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