1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libvpx/vp8/encoder/treewriter.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,126 @@
1.4 +/*
1.5 + * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license
1.8 + * that can be found in the LICENSE file in the root of the source
1.9 + * tree. An additional intellectual property rights grant can be found
1.10 + * in the file PATENTS. All contributing project authors may
1.11 + * be found in the AUTHORS file in the root of the source tree.
1.12 + */
1.13 +
1.14 +
1.15 +#ifndef __INC_TREEWRITER_H
1.16 +#define __INC_TREEWRITER_H
1.17 +
1.18 +/* Trees map alphabets into huffman-like codes suitable for an arithmetic
1.19 + bit coder. Timothy S Murphy 11 October 2004 */
1.20 +
1.21 +#include "vp8/common/treecoder.h"
1.22 +
1.23 +#include "boolhuff.h" /* for now */
1.24 +
1.25 +typedef BOOL_CODER vp8_writer;
1.26 +
1.27 +#define vp8_write vp8_encode_bool
1.28 +#define vp8_write_literal vp8_encode_value
1.29 +#define vp8_write_bit( W, V) vp8_write( W, V, vp8_prob_half)
1.30 +
1.31 +#define vp8bc_write vp8bc_write_bool
1.32 +#define vp8bc_write_literal vp8bc_write_bits
1.33 +#define vp8bc_write_bit( W, V) vp8bc_write_bits( W, V, 1)
1.34 +
1.35 +
1.36 +/* Approximate length of an encoded bool in 256ths of a bit at given prob */
1.37 +
1.38 +#define vp8_cost_zero( x) ( vp8_prob_cost[x])
1.39 +#define vp8_cost_one( x) vp8_cost_zero( vp8_complement(x))
1.40 +
1.41 +#define vp8_cost_bit( x, b) vp8_cost_zero( (b)? vp8_complement(x) : (x) )
1.42 +
1.43 +/* VP8BC version is scaled by 2^20 rather than 2^8; see bool_coder.h */
1.44 +
1.45 +
1.46 +/* Both of these return bits, not scaled bits. */
1.47 +
1.48 +static unsigned int vp8_cost_branch(const unsigned int ct[2], vp8_prob p)
1.49 +{
1.50 + /* Imitate existing calculation */
1.51 +
1.52 + return ((ct[0] * vp8_cost_zero(p))
1.53 + + (ct[1] * vp8_cost_one(p))) >> 8;
1.54 +}
1.55 +
1.56 +/* Small functions to write explicit values and tokens, as well as
1.57 + estimate their lengths. */
1.58 +
1.59 +static void vp8_treed_write
1.60 +(
1.61 + vp8_writer *const w,
1.62 + vp8_tree t,
1.63 + const vp8_prob *const p,
1.64 + int v,
1.65 + int n /* number of bits in v, assumed nonzero */
1.66 +)
1.67 +{
1.68 + vp8_tree_index i = 0;
1.69 +
1.70 + do
1.71 + {
1.72 + const int b = (v >> --n) & 1;
1.73 + vp8_write(w, b, p[i>>1]);
1.74 + i = t[i+b];
1.75 + }
1.76 + while (n);
1.77 +}
1.78 +static void vp8_write_token
1.79 +(
1.80 + vp8_writer *const w,
1.81 + vp8_tree t,
1.82 + const vp8_prob *const p,
1.83 + vp8_token *const x
1.84 +)
1.85 +{
1.86 + vp8_treed_write(w, t, p, x->value, x->Len);
1.87 +}
1.88 +
1.89 +static int vp8_treed_cost(
1.90 + vp8_tree t,
1.91 + const vp8_prob *const p,
1.92 + int v,
1.93 + int n /* number of bits in v, assumed nonzero */
1.94 +)
1.95 +{
1.96 + int c = 0;
1.97 + vp8_tree_index i = 0;
1.98 +
1.99 + do
1.100 + {
1.101 + const int b = (v >> --n) & 1;
1.102 + c += vp8_cost_bit(p[i>>1], b);
1.103 + i = t[i+b];
1.104 + }
1.105 + while (n);
1.106 +
1.107 + return c;
1.108 +}
1.109 +static int vp8_cost_token
1.110 +(
1.111 + vp8_tree t,
1.112 + const vp8_prob *const p,
1.113 + vp8_token *const x
1.114 +)
1.115 +{
1.116 + return vp8_treed_cost(t, p, x->value, x->Len);
1.117 +}
1.118 +
1.119 +/* Fill array of costs for all possible token values. */
1.120 +
1.121 +void vp8_cost_tokens(
1.122 + int *Costs, const vp8_prob *, vp8_tree
1.123 +);
1.124 +
1.125 +void vp8_cost_tokens2(
1.126 + int *Costs, const vp8_prob *, vp8_tree, int
1.127 +);
1.128 +
1.129 +#endif
