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

Michael Niedermayer michaelni
Fri Mar 6 00:20:33 CET 2009


On Thu, Mar 05, 2009 at 10:32:42PM +0100, Ivan Schreter wrote:
> madshi wrote:
> > Ivan Schreter schrieb:
> >   
> >> Hi,
> >>
> >> I just found out that my new seeking code doesn't work with AVCHD 
> >> files from a Canon camcorder. The reason being, no key frames are 
> >> detected (except first IDR slice), since this camcorder doesn't store 
> >> SEI recovery point. In this case, I-slices are taken as key frames.
> >>
> >> So I'm afraid, we need to consider I-slice as a key frame, even if 
> >> recovery point is not set (see attached patch).
> >>
> >> BTW, as we already discussed with Michael, convergence handling needs 
> >> to be cleaned up anyway, since H.264 does it a little differently than 
> >> originally thought.
> >>
> >> Regards,
> >>
> >> Ivan
> >>
> >>     
> >
> > 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.
> >
> > Just a suggestion...
> >   
> It is a possibility, yes.
> 
> Michael: What do you think?

can streams from such camera be detected?
any ids in there identifying the encoder?

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20090306/f14a2fcd/attachment.pgp>



More information about the ffmpeg-devel mailing list