(ctx, "Skipping transcoding profile: lossless target exceeds bitrate limit",
+					"targetFormat", targetFormat, "sourceBitrate", sourceBitrate, "maxAudioBitrate", clientInfo.MaxAudioBitrate)
+				return false
+			}
+		}
+	} else {
+		ts.Bitrate = sourceBitrate
+	}
+
+	// Apply maxAudioBitrate as final cap
+	if clientInfo.MaxAudioBitrate > 0 && ts.Bitrate > 0 && ts.Bitrate > clientInfo.MaxAudioBitrate {
+		ts.Bitrate = clientInfo.MaxAudioBitrate
+	}
+	return true
+}
+
+// applyCodecLimitations applies codec profile limitations to the transcoded stream.
+// Returns false if the profile should be rejected.
+func (s *deciderService) applyCodecLimitations(ctx context.Context, sourceBitrate int, targetFormat string, targetIsLossless bool, clientInfo *ClientInfo, ts *StreamDetails) bool {
+	targetCodec := ts.Codec
+	for _, codecProfile := range clientInfo.CodecProfiles {
+		if !strings.EqualFold(codecProfile.Type, CodecProfileTypeAudio) {
+			continue
+		}
+		if !matchesCodec(targetCodec, []string{codecProfile.Name}) {
+			continue
+		}
+		for _, lim := range codecProfile.Limitations {
+			result := applyLimitation(sourceBitrate, &lim, ts)
+			if strings.EqualFold(lim.Name, LimitationAudioBitrate) && targetIsLossless && result == adjustAdjusted {
+				log.Trace(ctx, "Skipping transcoding profile: cannot adjust bitrate for lossless target",
+					"targetFormat", targetFormat, "codec", targetCodec, "limitation", lim.Name)
+				return false
+			}
+			if result == adjustCannotFit {
+				log.Trace(ctx, "Skipping transcoding profile: codec limitation cannot be satisfied",
+					"targetFormat", targetFormat, "codec", targetCodec, "limitation", lim.Name,
+					"comparison", lim.Comparison, "values", lim.Values)
+				return false
+			}
+		}
+	}
+	return true
+}
+
+func (s *deciderService) CreateTranscodeParams(decision *Decision) (string, error) {
+	exp := time.Now().Add(tokenTTL)
+	claims := map[string]any{
+		"mid": decision.MediaID,
+		"dp":  decision.CanDirectPlay,
+	}
+	if decision.CanTranscode && decision.TargetFormat != "" {
+		claims["fmt"] = decision.TargetFormat
+		claims["br"] = decision.TargetBitrate
+		if decision.TargetChannels > 0 {
+			claims["ch"] = decision.TargetChannels
+		}
+		if decision.TargetSampleRate > 0 {
+			claims["sr"] = decision.TargetSampleRate
+		}
+		if decision.TargetBitDepth > 0 {
+			claims["bd"] = decision.TargetBitDepth
+		}
+	}
+	return auth.CreateExpiringPublicToken(exp, claims)
+}
+
+func (s *deciderService) ParseTranscodeParams(token string) (*Params, error) {
+	claims, err := auth.Validate(token)
+	if err != nil {
+		return nil, err
+	}
+
+	params := &Params{}
+
+	// Required claims
+	mid, ok := claims["mid"].(string)
+	if !ok || mid == "" {
+		return nil, fmt.Errorf("invalid transcode token: missing media ID")
+	}
+	params.MediaID = mid
+
+	dp, ok := claims["dp"].(bool)
+	if !ok {
+		return nil, fmt.Errorf("invalid transcode token: missing direct play flag")
+	}
+	params.DirectPlay = dp
+
+	// Optional claims (legitimately absent for direct-play tokens)
+	if f, ok := claims["fmt"].(string); ok {
+		params.TargetFormat = f
+	}
+	if br, ok := claims["br"].(float64); ok {
+		params.TargetBitrate = int(br)
+	}
+	if ch, ok := claims["ch"].(float64); ok {
+		params.TargetChannels = int(ch)
+	}
+	if sr, ok := claims["sr"].(float64); ok {
+		params.TargetSampleRate = int(sr)
+	}
+	if bd, ok := claims["bd"].(float64); ok {
+		params.TargetBitDepth = int(bd)
+	}
+
+	return params, nil
+}

core/transcode/transcode_suite_test.go

@@ -0,0 +1,17 @@
+package transcode
+
+import (
+	"testing"
+
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+func TestTranscode(t *testing.T) {
+	tests.Init(t, false)
+	log.SetLevel(log.LevelFatal)
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Transcode Suite")
+}

core/transcode/transcode_test.go

@@ -0,0 +1,976 @@
+package transcode
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/core/auth"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Decider", func() {
+	var (
+		ds  *tests.MockDataStore
+		svc Decider
+		ctx context.Context
+	)
+
+	BeforeEach(func() {
+		ctx = context.Background()
+		ds = &tests.MockDataStore{
+			MockedProperty:    &tests.MockedPropertyRepo{},
+			MockedTranscoding: &tests.MockTranscodingRepo{},
+		}
+		auth.Init(ds)
+		svc = NewDecider(ds)
+	})
+
+	Describe("MakeDecision", func() {
+		Context("Direct Play", func() {
+			It("allows direct play when profile matches", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 320, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, AudioCodecs: []string{"mp3"}, Protocols: []string{"http"}, MaxAudioChannels: 2},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+				Expect(decision.CanTranscode).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(BeEmpty())
+			})
+
+			It("rejects direct play when container doesn't match", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("container not supported"))
+			})
+
+			It("rejects direct play when codec doesn't match", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "ALAC", BitRate: 1000, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"m4a"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio codec not supported"))
+			})
+
+			It("rejects direct play when channels exceed limit", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 6}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}, MaxAudioChannels: 2},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio channels not supported"))
+			})
+
+			It("handles container aliases (aac -> m4a)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "AAC", BitRate: 256, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"aac"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("handles container aliases (mp4 -> m4a)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "AAC", BitRate: 256, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp4"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("handles codec aliases (adts -> aac)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "AAC", BitRate: 256, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"m4a"}, AudioCodecs: []string{"adts"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("allows when protocol list is empty (any protocol)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, AudioCodecs: []string{"flac"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("allows when both container and codec lists are empty (wildcard)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 128, Channels: 2}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{}, AudioCodecs: []string{}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+		})
+
+		Context("MaxAudioBitrate constraint", func() {
+			It("revokes direct play when bitrate exceeds maxAudioBitrate", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1500, Channels: 2}
+				ci := &ClientInfo{
+					MaxAudioBitrate: 500, // kbps
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio bitrate not supported"))
+			})
+		})
+
+		Context("Transcoding", func() {
+			It("selects transcoding when direct play isn't possible", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 256, // kbps
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, Protocols: []string{"http"}},
+					},
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http", MaxAudioChannels: 2},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("mp3"))
+				Expect(decision.TargetBitrate).To(Equal(256)) // kbps
+				Expect(decision.TranscodeReasons).To(ContainElement("container not supported"))
+			})
+
+			It("rejects lossy to lossless transcoding", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 320, Channels: 2}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeFalse())
+			})
+
+			It("uses default bitrate when client doesn't specify", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, BitDepth: 16}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetBitrate).To(Equal(defaultBitrate)) // 256 kbps
+			})
+
+			It("preserves lossy bitrate when under max", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "ogg", BitRate: 192, Channels: 2}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 256, // kbps
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetBitrate).To(Equal(192)) // source bitrate in kbps
+			})
+
+			It("rejects unsupported transcoding format", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "wav", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeFalse())
+			})
+
+			It("applies maxAudioBitrate as final cap on transcoded stream", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 320, Channels: 2}
+				ci := &ClientInfo{
+					MaxAudioBitrate: 96, // kbps
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetBitrate).To(Equal(96)) // capped by maxAudioBitrate
+			})
+
+			It("selects first valid transcoding profile in order", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 48000, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, Protocols: []string{"http"}},
+					},
+					TranscodingProfiles: []Profile{
+						{Container: "opus", AudioCodec: "opus", Protocol: "http"},
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http", MaxAudioChannels: 2},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("opus"))
+			})
+		})
+
+		Context("Lossless to lossless transcoding", func() {
+			It("allows lossless to lossless when samplerate needs downsampling", func() {
+				// MockTranscodingRepo doesn't support "flac" format, so this would fail to find a config.
+				// This test documents the behavior: lossless→lossless requires server transcoding config.
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 176400, BitDepth: 1}
+				ci := &ClientInfo{
+					MaxAudioBitrate: 1000,
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("mp3"))
+			})
+
+			It("sets IsLossless=true on transcoded stream when target is lossless", func() {
+				// Simulate DSD→FLAC transcoding by using a mock that supports "flac"
+				mockTranscoding := &tests.MockTranscodingRepo{}
+				ds.MockedTranscoding = mockTranscoding
+				svc = NewDecider(ds)
+
+				// MockTranscodingRepo doesn't support flac, so this will skip lossless profile.
+				// Use mp3 which is supported as the fallback.
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.IsLossless).To(BeFalse()) // mp3 is lossy
+			})
+		})
+
+		Context("No compatible profile", func() {
+			It("returns error when nothing matches", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 6}
+				ci := &ClientInfo{}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.CanTranscode).To(BeFalse())
+				Expect(decision.ErrorReason).To(Equal("no compatible playback profile found"))
+			})
+		})
+
+		Context("Codec limitations on direct play", func() {
+			It("rejects direct play when codec limitation fails (required)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 512, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, AudioCodecs: []string{"mp3"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioBitrate, Comparison: ComparisonLessThanEqual, Values: []string{"320"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio bitrate not supported"))
+			})
+
+			It("allows direct play when optional limitation fails", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 512, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"mp3"}, AudioCodecs: []string{"mp3"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioBitrate, Comparison: ComparisonLessThanEqual, Values: []string{"320"}, Required: false},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("handles Equals comparison with multiple values", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioChannels, Comparison: ComparisonEquals, Values: []string{"1", "2"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("rejects when Equals comparison doesn't match any value", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 6, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioChannels, Comparison: ComparisonEquals, Values: []string{"1", "2"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+			})
+
+			It("rejects direct play when audioProfile limitation fails (required)", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "AAC", BitRate: 256, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"m4a"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "aac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioProfile, Comparison: ComparisonEquals, Values: []string{"LC"}, Required: true},
+							},
+						},
+					},
+				}
+				// Source profile is empty (not yet populated from scanner), so Equals("LC") fails
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio profile not supported"))
+			})
+
+			It("allows direct play when audioProfile limitation is optional", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "m4a", Codec: "AAC", BitRate: 256, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"m4a"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "aac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioProfile, Comparison: ComparisonEquals, Values: []string{"LC"}, Required: false},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeTrue())
+			})
+
+			It("rejects direct play due to samplerate limitation", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioSamplerate, Comparison: ComparisonLessThanEqual, Values: []string{"48000"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(ContainElement("audio samplerate not supported"))
+			})
+		})
+
+		Context("Codec limitations on transcoded output", func() {
+			It("applies bitrate limitation to transcoded stream", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "mp3", Codec: "MP3", BitRate: 192, Channels: 2, SampleRate: 44100}
+				ci := &ClientInfo{
+					MaxAudioBitrate: 96, // force transcode
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioBitrate, Comparison: ComparisonLessThanEqual, Values: []string{"96"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.Bitrate).To(Equal(96))
+			})
+
+			It("applies channel limitation to transcoded stream", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 6, SampleRate: 48000, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioChannels, Comparison: ComparisonLessThanEqual, Values: []string{"2"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.Channels).To(Equal(2))
+			})
+
+			It("applies samplerate limitation to transcoded stream", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioSamplerate, Comparison: ComparisonLessThanEqual, Values: []string{"48000"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+			})
+
+			It("applies bitdepth limitation to transcoded stream", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", AudioCodec: "flac", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioBitdepth, Comparison: ComparisonLessThanEqual, Values: []string{"16"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(16))
+				Expect(decision.TargetBitDepth).To(Equal(16))
+			})
+
+			It("preserves source bit depth when no limitation applies", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 24}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", AudioCodec: "flac", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(24))
+				Expect(decision.TargetBitDepth).To(Equal(24))
+			})
+
+			It("rejects transcoding profile when GreaterThanEqual cannot be satisfied", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "mp3",
+							Limitations: []Limitation{
+								{Name: LimitationAudioSamplerate, Comparison: ComparisonGreaterThanEqual, Values: []string{"96000"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeFalse())
+			})
+		})
+
+		Context("DSD sample rate conversion", func() {
+			It("converts DSD sample rate to PCM-equivalent in decision", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 2822400, BitDepth: 1}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("mp3"))
+				// DSD64 2822400 / 8 = 352800, capped by MP3 max of 48000
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+				Expect(decision.TargetSampleRate).To(Equal(48000))
+				// DSD 1-bit → 24-bit PCM
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(24))
+				Expect(decision.TargetBitDepth).To(Equal(24))
+			})
+
+			It("converts DSD sample rate for FLAC target without codec limit", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 2822400, BitDepth: 1}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", AudioCodec: "flac", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("flac"))
+				// DSD64 2822400 / 8 = 352800, FLAC has no hard max
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(352800))
+				Expect(decision.TargetSampleRate).To(Equal(352800))
+				// DSD 1-bit → 24-bit PCM
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(24))
+				Expect(decision.TargetBitDepth).To(Equal(24))
+			})
+
+			It("applies codec profile limit to DSD-converted FLAC sample rate", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 2822400, BitDepth: 1}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", AudioCodec: "flac", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioSamplerate, Comparison: ComparisonLessThanEqual, Values: []string{"48000"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				// DSD64 2822400 / 8 = 352800, capped by codec profile limit of 48000
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+				Expect(decision.TargetSampleRate).To(Equal(48000))
+				// DSD 1-bit → 24-bit PCM
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(24))
+				Expect(decision.TargetBitDepth).To(Equal(24))
+			})
+
+			It("applies audioBitdepth limitation to DSD-converted bit depth", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 2822400, BitDepth: 1}
+				ci := &ClientInfo{
+					TranscodingProfiles: []Profile{
+						{Container: "flac", AudioCodec: "flac", Protocol: "http"},
+					},
+					CodecProfiles: []CodecProfile{
+						{
+							Type: CodecProfileTypeAudio,
+							Name: "flac",
+							Limitations: []Limitation{
+								{Name: LimitationAudioBitdepth, Comparison: ComparisonLessThanEqual, Values: []string{"16"}, Required: true},
+							},
+						},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				// DSD 1-bit → 24-bit PCM, then capped by codec profile limit to 16-bit
+				Expect(decision.TranscodeStream.BitDepth).To(Equal(16))
+				Expect(decision.TargetBitDepth).To(Equal(16))
+			})
+		})
+
+		Context("Opus fixed sample rate", func() {
+			It("sets Opus output to 48000Hz regardless of input", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 128,
+					TranscodingProfiles: []Profile{
+						{Container: "opus", AudioCodec: "opus", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("opus"))
+				// Opus always outputs 48000Hz
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+				Expect(decision.TargetSampleRate).To(Equal(48000))
+			})
+
+			It("sets Opus output to 48000Hz even for 96kHz input", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1500, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 128,
+					TranscodingProfiles: []Profile{
+						{Container: "opus", AudioCodec: "opus", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+			})
+		})
+
+		Context("Container vs format separation", func() {
+			It("preserves mp4 container when falling back to aac format", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 256,
+					TranscodingProfiles: []Profile{
+						{Container: "mp4", AudioCodec: "aac", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				// TargetFormat is the internal format used for DB lookup ("aac")
+				Expect(decision.TargetFormat).To(Equal("aac"))
+				// Container in the response preserves what the client asked ("mp4")
+				Expect(decision.TranscodeStream.Container).To(Equal("mp4"))
+				Expect(decision.TranscodeStream.Codec).To(Equal("aac"))
+			})
+
+			It("uses container as format when container matches transcoding config", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 256,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TargetFormat).To(Equal("mp3"))
+				Expect(decision.TranscodeStream.Container).To(Equal("mp3"))
+			})
+		})
+
+		Context("MP3 max sample rate", func() {
+			It("caps sample rate at 48000 for MP3", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1500, Channels: 2, SampleRate: 96000, BitDepth: 24}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(48000))
+			})
+
+			It("preserves sample rate at 44100 for MP3", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 44100, BitDepth: 16}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(44100))
+			})
+		})
+
+		Context("AAC max sample rate", func() {
+			It("caps sample rate at 96000 for AAC", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "dsf", Codec: "DSD", BitRate: 5644, Channels: 2, SampleRate: 2822400, BitDepth: 1}
+				ci := &ClientInfo{
+					MaxTranscodingAudioBitrate: 320,
+					TranscodingProfiles: []Profile{
+						{Container: "aac", AudioCodec: "aac", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanTranscode).To(BeTrue())
+				// DSD64 2822400 / 8 = 352800, capped by AAC max of 96000
+				Expect(decision.TranscodeStream.SampleRate).To(Equal(96000))
+			})
+		})
+
+		Context("Typed transcode reasons from multiple profiles", func() {
+			It("collects reasons from each failed direct play profile", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "ogg", Codec: "Vorbis", BitRate: 128, Channels: 2, SampleRate: 48000}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+						{Containers: []string{"mp3"}, AudioCodecs: []string{"mp3"}, Protocols: []string{"http"}},
+						{Containers: []string{"m4a", "mp4"}, AudioCodecs: []string{"aac"}, Protocols: []string{"http"}},
+					},
+					TranscodingProfiles: []Profile{
+						{Container: "mp3", AudioCodec: "mp3", Protocol: "http"},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.CanDirectPlay).To(BeFalse())
+				Expect(decision.TranscodeReasons).To(HaveLen(3))
+				Expect(decision.TranscodeReasons[0]).To(Equal("container not supported"))
+				Expect(decision.TranscodeReasons[1]).To(Equal("container not supported"))
+				Expect(decision.TranscodeReasons[2]).To(Equal("container not supported"))
+			})
+		})
+
+		Context("Source stream details", func() {
+			It("populates source stream correctly with kbps bitrate", func() {
+				mf := &model.MediaFile{ID: "1", Suffix: "flac", Codec: "FLAC", BitRate: 1000, Channels: 2, SampleRate: 96000, BitDepth: 24, Duration: 300.5, Size: 50000000}
+				ci := &ClientInfo{
+					DirectPlayProfiles: []DirectPlayProfile{
+						{Containers: []string{"flac"}, Protocols: []string{"http"}},
+					},
+				}
+				decision, err := svc.MakeDecision(ctx, mf, ci)
+				Expect(err).ToNot(HaveOccurred())
+				Expect(decision.SourceStream.Container).To(Equal("flac"))
+				Expect(decision.SourceStream.Codec).To(Equal("flac"))
+				Expect(decision.SourceStream.Bitrate).To(Equal(1000)) // kbps
+				Expect(decision.SourceStream.SampleRate).To(Equal(96000))
+				Expect(decision.SourceStream.BitDepth).To(Equal(24))
+				Expect(decision.SourceStream.Channels).To(Equal(2))
+			})
+		})
+	})
+
+	Describe("Token round-trip", func() {
+		It("creates and parses a direct play token", func() {
+			decision := &Decision{
+				MediaID:       "media-123",
+				CanDirectPlay: true,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(token).ToNot(BeEmpty())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.MediaID).To(Equal("media-123"))
+			Expect(params.DirectPlay).To(BeTrue())
+			Expect(params.TargetFormat).To(BeEmpty())
+		})
+
+		It("creates and parses a transcode token with kbps bitrate", func() {
+			decision := &Decision{
+				MediaID:        "media-456",
+				CanDirectPlay:  false,
+				CanTranscode:   true,
+				TargetFormat:   "mp3",
+				TargetBitrate:  256, // kbps
+				TargetChannels: 2,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.MediaID).To(Equal("media-456"))
+			Expect(params.DirectPlay).To(BeFalse())
+			Expect(params.TargetFormat).To(Equal("mp3"))
+			Expect(params.TargetBitrate).To(Equal(256)) // kbps
+			Expect(params.TargetChannels).To(Equal(2))
+		})
+
+		It("creates and parses a transcode token with sample rate", func() {
+			decision := &Decision{
+				MediaID:          "media-789",
+				CanDirectPlay:    false,
+				CanTranscode:     true,
+				TargetFormat:     "flac",
+				TargetBitrate:    0,
+				TargetChannels:   2,
+				TargetSampleRate: 48000,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.MediaID).To(Equal("media-789"))
+			Expect(params.DirectPlay).To(BeFalse())
+			Expect(params.TargetFormat).To(Equal("flac"))
+			Expect(params.TargetSampleRate).To(Equal(48000))
+			Expect(params.TargetChannels).To(Equal(2))
+		})
+
+		It("creates and parses a transcode token with bit depth", func() {
+			decision := &Decision{
+				MediaID:        "media-bd",
+				CanDirectPlay:  false,
+				CanTranscode:   true,
+				TargetFormat:   "flac",
+				TargetBitrate:  0,
+				TargetChannels: 2,
+				TargetBitDepth: 24,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.MediaID).To(Equal("media-bd"))
+			Expect(params.TargetBitDepth).To(Equal(24))
+		})
+
+		It("omits bit depth from token when 0", func() {
+			decision := &Decision{
+				MediaID:        "media-nobd",
+				CanDirectPlay:  false,
+				CanTranscode:   true,
+				TargetFormat:   "mp3",
+				TargetBitrate:  256,
+				TargetBitDepth: 0,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.TargetBitDepth).To(Equal(0))
+		})
+
+		It("omits sample rate from token when 0", func() {
+			decision := &Decision{
+				MediaID:          "media-100",
+				CanDirectPlay:    false,
+				CanTranscode:     true,
+				TargetFormat:     "mp3",
+				TargetBitrate:    256,
+				TargetSampleRate: 0,
+			}
+			token, err := svc.CreateTranscodeParams(decision)
+			Expect(err).ToNot(HaveOccurred())
+
+			params, err := svc.ParseTranscodeParams(token)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(params.TargetSampleRate).To(Equal(0))
+		})
+
+		It("rejects an invalid token", func() {
+			_, err := svc.ParseTranscodeParams("invalid-token")
+			Expect(err).To(HaveOccurred())
+		})
+	})
+})

core/transcode/types.go

@@ -0,0 +1,129 @@
+package transcode
+
+import (
+	"context"
+
+	"github.com/navidrome/navidrome/model"
+)
+
+// Decider is the core service interface for making transcoding decisions
+type Decider interface {
+	MakeDecision(ctx context.Context, mf *model.MediaFile, clientInfo *ClientInfo) (*Decision, error)
+	CreateTranscodeParams(decision *Decision) (string, error)
+	ParseTranscodeParams(token string) (*Params, error)
+}
+
+// ClientInfo represents client playback capabilities.
+// All bitrate values are in kilobits per second (kbps)
+type ClientInfo struct {
+	Name                       string
+	Platform                   string
+	MaxAudioBitrate            int
+	MaxTranscodingAudioBitrate int
+	DirectPlayProfiles         []DirectPlayProfile
+	TranscodingProfiles        []Profile
+	CodecProfiles              []CodecProfile
+}
+
+// DirectPlayProfile describes a format the client can play directly
+type DirectPlayProfile struct {
+	Containers       []string
+	AudioCodecs      []string
+	Protocols        []string
+	MaxAudioChannels int
+}
+
+// Profile describes a transcoding target the client supports
+type Profile struct {
+	Container        string
+	AudioCodec       string
+	Protocol         string
+	MaxAudioChannels int
+}
+
+// CodecProfile describes codec-specific limitations
+type CodecProfile struct {
+	Type        string
+	Name        string
+	Limitations []Limitation
+}
+
+// Limitation describes a specific codec limitation
+type Limitation struct {
+	Name       string
+	Comparison string
+	Values     []string
+	Required   bool
+}
+
+// Protocol values (OpenSubsonic spec enum)
+const (
+	ProtocolHTTP = "http"
+	ProtocolHLS  = "hls"
+)
+
+// Comparison operators (OpenSubsonic spec enum)
+const (
+	ComparisonEquals           = "Equals"
+	ComparisonNotEquals        = "NotEquals"
+	ComparisonLessThanEqual    = "LessThanEqual"
+	ComparisonGreaterThanEqual = "GreaterThanEqual"
+)
+
+// Limitation names (OpenSubsonic spec enum)
+const (
+	LimitationAudioChannels   = "audioChannels"
+	LimitationAudioBitrate    = "audioBitrate"
+	LimitationAudioProfile    = "audioProfile"
+	LimitationAudioSamplerate = "audioSamplerate"
+	LimitationAudioBitdepth   = "audioBitdepth"
+)
+
+// Codec profile types (OpenSubsonic spec enum)
+const (
+	CodecProfileTypeAudio = "AudioCodec"
+)
+
+// Decision represents the internal decision result.
+// All bitrate values are in kilobits per second (kbps).
+type Decision struct {
+	MediaID          string
+	CanDirectPlay    bool
+	CanTranscode     bool
+	TranscodeReasons []string
+	ErrorReason      string
+	TargetFormat     string
+	TargetBitrate    int
+	TargetChannels   int
+	TargetSampleRate int
+	TargetBitDepth   int
+	SourceStream     StreamDetails
+	TranscodeStream  *StreamDetails
+}
+
+// StreamDetails describes audio stream properties.
+// Bitrate is in kilobits per second (kbps).
+type StreamDetails struct {
+	Container  string
+	Codec      string
+	Profile    string // Audio profile (e.g., "LC", "HE-AAC"). Empty until scanner support is added.
+	Bitrate    int
+	SampleRate int
+	BitDepth   int
+	Channels   int
+	Duration   float32
+	Size       int64
+	IsLossless bool
+}
+
+// Params contains the parameters extracted from a transcode token.
+// TargetBitrate is in kilobits per second (kbps).
+type Params struct {
+	MediaID          string
+	DirectPlay       bool
+	TargetFormat     string
+	TargetBitrate    int
+	TargetChannels   int
+	TargetSampleRate int
+	TargetBitDepth   int
+}

core/user.go

@@ -50,12 +50,12 @@ type userRepositoryWrapper struct {
 }
 
 // Save implements rest.Persistable by delegating to the underlying repository.
-func (r *userRepositoryWrapper) Save(entity interface{}) (string, error) {
+func (r *userRepositoryWrapper) Save(entity any) (string, error) {
 	return r.UserRepository.(rest.Persistable).Save(entity)
 }
 
 // Update implements rest.Persistable by delegating to the underlying repository.
-func (r *userRepositoryWrapper) Update(id string, entity interface{}, cols ...string) error {
+func (r *userRepositoryWrapper) Update(id string, entity any, cols ...string) error {
 	return r.UserRepository.(rest.Persistable).Update(id, entity, cols...)
 }
 

core/wire_providers.go

@@ -8,6 +8,7 @@ import (
 	"github.com/navidrome/navidrome/core/metrics"
 	"github.com/navidrome/navidrome/core/playback"
 	"github.com/navidrome/navidrome/core/scrobbler"
+	"github.com/navidrome/navidrome/core/transcode"
 )
 
 var Set = wire.NewSet(
@@ -20,6 +21,7 @@ var Set = wire.NewSet(
 	NewLibrary,
 	NewUser,
 	NewMaintenance,
+	transcode.NewDecider,
 	agents.GetAgents,
 	external.NewProvider,
 	wire.Bind(new(external.Agents), new(*agents.Agents)),

db/db.go

@@ -126,7 +126,7 @@ func Optimize(ctx context.Context) {
 	}
 	log.Debug(ctx, "Optimizing open connections", "numConns", numConns)
 	var conns []*sql.Conn
-	for i := 0; i < numConns; i++ {
+	for range numConns {
 		conn, err := Db().Conn(ctx)
 		conns = append(conns, conn)
 		if err != nil {
@@ -147,8 +147,8 @@ func Optimize(ctx context.Context) {
 
 type statusLogger struct{ numPending int }
 
-func (*statusLogger) Fatalf(format string, v ...interface{}) { log.Fatal(fmt.Sprintf(format, v...)) }
-func (l *statusLogger) Printf(format string, v ...interface{}) {
+func (*statusLogger) Fatalf(format string, v ...any) { log.Fatal(fmt.Sprintf(format, v...)) }
+func (l *statusLogger) Printf(format string, v ...any) {
 	if len(v) < 1 {
 		return
 	}
@@ -183,27 +183,27 @@ type logAdapter struct {
 	silent bool
 }
 
-func (l *logAdapter) Fatal(v ...interface{}) {
+func (l *logAdapter) Fatal(v ...any) {
 	log.Fatal(l.ctx, fmt.Sprint(v...))
 }
 
-func (l *logAdapter) Fatalf(format string, v ...interface{}) {
+func (l *logAdapter) Fatalf(format string, v ...any) {
 	log.Fatal(l.ctx, fmt.Sprintf(format, v...))
 }
 
-func (l *logAdapter) Print(v ...interface{}) {
+func (l *logAdapter) Print(v ...any) {
 	if !l.silent {
 		log.Info(l.ctx, fmt.Sprint(v...))
 	}
 }
 
-func (l *logAdapter) Println(v ...interface{}) {
+func (l *logAdapter) Println(v ...any) {
 	if !l.silent {
 		log.Info(l.ctx, fmt.Sprintln(v...))
 	}
 }
 
-func (l *logAdapter) Printf(format string, v ...interface{}) {
+func (l *logAdapter) Printf(format string, v ...any) {
 	if !l.silent {
 		log.Info(l.ctx, fmt.Sprintf(format, v...))
 	}

db/migrations/20260205120000_add_codec_and_update_transcodings.go

@@ -0,0 +1,63 @@
+package migrations
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/navidrome/navidrome/model/id"
+	"github.com/pressly/goose/v3"
+)
+
+func init() {
+	goose.AddMigrationContext(upAddCodecAndUpdateTranscodings, downAddCodecAndUpdateTranscodings)
+}
+
+func upAddCodecAndUpdateTranscodings(_ context.Context, tx *sql.Tx) error {
+	// Add codec column to media_file.
+	_, err := tx.Exec(`ALTER TABLE media_file ADD COLUMN codec VARCHAR(255) DEFAULT '' NOT NULL`)
+	if err != nil {
+		return err
+	}
+	_, err = tx.Exec(`CREATE INDEX IF NOT EXISTS media_file_codec ON media_file(codec)`)
+	if err != nil {
+		return err
+	}
+
+	// Update old AAC default (adts) to new default (ipod with fragmented MP4).
+	// Only affects users who still have the unmodified old default command.
+	_, err = tx.Exec(
+		`UPDATE transcoding SET command = ? WHERE target_format = 'aac' AND command = ?`,
+		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f ipod -movflags frag_keyframe+empty_moov -",
+		"ffmpeg -i %s -ss %t -map 0:a:0 -b:a %bk -v 0 -c:a aac -f adts -",
+	)
+	if err != nil {
+		return err
+	}
+
+	// Add FLAC transcoding for existing installations that were seeded before FLAC was added.
+	var count int
+	err = tx.QueryRow("SELECT COUNT(*) FROM transcoding WHERE target_format = 'flac'").Scan(&count)
+	if err != nil {
+		return err
+	}
+	if count == 0 {
+		_, err = tx.Exec(
+			"INSERT INTO transcoding (id, name, target_format, default_bit_rate, command) VALUES (?, ?, ?, ?, ?)",
+			id.NewRandom(), "flac audio", "flac", 0,
+			"ffmpeg -i %s -ss %t -map 0:a:0 -v 0 -c:a flac -f flac -",
+		)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func downAddCodecAndUpdateTranscodings(_ context.Context, tx *sql.Tx) error {
+	_, err := tx.Exec(`DROP INDEX IF EXISTS media_file_codec`)
+	if err != nil {
+		return err
+	}
+	_, err = tx.Exec(`ALTER TABLE media_file DROP COLUMN codec`)
+	return err
+}

go.mod

@@ -7,7 +7,7 @@ replace (
 	github.com/dhowden/tag v0.0.0-20240417053706-3d75831295e8 => github.com/deluan/tag v0.0.0-20241002021117-dfe5e6ea396d
 
 	// Fork to implement raw tags support
-	go.senan.xyz/taglib => github.com/deluan/go-taglib v0.0.0-20260119020817-8753c7531798
+	go.senan.xyz/taglib => github.com/deluan/go-taglib v0.0.0-20260205042457-5d80806aee57
 )
 
 require (

go.sum

@@ -36,8 +36,8 @@ github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 h1:NMZiJj8QnKe1LgsbDayM4UoHwbvwDRwnI3hwNaAHRnc=
 github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0/go.mod h1:ZXNYxsqcloTdSy/rNShjYzMhyjf0LaoftYK0p+A3h40=
-github.com/deluan/go-taglib v0.0.0-20260119020817-8753c7531798 h1:q4fvcIK/LxElpyQILCejG6WPYjVb2F/4P93+k017ANk=
-github.com/deluan/go-taglib v0.0.0-20260119020817-8753c7531798/go.mod h1:sKDN0U4qXDlq6LFK+aOAkDH4Me5nDV1V/A4B+B69xBA=
+github.com/deluan/go-taglib v0.0.0-20260205042457-5d80806aee57 h1:SXIwfjzTv0UzoUWpFREl8p3AxXVLmbcto1/ISih11a0=
+github.com/deluan/go-taglib v0.0.0-20260205042457-5d80806aee57/go.mod h1:sKDN0U4qXDlq6LFK+aOAkDH4Me5nDV1V/A4B+B69xBA=
 github.com/deluan/rest v0.0.0-20211102003136-6260bc399cbf h1:tb246l2Zmpt/GpF9EcHCKTtwzrd0HGfEmoODFA/qnk4=
 github.com/deluan/rest v0.0.0-20211102003136-6260bc399cbf/go.mod h1:tSgDythFsl0QgS/PFWfIZqcJKnkADWneY80jaVRlqK8=
 github.com/deluan/sanitize v0.0.0-20241120162836-fdfd8fdfaa55 h1:wSCnggTs2f2ji6nFwQmfwgINcmSMj0xF0oHnoyRSPe4=

log/log.go

@@ -19,7 +19,7 @@ import (
 
 type Level uint32
 
-type LevelFunc = func(ctx interface{}, msg interface{}, keyValuePairs ...interface{})
+type LevelFunc = func(ctx any, msg any, keyValuePairs ...any)
 
 var redacted = &Hook{
 	AcceptedLevels: logrus.AllLevels,
@@ -152,7 +152,7 @@ func Redact(msg string) string {
 	return r
 }
 
-func NewContext(ctx context.Context, keyValuePairs ...interface{}) context.Context {
+func NewContext(ctx context.Context, keyValuePairs ...any) context.Context {
 	if ctx == nil {
 		ctx = context.Background()
 	}
@@ -184,32 +184,32 @@ func IsGreaterOrEqualTo(level Level) bool {
 	return shouldLog(level, 2)
 }
 
-func Fatal(args ...interface{}) {
+func Fatal(args ...any) {
 	Log(LevelFatal, args...)
 	os.Exit(1)
 }
 
-func Error(args ...interface{}) {
+func Error(args ...any) {
 	Log(LevelError, args...)
 }
 
-func Warn(args ...interface{}) {
+func Warn(args ...any) {
 	Log(LevelWarn, args...)
 }
 
-func Info(args ...interface{}) {
+func Info(args ...any) {
 	Log(LevelInfo, args...)
 }
 
-func Debug(args ...interface{}) {
+func Debug(args ...any) {
 	Log(LevelDebug, args...)
 }
 
-func Trace(args ...interface{}) {
+func Trace(args ...any) {
 	Log(LevelTrace, args...)
 }
 
-func Log(level Level, args ...interface{}) {
+func Log(level Level, args ...any) {
 	if !shouldLog(level, 3) {
 		return
 	}
@@ -250,7 +250,7 @@ func shouldLog(requiredLevel Level, skip int) bool {
 	return false
 }
 
-func parseArgs(args []interface{}) (*logrus.Entry, string) {
+func parseArgs(args []any) (*logrus.Entry, string) {
 	var l *logrus.Entry
 	var err error
 	if args[0] == nil {
@@ -289,7 +289,7 @@ func parseArgs(args []interface{}) (*logrus.Entry, string) {
 	return l, ""
 }
 
-func addFields(logger *logrus.Entry, keyValuePairs []interface{}) *logrus.Entry {
+func addFields(logger *logrus.Entry, keyValuePairs []any) *logrus.Entry {
 	for i := 0; i < len(keyValuePairs); i += 2 {
 		switch name := keyValuePairs[i].(type) {
 		case error:
@@ -316,7 +316,7 @@ func addFields(logger *logrus.Entry, keyValuePairs []interface{}) *logrus.Entry
 	return logger
 }
 
-func extractLogger(ctx interface{}) (*logrus.Entry, error) {
+func extractLogger(ctx any) (*logrus.Entry, error) {
 	switch ctx := ctx.(type) {
 	case *logrus.Entry:
 		return ctx, nil

model/datastore.go

@@ -41,7 +41,7 @@ type DataStore interface {
 	Scrobble(ctx context.Context) ScrobbleRepository
 	Plugin(ctx context.Context) PluginRepository
 
-	Resource(ctx context.Context, model interface{}) ResourceRepository
+	Resource(ctx context.Context, model any) ResourceRepository
 
 	WithTx(block func(tx DataStore) error, scope ...string) error
 	WithTxImmediate(block func(tx DataStore) error, scope ...string) error

model/get_entity.go

@@ -5,7 +5,7 @@ import (
 )
 
 // TODO: Should the type be encoded in the ID?
-func GetEntityByID(ctx context.Context, ds DataStore, id string) (interface{}, error) {
+func GetEntityByID(ctx context.Context, ds DataStore, id string) (any, error) {
 	ar, err := ds.Artist(ctx).Get(id)
 	if err == nil {
 		return ar, nil

model/mediafile.go

@@ -14,6 +14,7 @@ import (
 
 	"github.com/gohugoio/hashstructure"
 	"github.com/navidrome/navidrome/conf"
+	confmime "github.com/navidrome/navidrome/conf/mime"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/utils"
 	"github.com/navidrome/navidrome/utils/slice"
@@ -56,6 +57,7 @@ type MediaFile struct {
 	SampleRate           int      `structs:"sample_rate" json:"sampleRate"`
 	BitDepth             int      `structs:"bit_depth" json:"bitDepth"`
 	Channels             int      `structs:"channels" json:"channels"`
+	Codec                string   `structs:"codec" json:"codec"`
 	Genre                string   `structs:"genre" json:"genre"`
 	Genres               Genres   `structs:"-" json:"genres,omitempty"`
 	SortTitle            string   `structs:"sort_title" json:"sortTitle,omitempty"`
@@ -140,7 +142,7 @@ func (mf MediaFile) Hash() string {
 	}
 	hash, _ := hashstructure.Hash(mf, opts)
 	sum := md5.New()
-	sum.Write([]byte(fmt.Sprintf("%d", hash)))
+	sum.Write(fmt.Appendf(nil, "%d", hash))
 	sum.Write(mf.Tags.Hash())
 	sum.Write(mf.Participants.Hash())
 	return fmt.Sprintf("%x", sum.Sum(nil))
@@ -161,6 +163,79 @@ func (mf MediaFile) AbsolutePath() string {
 	return filepath.Join(mf.LibraryPath, mf.Path)
 }
 
+// AudioCodec returns the audio codec for this file.
+// Uses the stored Codec field if available, otherwise infers from Suffix and audio properties.
+func (mf MediaFile) AudioCodec() string {
+	// If we have a stored codec from scanning, normalize and return it
+	if mf.Codec != "" {
+		return strings.ToLower(mf.Codec)
+	}
+	// Fallback: infer from Suffix + BitDepth
+	return mf.inferCodecFromSuffix()
+}
+
+// inferCodecFromSuffix infers the codec from the file extension when Codec field is empty.
+func (mf MediaFile) inferCodecFromSuffix() string {
+	switch strings.ToLower(mf.Suffix) {
+	case "mp3", "mpga":
+		return "mp3"
+	case "mp2":
+		return "mp2"
+	case "ogg", "oga":
+		return "vorbis"
+	case "opus":
+		return "opus"
+	case "mpc":
+		return "mpc"
+	case "wma":
+		return "wma"
+	case "flac":
+		return "flac"
+	case "wav":
+		return "pcm"
+	case "aif", "aiff", "aifc":
+		return "pcm"
+	case "ape":
+		return "ape"
+	case "wv", "wvp":
+		return "wv"
+	case "tta":
+		return "tta"
+	case "tak":
+		return "tak"
+	case "shn":
+		return "shn"
+	case "dsf", "dff":
+		return "dsd"
+	case "m4a":
+		// AAC if BitDepth==0, ALAC if BitDepth>0
+		if mf.BitDepth > 0 {
+			return "alac"
+		}
+		return "aac"
+	case "m4b", "m4p", "m4r":
+		return "aac"
+	default:
+		return ""
+	}
+}
+
+// IsLossless returns true if this file uses a lossless codec.
+func (mf MediaFile) IsLossless() bool {
+	codec := mf.AudioCodec()
+	// Primary: codec-based check (most accurate for containers like M4A)
+	switch codec {
+	case "flac", "alac", "pcm", "ape", "wv", "tta", "tak", "shn", "dsd":
+		return true
+	}
+	// Secondary: suffix-based check using configurable list from YAML
+	if slices.Contains(confmime.LosslessFormats, mf.Suffix) {
+		return true
+	}
+	// Fallback heuristic: if BitDepth is set, it's likely lossless
+	return mf.BitDepth > 0
+}
+
 type MediaFiles []MediaFile
 
 // ToAlbum creates an Album object based on the attributes of this MediaFiles collection.

model/mediafile_test.go

@@ -475,7 +475,7 @@ var _ = Describe("MediaFile", func() {
 		DeferCleanup(configtest.SetupConfig())
 		conf.Server.EnableMediaFileCoverArt = true
 	})
-	Describe(".CoverArtId()", func() {
+	Describe("CoverArtId", func() {
 		It("returns its own id if it HasCoverArt", func() {
 			mf := MediaFile{ID: "111", AlbumID: "1", HasCoverArt: true}
 			id := mf.CoverArtID()
@@ -496,6 +496,94 @@ var _ = Describe("MediaFile", func() {
 			Expect(id.ID).To(Equal(mf.AlbumID))
 		})
 	})
+
+	Describe("AudioCodec", func() {
+		It("returns normalized stored codec when available", func() {
+			mf := MediaFile{Codec: "AAC", Suffix: "m4a"}
+			Expect(mf.AudioCodec()).To(Equal("aac"))
+		})
+
+		It("returns stored codec lowercased", func() {
+			mf := MediaFile{Codec: "ALAC", Suffix: "m4a"}
+			Expect(mf.AudioCodec()).To(Equal("alac"))
+		})
+
+		DescribeTable("infers codec from suffix when Codec field is empty",
+			func(suffix string, bitDepth int, expected string) {
+				mf := MediaFile{Suffix: suffix, BitDepth: bitDepth}
+				Expect(mf.AudioCodec()).To(Equal(expected))
+			},
+			Entry("mp3", "mp3", 0, "mp3"),
+			Entry("mpga", "mpga", 0, "mp3"),
+			Entry("mp2", "mp2", 0, "mp2"),
+			Entry("ogg", "ogg", 0, "vorbis"),
+			Entry("oga", "oga", 0, "vorbis"),
+			Entry("opus", "opus", 0, "opus"),
+			Entry("mpc", "mpc", 0, "mpc"),
+			Entry("wma", "wma", 0, "wma"),
+			Entry("flac", "flac", 0, "flac"),
+			Entry("wav", "wav", 0, "pcm"),
+			Entry("aif", "aif", 0, "pcm"),
+			Entry("aiff", "aiff", 0, "pcm"),
+			Entry("aifc", "aifc", 0, "pcm"),
+			Entry("ape", "ape", 0, "ape"),
+			Entry("wv", "wv", 0, "wv"),
+			Entry("wvp", "wvp", 0, "wv"),
+			Entry("tta", "tta", 0, "tta"),
+			Entry("tak", "tak", 0, "tak"),
+			Entry("shn", "shn", 0, "shn"),
+			Entry("dsf", "dsf", 0, "dsd"),
+			Entry("dff", "dff", 0, "dsd"),
+			Entry("m4a with BitDepth=0 (AAC)", "m4a", 0, "aac"),
+			Entry("m4a with BitDepth>0 (ALAC)", "m4a", 16, "alac"),
+			Entry("m4b", "m4b", 0, "aac"),
+			Entry("m4p", "m4p", 0, "aac"),
+			Entry("m4r", "m4r", 0, "aac"),
+			Entry("unknown suffix", "xyz", 0, ""),
+		)
+
+		It("prefers stored codec over suffix inference", func() {
+			mf := MediaFile{Codec: "ALAC", Suffix: "m4a", BitDepth: 0}
+			Expect(mf.AudioCodec()).To(Equal("alac"))
+		})
+	})
+
+	Describe("IsLossless", func() {
+		BeforeEach(func() {
+			DeferCleanup(configtest.SetupConfig())
+		})
+
+		DescribeTable("detects lossless codecs",
+			func(codec string, suffix string, bitDepth int, expected bool) {
+				mf := MediaFile{Codec: codec, Suffix: suffix, BitDepth: bitDepth}
+				Expect(mf.IsLossless()).To(Equal(expected))
+			},
+			Entry("flac", "FLAC", "flac", 16, true),
+			Entry("alac", "ALAC", "m4a", 24, true),
+			Entry("pcm via wav", "", "wav", 16, true),
+			Entry("pcm via aiff", "", "aiff", 24, true),
+			Entry("ape", "", "ape", 16, true),
+			Entry("wv", "", "wv", 0, true),
+			Entry("tta", "", "tta", 0, true),
+			Entry("tak", "", "tak", 0, true),
+			Entry("shn", "", "shn", 0, true),
+			Entry("dsd", "", "dsf", 0, true),
+			Entry("mp3 is lossy", "MP3", "mp3", 0, false),
+			Entry("aac is lossy", "AAC", "m4a", 0, false),
+			Entry("vorbis is lossy", "", "ogg", 0, false),
+			Entry("opus is lossy", "", "opus", 0, false),
+		)
+
+		It("detects lossless via BitDepth fallback when codec is unknown", func() {
+			mf := MediaFile{Suffix: "xyz", BitDepth: 24}
+			Expect(mf.IsLossless()).To(BeTrue())
+		})
+
+		It("returns false for unknown with no BitDepth", func() {
+			mf := MediaFile{Suffix: "xyz", BitDepth: 0}
+			Expect(mf.IsLossless()).To(BeFalse())
+		})
+	})
 })
 
 func t(v string) time.Time {

model/metadata/map_mediafile.go

@@ -65,6 +65,7 @@ func (md Metadata) ToMediaFile(libID int, folderID string) model.MediaFile {
 	mf.SampleRate = md.AudioProperties().SampleRate
 	mf.BitDepth = md.AudioProperties().BitDepth
 	mf.Channels = md.AudioProperties().Channels
+	mf.Codec = md.AudioProperties().Codec
 	mf.Path = md.FilePath()
 	mf.Suffix = md.Suffix()
 	mf.Size = md.Size()

model/metadata/metadata.go

@@ -35,6 +35,7 @@ type AudioProperties struct {
 	BitDepth   int
 	SampleRate int
 	Channels   int
+	Codec      string
 }
 
 type Date string
@@ -268,8 +269,8 @@ func parseID3Pairs(name model.TagName, lowered model.Tags) []string {
 	prefix := string(name) + ":"
 	for tagKey, tagValues := range lowered {
 		keyStr := string(tagKey)
-		if strings.HasPrefix(keyStr, prefix) {
-			keyPart := strings.TrimPrefix(keyStr, prefix)
+		if after, ok := strings.CutPrefix(keyStr, prefix); ok {
+			keyPart := after
 			if keyPart == string(name) {
 				keyPart = ""
 			}

model/metadata/persistent_ids.go

@@ -49,8 +49,8 @@ func createGetPID(hash hashFunc) getPIDFunc {
 	}
 	getPID = func(mf model.MediaFile, md Metadata, spec string, prependLibId bool) string {
 		pid := ""
-		fields := strings.Split(spec, "|")
-		for _, field := range fields {
+		fields := strings.SplitSeq(spec, "|")
+		for field := range fields {
 			attributes := strings.Split(field, ",")
 			hasValue := false
 			values := slice.Map(attributes, func(attr string) string {

model/scanner.go

@@ -51,13 +51,13 @@ func ParseTargets(libFolders []string) ([]ScanTarget, error) {
 		}
 
 		// Split by the first colon
-		colonIdx := strings.Index(part, ":")
-		if colonIdx == -1 {
+		before, after, ok := strings.Cut(part, ":")
+		if !ok {
 			return nil, fmt.Errorf("invalid target format: %q (expected libraryID:folderPath)", part)
 		}
 
-		libIDStr := part[:colonIdx]
-		folderPath := part[colonIdx+1:]
+		libIDStr := before
+		folderPath := after
 
 		libID, err := strconv.Atoi(libIDStr)
 		if err != nil {

model/share.go

@@ -22,8 +22,8 @@ type Share struct {
 	Format        string     `structs:"format" json:"format,omitempty"`
 	MaxBitRate    int        `structs:"max_bit_rate" json:"maxBitRate,omitempty"`
 	VisitCount    int        `structs:"visit_count" json:"visitCount,omitempty"`
-	CreatedAt     time.Time  `structs:"created_at" json:"createdAt,omitempty"`
-	UpdatedAt     time.Time  `structs:"updated_at" json:"updatedAt,omitempty"`
+	CreatedAt     time.Time  `structs:"created_at" json:"createdAt"`
+	UpdatedAt     time.Time  `structs:"updated_at" json:"updatedAt"`
 	Tracks        MediaFiles `structs:"-" json:"tracks,omitempty"`
 	Albums        Albums     `structs:"-" json:"albums,omitempty"`
 	URL           string     `structs:"-" json:"-"`

model/tag.go

@@ -144,10 +144,8 @@ func (t Tags) Merge(tags Tags) {
 }
 
 func (t Tags) Add(name TagName, v string) {
-	for _, existing := range t[name] {
-		if existing == v {
-			return
-		}
+	if slices.Contains(t[name], v) {
+		return
 	}
 	t[name] = append(t[name], v)
 }

persistence/album_repository.go

@@ -145,11 +145,11 @@ func recentlyAddedSort() string {
 	return "created_at"
 }
 
-func recentlyPlayedFilter(string, interface{}) Sqlizer {
+func recentlyPlayedFilter(string, any) Sqlizer {
 	return Gt{"play_count": 0}
 }
 
-func yearFilter(_ string, value interface{}) Sqlizer {
+func yearFilter(_ string, value any) Sqlizer {
 	return Or{
 		And{
 			Gt{"min_year": 0},
@@ -160,14 +160,14 @@ func yearFilter(_ string, value interface{}) Sqlizer {
 	}
 }
 
-func artistFilter(_ string, value interface{}) Sqlizer {
+func artistFilter(_ string, value any) Sqlizer {
 	return Or{
 		Exists("json_tree(participants, '$.albumartist')", Eq{"value": value}),
 		Exists("json_tree(participants, '$.artist')", Eq{"value": value}),
 	}
 }
 
-func artistRoleFilter(name string, value interface{}) Sqlizer {
+func artistRoleFilter(name string, value any) Sqlizer {
 	roleName := strings.TrimSuffix(strings.TrimPrefix(name, "role_"), "_id")
 
 	// Check if the role name is valid. If not, return an invalid filter
@@ -177,7 +177,7 @@ func artistRoleFilter(name string, value interface{}) Sqlizer {
 	return Exists(fmt.Sprintf("json_tree(participants, '$.%s')", roleName), Eq{"value": value})
 }
 
-func allRolesFilter(_ string, value interface{}) Sqlizer {
+func allRolesFilter(_ string, value any) Sqlizer {
 	return Like{"participants": fmt.Sprintf(`%%"%s"%%`, value)}
 }
 
@@ -248,7 +248,7 @@ func (r *albumRepository) CopyAttributes(fromID, toID string, columns ...string)
 	if err != nil {
 		return fmt.Errorf("getting album to copy fields from: %w", err)
 	}
-	to := make(map[string]interface{})
+	to := make(map[string]any)
 	for _, col := range columns {
 		to[col] = from[col]
 	}
@@ -370,11 +370,11 @@ func (r *albumRepository) Count(options ...rest.QueryOptions) (int64, error) {
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *albumRepository) Read(id string) (interface{}, error) {
+func (r *albumRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *albumRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *albumRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
@@ -382,7 +382,7 @@ func (r *albumRepository) EntityName() string {
 	return "album"
 }
 
-func (r *albumRepository) NewInstance() interface{} {
+func (r *albumRepository) NewInstance() any {
 	return &model.Album{}
 }
 

persistence/album_repository_test.go

@@ -162,7 +162,7 @@ var _ = Describe("AlbumRepository", func() {
 
 				newID := id.NewRandom()
 				Expect(albumRepo.Put(&model.Album{LibraryID: 1, ID: newID, Name: "name", SongCount: songCount})).To(Succeed())
-				for i := 0; i < playCount; i++ {
+				for range playCount {
 					Expect(albumRepo.IncPlayCount(newID, time.Now())).To(Succeed())
 				}
 
@@ -185,7 +185,7 @@ var _ = Describe("AlbumRepository", func() {
 
 				newID := id.NewRandom()
 				Expect(albumRepo.Put(&model.Album{LibraryID: 1, ID: newID, Name: "name", SongCount: songCount})).To(Succeed())
-				for i := 0; i < playCount; i++ {
+				for range playCount {
 					Expect(albumRepo.IncPlayCount(newID, time.Now())).To(Succeed())
 				}
 
@@ -406,7 +406,7 @@ var _ = Describe("AlbumRepository", func() {
 				sql, args, err := sqlizer.ToSql()
 				Expect(err).ToNot(HaveOccurred())
 				Expect(sql).To(Equal(expectedSQL))
-				Expect(args).To(Equal([]interface{}{artistID}))
+				Expect(args).To(Equal([]any{artistID}))
 			},
 			Entry("artist role", "role_artist_id", "123",
 				"exists (select 1 from json_tree(participants, '$.artist') where value = ?)"),
@@ -428,7 +428,7 @@ var _ = Describe("AlbumRepository", func() {
 				sql, args, err := sqlizer.ToSql()
 				Expect(err).ToNot(HaveOccurred())
 				Expect(sql).To(Equal(fmt.Sprintf("exists (select 1 from json_tree(participants, '$.%s') where value = ?)", roleName)))
-				Expect(args).To(Equal([]interface{}{"test-id"}))
+				Expect(args).To(Equal([]any{"test-id"}))
 			}
 		})
 

persistence/artist_repository.go

@@ -164,7 +164,7 @@ func roleFilter(_ string, role any) Sqlizer {
 }
 
 // artistLibraryIdFilter filters artists based on library access through the library_artist table
-func artistLibraryIdFilter(_ string, value interface{}) Sqlizer {
+func artistLibraryIdFilter(_ string, value any) Sqlizer {
 	return Eq{"library_artist.library_id": value}
 }
 
@@ -534,11 +534,11 @@ func (r *artistRepository) Count(options ...rest.QueryOptions) (int64, error) {
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *artistRepository) Read(id string) (interface{}, error) {
+func (r *artistRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *artistRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *artistRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	role := "total"
 	if len(options) > 0 {
 		if v, ok := options[0].Filters["role"].(string); ok {
@@ -555,7 +555,7 @@ func (r *artistRepository) EntityName() string {
 	return "artist"
 }
 
-func (r *artistRepository) NewInstance() interface{} {
+func (r *artistRepository) NewInstance() any {
 	return &model.Artist{}
 }
 

persistence/folder_repository.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"maps"
 	"os"
 	"path/filepath"
 	"slices"
@@ -117,9 +118,7 @@ func (r folderRepository) GetFolderUpdateInfo(lib model.Library, targetPaths ...
 		if err != nil {
 			return nil, err
 		}
-		for id, info := range batchResult {
-			result[id] = info
-		}
+		maps.Copy(result, batchResult)
 	}
 
 	return result, nil

persistence/genre_repository.go

@@ -33,18 +33,18 @@ func (r *genreRepository) GetAll(opt ...model.QueryOptions) (model.Genres, error
 
 // Override ResourceRepository methods to return Genre objects instead of Tag objects
 
-func (r *genreRepository) Read(id string) (interface{}, error) {
+func (r *genreRepository) Read(id string) (any, error) {
 	sel := r.selectGenre().Where(Eq{"tag.id": id})
 	var res model.Genre
 	err := r.queryOne(sel, &res)
 	return &res, err
 }
 
-func (r *genreRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *genreRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *genreRepository) NewInstance() interface{} {
+func (r *genreRepository) NewInstance() any {
 	return &model.Genre{}
 }
 

persistence/genre_repository_test.go

@@ -182,7 +182,7 @@ var _ = Describe("GenreRepository", func() {
 		It("should filter by name using like match", func() {
 			// Test filtering by partial name match using the "name" filter which maps to containsFilter("tag_value")
 			options := rest.QueryOptions{
-				Filters: map[string]interface{}{"name": "%rock%"},
+				Filters: map[string]any{"name": "%rock%"},
 			}
 			count, err := restRepo.Count(options)
 			Expect(err).ToNot(HaveOccurred())
@@ -289,7 +289,7 @@ var _ = Describe("GenreRepository", func() {
 			It("should allow headless processes to apply explicit library_id filters", func() {
 				// Filter by specific library
 				genres, err := headlessRestRepo.ReadAll(rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": 2},
+					Filters: map[string]any{"library_id": 2},
 				})
 				Expect(err).ToNot(HaveOccurred())
 

persistence/helpers.go

@@ -15,7 +15,7 @@ type PostMapper interface {
 	PostMapArgs(map[string]any) error
 }
 
-func toSQLArgs(rec interface{}) (map[string]interface{}, error) {
+func toSQLArgs(rec any) (map[string]any, error) {
 	m := structs.Map(rec)
 	for k, v := range m {
 		switch t := v.(type) {
@@ -71,7 +71,7 @@ type existsCond struct {
 	not      bool
 }
 
-func (e existsCond) ToSql() (string, []interface{}, error) {
+func (e existsCond) ToSql() (string, []any, error) {
 	sql, args, err := e.cond.ToSql()
 	sql = fmt.Sprintf("exists (select 1 from %s where %s)", e.subTable, sql)
 	if e.not {

persistence/library_repository.go

@@ -305,7 +305,7 @@ func (r *libraryRepository) Count(options ...rest.QueryOptions) (int64, error) {
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *libraryRepository) Read(id string) (interface{}, error) {
+func (r *libraryRepository) Read(id string) (any, error) {
 	idInt, err := strconv.Atoi(id)
 	if err != nil {
 		log.Trace(r.ctx, "invalid library id: %s", id, err)
@@ -314,7 +314,7 @@ func (r *libraryRepository) Read(id string) (interface{}, error) {
 	return r.Get(idInt)
 }
 
-func (r *libraryRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *libraryRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
@@ -322,11 +322,11 @@ func (r *libraryRepository) EntityName() string {
 	return "library"
 }
 
-func (r *libraryRepository) NewInstance() interface{} {
+func (r *libraryRepository) NewInstance() any {
 	return &model.Library{}
 }
 
-func (r *libraryRepository) Save(entity interface{}) (string, error) {
+func (r *libraryRepository) Save(entity any) (string, error) {
 	lib := entity.(*model.Library)
 	lib.ID = 0 // Reset ID to ensure we create a new library
 	err := r.Put(lib)
@@ -336,7 +336,7 @@ func (r *libraryRepository) Save(entity interface{}) (string, error) {
 	return strconv.Itoa(lib.ID), nil
 }
 
-func (r *libraryRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *libraryRepository) Update(id string, entity any, cols ...string) error {
 	lib := entity.(*model.Library)
 	idInt, err := strconv.Atoi(id)
 	if err != nil {

persistence/mediafile_repository.go

@@ -443,11 +443,11 @@ func (r *mediaFileRepository) Count(options ...rest.QueryOptions) (int64, error)
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *mediaFileRepository) Read(id string) (interface{}, error) {
+func (r *mediaFileRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *mediaFileRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *mediaFileRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
@@ -455,7 +455,7 @@ func (r *mediaFileRepository) EntityName() string {
 	return "mediafile"
 }
 
-func (r *mediaFileRepository) NewInstance() interface{} {
+func (r *mediaFileRepository) NewInstance() any {
 	return &model.MediaFile{}
 }
 

persistence/mediafile_repository_test.go

@@ -310,7 +310,7 @@ var _ = Describe("MediaRepository", func() {
 
 				// Update "Old Song": created long ago, updated recently
 				_, err := db.Update("media_file",
-					map[string]interface{}{
+					map[string]any{
 						"created_at": oldTime,
 						"updated_at": newTime,
 					},
@@ -319,7 +319,7 @@ var _ = Describe("MediaRepository", func() {
 
 				// Update "Middle Song": created and updated at the same middle time
 				_, err = db.Update("media_file",
-					map[string]interface{}{
+					map[string]any{
 						"created_at": middleTime,
 						"updated_at": middleTime,
 					},
@@ -328,7 +328,7 @@ var _ = Describe("MediaRepository", func() {
 
 				// Update "New Song": created recently, updated long ago
 				_, err = db.Update("media_file",
-					map[string]interface{}{
+					map[string]any{
 						"created_at": newTime,
 						"updated_at": oldTime,
 					},

persistence/persistence.go

@@ -97,7 +97,7 @@ func (s *SQLStore) Plugin(ctx context.Context) model.PluginRepository {
 	return NewPluginRepository(ctx, s.getDBXBuilder())
 }
 
-func (s *SQLStore) Resource(ctx context.Context, m interface{}) model.ResourceRepository {
+func (s *SQLStore) Resource(ctx context.Context, m any) model.ResourceRepository {
 	switch m.(type) {
 	case model.User:
 		return s.User(ctx).(model.ResourceRepository)

persistence/player_repository.go

@@ -103,14 +103,14 @@ func (r *playerRepository) Count(options ...rest.QueryOptions) (int64, error) {
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *playerRepository) Read(id string) (interface{}, error) {
+func (r *playerRepository) Read(id string) (any, error) {
 	sel := r.newRestSelect().Where(Eq{"player.id": id})
 	var res model.Player
 	err := r.queryOne(sel, &res)
 	return &res, err
 }
 
-func (r *playerRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *playerRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	sel := r.newRestSelect(r.parseRestOptions(r.ctx, options...))
 	res := model.Players{}
 	err := r.queryAll(sel, &res)
@@ -121,7 +121,7 @@ func (r *playerRepository) EntityName() string {
 	return "player"
 }
 
-func (r *playerRepository) NewInstance() interface{} {
+func (r *playerRepository) NewInstance() any {
 	return &model.Player{}
 }
 
@@ -130,7 +130,7 @@ func (r *playerRepository) isPermitted(p *model.Player) bool {
 	return u.IsAdmin || p.UserId == u.ID
 }
 
-func (r *playerRepository) Save(entity interface{}) (string, error) {
+func (r *playerRepository) Save(entity any) (string, error) {
 	t := entity.(*model.Player)
 	if !r.isPermitted(t) {
 		return "", rest.ErrPermissionDenied
@@ -142,7 +142,7 @@ func (r *playerRepository) Save(entity interface{}) (string, error) {
 	return id, err
 }
 
-func (r *playerRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *playerRepository) Update(id string, entity any, cols ...string) error {
 	t := entity.(*model.Player)
 	t.ID = id
 	if !r.isPermitted(t) {

persistence/playlist_repository.go

@@ -61,14 +61,14 @@ func NewPlaylistRepository(ctx context.Context, db dbx.Builder) model.PlaylistRe
 	return r
 }
 
-func playlistFilter(_ string, value interface{}) Sqlizer {
+func playlistFilter(_ string, value any) Sqlizer {
 	return Or{
 		substringFilter("playlist.name", value),
 		substringFilter("playlist.comment", value),
 	}
 }
 
-func smartPlaylistFilter(string, interface{}) Sqlizer {
+func smartPlaylistFilter(string, any) Sqlizer {
 	return Or{
 		Eq{"rules": ""},
 		Eq{"rules": nil},
@@ -421,11 +421,11 @@ func (r *playlistRepository) Count(options ...rest.QueryOptions) (int64, error)
 	return r.CountAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *playlistRepository) Read(id string) (interface{}, error) {
+func (r *playlistRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *playlistRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *playlistRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
@@ -433,11 +433,11 @@ func (r *playlistRepository) EntityName() string {
 	return "playlist"
 }
 
-func (r *playlistRepository) NewInstance() interface{} {
+func (r *playlistRepository) NewInstance() any {
 	return &model.Playlist{}
 }
 
-func (r *playlistRepository) Save(entity interface{}) (string, error) {
+func (r *playlistRepository) Save(entity any) (string, error) {
 	pls := entity.(*model.Playlist)
 	pls.OwnerID = loggedUser(r.ctx).ID
 	pls.ID = "" // Make sure we don't override an existing playlist
@@ -448,7 +448,7 @@ func (r *playlistRepository) Save(entity interface{}) (string, error) {
 	return pls.ID, err
 }
 
-func (r *playlistRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *playlistRepository) Update(id string, entity any, cols ...string) error {
 	pls := dbPlaylist{Playlist: *entity.(*model.Playlist)}
 	current, err := r.Get(id)
 	if err != nil {

persistence/playlist_track_repository.go

@@ -84,7 +84,7 @@ func (r *playlistTrackRepository) Count(options ...rest.QueryOptions) (int64, er
 	return r.count(query, r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *playlistTrackRepository) Read(id string) (interface{}, error) {
+func (r *playlistTrackRepository) Read(id string) (any, error) {
 	userID := loggedUser(r.ctx).ID
 	sel := r.newSelect().
 		LeftJoin("annotation on ("+
@@ -128,7 +128,7 @@ func (r *playlistTrackRepository) GetAlbumIDs(options ...model.QueryOptions) ([]
 	return ids, nil
 }
 
-func (r *playlistTrackRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *playlistTrackRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
@@ -136,7 +136,7 @@ func (r *playlistTrackRepository) EntityName() string {
 	return "playlist_tracks"
 }
 
-func (r *playlistTrackRepository) NewInstance() interface{} {
+func (r *playlistTrackRepository) NewInstance() any {
 	return &model.PlaylistTrack{}
 }
 

persistence/playqueue_repository.go

@@ -122,8 +122,8 @@ func (r *playQueueRepository) toModel(pq *playQueue) model.PlayQueue {
 		UpdatedAt: pq.UpdatedAt,
 	}
 	if strings.TrimSpace(pq.Items) != "" {
-		tracks := strings.Split(pq.Items, ",")
-		for _, t := range tracks {
+		tracks := strings.SplitSeq(pq.Items, ",")
+		for t := range tracks {
 			q.Items = append(q.Items, model.MediaFile{ID: t})
 		}
 	}

persistence/radio_repository.go

@@ -63,7 +63,7 @@ func (r *radioRepository) Put(radio *model.Radio) error {
 		return rest.ErrPermissionDenied
 	}
 
-	var values map[string]interface{}
+	var values map[string]any
 
 	radio.UpdatedAt = time.Now()
 
@@ -97,19 +97,19 @@ func (r *radioRepository) EntityName() string {
 	return "radio"
 }
 
-func (r *radioRepository) NewInstance() interface{} {
+func (r *radioRepository) NewInstance() any {
 	return &model.Radio{}
 }
 
-func (r *radioRepository) Read(id string) (interface{}, error) {
+func (r *radioRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *radioRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *radioRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	return r.GetAll(r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *radioRepository) Save(entity interface{}) (string, error) {
+func (r *radioRepository) Save(entity any) (string, error) {
 	t := entity.(*model.Radio)
 	if !r.isPermitted() {
 		return "", rest.ErrPermissionDenied
@@ -121,7 +121,7 @@ func (r *radioRepository) Save(entity interface{}) (string, error) {
 	return t.ID, err
 }
 
-func (r *radioRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *radioRepository) Update(id string, entity any, cols ...string) error {
 	t := entity.(*model.Radio)
 	t.ID = id
 	if !r.isPermitted() {

persistence/scrobble_buffer_repository.go

@@ -51,7 +51,7 @@ func (r *scrobbleBufferRepository) UserIDs(service string) ([]string, error) {
 }
 
 func (r *scrobbleBufferRepository) Enqueue(service, userId, mediaFileId string, playTime time.Time) error {
-	ins := Insert(r.tableName).SetMap(map[string]interface{}{
+	ins := Insert(r.tableName).SetMap(map[string]any{
 		"id":            id.NewRandom(),
 		"user_id":       userId,
 		"service":       service,

persistence/scrobble_buffer_repository_test.go

@@ -24,7 +24,7 @@ var _ = Describe("ScrobbleBufferRepository", func() {
 		id := id.NewRandom()
 		ids = append(ids, id)
 
-		ins := squirrel.Insert("scrobble_buffer").SetMap(map[string]interface{}{
+		ins := squirrel.Insert("scrobble_buffer").SetMap(map[string]any{
 			"id":            id,
 			"user_id":       userId,
 			"service":       service,

persistence/scrobble_repository.go

@@ -23,7 +23,7 @@ func NewScrobbleRepository(ctx context.Context, db dbx.Builder) model.ScrobbleRe
 
 func (r *scrobbleRepository) RecordScrobble(mediaFileID string, submissionTime time.Time) error {
 	userID := loggedUser(r.ctx).ID
-	values := map[string]interface{}{
+	values := map[string]any{
 		"media_file_id":   mediaFileID,
 		"user_id":         userID,
 		"submission_time": submissionTime.Unix(),

persistence/share_repository.go

@@ -138,7 +138,7 @@ func sortByIdPosition(mfs model.MediaFiles, ids []string) model.MediaFiles {
 	return sorted
 }
 
-func (r *shareRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *shareRepository) Update(id string, entity any, cols ...string) error {
 	s := entity.(*model.Share)
 	// TODO Validate record
 	s.ID = id
@@ -151,7 +151,7 @@ func (r *shareRepository) Update(id string, entity interface{}, cols ...string)
 	return err
 }
 
-func (r *shareRepository) Save(entity interface{}) (string, error) {
+func (r *shareRepository) Save(entity any) (string, error) {
 	s := entity.(*model.Share)
 	// TODO Validate record
 	u := loggedUser(r.ctx)
@@ -179,18 +179,18 @@ func (r *shareRepository) EntityName() string {
 	return "share"
 }
 
-func (r *shareRepository) NewInstance() interface{} {
+func (r *shareRepository) NewInstance() any {
 	return &model.Share{}
 }
 
-func (r *shareRepository) Read(id string) (interface{}, error) {
+func (r *shareRepository) Read(id string) (any, error) {
 	sel := r.selectShare().Where(Eq{"share.id": id})
 	var res model.Share
 	err := r.queryOne(sel, &res)
 	return &res, err
 }
 
-func (r *shareRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *shareRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	sq := r.selectShare(r.parseRestOptions(r.ctx, options...))
 	res := model.Shares{}
 	err := r.queryAll(sq, &res)

persistence/share_repository_test.go

@@ -47,7 +47,7 @@ var _ = Describe("ShareRepository", func() {
 				_, err := GetDBXBuilder().NewQuery(`
 					INSERT INTO share (id, user_id, description, resource_type, resource_ids, created_at, updated_at) 
 					VALUES ({:id}, {:user}, {:desc}, {:type}, {:ids}, {:created}, {:updated})
-				`).Bind(map[string]interface{}{
+				`).Bind(map[string]any{
 					"id":      shareID,
 					"user":    adminUser.ID,
 					"desc":    "Headless Test Share",
@@ -79,7 +79,7 @@ var _ = Describe("ShareRepository", func() {
 				_, err := GetDBXBuilder().NewQuery(`
 					INSERT INTO share (id, user_id, description, resource_type, resource_ids, created_at, updated_at) 
 					VALUES ({:id}, {:user}, {:desc}, {:type}, {:ids}, {:created}, {:updated})
-				`).Bind(map[string]interface{}{
+				`).Bind(map[string]any{
 					"id":      shareID,
 					"user":    adminUser.ID,
 					"desc":    "Headless Get Share",
@@ -110,7 +110,7 @@ var _ = Describe("ShareRepository", func() {
 			_, err := GetDBXBuilder().NewQuery(`
 				INSERT INTO share (id, user_id, description, resource_type, resource_ids, created_at, updated_at) 
 				VALUES ({:id}, {:user}, {:desc}, {:type}, {:ids}, {:created}, {:updated})
-			`).Bind(map[string]interface{}{
+			`).Bind(map[string]any{
 				"id":      shareID,
 				"user":    adminUser.ID,
 				"desc":    "SQL Test Share",

persistence/sql_annotations.go

@@ -66,7 +66,7 @@ func (r sqlRepository) annId(itemID ...string) And {
 	}
 }
 
-func (r sqlRepository) annUpsert(values map[string]interface{}, itemIDs ...string) error {
+func (r sqlRepository) annUpsert(values map[string]any, itemIDs ...string) error {
 	upd := Update(annotationTable).Where(r.annId(itemIDs...))
 	for f, v := range values {
 		upd = upd.Set(f, v)
@@ -90,12 +90,12 @@ func (r sqlRepository) annUpsert(values map[string]interface{}, itemIDs ...strin
 
 func (r sqlRepository) SetStar(starred bool, ids ...string) error {
 	starredAt := time.Now()
-	return r.annUpsert(map[string]interface{}{"starred": starred, "starred_at": starredAt}, ids...)
+	return r.annUpsert(map[string]any{"starred": starred, "starred_at": starredAt}, ids...)
 }
 
 func (r sqlRepository) SetRating(rating int, itemID string) error {
 	ratedAt := time.Now()
-	err := r.annUpsert(map[string]interface{}{"rating": rating, "rated_at": ratedAt}, itemID)
+	err := r.annUpsert(map[string]any{"rating": rating, "rated_at": ratedAt}, itemID)
 	if err != nil {
 		return err
 	}
@@ -121,7 +121,7 @@ func (r sqlRepository) IncPlayCount(itemID string, ts time.Time) error {
 
 	if c == 0 || errors.Is(err, sql.ErrNoRows) {
 		userID := loggedUser(r.ctx).ID
-		values := map[string]interface{}{}
+		values := map[string]any{}
 		values["user_id"] = userID
 		values["item_type"] = r.tableName
 		values["item_id"] = itemID

persistence/sql_annotations_test.go

@@ -32,17 +32,17 @@ var _ = Describe("Annotation Filters", func() {
 
 	Describe("annotationBoolFilter", func() {
 		DescribeTable("creates correct SQL expressions",
-			func(field, value string, expectedSQL string, expectedArgs []interface{}) {
+			func(field, value string, expectedSQL string, expectedArgs []any) {
 				sqlizer := annotationBoolFilter(field)(field, value)
 				sql, args, err := sqlizer.ToSql()
 				Expect(err).ToNot(HaveOccurred())
 				Expect(sql).To(Equal(expectedSQL))
 				Expect(args).To(Equal(expectedArgs))
 			},
-			Entry("starred=true", "starred", "true", "COALESCE(starred, 0) > 0", []interface{}(nil)),
-			Entry("starred=false", "starred", "false", "COALESCE(starred, 0) = 0", []interface{}(nil)),
-			Entry("starred=True (case insensitive)", "starred", "True", "COALESCE(starred, 0) > 0", []interface{}(nil)),
-			Entry("rating=true", "rating", "true", "COALESCE(rating, 0) > 0", []interface{}(nil)),
+			Entry("starred=true", "starred", "true", "COALESCE(starred, 0) > 0", []any(nil)),
+			Entry("starred=false", "starred", "false", "COALESCE(starred, 0) = 0", []any(nil)),
+			Entry("starred=True (case insensitive)", "starred", "True", "COALESCE(starred, 0) > 0", []any(nil)),
+			Entry("rating=true", "rating", "true", "COALESCE(rating, 0) > 0", []any(nil)),
 		)
 
 		It("returns nil if value is not a string", func() {

persistence/sql_base_repository.go

@@ -196,7 +196,7 @@ func (r *sqlRepository) withTableName(filter filterFunc) filterFunc {
 }
 
 // libraryIdFilter is a filter function to be added to resources that have a library_id column.
-func libraryIdFilter(_ string, value interface{}) Sqlizer {
+func libraryIdFilter(_ string, value any) Sqlizer {
 	return Eq{"library_id": value}
 }
 
@@ -281,7 +281,7 @@ func (r sqlRepository) toSQL(sq Sqlizer) (string, dbx.Params, error) {
 	return result, params, nil
 }
 
-func (r sqlRepository) queryOne(sq Sqlizer, response interface{}) error {
+func (r sqlRepository) queryOne(sq Sqlizer, response any) error {
 	query, args, err := r.toSQL(sq)
 	if err != nil {
 		return err
@@ -328,7 +328,7 @@ func queryWithStableResults[T any](r sqlRepository, sq SelectBuilder, options ..
 	}, nil
 }
 
-func (r sqlRepository) queryAll(sq SelectBuilder, response interface{}, options ...model.QueryOptions) error {
+func (r sqlRepository) queryAll(sq SelectBuilder, response any, options ...model.QueryOptions) error {
 	if len(options) > 0 && options[0].Offset > 0 {
 		sq = r.optimizePagination(sq, options[0])
 	}
@@ -347,7 +347,7 @@ func (r sqlRepository) queryAll(sq SelectBuilder, response interface{}, options
 }
 
 // queryAllSlice is a helper function to query a single column and return the result in a slice
-func (r sqlRepository) queryAllSlice(sq SelectBuilder, response interface{}) error {
+func (r sqlRepository) queryAllSlice(sq SelectBuilder, response any) error {
 	query, args, err := r.toSQL(sq)
 	if err != nil {
 		return err
@@ -394,7 +394,7 @@ func (r sqlRepository) count(countQuery SelectBuilder, options ...model.QueryOpt
 	return res.Count, err
 }
 
-func (r sqlRepository) putByMatch(filter Sqlizer, id string, m interface{}, colsToUpdate ...string) (string, error) {
+func (r sqlRepository) putByMatch(filter Sqlizer, id string, m any, colsToUpdate ...string) (string, error) {
 	if id != "" {
 		return r.put(id, m, colsToUpdate...)
 	}
@@ -408,14 +408,14 @@ func (r sqlRepository) putByMatch(filter Sqlizer, id string, m interface{}, cols
 	return r.put(res.ID, m, colsToUpdate...)
 }
 
-func (r sqlRepository) put(id string, m interface{}, colsToUpdate ...string) (newId string, err error) {
+func (r sqlRepository) put(id string, m any, colsToUpdate ...string) (newId string, err error) {
 	values, err := toSQLArgs(m)
 	if err != nil {
 		return "", fmt.Errorf("error preparing values to write to DB: %w", err)
 	}
 	// If there's an ID, try to update first
 	if id != "" {
-		updateValues := map[string]interface{}{}
+		updateValues := map[string]any{}
 
 		// This is a map of the columns that need to be updated, if specified
 		c2upd := slice.ToMap(colsToUpdate, func(s string) (string, struct{}) {

persistence/sql_bookmarks.go

@@ -37,7 +37,7 @@ func (r sqlRepository) bmkID(itemID ...string) And {
 func (r sqlRepository) bmkUpsert(itemID, comment string, position int64) error {
 	client, _ := request.ClientFrom(r.ctx)
 	user, _ := request.UserFrom(r.ctx)
-	values := map[string]interface{}{
+	values := map[string]any{
 		"comment":    comment,
 		"position":   position,
 		"updated_at": time.Now(),

persistence/sql_restful_test.go

@@ -30,7 +30,7 @@ var _ = Describe("sqlRestful", func() {
 			r.filterMappings = map[string]filterFunc{
 				"name": fullTextFilter("table"),
 			}
-			options.Filters = map[string]interface{}{"name": "'"}
+			options.Filters = map[string]any{"name": "'"}
 			Expect(r.parseRestFilters(context.Background(), options)).To(BeEmpty())
 		})
 
@@ -40,32 +40,32 @@ var _ = Describe("sqlRestful", func() {
 					return nil
 				},
 			}
-			options.Filters = map[string]interface{}{"name": "joe"}
+			options.Filters = map[string]any{"name": "joe"}
 			Expect(r.parseRestFilters(context.Background(), options)).To(BeEmpty())
 		})
 
 		It("returns a '=' condition for 'id' filter", func() {
-			options.Filters = map[string]interface{}{"id": "123"}
+			options.Filters = map[string]any{"id": "123"}
 			Expect(r.parseRestFilters(context.Background(), options)).To(Equal(squirrel.And{squirrel.Eq{"id": "123"}}))
 		})
 
 		It("returns a 'in' condition for multiples 'id' filters", func() {
-			options.Filters = map[string]interface{}{"id": []string{"123", "456"}}
+			options.Filters = map[string]any{"id": []string{"123", "456"}}
 			Expect(r.parseRestFilters(context.Background(), options)).To(Equal(squirrel.And{squirrel.Eq{"id": []string{"123", "456"}}}))
 		})
 
 		It("returns a 'like' condition for other filters", func() {
-			options.Filters = map[string]interface{}{"name": "joe"}
+			options.Filters = map[string]any{"name": "joe"}
 			Expect(r.parseRestFilters(context.Background(), options)).To(Equal(squirrel.And{squirrel.Like{"name": "joe%"}}))
 		})
 
 		It("uses the custom filter", func() {
 			r.filterMappings = map[string]filterFunc{
-				"test": func(field string, value interface{}) squirrel.Sqlizer {
+				"test": func(field string, value any) squirrel.Sqlizer {
 					return squirrel.Gt{field: value}
 				},
 			}
-			options.Filters = map[string]interface{}{"test": 100}
+			options.Filters = map[string]any{"test": 100}
 			Expect(r.parseRestFilters(context.Background(), options)).To(Equal(squirrel.And{squirrel.Gt{"test": 100}}))
 		})
 	})

persistence/sql_tags.go

@@ -60,7 +60,7 @@ func tagIDFilter(name string, idValue any) Sqlizer {
 }
 
 // tagLibraryIdFilter filters tags based on library access through the library_tag table
-func tagLibraryIdFilter(_ string, value interface{}) Sqlizer {
+func tagLibraryIdFilter(_ string, value any) Sqlizer {
 	return Eq{"library_tag.library_id": value}
 }
 
@@ -142,14 +142,14 @@ func (r *baseTagRepository) Count(options ...rest.QueryOptions) (int64, error) {
 	return r.count(sq, r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *baseTagRepository) Read(id string) (interface{}, error) {
+func (r *baseTagRepository) Read(id string) (any, error) {
 	query := r.newSelect().Where(Eq{"id": id})
 	var res model.Tag
 	err := r.queryOne(query, &res)
 	return &res, err
 }
 
-func (r *baseTagRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *baseTagRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	query := r.newSelect(r.parseRestOptions(r.ctx, options...))
 	var res model.TagList
 	err := r.queryAll(query, &res)
@@ -160,7 +160,7 @@ func (r *baseTagRepository) EntityName() string {
 	return "tag"
 }
 
-func (r *baseTagRepository) NewInstance() interface{} {
+func (r *baseTagRepository) NewInstance() any {
 	return model.Tag{}
 }
 

persistence/tag_library_filtering_test.go

@@ -165,7 +165,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should respect explicit library_id filters within accessible libraries", func() {
 				tags := readAllTags(&regularUser, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID2},
+					Filters: map[string]any{"library_id": libraryID2},
 				})
 				// Should see only tags from library 2: pop and rock(lib2)
 				Expect(tags).To(HaveLen(2))
@@ -174,7 +174,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should not return tags when filtering by inaccessible library", func() {
 				tags := readAllTags(&regularUser, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID3},
+					Filters: map[string]any{"library_id": libraryID3},
 				})
 				// Should return no tags since user can't access library 3
 				Expect(tags).To(HaveLen(0))
@@ -182,7 +182,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should filter by library 1 correctly", func() {
 				tags := readAllTags(&regularUser, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID1},
+					Filters: map[string]any{"library_id": libraryID1},
 				})
 				// Should see only rock from library 1
 				Expect(tags).To(HaveLen(1))
@@ -227,7 +227,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should allow headless processes to apply explicit library_id filters", func() {
 				tags := readAllTags(nil, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID3},
+					Filters: map[string]any{"library_id": libraryID3},
 				})
 				// Should see only jazz from library 3
 				Expect(tags).To(HaveLen(1))
@@ -243,7 +243,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should respect explicit library_id filters", func() {
 				tags := readAllTags(&adminUser, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID3},
+					Filters: map[string]any{"library_id": libraryID3},
 				})
 				// Should see only jazz from library 3
 				Expect(tags).To(HaveLen(1))
@@ -252,7 +252,7 @@ var _ = Describe("Tag Library Filtering", func() {
 
 			It("should filter by library 2 correctly", func() {
 				tags := readAllTags(&adminUser, rest.QueryOptions{
-					Filters: map[string]interface{}{"library_id": libraryID2},
+					Filters: map[string]any{"library_id": libraryID2},
 				})
 				// Should see pop and rock from library 2
 				Expect(tags).To(HaveLen(2))

persistence/tag_repository_test.go

@@ -234,7 +234,7 @@ var _ = Describe("TagRepository", func() {
 
 		It("should filter tags by partial value correctly", func() {
 			options := rest.QueryOptions{
-				Filters: map[string]interface{}{"name": "%rock%"}, // Tags containing 'rock'
+				Filters: map[string]any{"name": "%rock%"}, // Tags containing 'rock'
 			}
 			result, err := restRepo.ReadAll(options)
 			Expect(err).ToNot(HaveOccurred())
@@ -249,7 +249,7 @@ var _ = Describe("TagRepository", func() {
 
 		It("should filter tags by partial value using LIKE", func() {
 			options := rest.QueryOptions{
-				Filters: map[string]interface{}{"name": "%e%"}, // Tags containing 'e'
+				Filters: map[string]any{"name": "%e%"}, // Tags containing 'e'
 			}
 			result, err := restRepo.ReadAll(options)
 			Expect(err).ToNot(HaveOccurred())
@@ -264,7 +264,7 @@ var _ = Describe("TagRepository", func() {
 
 		It("should sort tags by value ascending", func() {
 			options := rest.QueryOptions{
-				Filters: map[string]interface{}{"name": "%r%"}, // Tags containing 'r'
+				Filters: map[string]any{"name": "%r%"}, // Tags containing 'r'
 				Sort:    "name",
 				Order:   "asc",
 			}
@@ -280,7 +280,7 @@ var _ = Describe("TagRepository", func() {
 
 		It("should sort tags by value descending", func() {
 			options := rest.QueryOptions{
-				Filters: map[string]interface{}{"name": "%r%"}, // Tags containing 'r'
+				Filters: map[string]any{"name": "%r%"}, // Tags containing 'r'
 				Sort:    "name",
 				Order:   "desc",
 			}

persistence/transcoding_repository.go

@@ -52,11 +52,11 @@ func (r *transcodingRepository) Count(options ...rest.QueryOptions) (int64, erro
 	return r.count(Select(), r.parseRestOptions(r.ctx, options...))
 }
 
-func (r *transcodingRepository) Read(id string) (interface{}, error) {
+func (r *transcodingRepository) Read(id string) (any, error) {
 	return r.Get(id)
 }
 
-func (r *transcodingRepository) ReadAll(options ...rest.QueryOptions) (interface{}, error) {
+func (r *transcodingRepository) ReadAll(options ...rest.QueryOptions) (any, error) {
 	sel := r.newSelect(r.parseRestOptions(r.ctx, options...)).Columns("*")
 	res := model.Transcodings{}
 	err := r.queryAll(sel, &res)
@@ -67,11 +67,11 @@ func (r *transcodingRepository) EntityName() string {
 	return "transcoding"
 }
 
-func (r *transcodingRepository) NewInstance() interface{} {
+func (r *transcodingRepository) NewInstance() any {
 	return &model.Transcoding{}
 }
 
-func (r *transcodingRepository) Save(entity interface{}) (string, error) {
+func (r *transcodingRepository) Save(entity any) (string, error) {
 	if !loggedUser(r.ctx).IsAdmin {
 		return "", rest.ErrPermissionDenied
 	}
@@ -83,7 +83,7 @@ func (r *transcodingRepository) Save(entity interface{}) (string, error) {
 	return id, err
 }
 
-func (r *transcodingRepository) Update(id string, entity interface{}, cols ...string) error {
+func (r *transcodingRepository) Update(id string, entity any, cols ...string) error {
 	if !loggedUser(r.ctx).IsAdmin {
 		return rest.ErrPermissionDenied
 	}

plugins/capabilities.go

@@ -1,5 +1,7 @@
 package plugins
 
+import "slices"
+
 // Capability represents a plugin capability type.
 // Capabilities are detected by checking which functions a plugin exports.
 type Capability string
@@ -25,11 +27,8 @@ func detectCapabilities(plugin functionExistsChecker) []Capability {
 	var capabilities []Capability
 
 	for cap, functions := range capabilityFunctions {
-		for _, fn := range functions {
-			if plugin.FunctionExists(fn) {
-				capabilities = append(capabilities, cap)
-				break // Found at least one function, plugin has this capability
-			}
+		if slices.ContainsFunc(functions, plugin.FunctionExists) {
+			capabilities = append(capabilities, cap) // Found at least one function, plugin has this capability
 		}
 	}
 
@@ -38,10 +37,5 @@ func detectCapabilities(plugin functionExistsChecker) []Capability {
 
 // hasCapability checks if the given capabilities slice contains a specific capability.
 func hasCapability(capabilities []Capability, cap Capability) bool {
-	for _, c := range capabilities {
-		if c == cap {
-			return true
-		}
-	}
-	return false
+	return slices.Contains(capabilities, cap)
 }

plugins/host_websocket.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"maps"
 	"net/http"
 	"net/url"
 	"strings"
@@ -200,9 +201,7 @@ func (s *webSocketServiceImpl) CloseConnection(ctx context.Context, connectionID
 func (s *webSocketServiceImpl) Close() error {
 	s.mu.Lock()
 	connections := make(map[string]*wsConnection, len(s.connections))
-	for k, v := range s.connections {
-		connections[k] = v
-	}
+	maps.Copy(connections, s.connections)
 	s.connections = make(map[string]*wsConnection)
 	s.mu.Unlock()
 

reflex.conf

@@ -1 +1 @@
--s -r "(\.go$$|\.cpp$$|\.h$$|navidrome.toml|resources|token_received.html)" -R "(^ui|^data|^db/migrations)" -- go run -race -tags netgo .
+-s -r "(\.go$$|\.cpp$$|\.h$$|navidrome.toml|resources|token_received.html)" -R "(^ui|^data|^db/migrations|_test\.go$$)" -- go run -race -tags netgo .

scanner/ignore_checker.go

@@ -65,8 +65,8 @@ func (ic *IgnoreChecker) PushAllParents(ctx context.Context, targetPath string)
 
 	// Load patterns for each parent directory
 	currentPath := "."
-	parts := strings.Split(path.Clean(targetPath), "/")
-	for _, part := range parts {
+	parts := strings.SplitSeq(path.Clean(targetPath), "/")
+	for part := range parts {
 		if part == "." || part == "" {
 			continue
 		}

scanner/metadata_old/metadata.go

@@ -215,8 +215,8 @@ func (t Tags) Lyrics() string {
 	}
 
 	for tag, value := range t.Tags {
-		if strings.HasPrefix(tag, "lyrics-") {
-			language := strings.TrimSpace(strings.TrimPrefix(tag, "lyrics-"))
+		if after, ok := strings.CutPrefix(tag, "lyrics-"); ok {
+			language := strings.TrimSpace(after)
 
 			if language == "" {
 				language = "xxx"

scheduler/log_adapter.go

@@ -6,16 +6,16 @@ import (
 
 type logger struct{}
 
-func (l *logger) Info(msg string, keysAndValues ...interface{}) {
-	args := []interface{}{
+func (l *logger) Info(msg string, keysAndValues ...any) {
+	args := []any{
 		"Scheduler: " + msg,
 	}
 	args = append(args, keysAndValues...)
 	log.Debug(args...)
 }
 
-func (l *logger) Error(err error, msg string, keysAndValues ...interface{}) {
-	args := []interface{}{
+func (l *logger) Error(err error, msg string, keysAndValues ...any) {
+	args := []any{
 		"Scheduler: " + msg,
 	}
 	args = append(args, keysAndValues...)

server/auth.go

@@ -68,8 +68,8 @@ func doLogin(ds model.DataStore, username string, password string, w http.Respon
 	_ = rest.RespondWithJSON(w, http.StatusOK, payload)
 }
 
-func buildAuthPayload(user *model.User) map[string]interface{} {
-	payload := map[string]interface{}{
+func buildAuthPayload(user *model.User) map[string]any {
+	payload := map[string]any{
 		"id":       user.ID,
 		"name":     user.Name,
 		"username": user.UserName,
@@ -288,7 +288,7 @@ func JWTRefresher(next http.Handler) http.Handler {
 	})
 }
 
-func handleLoginFromHeaders(ds model.DataStore, r *http.Request) map[string]interface{} {
+func handleLoginFromHeaders(ds model.DataStore, r *http.Request) map[string]any {
 	username := UsernameFromConfig(r)
 	if username == "" {
 		username = UsernameFromExtAuthHeader(r)

server/auth_test.go

@@ -53,7 +53,7 @@ var _ = Describe("Auth", func() {
 
 			It("returns the expected payload", func() {
 				Expect(resp.Code).To(Equal(http.StatusOK))
-				var parsed map[string]interface{}
+				var parsed map[string]any
 				Expect(json.Unmarshal(resp.Body.Bytes(), &parsed)).To(BeNil())
 				Expect(parsed["isAdmin"]).To(Equal(true))
 				Expect(parsed["username"]).To(Equal("johndoe"))
@@ -88,7 +88,7 @@ var _ = Describe("Auth", func() {
 				serveIndex(ds, fs, nil)(resp, req)
 
 				config := extractAppConfig(resp.Body.String())
-				parsed := config["auth"].(map[string]interface{})
+				parsed := config["auth"].(map[string]any)
 
 				Expect(parsed["id"]).To(Equal("111"))
 			})
@@ -106,7 +106,7 @@ var _ = Describe("Auth", func() {
 				serveIndex(ds, fs, nil)(resp, req)
 
 				config := extractAppConfig(resp.Body.String())
-				parsed := config["auth"].(map[string]interface{})
+				parsed := config["auth"].(map[string]any)
 
 				Expect(parsed["id"]).To(Equal("111"))
 			})
@@ -127,7 +127,7 @@ var _ = Describe("Auth", func() {
 				serveIndex(ds, fs, nil)(resp, req)
 
 				config := extractAppConfig(resp.Body.String())
-				parsed := config["auth"].(map[string]interface{})
+				parsed := config["auth"].(map[string]any)
 
 				Expect(parsed["username"]).To(Equal(newUser))
 			})
@@ -137,7 +137,7 @@ var _ = Describe("Auth", func() {
 				serveIndex(ds, fs, nil)(resp, req)
 
 				config := extractAppConfig(resp.Body.String())
-				parsed := config["auth"].(map[string]interface{})
+				parsed := config["auth"].(map[string]any)
 
 				Expect(parsed["id"]).To(Equal("111"))
 				Expect(parsed["isAdmin"]).To(BeFalse())
@@ -182,7 +182,7 @@ var _ = Describe("Auth", func() {
 				serveIndex(ds, fs, nil)(resp, req)
 
 				config := extractAppConfig(resp.Body.String())
-				parsed := config["auth"].(map[string]interface{})
+				parsed := config["auth"].(map[string]any)
 
 				Expect(parsed["id"]).To(Equal("111"))
 			})
@@ -206,7 +206,7 @@ var _ = Describe("Auth", func() {
 				login(ds)(resp, req)
 				Expect(resp.Code).To(Equal(http.StatusOK))
 
-				var parsed map[string]interface{}
+				var parsed map[string]any
 				Expect(json.Unmarshal(resp.Body.Bytes(), &parsed)).To(BeNil())
 				Expect(parsed["isAdmin"]).To(Equal(false))
 				Expect(parsed["username"]).To(Equal("janedoe"))

server/middlewares.go

@@ -37,7 +37,7 @@ func requestLogger(next http.Handler) http.Handler {
 		status := ww.Status()
 
 		message := fmt.Sprintf("HTTP: %s %s://%s%s", r.Method, scheme, r.Host, r.RequestURI)
-		logArgs := []interface{}{
+		logArgs := []any{
 			r.Context(),
 			message,
 			"remoteAddr", r.RemoteAddr,

server/nativeapi/config.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net/http"
+	"slices"
 	"strings"
 
 	"github.com/navidrome/navidrome/conf"
@@ -35,9 +36,9 @@ var sensitiveFieldsFullMask = []string{
 }
 
 type configResponse struct {
-	ID         string                 `json:"id"`
-	ConfigFile string                 `json:"configFile"`
-	Config     map[string]interface{} `json:"config"`
+	ID         string         `json:"id"`
+	ConfigFile string         `json:"configFile"`
+	Config     map[string]any `json:"config"`
 }
 
 func redactValue(key string, value string) string {
@@ -47,10 +48,8 @@ func redactValue(key string, value string) string {
 	}
 
 	// Check if this field should be fully masked
-	for _, field := range sensitiveFieldsFullMask {
-		if field == key {
-			return "****"
-		}
+	if slices.Contains(sensitiveFieldsFullMask, key) {
+		return "****"
 	}
 
 	// Check if this field should be partially masked
@@ -69,7 +68,7 @@ func redactValue(key string, value string) string {
 }
 
 // applySensitiveFieldMasking recursively applies masking to sensitive fields in the configuration map
-func applySensitiveFieldMasking(ctx context.Context, config map[string]interface{}, prefix string) {
+func applySensitiveFieldMasking(ctx context.Context, config map[string]any, prefix string) {
 	for key, value := range config {
 		fullKey := key
 		if prefix != "" {
@@ -77,7 +76,7 @@ func applySensitiveFieldMasking(ctx context.Context, config map[string]interface
 		}
 
 		switch v := value.(type) {
-		case map[string]interface{}:
+		case map[string]any:
 			// Recursively process nested maps
 			applySensitiveFieldMasking(ctx, v, fullKey)
 		case string:
@@ -108,7 +107,7 @@ func getConfig(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Unmarshal back to map to get the structure with proper field names
-	var configMap map[string]interface{}
+	var configMap map[string]any
 	err = json.Unmarshal(configBytes, &configMap)
 	if err != nil {
 		log.Error(ctx, "Error unmarshaling config to map", err)

server/nativeapi/config_test.go

@@ -93,12 +93,12 @@ var _ = Describe("Config API", func() {
 				Expect(json.Unmarshal(w.Body.Bytes(), &resp)).To(Succeed())
 
 				// Check LastFM.ApiKey (partially masked)
-				lastfm, ok := resp.Config["LastFM"].(map[string]interface{})
+				lastfm, ok := resp.Config["LastFM"].(map[string]any)
 				Expect(ok).To(BeTrue())
 				Expect(lastfm["ApiKey"]).To(Equal("s*************3"))
 
 				// Check Spotify.Secret (partially masked)
-				spotify, ok := resp.Config["Spotify"].(map[string]interface{})
+				spotify, ok := resp.Config["Spotify"].(map[string]any)
 				Expect(ok).To(BeTrue())
 				Expect(spotify["Secret"]).To(Equal("s**************6"))
 
@@ -109,7 +109,7 @@ var _ = Describe("Config API", func() {
 				Expect(resp.Config["DevAutoCreateAdminPassword"]).To(Equal("****"))
 
 				// Check Prometheus.Password (fully masked)
-				prometheus, ok := resp.Config["Prometheus"].(map[string]interface{})
+				prometheus, ok := resp.Config["Prometheus"].(map[string]any)
 				Expect(ok).To(BeTrue())
 				Expect(prometheus["Password"]).To(Equal("****"))
 			})
@@ -128,7 +128,7 @@ var _ = Describe("Config API", func() {
 				Expect(json.Unmarshal(w.Body.Bytes(), &resp)).To(Succeed())
 
 				// Check LastFM.ApiKey - should be preserved because it's sensitive
-				lastfm, ok := resp.Config["LastFM"].(map[string]interface{})
+				lastfm, ok := resp.Config["LastFM"].(map[string]any)
 				Expect(ok).To(BeTrue())
 				Expect(lastfm["ApiKey"]).To(Equal(""))
 

server/nativeapi/native_api.go

@@ -95,7 +95,7 @@ func (api *Router) routes() http.Handler {
 	return r
 }
 
-func (api *Router) R(r chi.Router, pathPrefix string, model interface{}, persistable bool) {
+func (api *Router) R(r chi.Router, pathPrefix string, model any, persistable bool) {
 	constructor := func(ctx context.Context) rest.Repository {
 		return api.ds.Resource(ctx, model)
 	}

server/nativeapi/playlists.go

@@ -218,7 +218,7 @@ func reorderItem(ds model.DataStore) http.HandlerFunc {
 			return
 		}
 
-		_, err = w.Write([]byte(fmt.Sprintf(`{"id":"%d"}`, id)))
+		_, err = w.Write(fmt.Appendf(nil, `{"id":"%d"}`, id))
 		if err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 		}

server/nativeapi/translations.go

@@ -28,7 +28,7 @@ func newTranslationRepository(context.Context) rest.Repository {
 
 type translationRepository struct{}
 
-func (r *translationRepository) Read(id string) (interface{}, error) {
+func (r *translationRepository) Read(id string) (any, error) {
 	translations, _ := loadTranslations()
 	if t, ok := translations[id]; ok {
 		return t, nil
@@ -43,7 +43,7 @@ func (r *translationRepository) Count(...rest.QueryOptions) (int64, error) {
 }
 
 // ReadAll simple implementation, only returns IDs. Does not support any `options`
-func (r *translationRepository) ReadAll(...rest.QueryOptions) (interface{}, error) {
+func (r *translationRepository) ReadAll(...rest.QueryOptions) (any, error) {
 	translations, _ := loadTranslations()
 	var result []translation
 	for _, t := range translations {
@@ -57,7 +57,7 @@ func (r *translationRepository) EntityName() string {
 	return "translation"
 }
 
-func (r *translationRepository) NewInstance() interface{} {
+func (r *translationRepository) NewInstance() any {
 	return &translation{}
 }
 
@@ -103,7 +103,7 @@ func loadTranslation(fsys fs.FS, fileName string) (translation translation, err
 	if err != nil {
 		return
 	}
-	var out map[string]interface{}
+	var out map[string]any
 	if err = json.Unmarshal(data, &out); err != nil {
 		return
 	}