* fix(transcoding): clamp target channels to codec limit (#5336)
When transcoding a multi-channel source (e.g. 6-channel FLAC) to MP3, the
decider passed the source channel count through to ffmpeg unchanged. The
default MP3 command path then emitted `-ac 6`, and the template path injected
`-ac 6` after the template's own `-ac 2`, causing ffmpeg to honor the last
occurrence and fail with exit code 234 since libmp3lame only supports up to
2 channels.
Introduce `codecMaxChannels()` in core/stream/codec.go (mp3→2, opus→8),
mirroring the existing `codecMaxSampleRate` pattern, and apply the clamp in
`computeTranscodedStream` right after the sample-rate clamps. Also fix a
pre-existing ordering bug where the profile's MaxAudioChannels check compared
against src.Channels rather than ts.Channels, which would have let a looser
profile setting raise the codec-clamped value back up. Comparing against the
already-clamped ts.Channels makes profile limits strictly narrowing, which
matches how the sample-rate block already behaves.
The ffmpeg buildTemplateArgs comment is refreshed to point at the new upstream
clamp, since the flags it injects are now always codec-safe.
Adds unit tests for codecMaxChannels and four decider scenarios covering the
literal issue repro (6-ch FLAC→MP3 clamps to 2), a stricter profile limit
winning over the codec clamp, a looser profile limit leaving the codec clamp
intact, and a codec with no hard limit (AAC) passing 6 channels through.
* test(e2e): pin codec channel clamp at the Subsonic API surface (#5336)
Add a 6-channel FLAC fixture to the e2e test suite and use it to assert the
codec channel clamp end-to-end on both Subsonic streaming endpoints:
- getTranscodeDecision (mp3OnlyClient, no MaxAudioChannels in profile):
expects TranscodeStream.AudioChannels == 2 for the 6-channel source. This
exercises the new codecMaxChannels() helper through the OpenSubsonic
decision endpoint, with no profile-level channel limit masking the bug.
- /rest/stream (legacy): requests format=mp3 against the multichannel
fixture and asserts streamerSpy.LastRequest.Channels == 2, confirming
the clamp propagates through ResolveRequest into the stream.Request that
the streamer receives.
The fixture is metadata-only (channels: 6 plumbed via the existing
storagetest.File helper) — no real audio bytes required, since the e2e
suite uses a spy streamer rather than invoking ffmpeg. Bumps the empty-query
search3 song count expectation from 13 to 14 to account for the new fixture.
* test(decider): clarify codec-clamp comment terminology
Distinguish "transcoding profile MaxAudioChannels" (Profile.MaxAudioChannels
field) from "LimitationAudioChannels" (CodecProfile rule constant). The
regression test bypasses the former, not the latter.
* refactor: rename core/transcode directory to core/stream
* refactor: update all imports from core/transcode to core/stream
* refactor: rename exported symbols to fit core/stream package name
* refactor: simplify MediaStreamer interface to single NewStream method
Remove the two-method interface (NewStream + DoStream) in favor of a
single NewStream(ctx, mf, req) method. Callers are now responsible for
fetching the MediaFile before calling NewStream. This removes the
implicit DB lookup from the streamer, making it a pure streaming
concern.
* refactor: update all callers from DoStream to NewStream
* chore: update wire_gen.go and stale comment for core/stream rename
* refactor: update wire command to handle GO_BUILD_TAGS correctly
Signed-off-by: Deluan <deluan@navidrome.org>
* fix: distinguish not-found from internal errors in public stream handler
* refactor: remove unused ID field from stream.Request
* refactor: simplify ResolveRequestFromToken to receive *model.MediaFile
Move MediaFile fetching responsibility to callers, making the method
focused on token validation and request resolution. Remove ErrMediaNotFound
(no longer produced). Update GetTranscodeStream handler to fetch the
media file before calling ResolveRequestFromToken.
* refactor: extend tokenTTL from 12 to 48 hours
Signed-off-by: Deluan <deluan@navidrome.org>
---------
Signed-off-by: Deluan <deluan@navidrome.org>
