[FFmpeg-trac] #6133(ffmpeg:new): TimeStamp Correction Incompetence

FFmpeg trac at avcodec.org
Wed Feb 8 16:54:28 EET 2017

#6133: TimeStamp Correction Incompetence
             Reporter:  ilkertezcan  |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffmpeg       |                  Version:  git-
             Keywords:               |  master
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
 While '''FFmpeg''' can reduce the file size to only certain amount of
 downloaded real data by triming gap bytes in the played audio / video
 files, The output (remux) file's the timestamp remains same with the
 original file.

 The info-graphics that I designed to representatived the issue:

 ffmpeg -i ElephantsDream_only_a_few_scenes.mkv -c:a copy -c:v copy

 The sample file:

 FFmpeg's report: [https://paste.ee/r/5Zwci]

 ElephantsDream_only_a_few_scenes.mkv's file-size: '''193 MB'''
 ElephantsDream_only_a_few_scenes.mkv's timestamp:
 == 00:10:58.13 ==

 Remuxed.mkv's file-size: '''23 MB'''
 Remuxed.mkv's timestamp:
 == 00:10:58.13 ==


 FFmpeg is deprived of timestamp correction but '''MEncoder''' isn't. How
 can MEncoder can manage things while FFMpeg cannot?

 MEncoder ElephantsDream_only_a_few_scenes.mkv -ni -ovc copy -oac copy
 -fafmttag 0x706D -of lavf -lavfopts format=mkv -o

 MEncoder's report: https://paste.ee/r/LzO4M

 Corrected_by_MEncoder.mkv's new timestamp:
 == 00:01:46 ==


 Also, [http://www.mkvrepair.com/ The Meteorite Project (A MKV Repair
 Engine)] software able to correct timestamp. (But Meteorite has its own
 issue which it has stuck at final stage -99%-. Order to overcome this, it
 will be necessary to re-mux the sample file with '''FFmpeg-3.1.5'''. In
 later versions of FFmpeg-3.1.5, the Meteorite directly crash without fix
 to the file).

 The sources codes of '''Meteorite''' CLI version (''I think,
 Meteoirite.cpp & MeteoireCLI.cpp files is enough''):

 FFmpeg -i ElephantsDream_only_a_few_scenes.mkv -c:a copy -c:v copy

 Meteoritecli ElephantsDream_only_a_few_scenes-ffmpeg-3-1-5-remuxed.mkv

 Meteorite's report: [https://paste.ee/r/VJWCS]

 Download for final fixed file]):
 == 00:01:41 ==

Ticket URL: <https://trac.ffmpeg.org/ticket/6133>
FFmpeg <https://ffmpeg.org>
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