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| author | Ronald S. Bultje <rsbultje@gmail.com> | 2012-03-08 17:09:27 -0800 |
|---|---|---|
| committer | Ronald S. Bultje <rsbultje@gmail.com> | 2012-03-10 12:03:53 -0800 |
| commit | 442c3a8cb1785d74f8e2d7ab35b1862b7088436b (patch) | |
| tree | 831579a42b9c2712a5903f1153281ea0800b00cc /libavcodec | |
| parent | 71af42bd964313b3869cdd8a8c0fb97a9ee90d49 (diff) | |
| download | ffmpeg-442c3a8cb1785d74f8e2d7ab35b1862b7088436b.tar.gz | |
cook: expand dither_tab[], and make sure indexes into it don't overflow.
Fixes overflows in accessing dither_tab[].
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/cook.c | 6 | ||||
| -rw-r--r-- | libavcodec/cookdata.h | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/libavcodec/cook.c b/libavcodec/cook.c index 65e16e4077..41ce0e528e 100644 --- a/libavcodec/cook.c +++ b/libavcodec/cook.c @@ -507,7 +507,11 @@ static inline void expand_category(COOKContext *q, int *category, { int i; for (i = 0; i < q->num_vectors; i++) - ++category[category_index[i]]; + { + int idx = category_index[i]; + if (++category[idx] >= FF_ARRAY_ELEMS(dither_tab)) + --category[idx]; + } } /** diff --git a/libavcodec/cookdata.h b/libavcodec/cookdata.h index 126010a985..c4c26fae5f 100644 --- a/libavcodec/cookdata.h +++ b/libavcodec/cookdata.h @@ -36,8 +36,8 @@ static const int expbits_tab[8] = { 52,47,43,37,29,22,16,0, }; -static const float dither_tab[8] = { - 0.0, 0.0, 0.0, 0.0, 0.0, 0.176777, 0.25, 0.707107, +static const float dither_tab[9] = { + 0.0, 0.0, 0.0, 0.0, 0.0, 0.176777, 0.25, 0.707107, 1.0 }; static const float quant_centroid_tab[7][14] = { |