[FFmpeg-user] adding black silence (for commercial break)

[johnd]

On Sat, Jan 12, 2013 at 01:15:20AM +0000, Carl Eugen Hoyos wrote:
> johnd <john <at> jjdev.com> writes:
> 
> > I've tried the following and  my blank video is not 
> > correct and the concat stuff doesn't work (the ending 
> > file is small)
> 
> Please add the complete, uncut console output (together 
> with the command line) for the failing step (and please 
> explain more verbose what goes wrong).
> 

Can I start over with a new question?  How do I generate a black
silent video that I can concat with an existing video?