modplug is a C++ library (including a C API). So we need the C++ linker,
at least when linking statically.

Signed-off-by: Pierre d'Herbemont <pdherbemont@free.fr>

This saves (from my test) more than 5 frames per seconds during live resize.

To convert from 4-bits to 8-bits channel, one should multiply by 17.
Acked-by: Antoine Cellerier <dionoea@videolan.org>

(not on some specific operating system)
Pointed-out-by: Ramiro Polla <ramiro.polla@gmail.com>

Don't force an explicit --disable-libva. This was especially silly on
non-libVA platforms.

Signed-off-by: Christophe Mutricy <xtophe@videolan.org>

Signed-off-by: Christophe Mutricy <xtophe@videolan.org>

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Use pkg-config to check for libmodplug, and check for version >= 0.8, which is needed for some functions like ModPlug_NumSamples(), ModPlug_GetMessage(), ModPlug_NumInstruments(), etc...
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

The check for presence has already done in configure.ac

It now autodetects the presence of libVA pkg:
It will fail if --enable-libva is defined and it is not present
It will be activated if nothing is specified and libVA pkg is present

Moreover, it will check the presence of the avcodec/libva.h