[FFmpeg-devel] [PATCH 1/2] ffmpeg: allow to set the thread message queue size.

[Reimar Döffinger]

On Thu, Feb 26, 2015 at 07:56:06PM +0100, Nicolas George wrote:
> Le septidi 7 ventôse, an CCXXIII, Michael Niedermayer a écrit :
> > i think the case i tested had HAVE_W32THREADS set
> > also theres HAVE_OS2THREADS
> 
> I suspect my question was too vague.
> 
> If I understand correctly,
> 
> HAVE_THREADS = HAVE_PTHREADS || HAVE_W32THREADS || HAVE_OS2THREADS
> 
> Am I right?
> 
> My main question is: do we have supported case where we do not HAVE_THREADS
> at all?

What do you consider "supported"?
I haven't tested recently, but BeOS/Haiku used to be able to compile and
back then didn't have pthreads in default install.
There is also the case of someone simply disable threading support, for
example because they want a as small as possible binary and single
threaded decoding is fast enough (e.g. someone using FFmpeg only for
hwaccel doesn't really have much use for thread support).
I don't know much about it, but I suspect some RTOSes will also either
not have thread support or only offer cooperative multithreading (which
is useless for some things), I guess they don't really count as
supported though. Still I wouldn't like making FFmpeg "unnecessarily"
hard to port to a bit unusual systems, at least the core features.