shithub: libvpx

Download patch

ref: f085d128f7e9d77cf112b49979e5097110e01f76
parent: debd0485311e455e9aa4394fb0586769704c06b3
author: Paul Wilkins <paulwilkins@google.com>
date: Fri May 23 15:01:43 EDT 2014 

Remove brightness weighting in two pass.

This code dates from the ancient past and
applied an error score weighting based on pixel
brightness. This not seem to be providing any
benefit metrics wise and could be making some
visual issues in dark frames worse.

The field is left in place in the FIRSTPASS_STATS data
structure in this patch, pending changes to unit tests that
use a pre-defined first pass file.

Change-Id: Id50f04205230234858e7548ce523f11acaf3567d


--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -169,7 +169,6 @@
   section->intra_error = 0.0;
   section->coded_error = 0.0;
   section->sr_coded_error = 0.0;
-  section->ssim_weighted_pred_err = 0.0;
   section->pcnt_inter  = 0.0;
   section->pcnt_motion  = 0.0;
   section->pcnt_second_ref = 0.0;
@@ -194,7 +193,6 @@
   section->intra_error += frame->intra_error;
   section->coded_error += frame->coded_error;
   section->sr_coded_error += frame->sr_coded_error;
-  section->ssim_weighted_pred_err += frame->ssim_weighted_pred_err;
   section->pcnt_inter  += frame->pcnt_inter;
   section->pcnt_motion += frame->pcnt_motion;
   section->pcnt_second_ref += frame->pcnt_second_ref;
@@ -217,7 +215,6 @@
   section->intra_error -= frame->intra_error;
   section->coded_error -= frame->coded_error;
   section->sr_coded_error -= frame->sr_coded_error;
-  section->ssim_weighted_pred_err -= frame->ssim_weighted_pred_err;
   section->pcnt_inter  -= frame->pcnt_inter;
   section->pcnt_motion -= frame->pcnt_motion;
   section->pcnt_second_ref -= frame->pcnt_second_ref;
@@ -241,7 +238,6 @@
   section->intra_error /= section->count;
   section->coded_error /= section->count;
   section->sr_coded_error /= section->count;
-  section->ssim_weighted_pred_err /= section->count;
   section->pcnt_inter  /= section->count;
   section->pcnt_second_ref /= section->count;
   section->pcnt_neutral /= section->count;
@@ -262,71 +258,14 @@
                                      const VP9EncoderConfig *oxcf,
                                      const FIRSTPASS_STATS *this_frame) {
   const FIRSTPASS_STATS *const stats = &twopass->total_stats;
-  const double av_err = stats->ssim_weighted_pred_err / stats->count;
+  const double av_err = stats->coded_error / stats->count;
   const double modified_error = av_err *
-      pow(this_frame->ssim_weighted_pred_err / DOUBLE_DIVIDE_CHECK(av_err),
+      pow(this_frame->coded_error / DOUBLE_DIVIDE_CHECK(av_err),
           oxcf->two_pass_vbrbias / 100.0);
   return fclamp(modified_error,
                 twopass->modified_error_min, twopass->modified_error_max);
 }
 
-static const double weight_table[256] = {
-  0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
-  0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
-  0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
-  0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
-  0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.031250, 0.062500,
-  0.093750, 0.125000, 0.156250, 0.187500, 0.218750, 0.250000, 0.281250,
-  0.312500, 0.343750, 0.375000, 0.406250, 0.437500, 0.468750, 0.500000,
-  0.531250, 0.562500, 0.593750, 0.625000, 0.656250, 0.687500, 0.718750,
-  0.750000, 0.781250, 0.812500, 0.843750, 0.875000, 0.906250, 0.937500,
-  0.968750, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
-  1.000000, 1.000000, 1.000000, 1.000000
-};
-
-static double simple_weight(const YV12_BUFFER_CONFIG *buf) {
-  int i, j;
-  double sum = 0.0;
-  const int w = buf->y_crop_width;
-  const int h = buf->y_crop_height;
-  const uint8_t *row = buf->y_buffer;
-
-  for (i = 0; i < h; ++i) {
-    const uint8_t *pixel = row;
-    for (j = 0; j < w; ++j)
-      sum += weight_table[*pixel++];
-    row += buf->y_stride;
-  }
-
-  return MAX(0.1, sum / (w * h));
-}
-
 // This function returns the maximum target rate per frame.
 static int frame_max_bits(const RATE_CONTROL *rc,
                           const VP9EncoderConfig *oxcf) {
@@ -796,7 +735,6 @@
     fps.intra_error = (double)(intra_error >> 8);
     fps.coded_error = (double)(coded_error >> 8);
     fps.sr_coded_error = (double)(sr_coded_error >> 8);
-    fps.ssim_weighted_pred_err = fps.coded_error * simple_weight(cpi->Source);
     fps.count = 1.0;
     fps.pcnt_inter = (double)intercount / cm->MBs;
     fps.pcnt_second_ref = (double)second_ref_count / cm->MBs;
@@ -1002,8 +940,8 @@
   // Scan the first pass file and calculate a modified total error based upon
   // the bias/power function used to allocate bits.
   {
-    const double avg_error = stats->ssim_weighted_pred_err /
-                                 DOUBLE_DIVIDE_CHECK(stats->count);
+    const double avg_error = stats->coded_error /
+                             DOUBLE_DIVIDE_CHECK(stats->count);
     const FIRSTPASS_STATS *s = twopass->stats_in;
     double modified_error_total = 0.0;
     twopass->modified_error_min = (avg_error *
@@ -1523,6 +1461,7 @@
   FIRSTPASS_STATS next_frame;
   const FIRSTPASS_STATS *const start_pos = twopass->stats_in;
   int i;
+
   double boost_score = 0.0;
   double old_boost_score = 0.0;
   double gf_group_err = 0.0;