* commit '82fc9f4b38244236a6ca7f946662ca653044a04c':
display: Include mathematics.h for fallback definition of NAN
Merged-by: Michael Niedermayer <michaelni@gmx.at>
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>