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