shithub: libvpx

Download patch

ref: 3caaf21c5be04d012426b3e6a1b58a5d2c9700a8
parent: d35541fe292fd8778d7212234a0bce633cda43af
parent: 9a7625652c94ab2d699cb1066ba6de24ceea3cfa
author: Paul Wilkins <paulwilkins@google.com>
date: Thu May 11 14:25:44 EDT 2017

Merge "Tuning of factor used to calculate Q range in two pass."

--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -42,8 +42,6 @@
 #define OUTPUT_FPF 0
 #define ARF_STATS_OUTPUT 0
 
-#define FACTOR_PT_LOW 0.70
-#define FACTOR_PT_HIGH 0.90
 #define FIRST_PASS_Q 10.0
 #define GF_MAX_BOOST 96.0
 #define INTRA_MODE_PENALTY 1024
@@ -50,7 +48,6 @@
 #define MIN_ARF_GF_BOOST 240
 #define MIN_DECAY_FACTOR 0.01
 #define NEW_MV_MODE_PENALTY 32
-#define SVC_FACTOR_PT_LOW 0.45
 #define DARK_THRESH 64
 #define DEFAULT_GRP_WEIGHT 1.0
 #define RC_FACTOR_MIN 0.75
@@ -1522,15 +1519,23 @@
   if (cpi->use_svc) vp9_inc_frame_in_layer(cpi);
 }
 
+static const double q_pow_term[(QINDEX_RANGE >> 5) + 1] = {
+  0.65, 0.70, 0.75, 0.85, 0.90, 0.90, 0.90, 1.00, 1.25
+};
+
 static double calc_correction_factor(double err_per_mb, double err_divisor,
-                                     double pt_low, double pt_high, int q,
-                                     vpx_bit_depth_t bit_depth) {
-  const double error_term = err_per_mb / err_divisor;
+                                     int q) {
+  const double error_term = err_per_mb / DOUBLE_DIVIDE_CHECK(err_divisor);
+  const int index = q >> 5;
+  double power_term;
 
-  // Adjustment based on actual quantizer to power term.
-  const double power_term =
-      VPXMIN(vp9_convert_qindex_to_q(q, bit_depth) * 0.01 + pt_low, pt_high);
+  assert((index >= 0) && (index < (QINDEX_RANGE >> 5)));
 
+  // Adjustment based on quantizer to the power term.
+  power_term =
+      q_pow_term[index] +
+      (((q_pow_term[index + 1] - q_pow_term[index]) * (q % 32)) / 32.0);
+
   // Calculate correction factor.
   if (power_term < 1.0) assert(error_term >= 0.0);
 
@@ -1567,11 +1572,7 @@
     const int target_norm_bits_per_mb =
         (int)(((uint64_t)target_rate << BPER_MB_NORMBITS) / active_mbs);
     int q;
-    int is_svc_upper_layer = 0;
 
-    if (is_two_pass_svc(cpi) && cpi->svc.spatial_layer_id > 0)
-      is_svc_upper_layer = 1;
-
     // based on recent history adjust expectations of bits per macroblock.
     last_group_rate_err =
         (double)twopass->rolling_arf_group_actual_bits /
@@ -1583,10 +1584,8 @@
     // Try and pick a max Q that will be high enough to encode the
     // content at the given rate.
     for (q = rc->best_quality; q < rc->worst_quality; ++q) {
-      const double factor = calc_correction_factor(
-          av_err_per_mb, ERR_DIVISOR,
-          is_svc_upper_layer ? SVC_FACTOR_PT_LOW : FACTOR_PT_LOW,
-          FACTOR_PT_HIGH, q, cpi->common.bit_depth);
+      const double factor =
+          calc_correction_factor(av_err_per_mb, ERR_DIVISOR, q);
       const int bits_per_mb = vp9_rc_bits_per_mb(
           INTER_FRAME, q,
           factor * speed_term * cpi->twopass.bpm_factor * noise_factor,