/media/libvpx/vp8/common/treecoder.h
http://github.com/zpao/v8monkey · C Header · 90 lines · 43 code · 26 blank · 21 comment · 0 complexity · a3c0c492651d3d54e9d345f4b7915077 MD5 · raw file
- /*
- * Copyright (c) 2010 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.
- */
- #ifndef __INC_TREECODER_H
- #define __INC_TREECODER_H
- typedef unsigned char vp8bc_index_t; /* probability index */
- typedef unsigned char vp8_prob;
- #define vp8_prob_half ( (vp8_prob) 128)
- typedef signed char vp8_tree_index;
- struct bool_coder_spec;
- typedef struct bool_coder_spec bool_coder_spec;
- typedef struct bool_writer bool_writer;
- typedef struct bool_reader bool_reader;
- typedef const bool_coder_spec c_bool_coder_spec;
- typedef const bool_writer c_bool_writer;
- typedef const bool_reader c_bool_reader;
- # define vp8_complement( x) (255 - x)
- /* We build coding trees compactly in arrays.
- Each node of the tree is a pair of vp8_tree_indices.
- Array index often references a corresponding probability table.
- Index <= 0 means done encoding/decoding and value = -Index,
- Index > 0 means need another bit, specification at index.
- Nonnegative indices are always even; processing begins at node 0. */
- typedef const vp8_tree_index vp8_tree[], *vp8_tree_p;
- typedef const struct vp8_token_struct
- {
- int value;
- int Len;
- } vp8_token;
- /* Construct encoding array from tree. */
- void vp8_tokens_from_tree(struct vp8_token_struct *, vp8_tree);
- void vp8_tokens_from_tree_offset(struct vp8_token_struct *, vp8_tree,
- int offset);
- /* Convert array of token occurrence counts into a table of probabilities
- for the associated binary encoding tree. Also writes count of branches
- taken for each node on the tree; this facilitiates decisions as to
- probability updates. */
- void vp8_tree_probs_from_distribution(
- int n, /* n = size of alphabet */
- vp8_token tok [ /* n */ ],
- vp8_tree tree,
- vp8_prob probs [ /* n-1 */ ],
- unsigned int branch_ct [ /* n-1 */ ] [2],
- const unsigned int num_events[ /* n */ ],
- unsigned int Pfactor,
- int Round
- );
- /* Variant of above using coder spec rather than hardwired 8-bit probs. */
- void vp8bc_tree_probs_from_distribution(
- int n, /* n = size of alphabet */
- vp8_token tok [ /* n */ ],
- vp8_tree tree,
- vp8_prob probs [ /* n-1 */ ],
- unsigned int branch_ct [ /* n-1 */ ] [2],
- const unsigned int num_events[ /* n */ ],
- c_bool_coder_spec *s
- );
- #endif