Prevents subsequent overreads when these numbers are used as indices
in arrays.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
(cherry picked from commit 64953f67

)
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Conflicts:

	libavcodec/qdm2.c