Support Vorbis comments from a multiplexed Ogg stream (#1370)

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Ogg::File::readPages() read pages from all logical bitstreams and
indexed their packets into one global list. In a multiplexed file the
Theora and Vorbis packets got interleaved, so packet 0 was a Theora
header rather than the expected Vorbis type-3 comment header.

Before reading packets, the Vorbis reader now selects the Vorbis
logical bitstream (the one whose first packet is the Vorbis
identification header), so it reads the correct stream regardless of
position. Packet parsing is scoped to the selected bitstream, so
packets from other codecs in the same file are ignored.

tests/data/multiplex.ogg is generated using

ffmpeg -hide_banner -y \
  -f lavfi -i "color=c=navy:s=500x500:r=1:d=2" \
  -f lavfi -i "sine=frequency=440:sample_rate=48000:duration=2" \
  -map 0:v -map 1:a \
  -c:v libtheora -q:v 3 \
  -c:a libvorbis -ac 2 -q:a 2 \
  -flags +bitexact -fflags +bitexact \
  -metadata:s:a:0 TITLE="Paper Lights" \
  -metadata:s:a:0 encoder= -metadata:s:v:0 encoder= \
  -f ogg tests/data/multiplex.ogg

...

This commit is contained in:

Urs Fleisch

2026-08-05 20:57:29 +02:00

committed by GitHub

parent d781aaed7f

commit e547578ae8

5 changed files with 142 additions and 22 deletions

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tests/data/multiplex.ogg

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