[FFmpeg-devel] AVCodecParserContext.keyframe does not match AVFrame.key_frame for an AVCHD sample

Michael Niedermayer michaelni at gmx.at
Tue Mar 12 18:47:58 CET 2013

On Fri, Mar 08, 2013 at 01:22:54PM +0100, Robert Krüger wrote:
> Hi,
> I have a sample camera file for which only the first frame is reported
> as a keyframe when decoding it (AVFrame.key_frame and ffprobe output
> confirms that) but for some frames
> AVCodecParserContext.keyframe is set to 1 and that would absolutely
> make sense taking into account what I know about the camera's GOP size
> from other sources. However, the field
> AVCodecParserContext.convergence_duration is never set to any other
> value but 0 and judging by its documentation it looks like it is the
> one I should really use to identify recovery points when parsing the
> stream. It would be nice if someone with knowledge of ffmpeg's h264
> internals could tell me if I can use this to identify recovery points
> in an h.264 stream or if the inconsistency between
> AVCodecParserContext.keyframe and AVFrame.key_frame should be fixed or
> if I'm getting it all wrong.
> What shall I do? File a ticket in trac? The sample is the same as for
> tickets 2336, 2337, 2338.

the file in this ticket contains 2 IDR frames and several recovery
I guess the decoder should set key_frame for these recovery points

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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