h264: fix ff_generate_sliding_window_mmcos() prototype.

It's been returning an error value since
bad446e251405dc250c3cbee199072e083a1e4b9

Also check for the errors it returns.
(cherry picked from commit ea382767ad2191acbe97e90624059723e15f0e4b)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avf_showwaves: fix null pointer dereference

Found-by: durandal_1707
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit e4eebc2da9da886e1bdf87d29e9a4c5b55111036)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
h264/ff_generate_sliding_window_mmcos: fix use of uninitialized variable

Fixes CID968587
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 3fba3e79a3e46d7611817f9051b33885eb1ff962)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
h264: print mismatching opcode details in check_opcodes()

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit dcbe15813ed09cf491e75a21cce0e751f5bc2b34)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
h264: fix use of uninitialized variable

Fixed CID968588

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit fc86f88b32a288b252a088ee3c77b4f6219d54d5)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>