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| author | Michael Niedermayer <michaelni@gmx.at> | 2011-11-12 01:40:37 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2011-11-12 03:02:49 +0100 |
| commit | 35fd7b2968834c5994bfd2a93edfbf0dea5e667e (patch) | |
| tree | 01755b951e3793e494c06ab8c3ac8729de47d9e5 /libavcodec/vble.c | |
| parent | c5e55e214cffc68641ec05fdf5a853df230ccfeb (diff) | |
| download | ffmpeg-35fd7b2968834c5994bfd2a93edfbf0dea5e667e.tar.gz | |
vble: use LUT for vble_read_reverse_unary()
slightly faster
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec/vble.c')
| -rw-r--r-- | libavcodec/vble.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/libavcodec/vble.c b/libavcodec/vble.c index b758e23d61..5f78e6a198 100644 --- a/libavcodec/vble.c +++ b/libavcodec/vble.c @@ -40,11 +40,21 @@ typedef struct { static uint8_t vble_read_reverse_unary(GetBitContext *gb) { + static const uint8_t LUT[256] = { + 8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + 5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0, + }; /* At most we need to read 9 bits total to get indices up to 8 */ int val = show_bits(gb, 8); if (val) { - val = 7 - av_log2_16bit(av_reverse[val]); + val = LUT[val]; skip_bits(gb, val + 1); return val; } else { |