[Ffmpeg-devel] VP6F decode bug

Aurelien Jacobs aurel
Sun Oct 22 22:57:13 CEST 2006


On Sun, 22 Oct 2006 22:29:45 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> Hi
> 
> On Sun, Oct 22, 2006 at 08:55:33PM +0200, Aurelien Jacobs wrote:
> > On Thu, 19 Oct 2006 12:16:31 +0700
> > Roine Gustafsson <roine at users.sourceforge.net> wrote:
> > 
> > > I've found an flv file which exhibits a decode bug: the bottom and  
> > > right edge macroblocks are smeared.
> > > Plays correctly in a flash player.
> > > File uploaded to mplayerhq as "good_one.flv".
> > 
> > Ok. The decoding was correct but the visible area was larger than
> > it should be. The attached patch fix this bug.
> > I just would like to know if such a usage of extradata is ok before
> > commiting it.
> > 
> > Note that reading the additionnal byte in vp6.c instead of flv.c is
> > not possible because swf.c also use the VP6F codec but don't have
> > the additionnal byte.
> 
> why dont you set AVCodecContext.width / height in flvdec.c?

That's what I thought first. But it seems width and height is not known
in the flv container. Only the adjutement to apply to these width / height
is know.
So to do this I would have to read the width / height from the VP6 header
into flvdec.c but this would break container / codec separation rule.
So should I do this, or apply my original (extradata) patch ?

Aurel




More information about the ffmpeg-devel mailing list