[Ffmpeg-devel] DAR and SAR FFmpeg option confusion

[Roman Shaposhnik]

Hi,

On Mon, 2007-03-12 at 15:32 +0000, Robert Swain wrote:
> > i'm not sure the one in utils.c should exist (if it is triggered, i'm
> > not sure it will lead to a good behavior)...
> > to verify this, you can try to use -vaspect option, which should use the
> > option in utils.c, and not the one in ffmpeg.c
> > there must also be a static in ffmepg.c to handle the aspect ratio,
> > which you should not use to set encoder param if you use -vaspect, too...
> 
> I'm encoding to x264 and I wrote the code in libavcodec/x264.c to use:
> 
> 192:    x4->params.vui.i_sar_width = avctx->sample_aspect_ratio.num;
> 193:    x4->params.vui.i_sar_height = avctx->sample_aspect_ratio.den;
> 
> I haven't done any print debugging but looking at the SAR reported by x264, 
> these values are not affected by -vaspect, grepping for vaspect in the code 
> returns no results and it isn't documented anywhere yet ffmpeg doesn't report 
> any unrecognised option error. :/

  I have the same issue with DV (not being able to use SAR for real) so
if you ever figure this out -- there'll be at least two clients for the
functionality.

Thanks,
Roman.