1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/media/libvpx/vp9/encoder/vp9_boolhuff.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,115 @@
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 +/****************************************************************************
1.16 +*
1.17 +* Module Title : vp9_boolhuff.h
1.18 +*
1.19 +* Description : Bool Coder header file.
1.20 +*
1.21 +****************************************************************************/
1.22 +#ifndef VP9_ENCODER_VP9_BOOLHUFF_H_
1.23 +#define VP9_ENCODER_VP9_BOOLHUFF_H_
1.24 +
1.25 +#include "vpx_ports/mem.h"
1.26 +
1.27 +typedef struct {
1.28 + unsigned int lowvalue;
1.29 + unsigned int range;
1.30 + unsigned int value;
1.31 + int count;
1.32 + unsigned int pos;
1.33 + uint8_t *buffer;
1.34 +
1.35 + // Variables used to track bit costs without outputing to the bitstream
1.36 + unsigned int measure_cost;
1.37 + unsigned long bit_counter;
1.38 +} vp9_writer;
1.39 +
1.40 +extern const unsigned int vp9_prob_cost[256];
1.41 +
1.42 +void vp9_start_encode(vp9_writer *bc, uint8_t *buffer);
1.43 +void vp9_stop_encode(vp9_writer *bc);
1.44 +
1.45 +DECLARE_ALIGNED(16, extern const unsigned char, vp9_norm[256]);
1.46 +
1.47 +static void vp9_write(vp9_writer *br, int bit, int probability) {
1.48 + unsigned int split;
1.49 + int count = br->count;
1.50 + unsigned int range = br->range;
1.51 + unsigned int lowvalue = br->lowvalue;
1.52 + register unsigned int shift;
1.53 +
1.54 +#ifdef ENTROPY_STATS
1.55 +#if defined(SECTIONBITS_OUTPUT)
1.56 +
1.57 + if (bit)
1.58 + Sectionbits[active_section] += vp9_prob_cost[255 - probability];
1.59 + else
1.60 + Sectionbits[active_section] += vp9_prob_cost[probability];
1.61 +
1.62 +#endif
1.63 +#endif
1.64 +
1.65 + split = 1 + (((range - 1) * probability) >> 8);
1.66 +
1.67 + range = split;
1.68 +
1.69 + if (bit) {
1.70 + lowvalue += split;
1.71 + range = br->range - split;
1.72 + }
1.73 +
1.74 + shift = vp9_norm[range];
1.75 +
1.76 + range <<= shift;
1.77 + count += shift;
1.78 +
1.79 + if (count >= 0) {
1.80 + int offset = shift - count;
1.81 +
1.82 + if ((lowvalue << (offset - 1)) & 0x80000000) {
1.83 + int x = br->pos - 1;
1.84 +
1.85 + while (x >= 0 && br->buffer[x] == 0xff) {
1.86 + br->buffer[x] = 0;
1.87 + x--;
1.88 + }
1.89 +
1.90 + br->buffer[x] += 1;
1.91 + }
1.92 +
1.93 + br->buffer[br->pos++] = (lowvalue >> (24 - offset));
1.94 + lowvalue <<= offset;
1.95 + shift = count;
1.96 + lowvalue &= 0xffffff;
1.97 + count -= 8;
1.98 + }
1.99 +
1.100 + lowvalue <<= shift;
1.101 + br->count = count;
1.102 + br->lowvalue = lowvalue;
1.103 + br->range = range;
1.104 +}
1.105 +
1.106 +static void vp9_write_bit(vp9_writer *w, int bit) {
1.107 + vp9_write(w, bit, 128); // vp9_prob_half
1.108 +}
1.109 +
1.110 +static void vp9_write_literal(vp9_writer *w, int data, int bits) {
1.111 + int bit;
1.112 +
1.113 + for (bit = bits - 1; bit >= 0; bit--)
1.114 + vp9_write_bit(w, 1 & (data >> bit));
1.115 +}
1.116 +
1.117 +
1.118 +#endif // VP9_ENCODER_VP9_BOOLHUFF_H_
