[FFmpeg-user] time padding when muxing

[Robin Gareus]

On 08/22/2012 09:36 AM, Nicolas George wrote:
> Le sextidi 6 fructidor, an CCXX, Robin Gareus a écrit :
>> Suppose I have a 1 minute video and a 2 minute audio track.
>>
>> I want a muxed version:
>>   20 sec black,  the 1 min video, 40 sec black
>> along with the 2min audio-track.
>>
>> Is this possible using a single command?
> 
> With the color video source and the concat video filter, it seems quite
> easy:
> 
> ffmpeg -i video.mkv -i audio.wav -vf "
> color=c=black:s=${SIZ}:d=20 [pre] ;
> color=c=black:s=${SIZ}:d=40 [post] ;
> [pre] [in] [post] concat=n=3" output.mkv
> 

Thanks! That looks cute.
I'm still on ffmpeg-0.10 (from debian-multimedia), though. The
color-filter syntax is different and it does not include the concat filter..

I'd still need to parse the size beforehand. Can ffmpeg expose that as
variables %w %h, or something?

Cheers!
robin