avcodec/mpegvideo: Make inlining is_mpeg12 more flexible

There are two types of checks for whether the current codec
is MPEG-1/2 in mpv_reconstruct_mb_internal(): Those that are
required for correctness and those that are not; an example
of the latter is "is_mpeg12 || (s->codec_id != AV_CODEC_ID_WMV2)".
The reason for the existence of such checks is that
mpv_reconstruct_mb_internal() has the av_always_inline attribute
and is_mpeg12 is usually inlined, so that in case we are dealing
with MPEG-1/2 the above check can be completely optimized away.

But is_mpeg12 is not always inlined: it is not in case
CONFIG_SMALL is true in which case is_mpeg12 is always zero,
so that the checks required for correctness need to check
out_format explicitly. This is currently done via a macro
in mpv_reconstruct_mb_internal(), so that the fact that
it is CONFIG_SMALL that determines this is encoded at two places.

This commit changes this by making is_mpeg12 a three-state:
DEFINITELY_MPEG12, MAY_BE_MPEG12 and NOT_MPEG12. In the second
case, one has to resort to check out_format, in the other cases
is_mpeg12 can be taken at face-value. This will allow to make
inlining is_mpeg12 more flexible in a future commit.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

0 files changed, 0 insertions, 0 deletions