* Add non-owning conversions via ConversionOptions.ownsOutput
A conversion with ownsOutput: false only adds tracks to the output and
drives their media data; starting, finalizing, and metadata tags remain
the caller's responsibility. This lets multiple conversions and
directly-added user tracks compose on a single Output (see upstream
issue #436).
- ownsOutput: false allows a pre-populated output (state must still be
'pending') and seeds track-capacity accounting from existing tracks
- execute() requires the output to be started and never finalizes it
- cancel() closes only the conversion's own sources, releasing internal
synchronizer waiters, and leaves the output usable
- tags cannot be combined with ownsOutput: false
- isValid requires at least one contributed track instead of the
format's minimum track counts
Prototype for API discussion; default (owning) behavior is unchanged.
Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AJdfnbY9AFh9i9dKgtrj6E
* Add external-audio example using a non-owning conversion
Demonstrates composing a user-owned audio track (synthesized voiceover
via OfflineAudioContext + AudioBufferSource) onto a picked video with
Conversion.init({ ownsOutput: false }), including progress reporting
and playback/download of the result.
Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AJdfnbY9AFh9i9dKgtrj6E
* Release synchronizer waiters when canceling during output finalization
A non-owning conversion's cancel() previously no-oped entirely when the
output (owned by someone else) was already finalizing or finalized,
leaving pump loops parked in the track synchronizer and hanging
execute() forever. Now it still marks the conversion canceled and
releases parked waiters in that state, without force-closing sources
(finalization owns flushing them at that point).
Also adds coverage: non-owning onProgress monotonicity, canceling one
of two sibling conversions, capacity seeding across sequential inits,
exact metadata exclusivity, and cancel-before-execute.
Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AJdfnbY9AFh9i9dKgtrj6E
* Document non-owning conversions on the converting-media-files guide page
Adds the doc section requested in #436: what ownsOutput: false does, the
required choreography (add tracks -> output.start() before execute() ->
run the conversion concurrently with your own sources -> finalize), the
cancellation split (conversion.cancel() leaves the output alive; cancel
both for a full abort and tear the output down on error paths), isValid
semantics in this mode, and the tags restriction with the
setMetadataTags() alternative. Also cross-links the fresh-output rule to
the new section. VitePress build passes with dead-link checking on.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
* Clean up conversion logic, add Output.tracks and .hasEnoughTracks(), move new conversion tests around, remove external audio example
* non-owning -> composable, and update docs
* Update
---------
Co-authored-by: Claude <[email protected]>
Co-authored-by: Vanilagy <[email protected]>
* Add per-sink decoder preferences to VideoSampleSink and CanvasSink
Adds an optional VideoSinkDecoderOptions ({ hardwareAcceleration,
optimizeForLatency }) parameter to VideoSampleSink, exposed on CanvasSink
via options.decoderOptions, applied to the decoder config before the
VideoDecoderWrapper is constructed.
Motivation: applications that run many sinks concurrently (multi-track
video editors) need to manage hardware decode sessions deliberately -
the number of concurrent hardware sessions is OS-limited, undocumented,
and exceeding it fails silently on some platforms (macOS VideoToolbox
accepts configure() and decode() and simply never outputs). Such an
application places overflow sinks on 'prefer-software' explicitly.
optimizeForLatency is exposed alongside it since it is the other
WebCodecs decoder-config preference an application may want per sink.
The override composes with the existing interlaced-AVC Chromium
workaround, which runs later and can only strengthen the preference
toward software.
Validation mirrors decode.ts's validateVideoDecodingConfig.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
* Modify docs
---------
Co-authored-by: Claude Opus 4.8 <[email protected]>
Co-authored-by: Vanilagy <[email protected]>
Vanilagy