[SCM] libav/experimental: vp6: ensure that huffman decoding table is sorted with descending symbol order Previous code worked by pure luck with glibc qsort implementation. patch by Peter Ross pross _at_ xvid _dot_ org

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit d47f16074ff4678d0ea968318354fc8ca6e0ba90
Author: Peter Ross <pross at xvid.org>
Date:   Sun Jun 22 13:20:41 2008 +0000

    vp6: ensure that huffman decoding table is sorted with descending symbol order
    Previous code worked by pure luck with glibc qsort implementation.
    patch by Peter Ross   pross _at_ xvid _dot_ org
    
    Originally committed as revision 13887 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/vp6.c b/libavcodec/vp6.c
index 74c62ff..c1cd6fe 100644
--- a/libavcodec/vp6.c
+++ b/libavcodec/vp6.c
@@ -202,10 +202,11 @@ static void vp6_parse_vector_models(vp56_context_t *s)
                 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);
 }
 
+/* nodes must ascend by count, but with descending symbol order */
 static int vp6_huff_cmp(const void *va, const void *vb)
 {
     const Node *a = va, *b = vb;
-    return a->count >= b->count;
+    return (a->count - b->count)*16 + (b->sym - a->sym);
 }
 
 static void vp6_build_huff_tree(vp56_context_t *s, uint8_t coeff_model[],

-- 
Libav/FFmpeg packaging