lavc/tiff: Don't apply strips-related logic to tiled images

Signed-off-by: Nick Renieris <velocityra@gmail.com>

libavcodec/tiff.c

@@ -1790,7 +1790,7 @@ again:
         }
     }
 
-    if (!s->strippos && !s->stripoff) {
+    if (!s->is_tiled && !s->strippos && !s->stripoff) {
         av_log(avctx, AV_LOG_ERROR, "Image data is missing\n");
         return AVERROR_INVALIDDATA;
     }
@@ -1798,6 +1798,7 @@ again:
     if ((ret = init_image(s, &frame)) < 0)
         return ret;
 
+    if (!s->is_tiled) {
         if (s->strips == 1 && !s->stripsize) {
             av_log(avctx, AV_LOG_WARNING, "Image data size missing\n");
             s->stripsize = avpkt->size - s->stripoff;
@@ -1820,6 +1821,7 @@ again:
             av_log(avctx, AV_LOG_ERROR, "rps %d invalid\n", s->rps);
             return AVERROR_INVALIDDATA;
         }
+    }
 
     /* Handle DNG images with JPEG-compressed tiles */