avcodec/hapdec : use gray8 for HapAlphaOnly decoding instead of RGB0

[ffmpeg] / libavcodec / snowdec.c

diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c
index 727e908fb5a4997b77b35686a43a68617b015b6b..a9bdb8da5ef0f4279f46fd319e114988d44e0c10 100644 (file)
--- a/libavcodec/snowdec.c
+++ b/libavcodec/snowdec.c
@@ -183,13 +183,22 @@ static int decode_q_branch(SnowContext *s, int level, int x, int y){
         int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
 
         type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
-
         if(type){
+            int ld, cbd, crd;
             pred_mv(s, &mx, &my, 0, left, top, tr);
-            l += get_symbol(&s->c, &s->block_state[32], 1);
+            ld = get_symbol(&s->c, &s->block_state[32], 1);
+            if (ld < -255 || ld > 255) {
+                return AVERROR_INVALIDDATA;
+            }
+            l += ld;
             if (s->nb_planes > 2) {
-                cb+= get_symbol(&s->c, &s->block_state[64], 1);
-                cr+= get_symbol(&s->c, &s->block_state[96], 1);
+                cbd = get_symbol(&s->c, &s->block_state[64], 1);
+                crd = get_symbol(&s->c, &s->block_state[96], 1);
+                if (cbd < -255 || cbd > 255 || crd < -255 || crd > 255) {
+                    return AVERROR_INVALIDDATA;
+                }
+                cb += cbd;
+                cr += crd;
             }
         }else{
             if(s->ref_frames > 1)
@@ -428,6 +437,8 @@ static int decode_blocks(SnowContext *s){
 
     for(y=0; y<h; y++){
         for(x=0; x<w; x++){
+            if (s->c.bytestream >= s->c.bytestream_end)
+                return AVERROR_INVALIDDATA;
             if ((res = decode_q_branch(s, 0, x, y)) < 0)
                 return res;
         }