Add transformation matrix API.

Add AV_PKT_DATA_DISPLAYMATRIX and AV_FRAME_DATA_DISPLAYMATRIX as stream and
frame side data (respectively) to describe a display transformation matrix
for linear transformation operations on the decoded video.

Add functions to easily extract a rotation angle from a matrix and
conversely to setup a matrix for a given rotation angle.

Signed-off-by: Anton Khirnov <anton@khirnov.net>
mov: store display matrix in a stream side data

Signed-off-by: Anton Khirnov <anton@khirnov.net>
display: Include mathematics.h for fallback definition of NAN

This fixes compilation with MSVC.

Signed-off-by: Martin Storsjö <martin@martin.st>
Merge commit 'bddd8cbf68551f6405b2bf77cc3e212af9fbe834'

* commit 'bddd8cbf68551f6405b2bf77cc3e212af9fbe834':
  Add transformation matrix API.

Conflicts:
	libavcodec/avcodec.h
	libavcodec/utils.c
	libavutil/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '853cc025d63ee2539fc0460dab62c5b9a3fd2043'

* commit '853cc025d63ee2539fc0460dab62c5b9a3fd2043':
  mov: store display matrix in a stream side data

Conflicts:
	libavformat/isom.h
	libavformat/mov.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '82fc9f4b38244236a6ca7f946662ca653044a04c'

* commit '82fc9f4b38244236a6ca7f946662ca653044a04c':
  display: Include mathematics.h for fallback definition of NAN

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/pthread_frame: remove unused variable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffmpeg/do_video_stats: fix used timebase

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavc: define STRIDE_ALIGN as 32 when compiling with AVX support

Signed-off-by: James Almer <jamrial@gmail.com>
Reviewed-by: "Ronald S. Bultje" <rsbultje@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/ppc/asm: fix build with ABI v2

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>