[FFmpeg-user] Execute several ffmpeg processes concurrently

[Carl Eugen Hoyos]

Miles Chan <morndust <at> gmail.com> writes:

> One of the error is  "Invalid data found when processing input",
> another is ffmpeg process exit with code 1.

Complete, uncut console output of the failing command 
missing.
And please show how the other commands look like.

Carl Eugen