michael@0: /*
michael@0:  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0:  *
michael@0:  *  Use of this source code is governed by a BSD-style license
michael@0:  *  that can be found in the LICENSE file in the root of the source
michael@0:  *  tree. An additional intellectual property rights grant can be found
michael@0:  *  in the file PATENTS.  All contributing project authors may
michael@0:  *  be found in the AUTHORS file in the root of the source tree.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef VP9_ENCODER_VP9_TREEWRITER_H_
michael@0: #define VP9_ENCODER_VP9_TREEWRITER_H_
michael@0: 
michael@0: /* Trees map alphabets into huffman-like codes suitable for an arithmetic
michael@0:    bit coder.  Timothy S Murphy  11 October 2004 */
michael@0: 
michael@0: #include "vp9/common/vp9_treecoder.h"
michael@0: 
michael@0: #include "vp9/encoder/vp9_boolhuff.h"       /* for now */
michael@0: 
michael@0: 
michael@0: #define vp9_write_prob(w, v) vp9_write_literal((w), (v), 8)
michael@0: 
michael@0: /* Approximate length of an encoded bool in 256ths of a bit at given prob */
michael@0: 
michael@0: #define vp9_cost_zero(x) (vp9_prob_cost[x])
michael@0: #define vp9_cost_one(x) vp9_cost_zero(vp9_complement(x))
michael@0: 
michael@0: #define vp9_cost_bit(x, b) vp9_cost_zero((b) ? vp9_complement(x) : (x))
michael@0: 
michael@0: /* VP8BC version is scaled by 2^20 rather than 2^8; see bool_coder.h */
michael@0: 
michael@0: 
michael@0: /* Both of these return bits, not scaled bits. */
michael@0: static INLINE unsigned int cost_branch256(const unsigned int ct[2],
michael@0:                                           vp9_prob p) {
michael@0:   return ct[0] * vp9_cost_zero(p) + ct[1] * vp9_cost_one(p);
michael@0: }
michael@0: 
michael@0: static INLINE unsigned int cost_branch(const unsigned int ct[2],
michael@0:                                        vp9_prob p) {
michael@0:   return cost_branch256(ct, p) >> 8;
michael@0: }
michael@0: 
michael@0: 
michael@0: static INLINE void treed_write(vp9_writer *w,
michael@0:                                vp9_tree tree, const vp9_prob *probs,
michael@0:                                int bits, int len) {
michael@0:   vp9_tree_index i = 0;
michael@0: 
michael@0:   do {
michael@0:     const int bit = (bits >> --len) & 1;
michael@0:     vp9_write(w, bit, probs[i >> 1]);
michael@0:     i = tree[i + bit];
michael@0:   } while (len);
michael@0: }
michael@0: 
michael@0: static INLINE void write_token(vp9_writer *w, vp9_tree tree,
michael@0:                                const vp9_prob *probs,
michael@0:                                const struct vp9_token *token) {
michael@0:   treed_write(w, tree, probs, token->value, token->len);
michael@0: }
michael@0: 
michael@0: static INLINE int treed_cost(vp9_tree tree, const vp9_prob *probs,
michael@0:                              int bits, int len) {
michael@0:   int cost = 0;
michael@0:   vp9_tree_index i = 0;
michael@0: 
michael@0:   do {
michael@0:     const int bit = (bits >> --len) & 1;
michael@0:     cost += vp9_cost_bit(probs[i >> 1], bit);
michael@0:     i = tree[i + bit];
michael@0:   } while (len);
michael@0: 
michael@0:   return cost;
michael@0: }
michael@0: 
michael@0: static INLINE int cost_token(vp9_tree tree, const vp9_prob *probs,
michael@0:                              const struct vp9_token *token) {
michael@0:   return treed_cost(tree, probs, token->value, token->len);
michael@0: }
michael@0: 
michael@0: void vp9_cost_tokens(int *costs, const vp9_prob *probs, vp9_tree tree);
michael@0: void vp9_cost_tokens_skip(int *costs, const vp9_prob *probs, vp9_tree tree);
michael@0: 
michael@0: #endif  // VP9_ENCODER_VP9_TREEWRITER_H_