[FFmpeg-devel] ffplay and the return values

Stefano Sabatini stefasab at gmail.com
Thu Apr 12 23:37:12 CEST 2012


On date Tuesday 2012-04-10 22:04:36 +0200, Marton Balint encoded:
> On Tue, 10 Apr 2012, Stefano Sabatini wrote:
[...]
> >I suggest to expose these codes, for example you could create an array
> >with extended explanation and an option to tell which code corresponds
> >to which error (-errors?), so the user doesn't need to rely on the
> >source.
> 
> I'd rather put that information into the man page.
> 
> >On the other hand I'm not too confortable with the idea of adopting
> >*application level* error codes and add more complexity/maintainance
> >overhead, and I don't think the user needs *that* level of control on
> >the exit reason.
> 
> Makes sense, probably a NormalExit, UserExit, InitError, OtherError
> and SigTermHandlerError is more than enough for everyday uses.
> 
> >An alternative implementation may simply expose the AVERROR* code to
> >an environment variable (FFPLAY_ERROR, FFPLAY_ERROR_REASON) - or a
> >possibly a more robust system (writing to a .pid file?) in case more
> >instances are run at the same time.
> >
> >Would be that enough for your use case? The application may set
> >$FFPLAY_ERROR to AVERROR_EXIT in case of user-requested early exit
> >(see libavutil/error.h).
> >
> >Another advantage of this approach is that it could be used by the
> >other ff* tools.
> >
> >This also may require to extend the error API in order to expose a tag
> >associated to the error (more portable than using an error code
> >numeric value, which may depend on the platform).
> 
> I think it is a very simple thing what the patch owner wanted, we
> should not overdesign this.

Well I won't object on that, and you're the ffplay maintainer after
all so you have the last word, provided that:
- it is documented somewhere (man page or help option)
- no excessive maintanance/complexity overhead is given

and I agree a few exit codes are better than too many specific ones.

Then we can extend the design if it turns out that it was
*underdesigned* for some specific use cases.
-- 
FFmpeg = Fundamentalist and Faithful Miracolous Patchable Elected Guru


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