1 | /* The copyright in this software is being made available under the BSD |
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2 | * License, included below. This software may be subject to other third party |
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3 | * and contributor rights, including patent rights, and no such rights are |
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4 | * granted under this license. |
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5 | * |
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6 | * Copyright (c) 2010-2015, ITU/ISO/IEC |
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7 | * All rights reserved. |
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8 | * |
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9 | * Redistribution and use in source and binary forms, with or without |
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10 | * modification, are permitted provided that the following conditions are met: |
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11 | * |
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12 | * * Redistributions of source code must retain the above copyright notice, |
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13 | * this list of conditions and the following disclaimer. |
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14 | * * Redistributions in binary form must reproduce the above copyright notice, |
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15 | * this list of conditions and the following disclaimer in the documentation |
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16 | * and/or other materials provided with the distribution. |
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17 | * * Neither the name of the ITU/ISO/IEC nor the names of its contributors may |
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18 | * be used to endorse or promote products derived from this software without |
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19 | * specific prior written permission. |
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20 | * |
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21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS |
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25 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
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31 | * THE POSSIBILITY OF SUCH DAMAGE. |
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32 | */ |
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33 | |
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34 | /** \file TEncBinCoderCABAC.cpp |
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35 | \brief binary entropy encoder of CABAC |
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36 | */ |
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37 | |
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38 | #include "TEncBinCoderCABAC.h" |
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39 | #include "TLibCommon/TComRom.h" |
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40 | #include "TLibCommon/Debug.h" |
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41 | |
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42 | //! \ingroup TLibEncoder |
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43 | //! \{ |
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44 | |
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45 | |
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46 | TEncBinCABAC::TEncBinCABAC() |
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47 | : m_pcTComBitIf( 0 ) |
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48 | , m_binCountIncrement( 0 ) |
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49 | #if FAST_BIT_EST |
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50 | , m_fracBits( 0 ) |
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51 | #endif |
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52 | { |
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53 | } |
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54 | |
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55 | TEncBinCABAC::~TEncBinCABAC() |
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56 | { |
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57 | } |
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58 | |
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59 | Void TEncBinCABAC::init( TComBitIf* pcTComBitIf ) |
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60 | { |
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61 | m_pcTComBitIf = pcTComBitIf; |
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62 | } |
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63 | |
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64 | Void TEncBinCABAC::uninit() |
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65 | { |
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66 | m_pcTComBitIf = 0; |
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67 | } |
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68 | |
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69 | Void TEncBinCABAC::start() |
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70 | { |
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71 | m_uiLow = 0; |
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72 | m_uiRange = 510; |
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73 | m_bitsLeft = 23; |
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74 | m_numBufferedBytes = 0; |
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75 | m_bufferedByte = 0xff; |
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76 | #if FAST_BIT_EST |
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77 | m_fracBits = 0; |
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78 | #endif |
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79 | } |
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80 | |
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81 | Void TEncBinCABAC::finish() |
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82 | { |
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83 | if ( m_uiLow >> ( 32 - m_bitsLeft ) ) |
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84 | { |
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85 | //assert( m_numBufferedBytes > 0 ); |
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86 | //assert( m_bufferedByte != 0xff ); |
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87 | m_pcTComBitIf->write( m_bufferedByte + 1, 8 ); |
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88 | while ( m_numBufferedBytes > 1 ) |
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89 | { |
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90 | m_pcTComBitIf->write( 0x00, 8 ); |
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91 | m_numBufferedBytes--; |
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92 | } |
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93 | m_uiLow -= 1 << ( 32 - m_bitsLeft ); |
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94 | } |
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95 | else |
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96 | { |
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97 | if ( m_numBufferedBytes > 0 ) |
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98 | { |
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99 | m_pcTComBitIf->write( m_bufferedByte, 8 ); |
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100 | } |
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101 | while ( m_numBufferedBytes > 1 ) |
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102 | { |
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103 | m_pcTComBitIf->write( 0xff, 8 ); |
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104 | m_numBufferedBytes--; |
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105 | } |
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106 | } |
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107 | m_pcTComBitIf->write( m_uiLow >> 8, 24 - m_bitsLeft ); |
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108 | } |
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109 | |
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110 | Void TEncBinCABAC::flush() |
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111 | { |
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112 | encodeBinTrm(1); |
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113 | finish(); |
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114 | m_pcTComBitIf->write(1, 1); |
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115 | m_pcTComBitIf->writeAlignZero(); |
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116 | |
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117 | start(); |
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118 | } |
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119 | |
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120 | /** Reset BAC register and counter values. |
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121 | * \returns Void |
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122 | */ |
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123 | Void TEncBinCABAC::resetBac() |
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124 | { |
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125 | start(); |
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126 | } |
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127 | |
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128 | /** Encode PCM alignment zero bits. |
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129 | * \returns Void |
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130 | */ |
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131 | Void TEncBinCABAC::encodePCMAlignBits() |
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132 | { |
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133 | finish(); |
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134 | m_pcTComBitIf->write(1, 1); |
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135 | m_pcTComBitIf->writeAlignZero(); // pcm align zero |
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136 | } |
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137 | |
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138 | /** Write a PCM code. |
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139 | * \param uiCode code value |
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140 | * \param uiLength code bit-depth |
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141 | * \returns Void |
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142 | */ |
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143 | Void TEncBinCABAC::xWritePCMCode(UInt uiCode, UInt uiLength) |
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144 | { |
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145 | m_pcTComBitIf->write(uiCode, uiLength); |
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146 | } |
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147 | |
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148 | Void TEncBinCABAC::copyState( const TEncBinIf* pcTEncBinIf ) |
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149 | { |
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150 | const TEncBinCABAC* pcTEncBinCABAC = pcTEncBinIf->getTEncBinCABAC(); |
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151 | m_uiLow = pcTEncBinCABAC->m_uiLow; |
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152 | m_uiRange = pcTEncBinCABAC->m_uiRange; |
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153 | m_bitsLeft = pcTEncBinCABAC->m_bitsLeft; |
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154 | m_bufferedByte = pcTEncBinCABAC->m_bufferedByte; |
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155 | m_numBufferedBytes = pcTEncBinCABAC->m_numBufferedBytes; |
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156 | #if FAST_BIT_EST |
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157 | m_fracBits = pcTEncBinCABAC->m_fracBits; |
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158 | #if NH_MV |
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159 | D_PRINT_INDENT(g_traceEncFracBits, "CopyState " + n2s(m_fracBits) ); |
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160 | #endif |
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161 | #endif |
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162 | } |
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163 | |
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164 | Void TEncBinCABAC::resetBits() |
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165 | { |
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166 | m_uiLow = 0; |
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167 | m_bitsLeft = 23; |
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168 | m_numBufferedBytes = 0; |
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169 | m_bufferedByte = 0xff; |
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170 | if ( m_binCountIncrement ) |
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171 | { |
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172 | m_uiBinsCoded = 0; |
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173 | } |
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174 | #if FAST_BIT_EST |
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175 | #if NH_MV |
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176 | D_PRINT_INDENT( g_traceEncFracBits, "Reset Bits Before" + n2s(m_fracBits) ); |
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177 | #endif |
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178 | m_fracBits &= 32767; |
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179 | #if NH_MV |
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180 | D_PRINT_INDENT( g_traceEncFracBits, "Reset Bits " + n2s(m_fracBits) ); |
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181 | #endif |
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182 | #endif |
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183 | } |
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184 | |
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185 | UInt TEncBinCABAC::getNumWrittenBits() |
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186 | { |
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187 | return m_pcTComBitIf->getNumberOfWrittenBits() + 8 * m_numBufferedBytes + 23 - m_bitsLeft; |
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188 | } |
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189 | |
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190 | /** |
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191 | * \brief Encode bin |
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192 | * |
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193 | * \param binValue bin value |
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194 | * \param rcCtxModel context model |
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195 | */ |
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196 | Void TEncBinCABAC::encodeBin( UInt binValue, ContextModel &rcCtxModel ) |
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197 | { |
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198 | #if !NH_MV |
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199 | //{ |
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200 | // DTRACE_CABAC_VL( g_nSymbolCounter++ ) |
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201 | // DTRACE_CABAC_T( "\tstate=" ) |
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202 | // DTRACE_CABAC_V( ( rcCtxModel.getState() << 1 ) + rcCtxModel.getMps() ) |
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203 | // DTRACE_CABAC_T( "\tsymbol=" ) |
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204 | // DTRACE_CABAC_V( binValue ) |
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205 | // DTRACE_CABAC_T( "\n" ) |
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206 | //} |
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207 | #endif |
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208 | #if DEBUG_CABAC_BINS |
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209 | const UInt startingRange = m_uiRange; |
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210 | #endif |
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211 | |
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212 | m_uiBinsCoded += m_binCountIncrement; |
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213 | rcCtxModel.setBinsCoded( 1 ); |
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214 | |
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215 | UInt uiLPS = TComCABACTables::sm_aucLPSTable[ rcCtxModel.getState() ][ ( m_uiRange >> 6 ) & 3 ]; |
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216 | m_uiRange -= uiLPS; |
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217 | |
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218 | if( binValue != rcCtxModel.getMps() ) |
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219 | { |
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220 | Int numBits = TComCABACTables::sm_aucRenormTable[ uiLPS >> 3 ]; |
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221 | m_uiLow = ( m_uiLow + m_uiRange ) << numBits; |
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222 | m_uiRange = uiLPS << numBits; |
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223 | rcCtxModel.updateLPS(); |
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224 | m_bitsLeft -= numBits; |
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225 | testAndWriteOut(); |
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226 | } |
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227 | else |
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228 | { |
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229 | rcCtxModel.updateMPS(); |
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230 | |
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231 | if ( m_uiRange < 256 ) |
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232 | { |
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233 | m_uiLow <<= 1; |
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234 | m_uiRange <<= 1; |
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235 | m_bitsLeft--; |
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236 | testAndWriteOut(); |
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237 | } |
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238 | } |
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239 | |
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240 | #if DEBUG_CABAC_BINS |
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241 | if ((g_debugCounter + debugCabacBinWindow) >= debugCabacBinTargetLine) |
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242 | { |
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243 | std::cout << g_debugCounter << ": coding bin value " << binValue << ", range = [" << startingRange << "->" << m_uiRange << "]\n"; |
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244 | } |
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245 | |
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246 | if (g_debugCounter >= debugCabacBinTargetLine) |
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247 | { |
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248 | Char breakPointThis; |
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249 | breakPointThis = 7; |
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250 | } |
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251 | if (g_debugCounter >= (debugCabacBinTargetLine + debugCabacBinWindow)) |
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252 | { |
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253 | exit(0); |
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254 | } |
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255 | |
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256 | g_debugCounter++; |
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257 | #endif |
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258 | } |
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259 | |
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260 | /** |
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261 | * \brief Encode equiprobable bin |
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262 | * |
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263 | * \param binValue bin value |
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264 | */ |
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265 | Void TEncBinCABAC::encodeBinEP( UInt binValue ) |
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266 | { |
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267 | if (false) |
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268 | { |
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269 | #if !NH_MV |
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270 | DTRACE_CABAC_VL( g_nSymbolCounter++ ) |
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271 | DTRACE_CABAC_T( "\tEPsymbol=" ) |
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272 | DTRACE_CABAC_V( binValue ) |
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273 | DTRACE_CABAC_T( "\n" ) |
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274 | #endif |
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275 | } |
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276 | |
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277 | m_uiBinsCoded += m_binCountIncrement; |
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278 | |
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279 | if (m_uiRange == 256) |
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280 | { |
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281 | encodeAlignedBinsEP(binValue, 1); |
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282 | return; |
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283 | } |
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284 | |
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285 | m_uiLow <<= 1; |
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286 | if( binValue ) |
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287 | { |
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288 | m_uiLow += m_uiRange; |
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289 | } |
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290 | m_bitsLeft--; |
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291 | |
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292 | testAndWriteOut(); |
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293 | } |
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294 | |
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295 | /** |
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296 | * \brief Encode equiprobable bins |
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297 | * |
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298 | * \param binValues bin values |
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299 | * \param numBins number of bins |
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300 | */ |
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301 | Void TEncBinCABAC::encodeBinsEP( UInt binValues, Int numBins ) |
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302 | { |
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303 | m_uiBinsCoded += numBins & -m_binCountIncrement; |
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304 | |
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305 | if (false) |
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306 | { |
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307 | for ( Int i = 0; i < numBins; i++ ) |
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308 | { |
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309 | #if !NH_MV |
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310 | DTRACE_CABAC_VL( g_nSymbolCounter++ ) |
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311 | DTRACE_CABAC_T( "\tEPsymbol=" ) |
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312 | DTRACE_CABAC_V( ( binValues >> ( numBins - 1 - i ) ) & 1 ) |
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313 | DTRACE_CABAC_T( "\n" ) |
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314 | #endif |
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315 | } |
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316 | } |
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317 | |
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318 | if (m_uiRange == 256) |
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319 | { |
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320 | encodeAlignedBinsEP(binValues, numBins); |
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321 | return; |
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322 | } |
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323 | |
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324 | while ( numBins > 8 ) |
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325 | { |
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326 | numBins -= 8; |
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327 | UInt pattern = binValues >> numBins; |
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328 | m_uiLow <<= 8; |
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329 | m_uiLow += m_uiRange * pattern; |
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330 | binValues -= pattern << numBins; |
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331 | m_bitsLeft -= 8; |
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332 | |
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333 | testAndWriteOut(); |
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334 | } |
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335 | |
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336 | m_uiLow <<= numBins; |
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337 | m_uiLow += m_uiRange * binValues; |
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338 | m_bitsLeft -= numBins; |
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339 | |
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340 | testAndWriteOut(); |
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341 | } |
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342 | |
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343 | Void TEncBinCABAC::align() |
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344 | { |
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345 | m_uiRange = 256; |
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346 | } |
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347 | |
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348 | Void TEncBinCABAC::encodeAlignedBinsEP( UInt binValues, Int numBins ) |
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349 | { |
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350 | Int binsRemaining = numBins; |
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351 | |
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352 | assert(m_uiRange == 256); //aligned encode only works when range = 256 |
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353 | |
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354 | while (binsRemaining > 0) |
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355 | { |
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356 | const UInt binsToCode = std::min<UInt>(binsRemaining, 8); //code bytes if able to take advantage of the system's byte-write function |
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357 | const UInt binMask = (1 << binsToCode) - 1; |
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358 | |
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359 | const UInt newBins = (binValues >> (binsRemaining - binsToCode)) & binMask; |
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360 | |
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361 | //The process of encoding an EP bin is the same as that of coding a normal |
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362 | //bin where the symbol ranges for 1 and 0 are both half the range: |
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363 | // |
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364 | // low = (low + range/2) << 1 (to encode a 1) |
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365 | // low = low << 1 (to encode a 0) |
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366 | // |
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367 | // i.e. |
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368 | // low = (low + (bin * range/2)) << 1 |
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369 | // |
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370 | // which is equivalent to: |
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371 | // |
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372 | // low = (low << 1) + (bin * range) |
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373 | // |
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374 | // this can be generalised for multiple bins, producing the following expression: |
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375 | // |
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376 | m_uiLow = (m_uiLow << binsToCode) + (newBins << 8); //range is known to be 256 |
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377 | |
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378 | binsRemaining -= binsToCode; |
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379 | m_bitsLeft -= binsToCode; |
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380 | |
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381 | testAndWriteOut(); |
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382 | } |
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383 | } |
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384 | |
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385 | /** |
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386 | * \brief Encode terminating bin |
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387 | * |
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388 | * \param binValue bin value |
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389 | */ |
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390 | Void TEncBinCABAC::encodeBinTrm( UInt binValue ) |
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391 | { |
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392 | m_uiBinsCoded += m_binCountIncrement; |
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393 | m_uiRange -= 2; |
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394 | if( binValue ) |
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395 | { |
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396 | m_uiLow += m_uiRange; |
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397 | m_uiLow <<= 7; |
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398 | m_uiRange = 2 << 7; |
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399 | m_bitsLeft -= 7; |
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400 | } |
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401 | else if ( m_uiRange >= 256 ) |
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402 | { |
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403 | return; |
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404 | } |
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405 | else |
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406 | { |
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407 | m_uiLow <<= 1; |
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408 | m_uiRange <<= 1; |
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409 | m_bitsLeft--; |
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410 | } |
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411 | |
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412 | testAndWriteOut(); |
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413 | } |
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414 | |
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415 | Void TEncBinCABAC::testAndWriteOut() |
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416 | { |
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417 | if ( m_bitsLeft < 12 ) |
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418 | { |
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419 | writeOut(); |
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420 | } |
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421 | } |
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422 | |
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423 | /** |
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424 | * \brief Move bits from register into bitstream |
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425 | */ |
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426 | Void TEncBinCABAC::writeOut() |
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427 | { |
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428 | UInt leadByte = m_uiLow >> (24 - m_bitsLeft); |
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429 | m_bitsLeft += 8; |
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430 | m_uiLow &= 0xffffffffu >> m_bitsLeft; |
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431 | |
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432 | if ( leadByte == 0xff ) |
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433 | { |
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434 | m_numBufferedBytes++; |
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435 | } |
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436 | else |
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437 | { |
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438 | if ( m_numBufferedBytes > 0 ) |
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439 | { |
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440 | UInt carry = leadByte >> 8; |
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441 | UInt byte = m_bufferedByte + carry; |
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442 | m_bufferedByte = leadByte & 0xff; |
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443 | m_pcTComBitIf->write( byte, 8 ); |
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444 | |
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445 | byte = ( 0xff + carry ) & 0xff; |
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446 | while ( m_numBufferedBytes > 1 ) |
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447 | { |
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448 | m_pcTComBitIf->write( byte, 8 ); |
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449 | m_numBufferedBytes--; |
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450 | } |
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451 | } |
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452 | else |
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453 | { |
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454 | m_numBufferedBytes = 1; |
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455 | m_bufferedByte = leadByte; |
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456 | } |
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457 | } |
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458 | } |
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459 | |
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460 | //! \} |
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