libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_aq_complexity.c

 /*
  *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include <limits.h>
 #include <math.h>
 
 #include "vp9/encoder/vp9_aq_variance.h"
 #include "vp9/encoder/vp9_encodeframe.h"
 #include "vp9/common/vp9_seg_common.h"
 #include "vp9/encoder/vp9_segmentation.h"
 
-#define AQ_C_SEGMENTS  3
-#define AQ_C_STRENGTHS  3
-static const int aq_c_active_segments[AQ_C_STRENGTHS] = {1, 2, 3};
+#define AQ_C_SEGMENTS  5
+#define DEFAULT_AQ2_SEG 3   // Neutral Q segment
+#define AQ_C_STRENGTHS 3
 static const double aq_c_q_adj_factor[AQ_C_STRENGTHS][AQ_C_SEGMENTS] =
-  {{1.0, 1.0, 1.0}, {1.0, 2.0, 1.0}, {1.0, 1.5, 2.5}};
+  { {1.75, 1.25, 1.05, 1.00, 0.90},
+    {2.00, 1.50, 1.15, 1.00, 0.85},
+    {2.50, 1.75, 1.25, 1.00, 0.80} };
 static const double aq_c_transitions[AQ_C_STRENGTHS][AQ_C_SEGMENTS] =
-  {{1.0, 1.0, 1.0}, {1.0, 0.25, 0.0}, {1.0, 0.5, 0.25}};
-static const double aq_c_var_thresholds[AQ_C_SEGMENTS] = {100.0, 12.0, 10.0};
+  { {0.15, 0.30, 0.55, 2.00, 100.0},
+    {0.20, 0.40, 0.65, 2.00, 100.0},
+    {0.25, 0.50, 0.75, 2.00, 100.0} };
+static const double aq_c_var_thresholds[AQ_C_STRENGTHS][AQ_C_SEGMENTS] =
+  { {-4.0, -3.0, -2.0, 100.00, 100.0},
+    {-3.5, -2.5, -1.5, 100.00, 100.0},
+    {-3.0, -2.0, -1.0, 100.00, 100.0} };
+
+#define DEFAULT_COMPLEXITY 64
+
 
 static int get_aq_c_strength(int q_index, vpx_bit_depth_t bit_depth) {
   // Approximate base quatizer (truncated to int)
   const int base_quant = vp9_ac_quant(q_index, 0, bit_depth) / 4;
-  return (base_quant > 20) + (base_quant > 45);
+  return (base_quant > 10) + (base_quant > 25);
 }
 
 void vp9_setup_in_frame_q_adj(VP9_COMP *cpi) {
   VP9_COMMON *const cm = &cpi->common;
   struct segmentation *const seg = &cm->seg;
 
   // Make SURE use of floating point in this function is safe.
   vp9_clear_system_state();
 
   if (cm->frame_type == KEY_FRAME ||
       cpi->refresh_alt_ref_frame ||
       (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
     int segment;
     const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->bit_depth);
-    const int active_segments = aq_c_active_segments[aq_strength];
 
     // Clear down the segment map.
-    vpx_memset(cpi->segmentation_map, 0, cm->mi_rows * cm->mi_cols);
-
-    // Clear down the complexity map used for rd.
-    vpx_memset(cpi->complexity_map, 0, cm->mi_rows * cm->mi_cols);
+    vpx_memset(cpi->segmentation_map, DEFAULT_AQ2_SEG,
+               cm->mi_rows * cm->mi_cols);
 
     vp9_clearall_segfeatures(seg);
 
     // Segmentation only makes sense if the target bits per SB is above a
     // threshold. Below this the overheads will usually outweigh any benefit.
     if (cpi->rc.sb64_target_rate < 256) {
       vp9_disable_segmentation(seg);
       return;
     }
 
     vp9_enable_segmentation(seg);
 
     // Select delta coding method.
     seg->abs_delta = SEGMENT_DELTADATA;
 
-    // Segment 0 "Q" feature is disabled so it defaults to the baseline Q.
-    vp9_disable_segfeature(seg, 0, SEG_LVL_ALT_Q);
+    // Default segment "Q" feature is disabled so it defaults to the baseline Q.
+    vp9_disable_segfeature(seg, DEFAULT_AQ2_SEG, SEG_LVL_ALT_Q);
 
     // Use some of the segments for in frame Q adjustment.
-    for (segment = 1; segment < active_segments; ++segment) {
-      int qindex_delta =
-          vp9_compute_qdelta_by_rate(&cpi->rc, cm->frame_type, cm->base_qindex,
-                                     aq_c_q_adj_factor[aq_strength][segment],
-                                     cm->bit_depth);
+    for (segment = 0; segment < AQ_C_SEGMENTS; ++segment) {
+      int qindex_delta;
+
+      if (segment == DEFAULT_AQ2_SEG)
+        continue;
+
+      qindex_delta =
+        vp9_compute_qdelta_by_rate(&cpi->rc, cm->frame_type, cm->base_qindex,
+                                   aq_c_q_adj_factor[aq_strength][segment],
+                                   cm->bit_depth);
+
 
       // For AQ complexity mode, we dont allow Q0 in a segment if the base
       // Q is not 0. Q0 (lossless) implies 4x4 only and in AQ mode 2 a segment
       // Q delta is sometimes applied without going back around the rd loop.
       // This could lead to an illegal combination of partition size and q.
       if ((cm->base_qindex != 0) && ((cm->base_qindex + qindex_delta) == 0)) {
         qindex_delta = -cm->base_qindex + 1;
       }
       if ((cm->base_qindex + qindex_delta) > 0) {
         vp9_enable_segfeature(seg, segment, SEG_LVL_ALT_Q);
         vp9_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta);
       }
     }
   }
 }
 
-// Select a segment for the current SB64 block.
+#define DEFAULT_LV_THRESH 10.0
+#define MIN_DEFAULT_LV_THRESH 8.0
+#define VAR_STRENGTH_STEP 0.25
+// Select a segment for the current block.
 // The choice of segment for a block depends on the ratio of the projected
-// bits for the block vs a target average.
-// An "aq_strength" value determines how many segments are supported,
-// the set of transition points to use and the extent of the quantizer
-// adjustment for each segment (configured in vp9_setup_in_frame_q_adj()).
-void vp9_select_in_frame_q_segment(VP9_COMP *cpi, MACROBLOCK *mb,
-                                   BLOCK_SIZE bs,
-                                   int mi_row, int mi_col,
-                                   int output_enabled, int projected_rate) {
+// bits for the block vs a target average and its spatial complexity.
+void vp9_caq_select_segment(VP9_COMP *cpi, MACROBLOCK *mb, BLOCK_SIZE bs,
+                            int mi_row, int mi_col, int projected_rate) {
   VP9_COMMON *const cm = &cpi->common;
 
   const int mi_offset = mi_row * cm->mi_cols + mi_col;
   const int bw = num_8x8_blocks_wide_lookup[BLOCK_64X64];
   const int bh = num_8x8_blocks_high_lookup[BLOCK_64X64];
-  const int xmis = MIN(cm->mi_cols - mi_col, bw);
-  const int ymis = MIN(cm->mi_rows - mi_row, bh);
-  int complexity_metric = 64;
+  const int xmis = MIN(cm->mi_cols - mi_col, num_8x8_blocks_wide_lookup[bs]);
+  const int ymis = MIN(cm->mi_rows - mi_row, num_8x8_blocks_high_lookup[bs]);
   int x, y;
-
+  int i;
   unsigned char segment;
 
-  if (!output_enabled) {
-    segment = 0;
+  if (0) {
+    segment = DEFAULT_AQ2_SEG;
   } else {
     // Rate depends on fraction of a SB64 in frame (xmis * ymis / bw * bh).
     // It is converted to bits * 256 units.
     const int target_rate = (cpi->rc.sb64_target_rate * xmis * ymis * 256) /
                             (bw * bh);
+    double logvar;
+    double low_var_thresh;
     const int aq_strength = get_aq_c_strength(cm->base_qindex, cm->bit_depth);
-    const int active_segments = aq_c_active_segments[aq_strength];
-    double logvar;
+
+    vp9_clear_system_state();
+    low_var_thresh = (cpi->oxcf.pass == 2)
+      ? MAX(cpi->twopass.mb_av_energy, MIN_DEFAULT_LV_THRESH)
+      : DEFAULT_LV_THRESH;
 
     vp9_setup_src_planes(mb, cpi->Source, mi_row, mi_col);
     logvar = vp9_log_block_var(cpi, mb, bs);
 
-    // The number of segments considered and the transition points used to
-    // select them is determined by the "aq_strength" value.
-    // Currently this loop only supports segments that reduce Q (i.e. where
-    // there is undershoot.
-    // The loop counts down towards segment 0 which is the default segment
-    // with no Q adjustment.
-    segment = active_segments - 1;
-    while (segment > 0) {
+    segment = AQ_C_SEGMENTS - 1;    // Just in case no break out below.
+    for (i = 0; i < AQ_C_SEGMENTS; ++i) {
+      // Test rate against a threshold value and variance against a threshold.
+      // Increasing segment number (higher variance and complexity) = higher Q.
       if ((projected_rate <
-          target_rate * aq_c_transitions[aq_strength][segment]) &&
-          (logvar < aq_c_var_thresholds[segment])) {
+           target_rate * aq_c_transitions[aq_strength][i]) &&
+          (logvar < (low_var_thresh + aq_c_var_thresholds[aq_strength][i]))) {
+        segment = i;
         break;
       }
-      --segment;
-    }
-
-    if (target_rate > 0) {
-      complexity_metric =
-        clamp((int)((projected_rate * 64) / target_rate), 16, 255);
     }
   }
 
   // Fill in the entires in the segment map corresponding to this SB64.
   for (y = 0; y < ymis; y++) {
     for (x = 0; x < xmis; x++) {
       cpi->segmentation_map[mi_offset + y * cm->mi_cols + x] = segment;
-      cpi->complexity_map[mi_offset + y * cm->mi_cols + x] =
-        (unsigned char)complexity_metric;
     }
   }
 }