[FFmpeg-user] Integration of ffmpeg

[Carl Zwanzig]

On 8/17/2021 12:45 AM, Phil Rhodes via ffmpeg-user wrote:
> I can't remember what the solution was, but I seem to recall that it was
> something to do with the fact that ffmpeg writes most of its status
> information not to standard output, but to standard error, presumably so
> as to keep standard output free for the media data it's producing.
I should have thought about that myself- lots of subprocess implementations 
assume that anything written to stderr is an actual error message and 
terminates the subprocess, and that may appear as a 'hang'. At least in tcl, 
you can use -ignorestderr to prevent this behavior or redirect stderr into 
stdout by ending the exec command with '2>@1' (or both).

Later,

z!