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

Robert Krüger krueger at lesspain.de
Sun Oct 20 14:03:49 CEST 2013


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

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

My requirement is, I want to find points in the stream suitable for
random access using libavformat/libavcodec. What are my options for
this kind of files?



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