diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 2af76199ab..8bbd3a7580 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -79,7 +79,6 @@ static int h263_decode_frame(AVCodecContext *avctx,
 {
     MpegEncContext *s = avctx->priv_data;
     int ret;
-    DCTELEM block[6][64];
     AVPicture *pict = data; 
 
 #ifdef DEBUG
@@ -131,17 +130,17 @@ static int h263_decode_frame(AVCodecContext *avctx,
                 s->c_dc_scale = 8;
             }
 
-            memset(block, 0, sizeof(block));
+            memset(s->block, 0, sizeof(s->block));
             s->mv_dir = MV_DIR_FORWARD;
             s->mv_type = MV_TYPE_16X16; 
             if (s->h263_msmpeg4) {
-                if (msmpeg4_decode_mb(s, block) < 0)
+                if (msmpeg4_decode_mb(s, s->block) < 0)
                     return -1;
             } else {
-                if (h263_decode_mb(s, block) < 0)
+                if (h263_decode_mb(s, s->block) < 0)
                     return -1;
             }
-            MPV_decode_mb(s, block);
+            MPV_decode_mb(s, s->block);
         }
     }
 
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index e9e1e27e1a..326f043863 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -1260,7 +1260,6 @@ static int mpeg_decode_slice(AVCodecContext *avctx,
     Mpeg1Context *s1 = avctx->priv_data;
     MpegEncContext *s = &s1->mpeg_enc_ctx;
     int ret;
-    DCTELEM block[6][64];
 
     start_code = (start_code - 1) & 0xff;
     if (start_code >= s->mb_height)
@@ -1288,14 +1287,14 @@ static int mpeg_decode_slice(AVCodecContext *avctx,
     }
 
     for(;;) {
-        memset(block, 0, sizeof(block));
-        ret = mpeg_decode_mb(s, block);
+        memset(s->block, 0, sizeof(s->block));
+        ret = mpeg_decode_mb(s, s->block);
         dprintf("ret=%d\n", ret);
         if (ret < 0)
             return -1;
         if (ret == 1)
             break;
-        MPV_decode_mb(s, block);
+        MPV_decode_mb(s, s->block);
     }
     
     /* end of slice reached */