ivi_common: Make sure color planes have been initialized

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
(cherry picked from commit a92538b7c0defc86c55fb91f55dfa36aad192673)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit 38bd229af9c4fa5897fc1a69e73a04c55f78647f)
mpeg4videodec: Check the width/height in mpeg4_decode_sprite_trajectory

This avoids a potential division by zero.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
(cherry picked from commit f875a732e36786d49f3650e3235272891a820600)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
(cherry picked from commit c8c93795e4afd04c2c5b74e29e8dec29b6a76b81)