Fix crop filter start_frame() for paletted formats different from

PAL8. Shift data[1] only if the input format is not paletted.

Originally committed as revision 20488 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavfilter/vf_crop.c

@@ -176,7 +176,11 @@ static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
     ref2->data[0] += crop->y * ref2->linesize[0];
     ref2->data[0] += (crop->x * crop->bpp) >> 3;
 
-    if (link->format != PIX_FMT_PAL8) {
+    if (link->format != PIX_FMT_PAL8      &&
+        link->format != PIX_FMT_BGR4_BYTE &&
+        link->format != PIX_FMT_RGB4_BYTE &&
+        link->format != PIX_FMT_BGR8      &&
+        link->format != PIX_FMT_RGB8) {
         for (i = 1; i < 3; i ++) {
             if (ref2->data[i]) {
                 ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];