libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_firstpass.c

Index: source/libvpx/vp9/encoder/vp9_firstpass.c
===================================================================
--- source/libvpx/vp9/encoder/vp9_firstpass.c	(revision 292072)
+++ source/libvpx/vp9/encoder/vp9_firstpass.c	(working copy)
@@ -35,26 +35,28 @@
 #include "vp9/encoder/vp9_rd.h"
 #include "vp9/encoder/vp9_variance.h"
 
-#define OUTPUT_FPF 0
+#define OUTPUT_FPF          0
+#define ARF_STATS_OUTPUT    0
 
-#define IIFACTOR   12.5
-#define IIKFACTOR1 12.5
-#define IIKFACTOR2 15.0
-#define RMAX       512.0
-#define GF_RMAX    96.0
-#define ERR_DIVISOR   150.0
-#define MIN_DECAY_FACTOR 0.1
-#define SVC_FACTOR_PT_LOW 0.45
-#define FACTOR_PT_LOW 0.5
-#define FACTOR_PT_HIGH 0.9
+#define BOOST_FACTOR        12.5
+#define ERR_DIVISOR         100.0
+#define FACTOR_PT_LOW       0.5
+#define FACTOR_PT_HIGH      0.9
+#define FIRST_PASS_Q        10.0
+#define GF_MAX_BOOST        96.0
+#define INTRA_MODE_PENALTY  1024
+#define KF_MAX_BOOST        128.0
+#define MIN_DECAY_FACTOR    0.01
+#define MIN_GF_INTERVAL     4
+#define MIN_KF_BOOST        300
+#define NEW_MV_MODE_PENALTY 32
+#define SVC_FACTOR_PT_LOW   0.45
 
-#define KF_MB_INTRA_MIN 150
-#define GF_MB_INTRA_MIN 100
-
 #define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x) - 0.000001 : (x) + 0.000001)
 
-#define MIN_KF_BOOST        300
-#define MIN_GF_INTERVAL     4
+#if ARF_STATS_OUTPUT
+unsigned int arf_count = 0;
+#endif
 
 static void swap_yv12(YV12_BUFFER_CONFIG *a, YV12_BUFFER_CONFIG *b) {
   YV12_BUFFER_CONFIG temp = *a;
@@ -62,8 +64,8 @@
   *b = temp;
 }
 
-static int gfboost_qadjust(int qindex) {
-  const double q = vp9_convert_qindex_to_q(qindex);
+static int gfboost_qadjust(int qindex, vpx_bit_depth_t bit_depth) {
+  const double q = vp9_convert_qindex_to_q(qindex, bit_depth);
   return (int)((0.00000828 * q * q * q) +
                (-0.0055 * q * q) +
                (1.32 * q) + 79.3);
@@ -297,9 +299,9 @@
   MV tmp_mv = {0, 0};
   MV ref_mv_full = {ref_mv->row >> 3, ref_mv->col >> 3};
   int num00, tmp_err, n;
-  const BLOCK_SIZE bsize = xd->mi[0]->mbmi.sb_type;
+  const BLOCK_SIZE bsize = xd->mi[0].src_mi->mbmi.sb_type;
   vp9_variance_fn_ptr_t v_fn_ptr = cpi->fn_ptr[bsize];
-  const int new_mv_mode_penalty = 256;
+  const int new_mv_mode_penalty = NEW_MV_MODE_PENALTY;
 
   int step_param = 3;
   int further_steps = (MAX_MVSEARCH_STEPS - 1) - step_param;
@@ -360,11 +362,11 @@
   }
 }
 
-static int find_fp_qindex() {
+static int find_fp_qindex(vpx_bit_depth_t bit_depth) {
   int i;
 
   for (i = 0; i < QINDEX_RANGE; ++i)
-    if (vp9_convert_qindex_to_q(i) >= 30.0)
+    if (vp9_convert_qindex_to_q(i, bit_depth) >= FIRST_PASS_Q)
       break;
 
   if (i == QINDEX_RANGE)
@@ -414,7 +416,7 @@
   int mvcount = 0;
   int intercount = 0;
   int second_ref_count = 0;
-  int intrapenalty = 256;
+  const int intrapenalty = INTRA_MODE_PENALTY;
   int neutral_count = 0;
   int new_mv_count = 0;
   int sum_in_vectors = 0;
@@ -434,44 +436,54 @@
   vp9_clear_system_state();
 
   set_first_pass_params(cpi);
-  vp9_set_quantizer(cm, find_fp_qindex());
+  vp9_set_quantizer(cm, find_fp_qindex(cm->bit_depth));
 
   if (lc != NULL) {
-    MV_REFERENCE_FRAME ref_frame = LAST_FRAME;
     twopass = &lc->twopass;
 
-    if (cpi->common.current_video_frame == 0) {
-      cpi->ref_frame_flags = 0;
+    cpi->lst_fb_idx = cpi->svc.spatial_layer_id;
+    cpi->ref_frame_flags = VP9_LAST_FLAG;
+
+    if (cpi->svc.number_spatial_layers + cpi->svc.spatial_layer_id <
+        REF_FRAMES) {
+      cpi->gld_fb_idx =
+          cpi->svc.number_spatial_layers + cpi->svc.spatial_layer_id;
+      cpi->ref_frame_flags |= VP9_GOLD_FLAG;
+      cpi->refresh_golden_frame = (lc->current_video_frame_in_layer == 0);
     } else {
-    if (lc->current_video_frame_in_layer <
-        (unsigned int)cpi->svc.number_temporal_layers)
-        cpi->ref_frame_flags = VP9_GOLD_FLAG;
-      else
-        cpi->ref_frame_flags = VP9_LAST_FLAG | VP9_GOLD_FLAG;
+      cpi->refresh_golden_frame = 0;
     }
 
+    if (lc->current_video_frame_in_layer == 0)
+      cpi->ref_frame_flags = 0;
+
     vp9_scale_references(cpi);
 
     // Use either last frame or alt frame for motion search.
     if (cpi->ref_frame_flags & VP9_LAST_FLAG) {
       first_ref_buf = vp9_get_scaled_ref_frame(cpi, LAST_FRAME);
-      ref_frame = LAST_FRAME;
       if (first_ref_buf == NULL)
         first_ref_buf = get_ref_frame_buffer(cpi, LAST_FRAME);
-    } else if (cpi->ref_frame_flags & VP9_GOLD_FLAG) {
-      first_ref_buf = vp9_get_scaled_ref_frame(cpi, GOLDEN_FRAME);
-      ref_frame = GOLDEN_FRAME;
-      if (first_ref_buf == NULL)
-        first_ref_buf = get_ref_frame_buffer(cpi, GOLDEN_FRAME);
     }
 
+    if (cpi->ref_frame_flags & VP9_GOLD_FLAG) {
+      const int ref_idx =
+          cm->ref_frame_map[get_ref_frame_idx(cpi, GOLDEN_FRAME)];
+      const int scaled_idx = cpi->scaled_ref_idx[GOLDEN_FRAME - 1];
+
+      gld_yv12 = (scaled_idx != ref_idx) ? &cm->frame_bufs[scaled_idx].buf :
+                 get_ref_frame_buffer(cpi, GOLDEN_FRAME);
+    } else {
+      gld_yv12 = NULL;
+    }
+
     recon_y_stride = new_yv12->y_stride;
     recon_uv_stride = new_yv12->uv_stride;
     uv_mb_height = 16 >> (new_yv12->y_height > new_yv12->uv_height);
 
-    // Disable golden frame for svc first pass for now.
-    gld_yv12 = NULL;
-    set_ref_ptrs(cm, xd, ref_frame, NONE);
+    set_ref_ptrs(cm, xd,
+                 (cpi->ref_frame_flags & VP9_LAST_FLAG) ? LAST_FRAME: NONE,
+                 (cpi->ref_frame_flags & VP9_GOLD_FLAG) ? GOLDEN_FRAME : NONE);
 
     cpi->Source = vp9_scale_if_required(cm, cpi->un_scaled_source,
                                         &cpi->scaled_source);
@@ -483,8 +495,8 @@
   vp9_setup_pre_planes(xd, 0, first_ref_buf, 0, 0, NULL);
   vp9_setup_dst_planes(xd->plane, new_yv12, 0, 0);
 
-  xd->mi = cm->mi_grid_visible;
-  xd->mi[0] = cm->mi;
+  xd->mi = cm->mi;
+  xd->mi[0].src_mi = &xd->mi[0];
 
   vp9_frame_init_quantizer(cpi);
 
@@ -531,8 +543,8 @@
       xd->plane[1].dst.buf = new_yv12->u_buffer + recon_uvoffset;
       xd->plane[2].dst.buf = new_yv12->v_buffer + recon_uvoffset;
       xd->left_available = (mb_col != 0);
-      xd->mi[0]->mbmi.sb_type = bsize;
-      xd->mi[0]->mbmi.ref_frame[0] = INTRA_FRAME;
+      xd->mi[0].src_mi->mbmi.sb_type = bsize;
+      xd->mi[0].src_mi->mbmi.ref_frame[0] = INTRA_FRAME;
       set_mi_row_col(xd, &tile,
                      mb_row << 1, num_8x8_blocks_high_lookup[bsize],
                      mb_col << 1, num_8x8_blocks_wide_lookup[bsize],
@@ -545,8 +557,8 @@
 
       // Do intra 16x16 prediction.
       x->skip_encode = 0;
-      xd->mi[0]->mbmi.mode = DC_PRED;
-      xd->mi[0]->mbmi.tx_size = use_dc_pred ?
+      xd->mi[0].src_mi->mbmi.mode = DC_PRED;
+      xd->mi[0].src_mi->mbmi.tx_size = use_dc_pred ?
          (bsize >= BLOCK_16X16 ? TX_16X16 : TX_8X8) : TX_4X4;
       vp9_encode_intra_block_plane(x, bsize, 0);
       this_error = vp9_get_mb_ss(x->plane[0].src_diff);
@@ -581,7 +593,8 @@
       x->mv_col_max = ((cm->mb_cols - 1 - mb_col) * 16) + BORDER_MV_PIXELS_B16;
 
       // Other than for the first frame do a motion search.
-      if (cm->current_video_frame > 0) {
+      if ((lc == NULL && cm->current_video_frame > 0) ||
+          (lc != NULL && lc->current_video_frame_in_layer > 0)) {
         int tmp_err, motion_error, raw_motion_error;
         // Assume 0,0 motion with no mv overhead.
         MV mv = {0, 0} , tmp_mv = {0, 0};
@@ -628,7 +641,9 @@
           }
 
           // Search in an older reference frame.
-          if (cm->current_video_frame > 1 && gld_yv12 != NULL) {
+          if (((lc == NULL && cm->current_video_frame > 1) ||
+               (lc != NULL && lc->current_video_frame_in_layer > 1))
+              && gld_yv12 != NULL) {
             // Assume 0,0 motion with no mv overhead.
             int gf_motion_error;
 
@@ -695,11 +710,11 @@
           mv.row *= 8;
           mv.col *= 8;
           this_error = motion_error;
-          xd->mi[0]->mbmi.mode = NEWMV;
-          xd->mi[0]->mbmi.mv[0].as_mv = mv;
-          xd->mi[0]->mbmi.tx_size = TX_4X4;
-          xd->mi[0]->mbmi.ref_frame[0] = LAST_FRAME;
-          xd->mi[0]->mbmi.ref_frame[1] = NONE;
+          xd->mi[0].src_mi->mbmi.mode = NEWMV;
+          xd->mi[0].src_mi->mbmi.mv[0].as_mv = mv;
+          xd->mi[0].src_mi->mbmi.tx_size = TX_4X4;
+          xd->mi[0].src_mi->mbmi.ref_frame[0] = LAST_FRAME;
+          xd->mi[0].src_mi->mbmi.ref_frame[1] = NONE;
           vp9_build_inter_predictors_sby(xd, mb_row << 1, mb_col << 1, bsize);
           vp9_encode_sby_pass1(x, bsize);
           sum_mvr += mv.row;
@@ -817,12 +832,18 @@
   vp9_clear_system_state();
   {
     FIRSTPASS_STATS fps;
+    // The minimum error here insures some bit alocation to frames even
+    // in static regions. The allocation per MB declines for larger formats
+    // where the typical "real" energy per MB also falls.
+    // Initial estimate here uses sqrt(mbs) to define the min_err, where the
+    // number of mbs is propotional to image area.
+    const double min_err = 200 * sqrt(cm->MBs);
 
     fps.frame = cm->current_video_frame;
     fps.spatial_layer_id = cpi->svc.spatial_layer_id;
-    fps.intra_error = (double)(intra_error >> 8);
-    fps.coded_error = (double)(coded_error >> 8);
-    fps.sr_coded_error = (double)(sr_coded_error >> 8);
+    fps.coded_error = (double)(coded_error >> 8) + min_err;
+    fps.sr_coded_error = (double)(sr_coded_error >> 8) + min_err;
+    fps.intra_error = (double)(intra_error >> 8) + min_err;
     fps.count = 1.0;
     fps.pcnt_inter = (double)intercount / cm->MBs;
     fps.pcnt_second_ref = (double)second_ref_count / cm->MBs;
@@ -893,7 +914,7 @@
 
   // Special case for the first frame. Copy into the GF buffer as a second
   // reference.
-  if (cm->current_video_frame == 0 && gld_yv12 != NULL) {
+  if (cm->current_video_frame == 0 && gld_yv12 != NULL && lc == NULL) {
     vp8_yv12_copy_frame(lst_yv12, gld_yv12);
   }
 
@@ -922,12 +943,13 @@
                                      double err_divisor,
                                      double pt_low,
                                      double pt_high,
-                                     int q) {
+                                     int q,
+                                     vpx_bit_depth_t bit_depth) {
   const double error_term = err_per_mb / err_divisor;
 
   // Adjustment based on actual quantizer to power term.
-  const double power_term = MIN(vp9_convert_qindex_to_q(q) * 0.0125 + pt_low,
-                                pt_high);
+  const double power_term =
+      MIN(vp9_convert_qindex_to_q(q, bit_depth) * 0.0125 + pt_low, pt_high);
 
   // Calculate correction factor.
   if (power_term < 1.0)
@@ -962,9 +984,11 @@
       const double factor =
           calc_correction_factor(err_per_mb, ERR_DIVISOR,
                                  is_svc_upper_layer ? SVC_FACTOR_PT_LOW :
-                                 FACTOR_PT_LOW, FACTOR_PT_HIGH, q);
+                                 FACTOR_PT_LOW, FACTOR_PT_HIGH, q,
+                                 cpi->common.bit_depth);
       const int bits_per_mb = vp9_rc_bits_per_mb(INTER_FRAME, q,
-                                                 factor * speed_term);
+                                                 factor * speed_term,
+                                                 cpi->common.bit_depth);
       if (bits_per_mb <= target_norm_bits_per_mb)
         break;
     }
@@ -1017,17 +1041,6 @@
                              10000000.0);
   }
 
-  // Calculate a minimum intra value to be used in determining the IIratio
-  // scores used in the second pass. We have this minimum to make sure
-  // that clips that are static but "low complexity" in the intra domain
-  // are still boosted appropriately for KF/GF/ARF.
-  if (!is_two_pass_svc) {
-    // We don't know the number of MBs for each layer at this point.
-    // So we will do it later.
-    twopass->kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
-    twopass->gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
-  }
-
   // This variable monitors how far behind the second ref update is lagging.
   twopass->sr_update_lag = 1;
 
@@ -1051,35 +1064,59 @@
 
   // Reset the vbr bits off target counter
   cpi->rc.vbr_bits_off_target = 0;
+
+  // Static sequence monitor variables.
+  twopass->kf_zeromotion_pct = 100;
+  twopass->last_kfgroup_zeromotion_pct = 100;
 }
 
-// This function gives an estimate of how badly we believe the prediction
-// quality is decaying from frame to frame.
-static double get_prediction_decay_rate(const VP9_COMMON *cm,
-                                        const FIRSTPASS_STATS *next_frame) {
-  // Look at the observed drop in prediction quality between the last frame
-  // and the GF buffer (which contains an older frame).
-  const double mb_sr_err_diff = (next_frame->sr_coded_error -
-                                     next_frame->coded_error) / cm->MBs;
-  const double second_ref_decay = mb_sr_err_diff <= 512.0
-      ? fclamp(pow(1.0 - (mb_sr_err_diff / 512.0), 0.5), 0.85, 1.0)
-      : 0.85;
+#define SR_DIFF_PART 0.0015
+#define MOTION_AMP_PART 0.003
+#define INTRA_PART 0.005
+#define DEFAULT_DECAY_LIMIT 0.75
+#define LOW_SR_DIFF_TRHESH 0.1
+#define SR_DIFF_MAX 128.0
 
-  return MIN(second_ref_decay, next_frame->pcnt_inter);
+static double get_sr_decay_rate(const VP9_COMMON *cm,
+                                const FIRSTPASS_STATS *frame) {
+  double sr_diff = (frame->sr_coded_error - frame->coded_error) / cm->MBs;
+  double sr_decay = 1.0;
+  const double motion_amplitude_factor =
+    frame->pcnt_motion * ((frame->mvc_abs + frame->mvr_abs) / 2);
+  const double pcnt_intra = 100 * (1.0 - frame->pcnt_inter);
+
+  if ((sr_diff > LOW_SR_DIFF_TRHESH)) {
+    sr_diff = MIN(sr_diff, SR_DIFF_MAX);
+    sr_decay = 1.0 - (SR_DIFF_PART * sr_diff) -
+               (MOTION_AMP_PART * motion_amplitude_factor) -
+               (INTRA_PART * pcnt_intra);
+  }
+  return MAX(sr_decay, MIN(DEFAULT_DECAY_LIMIT, frame->pcnt_inter));
 }
 
 // This function gives an estimate of how badly we believe the prediction
 // quality is decaying from frame to frame.
-static double get_zero_motion_factor(const FIRSTPASS_STATS *frame) {
-  const double sr_ratio = frame->coded_error /
-                          DOUBLE_DIVIDE_CHECK(frame->sr_coded_error);
+static double get_zero_motion_factor(const VP9_COMMON *cm,
+                                     const FIRSTPASS_STATS *frame) {
   const double zero_motion_pct = frame->pcnt_inter -
                                  frame->pcnt_motion;
+  double sr_decay = get_sr_decay_rate(cm, frame);
+  return MIN(sr_decay, zero_motion_pct);
+}
 
-  return MIN(sr_ratio, zero_motion_pct);
+#define ZM_POWER_FACTOR 0.75
+
+static double get_prediction_decay_rate(const VP9_COMMON *cm,
+                                        const FIRSTPASS_STATS *next_frame) {
+  const double sr_decay_rate = get_sr_decay_rate(cm, next_frame);
+  const double zero_motion_factor =
+    (0.95 * pow((next_frame->pcnt_inter - next_frame->pcnt_motion),
+                ZM_POWER_FACTOR));
+
+  return MAX(zero_motion_factor,
+             (sr_decay_rate + ((1.0 - sr_decay_rate) * zero_motion_factor)));
 }
 
-
 // Function to test for a condition where a complex transition is followed
 // by a static section. For example in slide shows where there is a fade
 // between slides. This is to help with more optimal kf and gf positioning.
@@ -1156,19 +1193,17 @@
   }
 }
 
-// Calculate a baseline boost number for the current frame.
-static double calc_frame_boost(const TWO_PASS *twopass,
+#define BASELINE_ERR_PER_MB 1000.0
+static double calc_frame_boost(VP9_COMP *cpi,
                                const FIRSTPASS_STATS *this_frame,
-                               double this_frame_mv_in_out) {
+                               double this_frame_mv_in_out,
+                               double max_boost) {
   double frame_boost;
 
-  // Underlying boost factor is based on inter intra error ratio.
-  if (this_frame->intra_error > twopass->gf_intra_err_min)
-    frame_boost = (IIFACTOR * this_frame->intra_error /
-                   DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
-  else
-    frame_boost = (IIFACTOR * twopass->gf_intra_err_min /
-                   DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
+  // Underlying boost factor is based on inter error ratio.
+  frame_boost = (BASELINE_ERR_PER_MB * cpi->common.MBs) /
+                DOUBLE_DIVIDE_CHECK(this_frame->coded_error);
+  frame_boost = frame_boost * BOOST_FACTOR;
 
   // Increase boost for frames where new data coming into frame (e.g. zoom out).
   // Slightly reduce boost if there is a net balance of motion out of the frame
@@ -1179,7 +1214,7 @@
   else
     frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
 
-  return MIN(frame_boost, GF_RMAX);
+  return MIN(frame_boost, max_boost);
 }
 
 static int calc_arf_boost(VP9_COMP *cpi, int offset,
@@ -1220,8 +1255,9 @@
                           ? MIN_DECAY_FACTOR : decay_accumulator;
     }
 
-    boost_score += decay_accumulator * calc_frame_boost(twopass, this_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
   }
 
   *f_boost = (int)boost_score;
@@ -1258,8 +1294,9 @@
                               ? MIN_DECAY_FACTOR : decay_accumulator;
     }
 
-    boost_score += decay_accumulator * calc_frame_boost(twopass, this_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, this_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
   }
   *b_boost = (int)boost_score;
 
@@ -1569,7 +1606,7 @@
     gf_group_err -= gf_first_frame_err;
 
   // Motion breakout threshold for loop below depends on image size.
-  mv_ratio_accumulator_thresh = (cpi->common.width + cpi->common.height) / 10.0;
+  mv_ratio_accumulator_thresh = (cpi->common.width + cpi->common.height) / 4.0;
 
   // Work out a maximum interval for the GF group.
   // If the image appears almost completely static we can extend beyond this.
@@ -1581,7 +1618,8 @@
    // At high Q when there are few bits to spare we are better with a longer
    // interval to spread the cost of the GF.
    active_max_gf_interval =
-     12 + ((int)vp9_convert_qindex_to_q(rc->last_q[INTER_FRAME]) >> 5);
+     12 + ((int)vp9_convert_qindex_to_q(rc->last_q[INTER_FRAME],
+                                        cpi->common.bit_depth) >> 5);
 
    if (active_max_gf_interval > rc->max_gf_interval)
      active_max_gf_interval = rc->max_gf_interval;
@@ -1612,11 +1650,13 @@
     if (!flash_detected) {
       last_loop_decay_rate = loop_decay_rate;
       loop_decay_rate = get_prediction_decay_rate(&cpi->common, &next_frame);
+
       decay_accumulator = decay_accumulator * loop_decay_rate;
 
       // Monitor for static sections.
-      zero_motion_accumulator = MIN(zero_motion_accumulator,
-                                    get_zero_motion_factor(&next_frame));
+      zero_motion_accumulator =
+        MIN(zero_motion_accumulator,
+            get_zero_motion_factor(&cpi->common, &next_frame));
 
       // Break clause to detect very still sections after motion. For example,
       // a static image after a fade or other transition.
@@ -1628,8 +1668,9 @@
     }
 
     // Calculate a boost number for this frame.
-    boost_score += decay_accumulator * calc_frame_boost(twopass, &next_frame,
-                                                        this_frame_mv_in_out);
+    boost_score += decay_accumulator * calc_frame_boost(cpi, &next_frame,
+                                                        this_frame_mv_in_out,
+                                                        GF_MAX_BOOST);
 
     // Break out conditions.
     if (
@@ -1638,38 +1679,21 @@
       (
         // Don't break out with a very short interval.
         (i > MIN_GF_INTERVAL) &&
-        ((boost_score > 125.0) || (next_frame.pcnt_inter < 0.75)) &&
         (!flash_detected) &&
         ((mv_ratio_accumulator > mv_ratio_accumulator_thresh) ||
          (abs_mv_in_out_accumulator > 3.0) ||
          (mv_in_out_accumulator < -2.0) ||
-         ((boost_score - old_boost_score) < IIFACTOR)))) {
+         ((boost_score - old_boost_score) < BOOST_FACTOR)))) {
       boost_score = old_boost_score;
       break;
     }
 
     *this_frame = next_frame;
-
     old_boost_score = boost_score;
   }
 
   twopass->gf_zeromotion_pct = (int)(zero_motion_accumulator * 1000.0);
 
-  // Don't allow a gf too near the next kf.
-  if ((rc->frames_to_key - i) < MIN_GF_INTERVAL) {
-    while (i < (rc->frames_to_key + !rc->next_key_frame_forced)) {
-      ++i;
-
-      if (EOF == input_stats(twopass, this_frame))
-        break;
-
-      if (i < rc->frames_to_key) {
-        mod_frame_err = calculate_modified_err(twopass, oxcf, this_frame);
-        gf_group_err += mod_frame_err;
-      }
-    }
-  }
-
   // Set the interval until the next gf.
   if (cpi->common.frame_type == KEY_FRAME || rc->source_alt_ref_active)
     rc->baseline_gf_interval = i - 1;
@@ -1696,10 +1720,7 @@
   // Should we use the alternate reference frame.
   if (allow_alt_ref &&
       (i < cpi->oxcf.lag_in_frames) &&
-      (i >= MIN_GF_INTERVAL) &&
-      // For real scene cuts (not forced kfs) don't allow arf very near kf.
-      (rc->next_key_frame_forced ||
-      (i <= (rc->frames_to_key - MIN_GF_INTERVAL)))) {
+      (i >= MIN_GF_INTERVAL)) {
     // Calculate the boost for alt ref.
     rc->gfu_boost = calc_arf_boost(cpi, 0, (i - 1), (i - 1), &f_boost,
                                    &b_boost);
@@ -1710,7 +1731,7 @@
       (cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
       (zero_motion_accumulator < 0.995)) ? 1 : 0;
   } else {
-    rc->gfu_boost = (int)boost_score;
+    rc->gfu_boost = MAX((int)boost_score, 125);
     rc->source_alt_ref_pending = 0;
   }
 
@@ -1723,7 +1744,8 @@
   // Calculate the extra bits to be used for boosted frame(s)
   {
     int q = rc->last_q[INTER_FRAME];
-    int boost = (rc->gfu_boost * gfboost_qadjust(q)) / 100;
+    int boost =
+        (rc->gfu_boost * gfboost_qadjust(q, cpi->common.bit_depth)) / 100;
 
     // Set max and minimum boost and hence minimum allocation.
     boost = clamp(boost, 125, (rc->baseline_gf_interval + 1) * 200);
@@ -1764,6 +1786,9 @@
   }
 }
 
+// TODO(PGW) Re-examine the use of II ration in this code in the light of#
+// changes elsewhere
+#define KF_II_MAX 128.0
 static int test_candidate_kf(TWO_PASS *twopass,
                              const FIRSTPASS_STATS *last_frame,
                              const FIRSTPASS_STATS *this_frame,
@@ -1793,11 +1818,11 @@
 
     // Examine how well the key frame predicts subsequent frames.
     for (i = 0; i < 16; ++i) {
-      double next_iiratio = (IIKFACTOR1 * local_next_frame.intra_error /
+      double next_iiratio = (BOOST_FACTOR * local_next_frame.intra_error /
                              DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error));
 
-      if (next_iiratio > RMAX)
-        next_iiratio = RMAX;
+      if (next_iiratio > KF_II_MAX)
+        next_iiratio = KF_II_MAX;
 
       // Cumulative effect of decay in prediction quality.
       if (local_next_frame.pcnt_inter > 0.85)
@@ -1852,7 +1877,9 @@
   FIRSTPASS_STATS next_frame;
   FIRSTPASS_STATS last_frame;
   int kf_bits = 0;
+  int loop_decay_counter = 0;
   double decay_accumulator = 1.0;
+  double av_decay_accumulator = 0.0;
   double zero_motion_accumulator = 1.0;
   double boost_score = 0.0;
   double kf_mod_err = 0.0;
@@ -2006,42 +2033,38 @@
   // Reset the first pass file position.
   reset_fpf_position(twopass, start_position);
 
-  // Scan through the kf group collating various stats used to deteermine
+  // Scan through the kf group collating various stats used to determine
   // how many bits to spend on it.
   decay_accumulator = 1.0;
   boost_score = 0.0;
-  for (i = 0; i < rc->frames_to_key; ++i) {
+  for (i = 0; i < (rc->frames_to_key - 1); ++i) {
     if (EOF == input_stats(twopass, &next_frame))
       break;
 
     // Monitor for static sections.
-    zero_motion_accumulator =MIN(zero_motion_accumulator,
-                                 get_zero_motion_factor(&next_frame));
+    zero_motion_accumulator =
+      MIN(zero_motion_accumulator,
+          get_zero_motion_factor(&cpi->common, &next_frame));
 
-    // For the first few frames collect data to decide kf boost.
-    if (i <= (rc->max_gf_interval * 2)) {
-      double r;
-      if (next_frame.intra_error > twopass->kf_intra_err_min)
-        r = (IIKFACTOR2 * next_frame.intra_error /
-             DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
-      else
-        r = (IIKFACTOR2 * twopass->kf_intra_err_min /
-             DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
+    // Not all frames in the group are necessarily used in calculating boost.
+    if ((i <= rc->max_gf_interval) ||
+        ((i <= (rc->max_gf_interval * 4)) && (decay_accumulator > 0.5))) {
+      const double frame_boost =
+        calc_frame_boost(cpi, this_frame, 0, KF_MAX_BOOST);
 
-      if (r > RMAX)
-        r = RMAX;
-
       // How fast is prediction quality decaying.
       if (!detect_flash(twopass, 0)) {
-        const double loop_decay_rate = get_prediction_decay_rate(&cpi->common,
-                                                                 &next_frame);
+        const double loop_decay_rate =
+          get_prediction_decay_rate(&cpi->common, &next_frame);
         decay_accumulator *= loop_decay_rate;
         decay_accumulator = MAX(decay_accumulator, MIN_DECAY_FACTOR);
+        av_decay_accumulator += decay_accumulator;
+        ++loop_decay_counter;
       }
-
-      boost_score += (decay_accumulator * r);
+      boost_score += (decay_accumulator * frame_boost);
     }
   }
+  av_decay_accumulator /= (double)loop_decay_counter;
 
   reset_fpf_position(twopass, start_position);
 
@@ -2053,14 +2076,12 @@
       calculate_section_intra_ratio(start_position, twopass->stats_in_end,
                                     rc->frames_to_key);
 
+  // Apply various clamps for min and max boost
+  rc->kf_boost = (int)(av_decay_accumulator * boost_score);
+  rc->kf_boost = MAX(rc->kf_boost, (rc->frames_to_key * 3));
+  rc->kf_boost = MAX(rc->kf_boost, MIN_KF_BOOST);
+
   // Work out how many bits to allocate for the key frame itself.
-  rc->kf_boost = (int)boost_score;
-
-  if (rc->kf_boost  < (rc->frames_to_key * 3))
-    rc->kf_boost  = (rc->frames_to_key * 3);
-  if (rc->kf_boost   < MIN_KF_BOOST)
-    rc->kf_boost = MIN_KF_BOOST;
-
   kf_bits = calculate_boost_bits((rc->frames_to_key - 1),
                                   rc->kf_boost, twopass->kf_group_bits);
 
@@ -2134,6 +2155,10 @@
       break;
   }
   if (is_two_pass_svc(cpi)) {
+    if (cpi->svc.temporal_layer_id > 0) {
+      cpi->refresh_last_frame = 0;
+      cpi->refresh_golden_frame = 0;
+    }
     if (cpi->svc.layer_context[cpi->svc.spatial_layer_id].gold_ref_idx < 0)
       cpi->refresh_golden_frame = 0;
     if (cpi->alt_ref_source == NULL)
@@ -2198,11 +2223,6 @@
 
   vp9_clear_system_state();
 
-  if (lc != NULL && twopass->kf_intra_err_min == 0) {
-    twopass->kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
-    twopass->gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
-  }
-
   if (cpi->oxcf.rc_mode == VPX_Q) {
     twopass->active_worst_quality = cpi->oxcf.cq_level;
   } else if (cm->current_video_frame == 0 ||
@@ -2214,7 +2234,7 @@
                                                 section_target_bandwidth);
     twopass->active_worst_quality = tmp_q;
     rc->ni_av_qi = tmp_q;
-    rc->avg_q = vp9_convert_qindex_to_q(tmp_q);
+    rc->avg_q = vp9_convert_qindex_to_q(tmp_q, cm->bit_depth);
   }
   vp9_zero(this_frame);
   if (EOF == input_stats(twopass, &this_frame))
@@ -2268,6 +2288,18 @@
     rc->frames_till_gf_update_due = rc->baseline_gf_interval;
     if (lc != NULL)
       cpi->refresh_golden_frame = 1;
+
+#if ARF_STATS_OUTPUT
+    {
+      FILE *fpfile;
+      fpfile = fopen("arf.stt", "a");
+      ++arf_count;
+      fprintf(fpfile, "%10d %10d %10d %10ld\n",
+              cm->current_video_frame, rc->kf_boost, arf_count, rc->gfu_boost);
+
+      fclose(fpfile);
+    }
+#endif
   }
 
   configure_buffer_updates(cpi);
@@ -2307,6 +2339,7 @@
   if (cpi->common.frame_type != KEY_FRAME &&
       !vp9_is_upper_layer_key_frame(cpi)) {
     twopass->kf_group_bits -= bits_used;
+    twopass->last_kfgroup_zeromotion_pct = twopass->kf_zeromotion_pct;
   }
   twopass->kf_group_bits = MAX(twopass->kf_group_bits, 0);