[FFmpeg-trac] #6306(undetermined:new): Wrong first frame using new decode API
FFmpeg
trac at avcodec.org
Tue Apr 11 16:08:35 EEST 2017
#6306: Wrong first frame using new decode API
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Reporter: s0m3 | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 1
Analyzed by developer: 0 |
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I'm developping a multimedia player based on ffmpeg.
To do frame stepping, I need to associate frame numbers and frame times
(timecodes).
If AVStream::nb_index_entries is != 0, I use AVIndexEntry structure,
otherwise, I build an "index" manually.
Building the "index" is as simple as decoding frames until we reach the
end of the file. When decoding frames, I can retrieve frame times (pts)
and store them.
My issue is that the first frame I get is not the first one, its pts is
not 0, its the (correct) pts of the third frame so I miss 2 frames.
I suspect frames content are correct (what is displayed) but their pts is
not. It's hard to tell because first frames of the sample file are
identical.
I use the new decoding API so it may be a bug there or I may not use it
correctly.
Anyway, a test case is provided.
The sample is "simpsons_movie_1080p_trailer.zip" from
http://www.h264info.com/clips.html. MD5 is
ff37f121ea26b09c926926a6ba737194
I tested it on windows with ffmpeg v3.2.4 and git version
20170404-1229007-win32 (win32 build)
--
Ticket URL: <https://trac.ffmpeg.org/ticket/6306>
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