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

madshi dear
Fri Mar 6 08:52:18 CET 2009

Loren Merritt schrieb:
> On Thu, 5 Mar 2009, madshi wrote:
>> Would it make sense to consider I-slices as key frames only
>> if no SEI recovery points are in the stream? Or in other
>> words: As soon as you find a recovery point, you might no
>> longer want to treat every I-slice as a key frame in that
>> particular stream.
> Not as a general strategy to apply to all streams. What about those that 
> have plenty of IDR-frames, and plenty of non-key I-frames, and no 
> recovery point SEIs? (i.e. everything generated by x264)
> --Loren Merritt

My suggestion is no worse in any way than the original
suggestion, which was to handle all I-frames as key frames
with no questions asked.

Ok, how about an improved version of my suggestion:


(1) there haven't been a new IDR frame for 3 (?) seconds runtime and
(2) there was not a single SEI recovery point in the stream as of yet

In this situation treat all I-frames as key frames.

Not sure about the runtime. In what distance does x264 usually
place IDR frames?

Regards, madshi.

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