Unbreaks windows systems not providing pkgconf files.
Reported-By: Rafaël Carré <funman@videolan.org>

Signed-off-by: Tim Walker <tdskywalker@gmail.com>

libavcodec/lagarith.c:671:16: warning: '#' flag used with ‘%u’ gnu_printf format [-Wformat]

There is no point in populating NuvContext with another DSPContext.

Also split static and dynamic initialization bits to avoid running the
static initialization parts over and over.

Arch-specific optimizations are handled this way everywhere else.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

This gets rid of aliasing completely unrelated structs to Picture.

Fixes the remaining compilation warnings in the vdpau code.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

The code passed H264Picture* and Picture*, and assumed the
hwaccel_picture_private field was in the same place in both
structs. Somehow this happened to work in Libav, but broke in
FFmpeg (and probably subtly breaks in Libav too).
Signed-off-by: Anton Khirnov <anton@khirnov.net>

This is in line with how the top-level libavcodec Makefile is structured.

This avoids recalculating the value over and over again.

This allows for a more natural macro usage.