[FFmpeg-devel] [PATCH]Fix linesize for pix_fmt pal8

[Carl Eugen Hoyos]

Stefano Sabatini <stefasab <at> gmail.com> writes:

> > +    else if (desc->flags & PIX_FMT_PAL) {
> > +        // 2 would be sufficient for QuickTime,
> > +        // but 4 works and is what avi and mov samples use
> > +        linesize = FFALIGN(linesize, 4);
> > +    }
> >      return linesize;
> 
> Can you elaborate why this is needed?

$ ./ffmpeg -i tests/lena.pnm -s 257x257 -pix_fmt pal8 -vcodec rawvideo out.avi
$ ./ffplay out.avi

> Note that the alignment is defined by av_image_alloc(), and in general
> I don't see why a paletted image should need an aligned size, so I'd
> prefer to avoid the special casing, or in other words this seems more
> a libavcodec issue (and should be addressed there).

Please elaborate.

Carl Eugen