vp9/encoder/vp9_aq_variance.c

   1 /*
   2  *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
   3  *
   4  *  Use of this source code is governed by a BSD-style license
   5  *  that can be found in the LICENSE file in the root of the source
   6  *  tree. An additional intellectual property rights grant can be found
   7  *  in the file PATENTS.  All contributing project authors may
   8  *  be found in the AUTHORS file in the root of the source tree.
   9  */
  10
  11 #include <math.h>
  12
  13 #include "vpx_ports/mem.h"
  14
  15 #include "vp9/encoder/vp9_aq_variance.h"
  16
  17 #include "vp9/common/vp9_seg_common.h"
  18
  19 #include "vp9/encoder/vp9_ratectrl.h"
  20 #include "vp9/encoder/vp9_rd.h"
  21 #include "vp9/encoder/vp9_segmentation.h"
  22 #include "vp9/common/vp9_systemdependent.h"
  23
  24 #define ENERGY_MIN (-4)
  25 #define ENERGY_MAX (1)
  26 #define ENERGY_SPAN (ENERGY_MAX - ENERGY_MIN +  1)
  27 #define ENERGY_IN_BOUNDS(energy)\
  28   assert((energy) >= ENERGY_MIN && (energy) <= ENERGY_MAX)
  29
  30 static const double rate_ratio[MAX_SEGMENTS] =
  31   {2.5, 2.0, 1.5, 1.0, 0.75, 1.0, 1.0, 1.0};
  32 static const int segment_id[ENERGY_SPAN] = {0, 1, 1, 2, 3, 4};
  33
  34 #define SEGMENT_ID(i) segment_id[(i) - ENERGY_MIN]
  35
  36 DECLARE_ALIGNED(16, static const uint8_t, vp9_64_zeros[64]) = {0};
  37 #if CONFIG_VP9_HIGHBITDEPTH
  38 DECLARE_ALIGNED(16, static const uint16_t, vp9_highbd_64_zeros[64]) = {0};
  39 #endif
  40
  41 unsigned int vp9_vaq_segment_id(int energy) {
  42   ENERGY_IN_BOUNDS(energy);
  43   return SEGMENT_ID(energy);
  44 }
  45
  46 void vp9_vaq_frame_setup(VP9_COMP *cpi) {
  47   VP9_COMMON *cm = &cpi->common;
  48   struct segmentation *seg = &cm->seg;
  49   int i;
  50
  51   if (cm->frame_type == KEY_FRAME ||
  52       cpi->refresh_alt_ref_frame ||
  53       (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) {
  54     vp9_enable_segmentation(seg);
  55     vp9_clearall_segfeatures(seg);
  56
  57     seg->abs_delta = SEGMENT_DELTADATA;
  58
  59     vp9_clear_system_state();
  60
  61     for (i = 0; i < MAX_SEGMENTS; ++i) {
  62       int qindex_delta =
  63           vp9_compute_qdelta_by_rate(&cpi->rc, cm->frame_type, cm->base_qindex,
  64                                      rate_ratio[i], cm->bit_depth);
  65
  66       // We don't allow qindex 0 in a segment if the base value is not 0.
  67       // Q index 0 (lossless) implies 4x4 encoding only and in AQ mode a segment
  68       // Q delta is sometimes applied without going back around the rd loop.
  69       // This could lead to an illegal combination of partition size and q.
  70       if ((cm->base_qindex != 0) && ((cm->base_qindex + qindex_delta) == 0)) {
  71         qindex_delta = -cm->base_qindex + 1;
  72       }
  73
  74       // No need to enable SEG_LVL_ALT_Q for this segment.
  75       if (rate_ratio[i] == 1.0) {
  76         continue;
  77       }
  78
  79       vp9_set_segdata(seg, i, SEG_LVL_ALT_Q, qindex_delta);
  80       vp9_enable_segfeature(seg, i, SEG_LVL_ALT_Q);
  81     }
  82   }
  83 }
  84
  85 /* TODO(agrange, paulwilkins): The block_variance calls the unoptimized versions
  86  * of variance() and highbd_8_variance(). It should not.
  87  */
  88 static void aq_variance(const uint8_t *a, int  a_stride,
  89                         const uint8_t *b, int  b_stride,
  90                         int  w, int  h, unsigned int *sse, int *sum) {
  91   int i, j;
  92
  93   *sum = 0;
  94   *sse = 0;
  95
  96   for (i = 0; i < h; i++) {
  97     for (j = 0; j < w; j++) {
  98       const int diff = a[j] - b[j];
  99       *sum += diff;
 100       *sse += diff * diff;
 101     }
 102
 103     a += a_stride;
 104     b += b_stride;
 105   }
 106 }
 107
 108 #if CONFIG_VP9_HIGHBITDEPTH
 109 static void aq_highbd_variance64(const uint8_t *a8, int  a_stride,
 110                                  const uint8_t *b8, int  b_stride,
 111                                  int w, int h, uint64_t *sse, uint64_t *sum) {
 112   int i, j;
 113
 114   uint16_t *a = CONVERT_TO_SHORTPTR(a8);
 115   uint16_t *b = CONVERT_TO_SHORTPTR(b8);
 116   *sum = 0;
 117   *sse = 0;
 118
 119   for (i = 0; i < h; i++) {
 120     for (j = 0; j < w; j++) {
 121       const int diff = a[j] - b[j];
 122       *sum += diff;
 123       *sse += diff * diff;
 124     }
 125     a += a_stride;
 126     b += b_stride;
 127   }
 128 }
 129
 130 static void aq_highbd_8_variance(const uint8_t *a8, int  a_stride,
 131                                  const uint8_t *b8, int  b_stride,
 132                                  int w, int h, unsigned int *sse, int *sum) {
 133   uint64_t sse_long = 0;
 134   uint64_t sum_long = 0;
 135   aq_highbd_variance64(a8, a_stride, b8, b_stride, w, h, &sse_long, &sum_long);
 136   *sse = (unsigned int)sse_long;
 137   *sum = (int)sum_long;
 138 }
 139 #endif  // CONFIG_VP9_HIGHBITDEPTH
 140
 141 static unsigned int block_variance(VP9_COMP *cpi, MACROBLOCK *x,
 142                                    BLOCK_SIZE bs) {
 143   MACROBLOCKD *xd = &x->e_mbd;
 144   unsigned int var, sse;
 145   int right_overflow = (xd->mb_to_right_edge < 0) ?
 146       ((-xd->mb_to_right_edge) >> 3) : 0;
 147   int bottom_overflow = (xd->mb_to_bottom_edge < 0) ?
 148       ((-xd->mb_to_bottom_edge) >> 3) : 0;
 149
 150   if (right_overflow || bottom_overflow) {
 151     const int bw = 8 * num_8x8_blocks_wide_lookup[bs] - right_overflow;
 152     const int bh = 8 * num_8x8_blocks_high_lookup[bs] - bottom_overflow;
 153     int avg;
 154 #if CONFIG_VP9_HIGHBITDEPTH
 155     if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
 156       aq_highbd_8_variance(x->plane[0].src.buf, x->plane[0].src.stride,
 157                            CONVERT_TO_BYTEPTR(vp9_highbd_64_zeros), 0, bw, bh,
 158                            &sse, &avg);
 159       sse >>= 2 * (xd->bd - 8);
 160       avg >>= (xd->bd - 8);
 161     } else {
 162       aq_variance(x->plane[0].src.buf, x->plane[0].src.stride,
 163                   vp9_64_zeros, 0, bw, bh, &sse, &avg);
 164     }
 165 #else
 166     aq_variance(x->plane[0].src.buf, x->plane[0].src.stride,
 167                 vp9_64_zeros, 0, bw, bh, &sse, &avg);
 168 #endif  // CONFIG_VP9_HIGHBITDEPTH
 169     var = sse - (((int64_t)avg * avg) / (bw * bh));
 170     return (256 * var) / (bw * bh);
 171   } else {
 172 #if CONFIG_VP9_HIGHBITDEPTH
 173     if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
 174       var = cpi->fn_ptr[bs].vf(x->plane[0].src.buf,
 175                                x->plane[0].src.stride,
 176                                CONVERT_TO_BYTEPTR(vp9_highbd_64_zeros),
 177                                0, &sse);
 178     } else {
 179       var = cpi->fn_ptr[bs].vf(x->plane[0].src.buf,
 180                                x->plane[0].src.stride,
 181                                vp9_64_zeros, 0, &sse);
 182     }
 183 #else
 184     var = cpi->fn_ptr[bs].vf(x->plane[0].src.buf,
 185                              x->plane[0].src.stride,
 186                              vp9_64_zeros, 0, &sse);
 187 #endif  // CONFIG_VP9_HIGHBITDEPTH
 188     return (256 * var) >> num_pels_log2_lookup[bs];
 189   }
 190 }
 191
 192 double vp9_log_block_var(VP9_COMP *cpi, MACROBLOCK *x, BLOCK_SIZE bs) {
 193   unsigned int var = block_variance(cpi, x, bs);
 194   vp9_clear_system_state();
 195   return log(var + 1.0);
 196 }
 197
 198 #define DEFAULT_E_MIDPOINT 10.0
 199 int vp9_block_energy(VP9_COMP *cpi, MACROBLOCK *x, BLOCK_SIZE bs) {
 200   double energy;
 201   double energy_midpoint;
 202   vp9_clear_system_state();
 203   energy_midpoint =
 204     (cpi->oxcf.pass == 2) ? cpi->twopass.mb_av_energy : DEFAULT_E_MIDPOINT;
 205   energy = vp9_log_block_var(cpi, x, bs) - energy_midpoint;
 206   return clamp((int)round(energy), ENERGY_MIN, ENERGY_MAX);
 207 }