[FFmpeg-user] Get fatal error informations

[Moritz Barsnick]

Hello Thibault,

On Wed, Mar 09, 2016 at 16:20:55 +0000, Thibault wrote:

> No, it was -loglevel error but you've helped me to get it. But now I
> understand that ffmpeg is mixing standard output and error output
> which is a problem for me because I need to calculate progression
> using the log.

A good way to parse the progression of conversion is not to take the
console output, but to use the "-progress <file|url>" option instead.

$ ffmpeg -loglevel error -progress myconversion.log [...]

You will see the error message on the console, and you can separately
parse the log file myconversion.log, which has all the values nicely
lined up in variable=value lines, much easier to parse.

I must emphasize that your very old version of ffmpeg probably doesn't
support the "-progress" option. As Carl Eugen pointed out, it may even
have security issues. Please get hold of the latest release, or of a
build of git master, or build it yourself.

Moritz