New Motion Reference Search

Alternative strategy for finding a list of candidate motion
vectors to use as reference values in mv coding and as
nearest and near.

Sort by sad in vp8_find_best_ref_mvs() rather than just
pick the best. Allow 0,0 as a best ref option but not a
nearest or near unless there are no alternatives.

Encode/Decode verified on at least some clips.

Some commented out experimental and stats code still in place.

Gain over existing code averages about 1% on derf (alll metrics)
with improvement on all clips. Other test results pending.

The entropy coding of the mode (nearest/near etc) still
depends upon and requires the old "findnear" code so
this needs looking at and may provide room for further gains.

Change-Id: I871d7cba1d1c379c4bad9bcccce1fb19c46b8247

1 files changed, 64 insertions, 3 deletions

diff --git a/vp8/encoder/rdopt.c b/vp8/encoder/rdopt.c
index d217f2ffc..d07c2383e 100644
--- a/vp8/encoder/rdopt.c
+++ b/vp8/encoder/rdopt.c
@@ -41,6 +41,10 @@
 #include "vp8/common/seg_common.h"
 #include "vp8/common/pred_common.h"
 
+#if CONFIG_NEW_MVREF
+#include "vp8/common/mvref_common.h"
+#endif
+
 #if CONFIG_RUNTIME_CPU_DETECT
 #define IF_RTCD(x)  (x)
 #else
@@ -2892,9 +2896,10 @@ void setup_buffer_inter(VP8_COMP *cpi, MACROBLOCK *x, int idx, int frame_type,
                         unsigned char *y_buffer[4], unsigned char *u_buffer[4],
                         unsigned char *v_buffer[4]) {
   YV12_BUFFER_CONFIG *yv12 = &cpi->common.yv12_fb[idx];
+  MACROBLOCKD *xd = &x->e_mbd;
 
-  vp8_find_near_mvs(&x->e_mbd, x->e_mbd.mode_info_context,
-                    x->e_mbd.prev_mode_info_context,
+  vp8_find_near_mvs(xd, xd->mode_info_context,
+                    xd->prev_mode_info_context,
                     &frame_nearest_mv[frame_type], &frame_near_mv[frame_type],
                     &frame_best_ref_mv[frame_type], frame_mdcounts[frame_type],
                     frame_type, cpi->common.ref_frame_sign_bias);
@@ -2902,8 +2907,27 @@ void setup_buffer_inter(VP8_COMP *cpi, MACROBLOCK *x, int idx, int frame_type,
   y_buffer[frame_type] = yv12->y_buffer + recon_yoffset;
   u_buffer[frame_type] = yv12->u_buffer + recon_uvoffset;
   v_buffer[frame_type] = yv12->v_buffer + recon_uvoffset;
+
 #if CONFIG_NEWBESTREFMV
-  vp8_find_best_ref_mvs(&x->e_mbd, y_buffer[frame_type],
+#if CONFIG_NEW_MVREF
+  // Update stats on relative distance of chosen vector to the
+  // possible best reference vectors.
+  {
+    MB_MODE_INFO * mbmi = &xd->mode_info_context->mbmi;
+
+    find_mv_refs(xd, xd->mode_info_context,
+                 xd->prev_mode_info_context,
+                 frame_type,
+                 mbmi->ref_mvs[frame_type],
+                 cpi->common.ref_frame_sign_bias );
+
+    // Copy over the mv candidates
+    vpx_memcpy(xd->ref_mv, mbmi->ref_mvs[frame_type],
+              (MAX_MV_REFS * sizeof(int_mv)) );
+  }
+#endif
+
+  vp8_find_best_ref_mvs(xd, y_buffer[frame_type],
                         yv12->y_stride,
                         &frame_best_ref_mv[frame_type],
                         &frame_nearest_mv[frame_type],
@@ -3407,6 +3431,43 @@ void vp8_rd_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int
             d->bmi.as_mv.first.as_int = tmp_mv.as_int;
             frame_mv[NEWMV][refs[0]].as_int = d->bmi.as_mv.first.as_int;
 
+#if CONFIG_NEW_MVREF
+            // Update stats on relative distance of chosen vector to the
+            // possible best reference vectors.
+            {
+              unsigned int distance;
+              MV_REFERENCE_FRAME ref = mbmi->ref_frame;
+              int_mv selected_best_ref;
+              unsigned int best_index = 0;
+
+              find_mv_refs(xd, xd->mode_info_context,
+                           xd->prev_mode_info_context,
+                           ref,
+                           mbmi->ref_mvs[ref],
+                           cpi->common.ref_frame_sign_bias );
+
+              distance = mv_distance(&tmp_mv, &best_ref_mv);
+              cpi->mv_ref_sum_distance[ref][CUR_BEST] += distance;
+
+              distance =
+                mv_distance(&tmp_mv,
+                            &mbmi->ref_mvs[ref][0]);
+              cpi->mv_ref_sum_distance[ref][NEW_BEST] += distance;
+
+              best_index = pick_best_mv_ref(tmp_mv, mbmi->ref_mvs[ref],
+                                            &selected_best_ref);
+
+              distance = mv_distance(&tmp_mv, &selected_best_ref);
+              mbmi->mv_ref_index[ref] = best_index;
+              cpi->mv_ref_sum_distance[ref][BEST_SELECTED] += distance;
+              cpi->best_ref_index_counts[best_index]++;
+
+              // Temp
+              //mbmi->mv_ref_index[ref] = 0;
+              //mbmi->ref_mvs[ref][0].as_int = best_ref_mv.as_int;
+            }
+#endif
+
             // Add the new motion vector cost to our rolling cost variable
             rate2 += vp8_mv_bit_cost(&tmp_mv, &best_ref_mv,
                                      XMVCOST, 96,