VP9/WebM-origin files stalled at 0ms in ExoPlayer on 2.17.0 and fell
back to MPV after ~40s. The ffmpeg demuxer published raw extradata as
the only initializationData entry; Android's Opus decoders consume
their first three input buffers as OpusHead/codec-delay/seek-pre-roll,
so they ate the first two real packets as configuration and silently
discarded every decoded sample, pinning the audio-driven clock at 0.
Vorbis (unsplit Xiph lacing) and FLAC (unmarked STREAMINFO) had the
same shape divergence.
Shape audio extradata into the layouts media3's own extractors emit
before publishing the track format.
close#2088
edde746
a9f2c1ff99