vp9_context_tree.c revision da49e34c1fb5e99681f4ad99c21d9cfd83eddb96 
1/*
2 *  Copyright (c) 2014 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 "vp9/encoder/vp9_context_tree.h"
12#include "vp9/encoder/vp9_encoder.h"
13
14static const BLOCK_SIZE square[] = {
15  BLOCK_8X8,
16  BLOCK_16X16,
17  BLOCK_32X32,
18  BLOCK_64X64,
19};
20
21static void alloc_mode_context(VP9_COMMON *cm, int num_4x4_blk,
22                               PICK_MODE_CONTEXT *ctx) {
23  const int num_blk = (num_4x4_blk < 4 ? 4 : num_4x4_blk);
24  const int num_pix = num_blk << 4;
25  int i, k;
26  ctx->num_4x4_blk = num_blk;
27
28  CHECK_MEM_ERROR(cm, ctx->zcoeff_blk,
29                  vpx_calloc(num_blk, sizeof(uint8_t)));
30  for (i = 0; i < MAX_MB_PLANE; ++i) {
31    for (k = 0; k < 3; ++k) {
32      CHECK_MEM_ERROR(cm, ctx->coeff[i][k],
33                      vpx_memalign(16, num_pix * sizeof(*ctx->coeff[i][k])));
34      CHECK_MEM_ERROR(cm, ctx->qcoeff[i][k],
35                      vpx_memalign(16, num_pix * sizeof(*ctx->qcoeff[i][k])));
36      CHECK_MEM_ERROR(cm, ctx->dqcoeff[i][k],
37                      vpx_memalign(16, num_pix * sizeof(*ctx->dqcoeff[i][k])));
38      CHECK_MEM_ERROR(cm, ctx->eobs[i][k],
39                      vpx_memalign(16, num_blk * sizeof(*ctx->eobs[i][k])));
40      ctx->coeff_pbuf[i][k]   = ctx->coeff[i][k];
41      ctx->qcoeff_pbuf[i][k]  = ctx->qcoeff[i][k];
42      ctx->dqcoeff_pbuf[i][k] = ctx->dqcoeff[i][k];
43      ctx->eobs_pbuf[i][k]    = ctx->eobs[i][k];
44    }
45  }
46}
47
48static void free_mode_context(PICK_MODE_CONTEXT *ctx) {
49  int i, k;
50  vpx_free(ctx->zcoeff_blk);
51  ctx->zcoeff_blk = 0;
52  for (i = 0; i < MAX_MB_PLANE; ++i) {
53    for (k = 0; k < 3; ++k) {
54      vpx_free(ctx->coeff[i][k]);
55      ctx->coeff[i][k] = 0;
56      vpx_free(ctx->qcoeff[i][k]);
57      ctx->qcoeff[i][k] = 0;
58      vpx_free(ctx->dqcoeff[i][k]);
59      ctx->dqcoeff[i][k] = 0;
60      vpx_free(ctx->eobs[i][k]);
61      ctx->eobs[i][k] = 0;
62    }
63  }
64}
65
66static void alloc_tree_contexts(VP9_COMMON *cm, PC_TREE *tree,
67                                int num_4x4_blk) {
68  alloc_mode_context(cm, num_4x4_blk, &tree->none);
69  alloc_mode_context(cm, num_4x4_blk/2, &tree->horizontal[0]);
70  alloc_mode_context(cm, num_4x4_blk/2, &tree->vertical[0]);
71
72  if (num_4x4_blk > 4) {
73    alloc_mode_context(cm, num_4x4_blk/2, &tree->horizontal[1]);
74    alloc_mode_context(cm, num_4x4_blk/2, &tree->vertical[1]);
75  } else {
76    memset(&tree->horizontal[1], 0, sizeof(tree->horizontal[1]));
77    memset(&tree->vertical[1], 0, sizeof(tree->vertical[1]));
78  }
79}
80
81static void free_tree_contexts(PC_TREE *tree) {
82  free_mode_context(&tree->none);
83  free_mode_context(&tree->horizontal[0]);
84  free_mode_context(&tree->horizontal[1]);
85  free_mode_context(&tree->vertical[0]);
86  free_mode_context(&tree->vertical[1]);
87}
88
89// This function sets up a tree of contexts such that at each square
90// partition level. There are contexts for none, horizontal, vertical, and
91// split.  Along with a block_size value and a selected block_size which
92// represents the state of our search.
93void vp9_setup_pc_tree(VP9_COMMON *cm, ThreadData *td) {
94  int i, j;
95  const int leaf_nodes = 64;
96  const int tree_nodes = 64 + 16 + 4 + 1;
97  int pc_tree_index = 0;
98  PC_TREE *this_pc;
99  PICK_MODE_CONTEXT *this_leaf;
100  int square_index = 1;
101  int nodes;
102
103  vpx_free(td->leaf_tree);
104  CHECK_MEM_ERROR(cm, td->leaf_tree, vpx_calloc(leaf_nodes,
105                                                sizeof(*td->leaf_tree)));
106  vpx_free(td->pc_tree);
107  CHECK_MEM_ERROR(cm, td->pc_tree, vpx_calloc(tree_nodes,
108                                              sizeof(*td->pc_tree)));
109
110  this_pc = &td->pc_tree[0];
111  this_leaf = &td->leaf_tree[0];
112
113  // 4x4 blocks smaller than 8x8 but in the same 8x8 block share the same
114  // context so we only need to allocate 1 for each 8x8 block.
115  for (i = 0; i < leaf_nodes; ++i)
116    alloc_mode_context(cm, 1, &td->leaf_tree[i]);
117
118  // Sets up all the leaf nodes in the tree.
119  for (pc_tree_index = 0; pc_tree_index < leaf_nodes; ++pc_tree_index) {
120    PC_TREE *const tree = &td->pc_tree[pc_tree_index];
121    tree->block_size = square[0];
122    alloc_tree_contexts(cm, tree, 4);
123    tree->leaf_split[0] = this_leaf++;
124    for (j = 1; j < 4; j++)
125      tree->leaf_split[j] = tree->leaf_split[0];
126  }
127
128  // Each node has 4 leaf nodes, fill each block_size level of the tree
129  // from leafs to the root.
130  for (nodes = 16; nodes > 0; nodes >>= 2) {
131    for (i = 0; i < nodes; ++i) {
132      PC_TREE *const tree = &td->pc_tree[pc_tree_index];
133      alloc_tree_contexts(cm, tree, 4 << (2 * square_index));
134      tree->block_size = square[square_index];
135      for (j = 0; j < 4; j++)
136        tree->split[j] = this_pc++;
137      ++pc_tree_index;
138    }
139    ++square_index;
140  }
141  td->pc_root = &td->pc_tree[tree_nodes - 1];
142  td->pc_root[0].none.best_mode_index = 2;
143}
144
145void vp9_free_pc_tree(ThreadData *td) {
146  const int tree_nodes = 64 + 16 + 4 + 1;
147  int i;
148
149  // Set up all 4x4 mode contexts
150  for (i = 0; i < 64; ++i)
151    free_mode_context(&td->leaf_tree[i]);
152
153  // Sets up all the leaf nodes in the tree.
154  for (i = 0; i < tree_nodes; ++i)
155    free_tree_contexts(&td->pc_tree[i]);
156
157  vpx_free(td->pc_tree);
158  td->pc_tree = NULL;
159  vpx_free(td->leaf_tree);
160  td->leaf_tree = NULL;
161}
162