diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index df82be5eca3a36f6261c4b39ef72dd3d82b08e52..e9b5aa25884db085ef9bc4899c5c7fcde7e2928c 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -35,26 +35,28 @@
 #include "vp9/encoder/vp9_rd.h"
 #include "vp9/encoder/vp9_variance.h"
 
-#define OUTPUT_FPF 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 KF_MB_INTRA_MIN 150
-#define GF_MB_INTRA_MIN 100
+#define OUTPUT_FPF          0
+#define ARF_STATS_OUTPUT    0
+
+#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 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;
@@ -299,7 +301,7 @@ static void first_pass_motion_search(VP9_COMP *cpi, MACROBLOCK *x,
   int num00, tmp_err, n;
   const BLOCK_SIZE bsize = xd->mi[0]->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;
@@ -364,7 +366,7 @@ 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, bit_depth) >= 30.0)
+    if (vp9_convert_qindex_to_q(i, bit_depth) >= FIRST_PASS_Q)
       break;
 
   if (i == QINDEX_RANGE)
@@ -414,7 +416,7 @@ void vp9_first_pass(VP9_COMP *cpi, const struct lookahead_entry *source) {
   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;
@@ -830,12 +832,18 @@ void vp9_first_pass(VP9_COMP *cpi, const struct lookahead_entry *source) {
   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;
@@ -1033,17 +1041,6 @@ void vp9_init_second_pass(VP9_COMP *cpi) {
                              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;
 
@@ -1067,34 +1064,58 @@ void vp9_init_second_pass(VP9_COMP *cpi) {
 
   // 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;
-
-  return MIN(second_ref_decay, next_frame->pcnt_inter);
+#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
+
+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;
-
-  return MIN(sr_ratio, zero_motion_pct);
+  double sr_decay = get_sr_decay_rate(cm, frame);
+  return MIN(sr_decay, 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
@@ -1172,19 +1193,17 @@ static void accumulate_frame_motion_stats(const FIRSTPASS_STATS *stats,
   }
 }
 
-// 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
@@ -1195,7 +1214,7 @@ static double calc_frame_boost(const TWO_PASS *twopass,
   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,
@@ -1236,8 +1255,9 @@ static int calc_arf_boost(VP9_COMP *cpi, int offset,
                           ? 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;
@@ -1274,8 +1294,9 @@ static int calc_arf_boost(VP9_COMP *cpi, int offset,
                               ? 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;
 
@@ -1585,7 +1606,7 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
     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.
@@ -1629,11 +1650,13 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
     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.
@@ -1645,8 +1668,9 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
     }
 
     // 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 (
@@ -1655,38 +1679,21 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
       (
         // 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;
@@ -1713,10 +1720,7 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
   // 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);
@@ -1727,7 +1731,7 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
       (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;
   }
 
@@ -1782,6 +1786,9 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
   }
 }
 
+// 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,
@@ -1811,11 +1818,11 @@ static int test_candidate_kf(TWO_PASS *twopass,
 
     // 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)
@@ -1870,7 +1877,9 @@ static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
   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;
@@ -2024,42 +2033,38 @@ static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
   // 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));
-
-    // 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));
+    zero_motion_accumulator =
+      MIN(zero_motion_accumulator,
+          get_zero_motion_factor(&cpi->common, &next_frame));
 
-      if (r > RMAX)
-        r = RMAX;
+    // 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);
 
       // 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);
 
@@ -2071,14 +2076,12 @@ static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
       calculate_section_intra_ratio(start_position, twopass->stats_in_end,
                                     rc->frames_to_key);
 
-  // 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;
+  // 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.
   kf_bits = calculate_boost_bits((rc->frames_to_key - 1),
                                   rc->kf_boost, twopass->kf_group_bits);
 
@@ -2216,11 +2219,6 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
 
   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 ||
@@ -2286,6 +2284,18 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
     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);
@@ -2325,6 +2335,7 @@ void vp9_twopass_postencode_update(VP9_COMP *cpi) {
   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);
 
diff --git a/vp9/encoder/vp9_firstpass.h b/vp9/encoder/vp9_firstpass.h
index aaa6b0311c62b172648d6e72a9def27269983f17..0b82d32fa76a66d89a45979f67fb909807837501 100644
--- a/vp9/encoder/vp9_firstpass.h
+++ b/vp9/encoder/vp9_firstpass.h
@@ -93,8 +93,6 @@ typedef struct {
   double modified_error_min;
   double modified_error_max;
   double modified_error_left;
-  double kf_intra_err_min;
-  double gf_intra_err_min;
 
 #if CONFIG_FP_MB_STATS
   uint8_t *frame_mb_stats_buf;
@@ -110,6 +108,7 @@ typedef struct {
   int sr_update_lag;
 
   int kf_zeromotion_pct;
+  int last_kfgroup_zeromotion_pct;
   int gf_zeromotion_pct;
 
   int active_worst_quality;
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index 94c0b64dd882f174dc398a57d8f1bd8823a6fa95..9b6c773988e6d084669277be66b106b41cf0c0e0 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -126,10 +126,10 @@ static void init_minq_luts(int *kf_low_m, int *kf_high_m,
   int i;
   for (i = 0; i < QINDEX_RANGE; i++) {
     const double maxq = vp9_convert_qindex_to_q(i, bit_depth);
-    kf_low_m[i] = get_minq_index(maxq, 0.000001, -0.0004, 0.125, bit_depth);
-    kf_high_m[i] = get_minq_index(maxq, 0.000002, -0.0012, 0.50, bit_depth);
+    kf_low_m[i] = get_minq_index(maxq, 0.000001, -0.0004, 0.150, bit_depth);
+    kf_high_m[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.55, bit_depth);
     arfgf_low[i] = get_minq_index(maxq, 0.0000015, -0.0009, 0.30, bit_depth);
-    arfgf_high[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.50, bit_depth);
+    arfgf_high[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.55, bit_depth);
     inter[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.90, bit_depth);
     rtc[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.70, bit_depth);
   }
@@ -175,7 +175,7 @@ int vp9_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
                        double correction_factor,
                        vpx_bit_depth_t bit_depth) {
   const double q = vp9_convert_qindex_to_q(qindex, bit_depth);
-  int enumerator = frame_type == KEY_FRAME ? 3300000 : 2250000;
+  int enumerator = frame_type == KEY_FRAME ? 2700000 : 1800000;
 
   // q based adjustment to baseline enumerator
   enumerator += (int)(enumerator * q) >> 12;
@@ -610,7 +610,7 @@ static int rc_pick_q_and_bounds_one_pass_cbr(const VP9_COMP *cpi,
 
   if (frame_is_intra_only(cm)) {
     active_best_quality = rc->best_quality;
-    // Handle the special case for key frames forced when we have75 reached
+    // Handle the special case for key frames forced when we have reached
     // the maximum key frame interval. Here force the Q to a range
     // based on the ambient Q to reduce the risk of popping.
     if (rc->this_key_frame_forced) {
@@ -880,6 +880,7 @@ static int rc_pick_q_and_bounds_one_pass_vbr(const VP9_COMP *cpi,
   return q;
 }
 
+#define STATIC_MOTION_THRESH 95
 static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
                                          int *bottom_index,
                                          int *top_index) {
@@ -894,16 +895,31 @@ static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
   ASSIGN_MINQ_TABLE(cm->bit_depth, inter_minq);
 
   if (frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi)) {
-    // Handle the special case for key frames forced when we have75 reached
+    // Handle the special case for key frames forced when we have reached
     // the maximum key frame interval. Here force the Q to a range
     // based on the ambient Q to reduce the risk of popping.
     if (rc->this_key_frame_forced) {
-      int qindex = rc->last_boosted_qindex;
-      double last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
-      int delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
-                                            last_boosted_q * 0.75,
-                                            cm->bit_depth);
-      active_best_quality = MAX(qindex + delta_qindex, rc->best_quality);
+      double last_boosted_q;
+      int delta_qindex;
+      int qindex;
+
+      if (cpi->twopass.last_kfgroup_zeromotion_pct >= STATIC_MOTION_THRESH) {
+        qindex = MIN(rc->last_kf_qindex, rc->last_boosted_qindex);
+        active_best_quality = qindex;
+        last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
+        delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
+                                              last_boosted_q * 1.25,
+                                              cm->bit_depth);
+        active_worst_quality = MIN(qindex + delta_qindex, active_worst_quality);
+
+      } else {
+        qindex = rc->last_boosted_qindex;
+        last_boosted_q = vp9_convert_qindex_to_q(qindex, cm->bit_depth);
+        delta_qindex = vp9_compute_qdelta(rc, last_boosted_q,
+                                              last_boosted_q * 0.75,
+                                              cm->bit_depth);
+        active_best_quality = MAX(qindex + delta_qindex, rc->best_quality);
+      }
     } else {
       // Not forced keyframe.
       double q_adj_factor = 1.0;
@@ -972,18 +988,12 @@ static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
     }
   }
 
-  // Clip the active best and worst quality values to limits.
-  active_best_quality = clamp(active_best_quality,
-                              rc->best_quality, rc->worst_quality);
-  active_worst_quality = clamp(active_worst_quality,
-                               active_best_quality, rc->worst_quality);
-
-  *top_index = active_worst_quality;
-  *bottom_index = active_best_quality;
-
 #if LIMIT_QRANGE_FOR_ALTREF_AND_KEY
   vp9_clear_system_state();
-  {
+  // Static forced key frames Q restrictions dealt with elsewhere.
+  if (!((frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi))) ||
+      !rc->this_key_frame_forced ||
+      (cpi->twopass.last_kfgroup_zeromotion_pct < STATIC_MOTION_THRESH)) {
     const GF_GROUP *const gf_group = &cpi->twopass.gf_group;
     const double rate_factor_deltas[RATE_FACTOR_LEVELS] = {
       1.00,  // INTER_NORMAL
@@ -997,27 +1007,43 @@ static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
     int qdelta = vp9_compute_qdelta_by_rate(&cpi->rc, cm->frame_type,
                                             active_worst_quality, rate_factor,
                                             cm->bit_depth);
-    *top_index = active_worst_quality + qdelta;
-    *top_index = (*top_index > *bottom_index) ? *top_index : *bottom_index;
+    active_worst_quality = active_worst_quality + qdelta;
+    active_worst_quality = MAX(active_worst_quality, active_best_quality);
   }
 #endif
 
+  // Clip the active best and worst quality values to limits.
+  active_best_quality = clamp(active_best_quality,
+                              rc->best_quality, rc->worst_quality);
+  active_worst_quality = clamp(active_worst_quality,
+                               active_best_quality, rc->worst_quality);
+
   if (oxcf->rc_mode == VPX_Q) {
     q = active_best_quality;
   // Special case code to try and match quality with forced key frames.
-  } else if ((cm->frame_type == KEY_FRAME) && rc->this_key_frame_forced) {
-    q = rc->last_boosted_qindex;
+  } else if ((frame_is_intra_only(cm) || vp9_is_upper_layer_key_frame(cpi)) &&
+             rc->this_key_frame_forced) {
+    // If static since last kf use better of last boosted and last kf q.
+    if (cpi->twopass.last_kfgroup_zeromotion_pct >= STATIC_MOTION_THRESH) {
+      q = MIN(rc->last_kf_qindex, rc->last_boosted_qindex);
+    } else {
+      q = rc->last_boosted_qindex;
+    }
   } else {
     q = vp9_rc_regulate_q(cpi, rc->this_frame_target,
                           active_best_quality, active_worst_quality);
-    if (q > *top_index) {
+    if (q > active_worst_quality) {
       // Special case when we are targeting the max allowed rate.
       if (rc->this_frame_target >= rc->max_frame_bandwidth)
-        *top_index = q;
+        active_worst_quality = q;
       else
-        q = *top_index;
+        q = active_worst_quality;
     }
   }
+  clamp(q, active_best_quality, active_worst_quality);
+
+  *top_index = active_worst_quality;
+  *bottom_index = active_best_quality;
 
   assert(*top_index <= rc->worst_quality &&
          *top_index >= rc->best_quality);
@@ -1161,11 +1187,12 @@ void vp9_rc_postencode_update(VP9_COMP *cpi, uint64_t bytes_used) {
   // better than that already stored.
   // This is used to help set quality in forced key frames to reduce popping
   if ((qindex < rc->last_boosted_qindex) ||
-      ((cpi->static_mb_pct < 100) &&
-       ((cm->frame_type == KEY_FRAME) || cpi->refresh_alt_ref_frame ||
+      (((cm->frame_type == KEY_FRAME) || cpi->refresh_alt_ref_frame ||
         (cpi->refresh_golden_frame && !rc->is_src_frame_alt_ref)))) {
     rc->last_boosted_qindex = qindex;
   }
+  if (cm->frame_type == KEY_FRAME)
+    rc->last_kf_qindex = qindex;
 
   update_buffer_level(cpi, rc->projected_frame_size);
 
diff --git a/vp9/encoder/vp9_ratectrl.h b/vp9/encoder/vp9_ratectrl.h
index 2ced8e6dd355c825268f687126b4b39573659857..edfb9fce94a3f7288e91c9d1889aaedafc3738ad 100644
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -42,6 +42,7 @@ typedef struct {
   int sb64_target_rate;
   int last_q[FRAME_TYPES];         // Separate values for Intra/Inter
   int last_boosted_qindex;         // Last boosted GF/KF/ARF q
+  int last_kf_qindex;              // Q index of the last key frame coded.
 
   int gfu_boost;
   int last_boost;