[FFmpeg-devel] [PATCH] H.264 I-frames with SEI are also key frames

madshi dear
Fri Mar 6 12:49:14 CET 2009

> A keyframe is defined as any frame which has no dependence on prior
> frames.  In H.264, this dependency is represented in the form of the
> reference list.  If, via whatever means are used, the reference list
> at the time at which a given I-frame is displayed is empty, the frame
> is a keyframe.
> MMCO is one method of forcing previous frames to be dumped from the
> reference frame list prematurely, to clear the reference list.
> Dark Shikari

Thanks! That sounds like the best solution to me.

In your experience is an MMCO of "5" the usual way to empty the
reference list? Or is it also usual to use multiple MMCOs "1", "2"
and "4"? Testing only for MMCO "5" would of course be the easiest
way. Because it would probably mean that the splitter/parser wouldn't
have to implement the whole reference list logic.

Regards, madshi.

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