Commit Graph

4 Commits

Author SHA1 Message Date
Ettore Di Giacinto
fe70b21139 backend(audio-cpp): serve the VAD and Diarize RPCs
Both emit float seconds, converted from the runtime's sample-index spans, and
both take a counted reference to the loaded model through snapshot() and hold it
for the whole call: a Free arriving mid-request drops only the global's
reference, so whichever request finishes last destroys the model instead of one
of them running on freed weights. An AddressSanitizer build reproduces exactly
that heap-use-after-free inside ggml_vec_dot_f32 when the handler keeps a raw
pointer instead, which is why the shape is what it is.

The inference lane is taken before session_for, not after. session_for reads and
writes an unsynchronised session cache and the offline run calls prepare(),
which mutates the session, so both belong inside the lane.

Diarize routes before it reads the input file, so a family that cannot diarize
at all says so rather than complaining about the audio first. Its per-segment
text stays empty because audio.cpp's SpeakerTurn carries a span and a speaker
label only, and nested or overlapping turns are passed through untouched: a
sortformer turn inside another speaker's turn is correct output for overlapped
speech, and LocalAI is overlap-tolerant downstream. Duration counts frames
rather than floats, so a stereo input does not report twice its length.

Verified end to end against upstream's bundled silero_vad, which needs no
download, using the bundled 16 kHz speech asset: a synthetic tone returns
nothing, correctly, because silero detects speech and a sine is not speech.

Assisted-by: Claude:claude-opus-5 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-07-29 19:03:32 +00:00
Ettore Di Giacinto
020b4b5d0f backend(audio-cpp): map NaN PCM samples to silence explicitly
f32_to_s16le relied on std::min argument order to keep a NaN sample away from
std::lround, whose result is unspecified for NaN. That was too subtle to rest on
a comment, and the comment was itself wrong: it warned against a spelling that
the outer std::max already catches, while three real spellings leak, including
std::clamp, which is the idiomatic C++17 way to write the same clamp and so the
likeliest future edit.

Divert NaN before the clamp and encode it as 0. A NaN sample rendered as a
full-scale click is worse audio than a dropped one, and this unit converts audio
that may have originated off the wire.

Pin it with an exact-value check rather than a range check, since all three
outcomes the plausible spellings produce are finite and inside full scale, plus
an invalid-operation check that fails unless the NaN is diverted before any
ordered comparison. That second check is what catches modernizing the clamp and
dropping the guard together.

Also bound the seconds round-trip comment, which claimed unconditionally what
holds only below roughly 2^23 samples, and document NaN, saturation and that
bound in the header.

Assisted-by: Claude:claude-opus-5 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-07-29 19:03:32 +00:00
Ettore Di Giacinto
4d73df4945 backend(audio-cpp): harden seconds_to_samples against NaN and overflow
seconds_to_samples is the one entry point fed by untrusted-shaped input: a
float-seconds timestamp off the wire, or a boundary from a model that diverged.
Its guard covered only the low side, so NaN and out-of-range values fell through
to an undefined double-to-int64 cast and came back as INT64_MIN. A hugely
negative sample index used later as an offset or a length is a wild pointer
rather than merely a wrong timestamp. Reject NaN with the !(x > 0) form and
saturate before the cast.

Also round instead of truncating there. These functions exist to cross the float
seconds boundary the VAD and diarize messages use, and truncation lost a sample
about half the time on the samples-to-seconds-and-back round trip, starting at
n=1.

Pin the decode scale at INT16_MIN, pin nanosecond truncation on a nonzero
fraction, and record why the clamp argument order in f32_to_s16le is
load-bearing for NaN.

Assisted-by: Claude:claude-opus-5 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-07-29 19:03:32 +00:00
Ettore Di Giacinto
0b030df961 backend(audio-cpp): convert sample, time and PCM units
Integer nanosecond conversion so 44.1 kHz stays exact, float seconds for the
VAD and diarization messages, and saturating s16le encode so an overshooting
sample cannot wrap to the opposite sign.

Assisted-by: Claude:claude-opus-5 [Claude Code]
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>
2026-07-29 19:03:32 +00:00