[FFmpeg-trac] #8728(undetermined:open): Misplaced chapters for mp3 files (ID3v2 Chapter Frame Addendum)
FFmpeg
trac at avcodec.org
Sun Feb 20 15:35:56 EET 2022
#8728: Misplaced chapters for mp3 files (ID3v2 Chapter Frame Addendum)
-------------------------------------+-------------------------------------
Reporter: sandreas | Owner: (none)
Type: defect | Status: open
Priority: normal | Component:
| undetermined
Version: unspecified | Resolution:
Keywords: chapters, | Blocked By:
mp3, misplaced |
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
Changes (by mkver):
* status: new => open
Comment:
1. Your file is gone; you should have uploaded it
[https://streams.videolan.org/upload/ here] or attached it to this ticket
in case of small samples.
2. A quick test of mine shows that the chapters are offset by an amount
corresponding to encoder delay. In fact, if one has an mp3 file with
chapters and a xing frame indicating encoder delay, then each round of
remuxing (without reencoding) offsets the chapters by this encoder delay.
The demuxer just signals the encoder delay via side data and the
AVStream's start_time. It is ffmpeg that offsets the chapters to
(presumably) somehow compensate for this. This is definitely a bug
(regardless of the missing sample).
--
Ticket URL: <https://trac.ffmpeg.org/ticket/8728#comment:1>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list