[FFmpeg-devel] [PATCH] Fix empty G-VOP header decoding in MPEG-4
Wed Feb 9 21:30:07 CET 2011
On 08.02.2011 22:00, M?ns Rullg?rd wrote:
> Anatoly Nenashev<anatoly.nenashev at ovsoft.ru> writes:
>> Hi all!
>> There are some cameras which send mpeg-4 streams with empty G-VOP header.
>> This part of stream looks like this:
>> ... 00 00 01 B3 00 00 00 01 B6 ...
>> Sample file uploaded in issue 2592.
>> FFmpeg reports "header damaged" and ignores first I-frame in G-VOP.
>> Attached patch fix this problem.
>> Looking at this, I wonder why this is there at all. The s->time_base
>> field is only used to incorrectly set the pts field of the decoded
>> frame (now I understand why those values always are wrong). The
>> actual PTS is passed from the input packet to the pkt_pts field of the
>> output frame.
>> IMO this nonsense should be removed. The time_code field in the
>> bitstream has nothing to do with PTS.
Hmm... So, if I understand you clearly, we just can ignore GOP header as
done in attached patch.
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