ref: b2597527a5364338f997c62e874083efcbef2f8a
dir: /vp9/encoder/vp9_context_tree.c/
/*
* Copyright (c) 2014 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "vp9/encoder/vp9_context_tree.h"
#include "vp9/encoder/vp9_encoder.h"
static const BLOCK_SIZE square[] = {
BLOCK_8X8,
BLOCK_16X16,
BLOCK_32X32,
BLOCK_64X64,
};
static void alloc_mode_context(VP9_COMMON *cm, int num_4x4_blk,
PICK_MODE_CONTEXT *ctx) {
const int num_blk = (num_4x4_blk < 4 ? 4 : num_4x4_blk);
const int num_pix = num_blk << 4;
int i, k;
ctx->num_4x4_blk = num_blk;
CHECK_MEM_ERROR(cm, ctx->zcoeff_blk,
vpx_calloc(num_blk, sizeof(uint8_t)));
for (i = 0; i < MAX_MB_PLANE; ++i) {
for (k = 0; k < 3; ++k) {
CHECK_MEM_ERROR(cm, ctx->coeff[i][k],
vpx_memalign(32, num_pix * sizeof(*ctx->coeff[i][k])));
CHECK_MEM_ERROR(cm, ctx->qcoeff[i][k],
vpx_memalign(32, num_pix * sizeof(*ctx->qcoeff[i][k])));
CHECK_MEM_ERROR(cm, ctx->dqcoeff[i][k],
vpx_memalign(32, num_pix * sizeof(*ctx->dqcoeff[i][k])));
CHECK_MEM_ERROR(cm, ctx->eobs[i][k],
vpx_memalign(32, num_blk * sizeof(*ctx->eobs[i][k])));
ctx->coeff_pbuf[i][k] = ctx->coeff[i][k];
ctx->qcoeff_pbuf[i][k] = ctx->qcoeff[i][k];
ctx->dqcoeff_pbuf[i][k] = ctx->dqcoeff[i][k];
ctx->eobs_pbuf[i][k] = ctx->eobs[i][k];
}
}
}
static void free_mode_context(PICK_MODE_CONTEXT *ctx) {
int i, k;
vpx_free(ctx->zcoeff_blk);
ctx->zcoeff_blk = 0;
for (i = 0; i < MAX_MB_PLANE; ++i) {
for (k = 0; k < 3; ++k) {
vpx_free(ctx->coeff[i][k]);
ctx->coeff[i][k] = 0;
vpx_free(ctx->qcoeff[i][k]);
ctx->qcoeff[i][k] = 0;
vpx_free(ctx->dqcoeff[i][k]);
ctx->dqcoeff[i][k] = 0;
vpx_free(ctx->eobs[i][k]);
ctx->eobs[i][k] = 0;
}
}
}
static void alloc_tree_contexts(VP9_COMMON *cm, PC_TREE *tree,
int num_4x4_blk) {
alloc_mode_context(cm, num_4x4_blk, &tree->none);
alloc_mode_context(cm, num_4x4_blk/2, &tree->horizontal[0]);
alloc_mode_context(cm, num_4x4_blk/2, &tree->vertical[0]);
if (num_4x4_blk > 4) {
alloc_mode_context(cm, num_4x4_blk/2, &tree->horizontal[1]);
alloc_mode_context(cm, num_4x4_blk/2, &tree->vertical[1]);
} else {
memset(&tree->horizontal[1], 0, sizeof(tree->horizontal[1]));
memset(&tree->vertical[1], 0, sizeof(tree->vertical[1]));
}
}
static void free_tree_contexts(PC_TREE *tree) {
free_mode_context(&tree->none);
free_mode_context(&tree->horizontal[0]);
free_mode_context(&tree->horizontal[1]);
free_mode_context(&tree->vertical[0]);
free_mode_context(&tree->vertical[1]);
}
// This function sets up a tree of contexts such that at each square
// partition level. There are contexts for none, horizontal, vertical, and
// split. Along with a block_size value and a selected block_size which
// represents the state of our search.
void vp9_setup_pc_tree(VP9_COMMON *cm, ThreadData *td) {
int i, j;
const int leaf_nodes = 64;
const int tree_nodes = 64 + 16 + 4 + 1;
int pc_tree_index = 0;
PC_TREE *this_pc;
PICK_MODE_CONTEXT *this_leaf;
int square_index = 1;
int nodes;
vpx_free(td->leaf_tree);
CHECK_MEM_ERROR(cm, td->leaf_tree, vpx_calloc(leaf_nodes,
sizeof(*td->leaf_tree)));
vpx_free(td->pc_tree);
CHECK_MEM_ERROR(cm, td->pc_tree, vpx_calloc(tree_nodes,
sizeof(*td->pc_tree)));
this_pc = &td->pc_tree[0];
this_leaf = &td->leaf_tree[0];
// 4x4 blocks smaller than 8x8 but in the same 8x8 block share the same
// context so we only need to allocate 1 for each 8x8 block.
for (i = 0; i < leaf_nodes; ++i)
alloc_mode_context(cm, 1, &td->leaf_tree[i]);
// Sets up all the leaf nodes in the tree.
for (pc_tree_index = 0; pc_tree_index < leaf_nodes; ++pc_tree_index) {
PC_TREE *const tree = &td->pc_tree[pc_tree_index];
tree->block_size = square[0];
alloc_tree_contexts(cm, tree, 4);
tree->leaf_split[0] = this_leaf++;
for (j = 1; j < 4; j++)
tree->leaf_split[j] = tree->leaf_split[0];
}
// Each node has 4 leaf nodes, fill each block_size level of the tree
// from leafs to the root.
for (nodes = 16; nodes > 0; nodes >>= 2) {
for (i = 0; i < nodes; ++i) {
PC_TREE *const tree = &td->pc_tree[pc_tree_index];
alloc_tree_contexts(cm, tree, 4 << (2 * square_index));
tree->block_size = square[square_index];
for (j = 0; j < 4; j++)
tree->split[j] = this_pc++;
++pc_tree_index;
}
++square_index;
}
td->pc_root = &td->pc_tree[tree_nodes - 1];
td->pc_root[0].none.best_mode_index = 2;
}
void vp9_free_pc_tree(ThreadData *td) {
const int tree_nodes = 64 + 16 + 4 + 1;
int i;
// Set up all 4x4 mode contexts
for (i = 0; i < 64; ++i)
free_mode_context(&td->leaf_tree[i]);
// Sets up all the leaf nodes in the tree.
for (i = 0; i < tree_nodes; ++i)
free_tree_contexts(&td->pc_tree[i]);
vpx_free(td->pc_tree);
td->pc_tree = NULL;
vpx_free(td->leaf_tree);
td->leaf_tree = NULL;
}