Changes to rd balance and multi-arf bug fix.

2 pass only change to calculation of rd mult based on Q.
Make a small adjustment based on frame type and also
replace adjustment based on iifactor with an one based
on the ambient GF/ARF boost level.

Also fix multi arf bug / issue.

Overall these change give an slight improvement in ssim
but hurt psnr a little.

Change-Id: I5e1751e3ff5390a26f543d7855059e6fbcce105e

vp9/encoder/vp9_encoder.c

@@ -742,9 +742,6 @@ VP9_COMP *vp9_create_compressor(VP9EncoderConfig *oxcf) {
 
   cm->current_video_frame = 0;
 
-  // Set reference frame sign bias for ALTREF frame to 1 (for now)
-  cm->ref_frame_sign_bias[ALTREF_FRAME] = 1;
-
   cpi->gold_is_last = 0;
   cpi->alt_is_last = 0;
   cpi->gold_is_alt = 0;
@@ -2061,6 +2058,22 @@ static void configure_skippable_frame(VP9_COMP *cpi) {
     twopass->stats_in->pcnt_inter - twopass->stats_in->pcnt_motion == 1);
 }
 
+static void set_arf_sign_bias(VP9_COMP *cpi) {
+  VP9_COMMON *const cm = &cpi->common;
+  int arf_sign_bias;
+
+  if ((cpi->pass == 2) && cpi->multi_arf_allowed) {
+    const GF_GROUP *const gf_group = &cpi->twopass.gf_group;
+    arf_sign_bias = cpi->rc.source_alt_ref_active &&
+                    (!cpi->refresh_alt_ref_frame ||
+                     (gf_group->rf_level[gf_group->index] == GF_ARF_LOW));
+  } else {
+    arf_sign_bias =
+      (cpi->rc.source_alt_ref_active && !cpi->refresh_alt_ref_frame);
+  }
+  cm->ref_frame_sign_bias[ALTREF_FRAME] = arf_sign_bias;
+}
+
 static void encode_frame_to_data_rate(VP9_COMP *cpi,
                                       size_t *size,
                                       uint8_t *dest,
@@ -2093,8 +2106,8 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   cpi->zbin_mode_boost = 0;
   cpi->zbin_mode_boost_enabled = 0;
 
-  // Current default encoder behavior for the altref sign bias.
-  cm->ref_frame_sign_bias[ALTREF_FRAME] = cpi->rc.source_alt_ref_active;
+  // Set the arf sign bias for this frame.
+  set_arf_sign_bias(cpi);
 
   // Set default state for segment based loop filter update flags.
   cm->lf.mode_ref_delta_update = 0;

vp9/encoder/vp9_firstpass.c

@@ -2192,14 +2192,6 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
     cpi->refresh_golden_frame = 1;
   }
 
-  {
-    FIRSTPASS_STATS next_frame;
-    if (lookup_next_frame_stats(twopass, &next_frame) != EOF) {
-      twopass->next_iiratio = (int)(next_frame.intra_error /
-                                 DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
-    }
-  }
-
   configure_buffer_updates(cpi);
 
   target_rate = twopass->gf_group.bit_allocation[twopass->gf_group.index];

vp9/encoder/vp9_firstpass.h

@@ -73,7 +73,6 @@ typedef struct {
 
 typedef struct {
   unsigned int section_intra_rating;
-  unsigned int next_iiratio;
   FIRSTPASS_STATS total_stats;
   FIRSTPASS_STATS this_frame_stats;
   const FIRSTPASS_STATS *stats_in;

vp9/encoder/vp9_rd.c

@@ -92,13 +92,6 @@ static void fill_token_costs(vp9_coeff_cost *c,
           }
 }
 
-static const uint8_t rd_iifactor[32] = {
-  4, 4, 3, 2, 1, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0,
-  0, 0, 0, 0, 0, 0, 0, 0,
-};
-
 // Values are now correlated to quantizer.
 static int sad_per_bit16lut[QINDEX_RANGE];
 static int sad_per_bit4lut[QINDEX_RANGE];
@@ -116,15 +109,25 @@ void vp9_init_me_luts() {
   }
 }
 
+static const int rd_boost_factor[16] = {
+  64, 32, 32, 32, 24, 16, 12, 12,
+  8, 8, 4, 4, 2, 2, 1, 0
+};
+static const int rd_frame_type_factor[FRAME_UPDATE_TYPES] = {
+128, 144, 128, 128, 144
+};
+
 int vp9_compute_rd_mult(const VP9_COMP *cpi, int qindex) {
   const int q = vp9_dc_quant(qindex, 0);
-  // TODO(debargha): Adjust the function below.
-  int rdmult = 88 * q * q / 25;
+  int rdmult = 88 * q * q / 24;
+
   if (cpi->pass == 2 && (cpi->common.frame_type != KEY_FRAME)) {
-    if (cpi->twopass.next_iiratio > 31)
-      rdmult += (rdmult * rd_iifactor[31]) >> 4;
-    else
-      rdmult += (rdmult * rd_iifactor[cpi->twopass.next_iiratio]) >> 4;
+    const GF_GROUP *const gf_group = &cpi->twopass.gf_group;
+    const FRAME_UPDATE_TYPE frame_type = gf_group->update_type[gf_group->index];
+    const int boost_index = MIN(15, (cpi->rc.gfu_boost / 100));
+
+    rdmult = (rdmult * rd_frame_type_factor[frame_type]) >> 7;
+    rdmult += ((rdmult * rd_boost_factor[boost_index]) >> 7);
   }
   return rdmult;
 }