[FFmpeg-devel] [PATCH 2/3] build: rely on pkg-config for libx264 probing

Carl Eugen Hoyos cehoyos at ag.or.at
Thu Aug 21 13:23:41 CEST 2014

Clément Bœsch <u <at> pkh.me> writes:

> > I thought the purpose is to allow educated developers 
> > to use pkg-config while (uneducated) users (like me) 
> > will not understand how this is easier than using 
> > configure parameters.
> Yes, it's also simpler for the users.

Please understand that we disagree on this point.
(It makes no difference though, I already accepted 
that some developers need pkg-config for x264, opus 
and hevc.)

> > > They will also almost never be tested,
> > 
> > I will care about the testing.
> Well, you probably won't test static linking of random 
> libs on various platforms typically.

If you don't allow testing this on your fate 
client, I will have to take care.

> pkg-config makes possible to completely ignore that 
> part since it moves the responsibility away from us.

Completely apart from the fact that we already know 
this doesn't work, I still consider it an undesired 
change of behaviour.

> That said, if you want to support a fallback as I 
> suggested above, it won't work as you expect:

I feel that all this only supports my point that we 
should not rely on pkg-config.
But since you insist, let's ignore the unavoidable 
problems, just make sure that a user who (already) 
knows about --extra-cflags and --extra-ldflags and 
remembers how he custom-compiled his library still 
has a chance to compile FFmpeg with the library 
even if he does not want to rely on pkg-config.

If the build system chooses the wrong one of two 
working libraries, this is the user's problem. 
What I try to avoid is just that the user installs 
a second version of the library because the system 
library doesn't work but cannot select it because 
the configure script blindly trusts the pkg-config 
return value.

Carl Eugen

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