Re: Using /dev/stdout in a sandboxed app

Sandor Szatmari


After several rereads I realize that Ffmpeg documentation does state this, but not in clear terms.

It states that any file/stream can be referenced as a pair, <file_no:stream_no>, hence pipe:1 == stdout

It talks about pipe almost within the same breath, but doesn’t explicitly connect the dots and say, to reference stdout/stdin/stderr you literally use the word pipe.

Reference section 2 (Description)


On Jul 9, 2019, at 07:38, Graham Cox <graham@...> wrote:

Ah, that worked a treat!!! Thanks so much Sandor.


On 9 Jul 2019, at 9:21 pm, Sandor Szatmari <> wrote:

I think you would pass

-progress pipe:1 will write out to stdout, 


pipe:2 to stderr.

Then just read from the pipe you associate.

I haven’t tried it myself, google told me to do it.

It might mess up your parsing if other messages are interspersed in the progress messages, but hopefully you can distinguish between the two types of information.  


Join { to automatically receive all group messages.