[FFmpeg-user] Syntax request for -vf to copy /pass through video stream

[Stefano Sabatini]

On date Thursday 2013-10-31 12:31:59 -0500, David Favor wrote:
> Stefano Sabatini wrote:
> >On date Thursday 2013-10-31 12:20:26 -0500, David Favor wrote:
> >[...]
> >>+ ffmpeg -y -i broken.mp4 -c:a copy -vf copy -vf setdar=dar=0 -vf setsar=sar=0 -t 10 vfcopy.mp4
> >
> >This command is broken in several ways, first you can't copy and
> >filter at the same time, and multiple -vf a -vf b -vf c have the
> >effect of the last -vf command (in this case -vf c).
> >
> >Please understand the meaning of the syntax and that you *CAN'T* copy
> >a stream and filter it at the same time.
> 

> So -v:c copy and -vf copy are effectively the same.

No, you're mixing two different things (and "-v:c" should be "-c:v"),
bitstream copy (to copy a stream from input to output stream with no
decoding and encoding) and copying data at the filtering level
(working with a decoded video stream).

> So there's no real way to copy (bit for bit) a video stream and
> change SAR or DAR...

There is the -aspect command if you want to bitstream-copy and change
the aspect ratio in the output container.
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