/* *  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 VPX_VP8_COMMON_TREECODER_H_#define VPX_VP8_COMMON_TREECODER_H_ #ifdef __cplusplusextern "C" {#endif 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); #ifdef __cplusplus}  // extern "C"#endif #endif  // VPX_VP8_COMMON_TREECODER_H_