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

[David Favor]

Stefano Sabatini wrote:
> 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).

According to http://ffmpeg.org/ffmpeg.html there is only -c:v (codec video).
There is no -v:c... so this is correct...

ffmpeg -y -i broken.mp4 -c:v copy -c:a copy -t 10 foo.mp4

and this is incorrect...

ffmpeg -y -i broken.mp4 -v:c copy -c:a copy -t 10 foo.mp4 (which produces...)
Invalid loglevel "copy". Possible levels are numbers or:
"quiet"
"panic"
"fatal"
"error"
"warning"
"info"
"verbose"
"debug"

>> 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.

Doing something like the following has no effect on SAR + DAR...

ffmpeg -y -i broken.mp4 -c:a copy -c:v copy -aspect 16:9 -t 10 foo.mp4

[SAR 64757:64800 DAR 319:180] is same in both input + output video, so
container aspect ratio [SAR] has not been effected.

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