[Libav-user] Criteria for h.264 key-frame detection

[Robert Krüger]

On Fri, Oct 25, 2013 at 5:59 PM, Paul B Mahol <onemda at gmail.com> wrote:
> On 10/20/13, Robert Krueger <krueger at lesspain.de> wrote:
>> Hi,
>>
>> I have AVCHD files from a camera (Panasonic Lumix GH1) that demux and
>> decode with libavformat/libavcodec detecting no other keyframe but the
>> first (both, the first video packet and video frame are marked as
>> keyframe), which is not what I would have expected for those clips as
>> the GOP structure of files produced by this camera is known to be
>> different.
>>
>> My question is now, what libavcodec/libavformat uses as criteria to
>> decide whether a packet is a keyframe packet or a frame is a keyframe
>> in this case. Does it only trigger in the case of IDRs or are recovery
>> point SEIs also detected? Should I open a trac issue for this with a
>> sample?
>
> AFAIK h264 key frame detection is in parser. And only in two places in
> code is key_frame set to 1.
>
> If key frame detection is wrong for certain file that it could be bug.
> Without sample it is impossible to find out.
>
> I would recommend to open trac issue.

http://trac.ffmpeg.org/ticket/3083

Carl, could you attach the samples I uploaded?