mxfdec: minor simplification.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
indeo2: move variable declarations into blocks using them.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
h264_i386: Optimize decode_significance_8x8_x86 for 64 bit.

11674 -> 10877 decicycles on my Phenom II.
Overall speedup was unfortunately within measurement error.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
h264_mb: Use smaller data type for refs in await_references.

As far as I can tell the value can never go outside
the int16_t type.
And especially the cost of the initialization is
reduced quite a bit by making it smaller.
Overall decoding speedup not measurable though.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
avcodec/libspeexdec: make array const

Found-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>