vp9-resize: Force reference masking off for external dynamic-resizing.

An issue exists with reference_masking in non-rd pickmode for spatial
scaling. It was kept off for internal dynamic resizing and svc, this
change is to keep it off also for external dynamic resizing.

Update to external resize test, and update TODO to re-enable this
at frame level when references have same scale as source.

Change-Id: If880a643572127def703ee5b2d16fd41bdbf256c

test/resize_test.cc

diff --git a/test/resize_test.cc b/test/resize_test.cc
index 10f7fe2..c5f05f3 100644
--- a/test/resize_test.cc
+++ b/test/resize_test.cc
@@ -387,6 +387,8 @@
 TEST_P(ResizeRealtimeTest, TestExternalResizeWorks) {
   ResizingVideoSource video;
   DefaultConfig();
+  // Disable internal resize for this test.
+  cfg_.rc_resize_allowed = 0;
   change_bitrate_ = false;
   ASSERT_NO_FATAL_FAILURE(RunLoop(&video));
 

vp9/encoder/vp9_encoder.c

diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index bd9813a..ff176fb 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -1525,6 +1525,7 @@
   if (last_w != cpi->oxcf.width || last_h != cpi->oxcf.height) {
     cm->width = cpi->oxcf.width;
     cm->height = cpi->oxcf.height;
+    cpi->external_resize = 1;
   }
 
   if (cpi->initial_width) {
@@ -1536,6 +1537,7 @@
       alloc_compressor_data(cpi);
       realloc_segmentation_maps(cpi);
       cpi->initial_width = cpi->initial_height = 0;
+      cpi->external_resize = 0;
     }
   }
   update_frame_size(cpi);
@@ -1671,6 +1673,7 @@
 
   cpi->use_svc = 0;
   cpi->resize_state = 0;
+  cpi->external_resize = 0;
   cpi->resize_avg_qp = 0;
   cpi->resize_buffer_underflow = 0;
   cpi->use_skin_detection = 0;

vp9/encoder/vp9_encoder.h

diff --git a/vp9/encoder/vp9_encoder.h b/vp9/encoder/vp9_encoder.h
index 838ceac..c486ac2 100644
--- a/vp9/encoder/vp9_encoder.h
+++ b/vp9/encoder/vp9_encoder.h
@@ -488,6 +488,7 @@
 
   int resize_pending;
   int resize_state;
+  int external_resize;
   int resize_scale_num;
   int resize_scale_den;
   int resize_avg_qp;

vp9/encoder/vp9_speed_features.c

diff --git a/vp9/encoder/vp9_speed_features.c b/vp9/encoder/vp9_speed_features.c
index b4f20fc..8a34fd9 100644
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -303,11 +303,13 @@
                                  FLAG_SKIP_INTRA_LOWVAR;
     sf->adaptive_pred_interp_filter = 2;
 
-    // Disable reference masking if using spatial scaling since
-    // pred_mv_sad will not be set (since vp9_mv_pred will not
-    // be called).
-    // TODO(marpan/agrange): Fix this condition.
-    sf->reference_masking = (cpi->oxcf.resize_mode != RESIZE_DYNAMIC &&
+    // Disable reference masking if using spatial scaling or for dynamic
+    // resizing (internal or external) since pred_mv_sad will not be set
+    // (since vp9_mv_pred will not be called).
+    // TODO(marpan): Fix this condition to allow reference masking for when
+    // all references have same resolution as source frame.
+    sf->reference_masking = (cpi->external_resize == 0 &&
+                             cpi->oxcf.resize_mode != RESIZE_DYNAMIC &&
                              cpi->svc.number_spatial_layers == 1) ? 1 : 0;
 
     sf->disable_filter_search_var_thresh = 50;