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| author | Mans Rullgard <mans@mansr.com> | 2011-10-11 12:58:31 +0100 |
|---|---|---|
| committer | Reinhard Tartler <siretart@tauware.de> | 2012-02-19 15:08:43 +0100 |
| commit | ccb3b71b424680dd4cd1d99002befeed6ac95d00 (patch) | |
| tree | 2c4cc3a83b00711184f8a6e6bd278abbac34d0c4 | |
| parent | 4ed486dc3aff211861dafa23ccec5b37b8bd9e38 (diff) | |
| download | ffmpeg-ccb3b71b424680dd4cd1d99002befeed6ac95d00.tar.gz | |
h264: fix invalid shifts in init_cavlc_level_tab()
The level_code expression includes a shift which is invalid in
those cases where the value is not used. Moving the calculation
to the branch where the result is used avoids these.
Signed-off-by: Mans Rullgard <mans@mansr.com>
(cherry picked from commit 8babfc033ecb6332155c1f8879e54dee41d16952)
Signed-off-by: Anton Khirnov <anton@khirnov.net>
| -rw-r--r-- | libavcodec/h264_cavlc.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c index 497166b423..2661ab2d17 100644 --- a/libavcodec/h264_cavlc.c +++ b/libavcodec/h264_cavlc.c @@ -238,17 +238,18 @@ static inline int pred_non_zero_count(H264Context *h, int n){ } static av_cold void init_cavlc_level_tab(void){ - int suffix_length, mask; + int suffix_length; unsigned int i; for(suffix_length=0; suffix_length<7; suffix_length++){ for(i=0; i<(1<<LEVEL_TAB_BITS); i++){ int prefix= LEVEL_TAB_BITS - av_log2(2*i); - int level_code= (prefix<<suffix_length) + (i>>(LEVEL_TAB_BITS-prefix-1-suffix_length)) - (1<<suffix_length); - mask= -(level_code&1); - level_code= (((2+level_code)>>1) ^ mask) - mask; if(prefix + 1 + suffix_length <= LEVEL_TAB_BITS){ + int level_code = (prefix << suffix_length) + + (i >> (av_log2(i) - suffix_length)) - (1 << suffix_length); + int mask = -(level_code&1); + level_code = (((2 + level_code) >> 1) ^ mask) - mask; cavlc_level_tab[suffix_length][i][0]= level_code; cavlc_level_tab[suffix_length][i][1]= prefix + 1 + suffix_length; }else if(prefix + 1 <= LEVEL_TAB_BITS){ |