From e30781ff80d931bc113a2dcb6970b1760c1feb1e Mon Sep 17 00:00:00 2001
From: Marco <marpan@google.com>
Date: Fri, 26 May 2017 11:36:45 -0700
Subject: [PATCH] vp9: SVC: Force subpel search off under certain conditions.

For SVC 1 pass non-rd mode:
Force subpel seach off for SVC for non-reference frames
under motion threshold.

Add flag to svc context to indicate if the frame is not used
as a reference.

Little/no quaity loss, ~2% speedup.

Change-Id: Ic433c44b514d19d08b28f80ff05231dc943b28e9
---
 vp9/encoder/vp9_pickmode.c         | 8 +++++++-
 vp9/encoder/vp9_speed_features.c   | 6 +++++-
 vp9/encoder/vp9_svc_layercontext.c | 7 +++++++
 vp9/encoder/vp9_svc_layercontext.h | 1 +
 4 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/vp9/encoder/vp9_pickmode.c b/vp9/encoder/vp9_pickmode.c
index b05f4184b..28d6a493d 100644
--- a/vp9/encoder/vp9_pickmode.c
+++ b/vp9/encoder/vp9_pickmode.c
@@ -158,6 +158,7 @@ static int combined_motion_search(VP9_COMP *cpi, MACROBLOCK *x,
   const MvLimits tmp_mv_limits = x->mv_limits;
   int rv = 0;
   int cost_list[5];
+  int search_subpel = 1;
   const YV12_BUFFER_CONFIG *scaled_ref_frame =
       vp9_get_scaled_ref_frame(cpi, ref);
   if (scaled_ref_frame) {
@@ -210,7 +211,12 @@ static int combined_motion_search(VP9_COMP *cpi, MACROBLOCK *x,
   rv =
       !(RDCOST(x->rdmult, x->rddiv, (*rate_mv + rate_mode), 0) > best_rd_sofar);
 
-  if (rv) {
+  // For SVC on non-reference frame, avoid subpel for (0, 0) motion.
+  if (cpi->use_svc && cpi->svc.non_reference_frame) {
+    if (mvp_full.row == 0 && mvp_full.col == 0) search_subpel = 0;
+  }
+
+  if (rv && search_subpel) {
     const int subpel_force_stop = cpi->sf.mv.subpel_force_stop;
     cpi->find_fractional_mv_step(
         x, &tmp_mv->as_mv, &ref_mv, cpi->common.allow_high_precision_mv,
diff --git a/vp9/encoder/vp9_speed_features.c b/vp9/encoder/vp9_speed_features.c
index 011be9710..cf8f0c1be 100644
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -534,7 +534,11 @@ static void set_rt_speed_feature_framesize_independent(
     if (cpi->svc.temporal_layer_id > 0) {
       sf->adaptive_rd_thresh = 4;
       sf->limit_newmv_early_exit = 0;
-      sf->mv.subpel_force_stop = (cpi->svc.temporal_layer_id == 1) ? 1 : 2;
+      // Use 1/2-pel for non-reference frame.
+      if (cpi->svc.non_reference_frame)
+        sf->mv.subpel_force_stop = 2;
+      else
+        sf->mv.subpel_force_stop = 1;
       sf->base_mv_aggressive =
           (cpi->svc.temporal_layer_id == cpi->svc.number_temporal_layers - 1)
               ? 1
diff --git a/vp9/encoder/vp9_svc_layercontext.c b/vp9/encoder/vp9_svc_layercontext.c
index 5867a6c38..71aa82065 100644
--- a/vp9/encoder/vp9_svc_layercontext.c
+++ b/vp9/encoder/vp9_svc_layercontext.c
@@ -36,6 +36,7 @@ void vp9_init_layer_context(VP9_COMP *const cpi) {
   svc->scaled_temp_is_alloc = 0;
   svc->scaled_one_half = 0;
   svc->current_superframe = 0;
+  svc->non_reference_frame = 0;
   for (i = 0; i < REF_FRAMES; ++i) svc->ref_frame_index[i] = -1;
   for (sl = 0; sl < oxcf->ss_number_layers; ++sl) {
     svc->ext_frame_flags[sl] = 0;
@@ -677,6 +678,12 @@ int vp9_one_pass_cbr_svc_start_layer(VP9_COMP *const cpi) {
     }
   }
 
+  cpi->svc.non_reference_frame = 0;
+  if (cpi->common.frame_type != KEY_FRAME && !cpi->ext_refresh_last_frame &&
+      !cpi->ext_refresh_golden_frame && !cpi->ext_refresh_alt_ref_frame) {
+    cpi->svc.non_reference_frame = 1;
+  }
+
   if (vp9_set_size_literal(cpi, width, height) != 0)
     return VPX_CODEC_INVALID_PARAM;
 
diff --git a/vp9/encoder/vp9_svc_layercontext.h b/vp9/encoder/vp9_svc_layercontext.h
index d8e6772b2..4e8aaf73f 100644
--- a/vp9/encoder/vp9_svc_layercontext.h
+++ b/vp9/encoder/vp9_svc_layercontext.h
@@ -87,6 +87,7 @@ typedef struct {
   int ref_frame_index[REF_FRAMES];
   int force_zero_mode_spatial_ref;
   int current_superframe;
+  int non_reference_frame;
   int use_base_mv;
   // Used to control the downscaling filter for source scaling, for 1 pass CBR.
   // downsample_filter_phase: = 0 will do sub-sampling (no weighted average),
-- 
2.40.0