avcodec/options_table: leave xvidmmx AVOption in place

Also mark it as deprecated through its help text

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
hevc_ps: verify P/T/L information

This makes the SPS parsing a little, but barely, safer.

Reviewed-by: Mickaël Raulet <mraulet@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
lavf/img2dec: Initialize a stack variable.

Fixes a valgrind warning about using unitialised memory.
Hopefully fixes crashes on several platforms reported through fate.