[FFmpeg-devel] [BUG] Theora decoder displays green line

[Michael Niedermayer]

On Sun, May 06, 2007 at 05:23:25PM +0200, Aurelien Jacobs wrote:
> On Sun, 6 May 2007 17:12:21 +0200
> Michael Niedermayer <michaelni at gmx.at> wrote:
> 
> > Hi
> > 
> > On Sun, May 06, 2007 at 02:26:36PM +0200, Diego Biurrun wrote:
> > > Try the following sample:
> > > 
> > > http://mirrors.creativecommons.org/getcreative/Creative_Commons_-_Get_Creative.ogg
> > > 
> > > ffplay displays a green line at the bottom (as does MPlayer with lavc
> > > decoder and lavf demuxer), while MPlayer with native demuxer and
> > > libtheora decoder works fine.
> > 
> > ffmpeg -i output could be usefull
> 
> coded size is 400x304, display size should be 400x300.
> Attached patch fixes this issue.
> 
> Aurel

> Index: libavcodec/vp3.c
> ===================================================================
> --- libavcodec/vp3.c	(revision 8918)
> +++ libavcodec/vp3.c	(working copy)
> @@ -1950,8 +1950,8 @@
>          s->version = 1;
>  
>      s->avctx = avctx;
> -    s->width = (avctx->width + 15) & 0xFFFFFFF0;
> -    s->height = (avctx->height + 15) & 0xFFFFFFF0;
> +    s->width = (avctx->coded_width + 15) & 0xFFFFFFF0;
> +    s->height = (avctx->coded_height + 15) & 0xFFFFFFF0;
>      avctx->pix_fmt = PIX_FMT_YUV420P;
>      if(avctx->idct_algo==FF_IDCT_AUTO)
>          avctx->idct_algo=FF_IDCT_VP3;
> @@ -2385,6 +2385,8 @@
>  
>      s->width = get_bits(gb, 16) << 4;
>      s->height = get_bits(gb, 16) << 4;
> +    avctx->width = get_bits_long(gb, 24);
> +    avctx->height = get_bits_long(gb, 24);

is there anything which ensures that the allocated buffer will
be large enough for the picture which gets decoded?

also, avcodec_set_dimensions() should be used


[...]
> Index: libavformat/oggparsetheora.c
> ===================================================================
> --- libavformat/oggparsetheora.c	(revision 8918)
> +++ libavformat/oggparsetheora.c	(working copy)
> @@ -70,13 +70,15 @@
>              return -1;
>          }
>  
> -        st->codec->width = get_bits(&gb, 16) << 4;
> -        st->codec->height = get_bits(&gb, 16) << 4;
> +        st->codec->coded_width = get_bits(&gb, 16) << 4;
> +        st->codec->coded_height = get_bits(&gb, 16) << 4;
> +        st->codec->width = get_bits_long(&gb, 24);
> +        st->codec->height = get_bits_long(&gb, 24);

coded_width=width unless lowres or other decoder side tricks
are used

the allocated buffer always has its w/h rounded up to the next multiple
of 16 with yv12
that is coded_width is not the allocated width (see avcodec_align_dimensions)




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

Many that live deserve death. And some that die deserve life. Can you give
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