Don't reject invalid warped motion model

Fallback to default warp params instead.
The extra assignment to DEFAULT_WMTYPE prevents an assertion.

Change-Id: If21a46cbb4cc9761e5c94bd2fcbc3a06342d677d

av1/decoder/decodemv.c

@@ -2729,7 +2729,9 @@ static void read_inter_block_mode_info(AV1Decoder *const pbi,
     if (find_projection(mbmi->num_proj_ref[0], pts, pts_inref, bsize,
                         mbmi->mv[0].as_mv.row, mbmi->mv[0].as_mv.col,
                         &mbmi->wm_params[0], mi_row, mi_col)) {
-      aom_internal_error(&cm->error, AOM_CODEC_ERROR, "Invalid Warped Model");
+      // Invalid warped model, fallback to default
+      mbmi->wm_params[0] = default_warp_params;
+      mbmi->motion_mode = SIMPLE_TRANSLATION;
     }
   }
 #endif  // CONFIG_WARPED_MOTION