slightly more correct spliting of frames

Originally committed as revision 9076 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h261_parser.c

@@ -38,7 +38,7 @@ static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const ui
     for(i=0; i<buf_size && !vop_found; i++){
         state= (state<<8) | buf[i];
         for(j=0; j<8; j++){
-            if(((state>>j)&0xFFFFF) == 0x00010){
+            if(((state>>j)&0xFFFFF0) == 0x000100){
                 vop_found=1;
                 break;
             }
@@ -48,10 +48,10 @@ static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const ui
         for(; i<buf_size; i++){
             state= (state<<8) | buf[i];
             for(j=0; j<8; j++){
-                if(((state>>j)&0xFFFFF) == 0x00010){
+                if(((state>>j)&0xFFFFF0) == 0x000100){
                     pc->frame_start_found=0;
-                    pc->state= state>>(2*8);
-                    return i-1;
+                    pc->state= (state>>(3*8))+0xFF00;
+                    return i-2;
                 }
             }
         }