[Libav-user] installing for Windows

Carl Eugen Hoyos cehoyos at ag.or.at
Mon Nov 26 16:10:39 CET 2012

René J.V. Bertin <rjvbertin at ...> writes:

> >> An ffmpeg that doesn't use the Console subsystem shouldn't 
> >> do this, right?
> > 
> > ffmpeg can only be used from the command line...
> Erm, I beg to differ. That may be the most usual way to 
> launch ffmpeg, but just how many applications are there
> that launch ffmpeg without asking the user to type things 
> onto a command line? On MS Windows, Mac OS X and
> Linux, GUI applications receive their arguments (files 
> dragged onto their icon) via argc/argv (or can at
> least obtain them in a comparable manner).

> Called that way, they run in a limited version of sh or similar,
> with standard input and outputs connected wherever the system decides.

The point I was trying to make was that ffmpeg is made to run 
inside a shell and cannot know that you want to run it "in a limited 
version of sh".

> I have a very basic GUI movie player without a menu or anything, 
> and it receives its arguments exactly that way. If it calls 
> functions in one of my DLLs that contain fprintf(stderr) 
> statements, their output just disappears (on MSWin), rather 
> than causing a CMD window to be opened.

I may misunderstand:
Do you mean your application does it differently than FFmpeg and 
you suggest to do it in FFmpeg like your application or do you 
mean your application uses libavcodec (etc.) and you have 
problems with its output? In this case please note that there are 
no direct calls to printf in libavcodec, you can set av_log 
callbacks to redirect output where you want it.

Carl Eugen

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