[FFmpeg-devel] [PATCH] Binary identicity for ffvc1 (was Re: [PATCH] VC-1 MMX DSP functions)

Kostya kostya.shishkov
Thu Jul 19 05:31:34 CEST 2007

On Wed, Jul 18, 2007 at 08:51:00PM +0200, Christophe GISQUET wrote:
> Could someone verify that the C code does decode a wmv video stream to a
> binary identical version of the dll codec output? Maybe VC-1 and WMV9
> have different ways of doing the MC interpolation?
> On a side note, should I have started a new thread? I consider the whole
> stuff very related, so I saw no need to do so.
> One way to test this is (people may come up with much easier solutions):
> - for the dll codec output:
> mplayer <stream>.wmv -fps 24 -nosound -benchmark -vo yuv4mpeg:file=i.y4m
> ffmpeg -i i.y4m -f rawvideo -y ref.yuv && rm i.y4m
> - for ffmpeg output
> ./ffmpeg -i Robotica_720.wmv -an -f rawvideo out.yuv
> The streams may be of different length, but we still easily compare most
> of it by running:
> cmp out.yuv ref.yuv
> If cmp returns EOF on either file without complaining about some byte
> being different, then I believe this is a good evidence that ffvc1
> output is binary identical to the dll codec.

It's problematic to me to verify against binary decoder but I will try to
compare it against reference decoder. If it is okay then I'll apply your patch.
> Best regards,
> -- 
> Christophe GISQUET

More information about the ffmpeg-devel mailing list