Check for huffman tree building error in vp6 decoder.

[ffmpeg] / libavcodec / vp6.c

diff --git a/libavcodec/vp6.c b/libavcodec/vp6.c
index e6132abeb6528b10a6866d4c66dbcaaa6be2c1a7..31af095e143068234acc0c877ac28513c4aae862 100644 (file)
--- a/libavcodec/vp6.c
+++ b/libavcodec/vp6.c
@@ -215,8 +215,8 @@ static int vp6_huff_cmp(const void *va, const void *vb)
     return (a->count - b->count)*16 + (b->sym - a->sym);
 }
 
-static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
-                                const uint8_t *map, unsigned size, VLC *vlc)
+static int vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
+                               const uint8_t *map, unsigned size, VLC *vlc)
 {
     Node nodes[2*VP6_MAX_HUFF_SIZE], *tmp = &nodes[size];
     int a, b, i;
@@ -231,12 +231,12 @@ static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],
     }
 
     free_vlc(vlc);
-    /* then build the huffman tree accodring to probabilities */
-    ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
-                       FF_HUFFMAN_FLAG_HNODE_FIRST);
+    /* then build the huffman tree according to probabilities */
+    return ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,
+                              FF_HUFFMAN_FLAG_HNODE_FIRST);
 }
 
-static void vp6_parse_coeff_models(VP56Context *s)
+static int vp6_parse_coeff_models(VP56Context *s)
 {
     VP56RangeCoder *c = &s->c;
     VP56Model *model = s->modelp;
@@ -281,15 +281,18 @@ static void vp6_parse_coeff_models(VP56Context *s)
 
     if (s->use_huffman) {
         for (pt=0; pt<2; pt++) {
-            vp6_build_huff_tree(s, model->coeff_dccv[pt],
-                                vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]);
-            vp6_build_huff_tree(s, model->coeff_runv[pt],
-                                vp6_huff_run_map, 9, &s->runv_vlc[pt]);
+            if (vp6_build_huff_tree(s, model->coeff_dccv[pt],
+                                    vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]))
+                return -1;
+            if (vp6_build_huff_tree(s, model->coeff_runv[pt],
+                                    vp6_huff_run_map, 9, &s->runv_vlc[pt]))
+                return -1;
             for (ct=0; ct<3; ct++)
                 for (cg = 0; cg < 6; cg++)
-                    vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
-                                        vp6_huff_coeff_map, 12,
-                                        &s->ract_vlc[pt][ct][cg]);
+                    if (vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],
+                                            vp6_huff_coeff_map, 12,
+                                            &s->ract_vlc[pt][ct][cg]))
+                        return -1;
         }
         memset(s->nb_null, 0, sizeof(s->nb_null));
     } else {
@@ -299,6 +302,7 @@ static void vp6_parse_coeff_models(VP56Context *s)
             for (node=0; node<5; node++)
                 model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);
     }
+    return 0;
 }
 
 static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)