Fix SEIs when splitting H264 input.

Patch by John Cox, jc A kynesim D co D uk

Originally committed as revision 18020 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264_parser.c

@@ -70,7 +70,7 @@ int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
             else            state>>=1; //2->1, 1->0, 0->0
         }else if(state<=5){
             int v= buf[i] & 0x1F;
-            if(v==7 || v==8 || v==9){
+            if(v==6 || v==7 || v==8 || v==9){
                 if(pc->frame_start_found){
                     i++;
                     goto found;