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 
14 static const BLOCK_SIZE square[] = {
15   BLOCK_8X8,
16   BLOCK_16X16,
17   BLOCK_32X32,
18   BLOCK_64X64,
19 };
20 
alloc_mode_context(VP9_COMMON * cm,int num_4x4_blk,PICK_MODE_CONTEXT * ctx)21 static 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_4x4_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(int16_t)));
34       CHECK_MEM_ERROR(cm, ctx->qcoeff[i][k],
35                       vpx_memalign(16, num_pix * sizeof(int16_t)));
36       CHECK_MEM_ERROR(cm, ctx->dqcoeff[i][k],
37                       vpx_memalign(16, num_pix * sizeof(int16_t)));
38       CHECK_MEM_ERROR(cm, ctx->eobs[i][k],
39                       vpx_memalign(16, num_pix * sizeof(uint16_t)));
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 
free_mode_context(PICK_MODE_CONTEXT * ctx)48 static 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 
alloc_tree_contexts(VP9_COMMON * cm,PC_TREE * tree,int num_4x4_blk)66 static 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   /* TODO(Jbb): for 4x8 and 8x4 these allocated values are not used.
73    * Figure out a better way to do this. */
74   alloc_mode_context(cm, num_4x4_blk/2, &tree->horizontal[1]);
75   alloc_mode_context(cm, num_4x4_blk/2, &tree->vertical[1]);
76 }
77 
free_tree_contexts(PC_TREE * tree)78 static void free_tree_contexts(PC_TREE *tree) {
79   free_mode_context(&tree->none);
80   free_mode_context(&tree->horizontal[0]);
81   free_mode_context(&tree->horizontal[1]);
82   free_mode_context(&tree->vertical[0]);
83   free_mode_context(&tree->vertical[1]);
84 }
85 
86 // This function sets up a tree of contexts such that at each square
87 // partition level. There are contexts for none, horizontal, vertical, and
88 // split.  Along with a block_size value and a selected block_size which
89 // represents the state of our search.
vp9_setup_pc_tree(VP9_COMMON * cm,VP9_COMP * cpi)90 void vp9_setup_pc_tree(VP9_COMMON *cm, VP9_COMP *cpi) {
91   int i, j;
92   const int leaf_nodes = 64;
93   const int tree_nodes = 64 + 16 + 4 + 1;
94   int pc_tree_index = 0;
95   PC_TREE *this_pc;
96   PICK_MODE_CONTEXT *this_leaf;
97   int square_index = 1;
98   int nodes;
99 
100   vpx_free(cpi->leaf_tree);
101   CHECK_MEM_ERROR(cm, cpi->leaf_tree, vpx_calloc(leaf_nodes,
102                                                  sizeof(*cpi->leaf_tree)));
103   vpx_free(cpi->pc_tree);
104   CHECK_MEM_ERROR(cm, cpi->pc_tree, vpx_calloc(tree_nodes,
105                                                sizeof(*cpi->pc_tree)));
106 
107   this_pc = &cpi->pc_tree[0];
108   this_leaf = &cpi->leaf_tree[0];
109 
110   // 4x4 blocks smaller than 8x8 but in the same 8x8 block share the same
111   // context so we only need to allocate 1 for each 8x8 block.
112   for (i = 0; i < leaf_nodes; ++i)
113     alloc_mode_context(cm, 1, &cpi->leaf_tree[i]);
114 
115   // Sets up all the leaf nodes in the tree.
116   for (pc_tree_index = 0; pc_tree_index < leaf_nodes; ++pc_tree_index) {
117     PC_TREE *const tree = &cpi->pc_tree[pc_tree_index];
118     tree->block_size = square[0];
119     alloc_tree_contexts(cm, tree, 4);
120     tree->leaf_split[0] = this_leaf++;
121     for (j = 1; j < 4; j++)
122       tree->leaf_split[j] = tree->leaf_split[0];
123   }
124 
125   // Each node has 4 leaf nodes, fill each block_size level of the tree
126   // from leafs to the root.
127   for (nodes = 16; nodes > 0; nodes >>= 2) {
128     for (i = 0; i < nodes; ++i) {
129       PC_TREE *const tree = &cpi->pc_tree[pc_tree_index];
130       alloc_tree_contexts(cm, tree, 4 << (2 * square_index));
131       tree->block_size = square[square_index];
132       for (j = 0; j < 4; j++)
133         tree->split[j] = this_pc++;
134       ++pc_tree_index;
135     }
136     ++square_index;
137   }
138   cpi->pc_root = &cpi->pc_tree[tree_nodes - 1];
139   cpi->pc_root[0].none.best_mode_index = 2;
140 }
141 
vp9_free_pc_tree(VP9_COMP * cpi)142 void vp9_free_pc_tree(VP9_COMP *cpi) {
143   const int tree_nodes = 64 + 16 + 4 + 1;
144   int i;
145 
146   // Set up all 4x4 mode contexts
147   for (i = 0; i < 64; ++i)
148     free_mode_context(&cpi->leaf_tree[i]);
149 
150   // Sets up all the leaf nodes in the tree.
151   for (i = 0; i < tree_nodes; ++i)
152     free_tree_contexts(&cpi->pc_tree[i]);
153 
154   vpx_free(cpi->pc_tree);
155   cpi->pc_tree = NULL;
156   vpx_free(cpi->leaf_tree);
157   cpi->leaf_tree = NULL;
158 }
159