[FFmpeg-user] Add a silent audio stream if no audio stream exists

[Michael Koch]

Am 11.11.2020 um 21:59 schrieb Jim DeLaHunt:
>
> 2. Generate a more elaborate FFmpeg invocation which will generate 
> silent audio streams for input files which have none. The details of 
> this should be in a separate thread with a separate Subject: line.
>

That's an interesting question. Can this be done in one command line?
If the input video has an audio stream, then leave it as it is. If no 
audio stream exists, then add silent audio.

Michael