MuditaOS/module-audio/Audio/decoder/decoderFLAC.cpp

/*
 *  @file decoderFLAC.cpp
 *  @author Mateusz Piesta (mateusz.piesta@mudita.com)
 *  @date 06.04.19
 *  @brief 
 *  @copyright Copyright (C) 2019 mudita.com
 *  @details
 */

#include "decoderFLAC.hpp"

#define DR_FLAC_IMPLEMENTATION
#define DR_FLAC_NO_STDIO
#define DR_FLAC_NO_OGG
#define DR_FLAC_NO_CRC
#define DR_FLAC_NO_SIMD

#include "dr_flac.h"

decoderFLAC::decoderFLAC(const char *fileName)
        : decoder(fileName),
          tags(std::make_unique<Tags>()) {

    flac = drflac_open_with_metadata(drflac_read, drflac_seek, drflac_meta, this);
    if (flac == NULL) {
        //error
    }
}


decoderFLAC::~decoderFLAC() {
    drflac_close(flac);
}


std::unique_ptr<Tags> decoderFLAC::fetchTags() {
    tags->filePath.append(filePath);
    if (tags->title.size() == 0) {
        auto pos = filePath.rfind("/");
        if (pos == std::string::npos) {
            tags->title.append(filePath);
        } else {
            tags->title.append(&filePath[pos + 1]);
        }
    }
    return std::make_unique<Tags>(*tags);
}


uint32_t decoderFLAC::decode(uint32_t samplesToRead, int16_t *pcmData) {

    uint32_t samples_read = 0;

    samples_read = drflac_read_s16(flac, samplesToRead, (drflac_int16 *) pcmData);

    if (samples_read) {
        /* Calculate frame duration in seconds */
        position += (float) ((float) (samplesToRead) / (float) sampleRate);
    }

    return samples_read;
}

void decoderFLAC::setPosition(float pos) {

    drflac_seek_to_sample(flac, totalSamplesCount * pos);

    // Calculate new position
    position = (float) ((float) (totalSamplesCount * pos) / chanNumber / (float) (sampleRate));
}


/* Data encoded in UTF-8 */
void decoderFLAC::flac_parse_text(uint8_t *in, uint32_t taglen, uint32_t datalen, uint8_t *out, uint32_t outlen) {
    /* Little Endian here. */
    uint32_t size = datalen - taglen > outlen - 1 ? outlen - 1 : datalen - taglen;
    memcpy(out, in + taglen, size);
    out[size] = '\0';
}


size_t decoderFLAC::drflac_read(void *pUserData, void *pBufferOut, size_t bytesToRead) {
    decoderFLAC *userdata = (decoderFLAC *) pUserData;
    return vfs.fread(pBufferOut, 1, bytesToRead, userdata->fd);
}


drflac_bool32 decoderFLAC::drflac_seek(void *pUserData, int offset, drflac_seek_origin origin) {
    decoderFLAC *userdata = (decoderFLAC *) pUserData;
    return !vfs.fseek(userdata->fd, offset, origin == drflac_seek_origin_start ? SEEK_SET : SEEK_CUR);
}


void decoderFLAC::drflac_meta(void *pUserData, drflac_metadata *pMetadata) {
    decoderFLAC *userdata = (decoderFLAC *) pUserData;

    /* We're only interested in VORBIS comments which contain album/track/artist info */
    if (pMetadata->type == DRFLAC_METADATA_BLOCK_TYPE_VORBIS_COMMENT) {
        uint8_t buff[128] = {0};

        /*ommit vendor string*/
        uint8_t *p = (uint8_t *) pMetadata->data.vorbis_comment.comments;

        uint8_t i = 0;
        for (i = 0; i < pMetadata->data.vorbis_comment.commentCount; i++) {
            /* Little Endian */
            uint32_t *taglen = (uint32_t *) p;
            p += sizeof(*taglen);


            uint8_t *pp = (uint8_t *) strchr((char *) p, '=');
            uint8_t j = 0;
            uint32_t tolower_size = pp - p;
            /*convert to lower case*/
            for (j = 0; j < tolower_size; ++j) p[j] = tolower(p[j]);

            if (!memcmp(p, "artist=", 7)) {
                userdata->flac_parse_text(p, 7, *taglen, buff, sizeof buff);
                userdata->tags->artist.append(reinterpret_cast<char *>(&buff[0]));
            }

            if (!memcmp(p, "title=", 6)) {
                userdata->flac_parse_text(p, 6, *taglen, buff, sizeof buff);
                userdata->tags->title.append(reinterpret_cast<char *>(&buff[0]));
            }

            if (!memcmp(p, "album=", 6)) {
                userdata->flac_parse_text(p, 6, *taglen, buff, sizeof buff);
                userdata->tags->album.append(reinterpret_cast<char *>(&buff[0]));
            }

            if (!memcmp(p, "genre=", 6)) {
                userdata->flac_parse_text(p, 6, *taglen, buff, sizeof buff);
                userdata->tags->genre.append(reinterpret_cast<char *>(&buff[0]));
            }

            if (!memcmp(p, "date=", 5)) {
                userdata->flac_parse_text(p, 5, *taglen, buff, sizeof buff);
                userdata->tags->year.append(reinterpret_cast<char *>(&buff[0]));
            }

            p += *taglen;
        }
    } else if (pMetadata->type == DRFLAC_METADATA_BLOCK_TYPE_STREAMINFO) {
        userdata->tags->total_duration_s =
                (pMetadata->data.streaminfo.totalSampleCount / (pMetadata->data.streaminfo.bitsPerSample / 8)) /
                pMetadata->data.streaminfo.sampleRate;

        if (pMetadata->data.streaminfo.channels == 1) {
            userdata->tags->total_duration_s *= 2;
        }

        userdata->tags->duration_min = userdata->tags->total_duration_s / 60;
        userdata->tags->duration_hour = userdata->tags->duration_min / 60;
        userdata->tags->duration_sec = userdata->tags->total_duration_s % 60;
        userdata->tags->sample_rate = pMetadata->data.streaminfo.sampleRate;
        userdata->tags->num_channel = pMetadata->data.streaminfo.channels;

        userdata->sampleRate = pMetadata->data.streaminfo.sampleRate;
        userdata->chanNumber = pMetadata->data.streaminfo.channels;

        userdata->totalSamplesCount = pMetadata->data.streaminfo.totalSampleCount;
    }

}