h264_cavlc: check the size of the intra PCM data.

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
gifdec: check that the image dimensions are non-zero

Also add an error message an return a more suitable error code
(INVALIDDATA, not EINVAL);
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
gifdec: convert to bytestream2
h264: check buffer size before accessing it

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
matroskadec: pad EBML_BIN data.

It might be passed to code requiring padding, such as lzo decompression.

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
matroskadec: use correct compression parameters for current track CodecPrivate

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
Signed-off-by: Anton Khirnov <anton@khirnov.net>
motionpixels: clip VLC codes.

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
vc1: fix a memleak.

Happens on a B-frame when neither low_delay nor last_picture_ptr is set
(probably corrupted streams only).

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
avidec: fix a memleak in the dv init code.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
truemotion1: make sure index does not go out of bounds

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org
pcx: round up in bits->bytes conversion in a buffer size check

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable@libav.org