[FFmpeg-devel] [RFC][PATCH] Allow include files to be installed into subdirectory

[Ivan Kalvachev]

On 8/13/14, Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:
> On 12.08.2014, at 02:21, Ivan Kalvachev <ikalvachev at gmail.com> wrote:
>> It would be decided by the gcc -I inclusion option.
>> It modifies the search paths for header files, so that it checks these
>> paths before the system/default ones (When using `#include
>> "libavcodec/avcodec.h" `)
>>
>> Libav headers are probably going to remain in the default /usr/include/ .
>> Usually this should not be a problem, unless a program uses `#include
>> <libavcodec/avcodec.h> ` that should be used for system headers (aka
>> checks the system/default paths first).
>
> Huh? The only difference between "" and <> is that "" also searches relative
> to the file's directory (and that first).
> -I applies equally to all.

My bad, I must have combined wrongly two separate peaces of information.

Reading this http://gcc.gnu.org/onlinedocs/cpp/Search-Path.html also
says I'm wrong about the -I/usr/include . Since it is a system
directory the option would be removed/ignored, to ensure the system
headers are included last.

So basically there is no problem at all with the header files.
We could have non-conflicting -dev packages.

> Anyone adding -I/usr/include explicitly deserves some beating.

I think that FFmpeg/Libav pkgconfig files do this, if installed in
--prefix=/usr .