[FFmpeg-devel] -vf copy does transcode rather than copy

[Reimar Döffinger]

On Thu, Oct 31, 2013 at 08:47:31PM +0100, wm4 wrote:
> On Thu, 31 Oct 2013 14:02:00 -0500
> David Favor <david at davidfavor.com> wrote:
> 
> > -c:v copy maintains SAR + DAR info.
> > 
> > -vf copy should allow (to me) a filter chain of something like...
> > 
> >      -vf copy,setdar=dar=0,setsar=sar=0
> > 
> > which should accomplish the following...
> > 
> >      1) copy the video stream (bit for bit) so no transcode
> > 
> >      2) completely remove SAR + DAR to repair broken videos
> 
> The video filter chain can't handle compressed video (and probably
> never will), so this can't work. You'll need a separate mechanism to
> adjust the aspect ratio.

Which possibly would fall into the domain of different filters,
"bitstream filters".