[Ffmpeg-devel] first frame wrong

[Michael Niedermayer]

Hi

On Tue, Mar 20, 2007 at 05:54:40PM -0400, Glenn Maynard wrote:
> > I've made a wrapper of the last ffmpeg for using in my program. I send all
> > the parameters to a function that replies the ffmpeg.c and I obtain the same
> > results as I was just using the ffmpeg.
> > But I still have a problem about the first frame of some file...
> > If I extract the first image of a video it looks damaged
> > If I extract a video from frame 0 to 30 for example (-vframes 31) I get a
> > video formed by 31 frames but starting from frame 2 and ending to the frame
> > 32 (fr 0 and fr 1 skipped).
> 
> I just hit this problem.  For me, it turned out to be that my protocol
> handler was being passed "AVSEEK_SIZE".  That's not a real fseek code;
> it ended up rewinding my stream.  If you're using a protocol handler,
> be sure to return -1 on unknown codes.
> 
> This bit me pretty badly during an upgrade, taking several hours to
> track down why looping videos were jerking on loop.  Maybe a sanity
> check is in order: in url_open, call url_seek with an invalid whence.
> If it doesn't return < 0, fail the open.  That way, the failure is
> much easier to diagnose.

patch welcome


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

The educated differ from the uneducated as much as the living from the
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