[313] | 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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[1246] | 4 | * granted under this license. |
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[313] | 5 | * |
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[1259] | 6 | * Copyright (c) 2010-2015, ITU/ISO/IEC |
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[313] | 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 TComBitStream.cpp |
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| 35 | \brief class for handling bitstream |
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| 36 | */ |
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| 37 | |
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| 38 | #include <stdint.h> |
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| 39 | #include <vector> |
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| 40 | #include "TComBitStream.h" |
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| 41 | #include <string.h> |
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| 42 | #include <memory.h> |
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| 43 | |
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| 44 | using namespace std; |
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| 45 | |
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| 46 | //! \ingroup TLibCommon |
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| 47 | //! \{ |
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| 48 | |
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| 49 | // ==================================================================================================================== |
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| 50 | // Constructor / destructor / create / destroy |
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| 51 | // ==================================================================================================================== |
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| 52 | |
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| 53 | TComOutputBitstream::TComOutputBitstream() |
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| 54 | { |
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| 55 | clear(); |
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| 56 | } |
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| 57 | |
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| 58 | TComOutputBitstream::~TComOutputBitstream() |
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| 59 | { |
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| 60 | } |
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| 61 | |
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| 62 | TComInputBitstream::TComInputBitstream(std::vector<uint8_t>* buf) |
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| 63 | { |
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| 64 | m_fifo = buf; |
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| 65 | m_fifo_idx = 0; |
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| 66 | m_held_bits = 0; |
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| 67 | m_num_held_bits = 0; |
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| 68 | m_numBitsRead = 0; |
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| 69 | } |
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| 70 | |
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| 71 | TComInputBitstream::~TComInputBitstream() |
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| 72 | { |
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| 73 | } |
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| 74 | |
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| 75 | // ==================================================================================================================== |
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| 76 | // Public member functions |
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| 77 | // ==================================================================================================================== |
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| 78 | |
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| 79 | Char* TComOutputBitstream::getByteStream() const |
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| 80 | { |
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[1029] | 81 | return (Char*) &m_fifo.front(); |
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[313] | 82 | } |
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| 83 | |
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| 84 | UInt TComOutputBitstream::getByteStreamLength() |
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| 85 | { |
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[1029] | 86 | return UInt(m_fifo.size()); |
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[313] | 87 | } |
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| 88 | |
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[1029] | 89 | Void TComOutputBitstream::clear() |
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[313] | 90 | { |
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[1029] | 91 | m_fifo.clear(); |
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[313] | 92 | m_held_bits = 0; |
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| 93 | m_num_held_bits = 0; |
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| 94 | } |
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| 95 | |
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| 96 | Void TComOutputBitstream::write ( UInt uiBits, UInt uiNumberOfBits ) |
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| 97 | { |
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| 98 | assert( uiNumberOfBits <= 32 ); |
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| 99 | assert( uiNumberOfBits == 32 || (uiBits & (~0 << uiNumberOfBits)) == 0 ); |
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| 100 | |
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| 101 | /* any modulo 8 remainder of num_total_bits cannot be written this time, |
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| 102 | * and will be held until next time. */ |
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| 103 | UInt num_total_bits = uiNumberOfBits + m_num_held_bits; |
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| 104 | UInt next_num_held_bits = num_total_bits % 8; |
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| 105 | |
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| 106 | /* form a byte aligned word (write_bits), by concatenating any held bits |
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| 107 | * with the new bits, discarding the bits that will form the next_held_bits. |
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| 108 | * eg: H = held bits, V = n new bits /---- next_held_bits |
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| 109 | * len(H)=7, len(V)=1: ... ---- HHHH HHHV . 0000 0000, next_num_held_bits=0 |
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| 110 | * len(H)=7, len(V)=2: ... ---- HHHH HHHV . V000 0000, next_num_held_bits=1 |
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| 111 | * if total_bits < 8, the value of v_ is not used */ |
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| 112 | UChar next_held_bits = uiBits << (8 - next_num_held_bits); |
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| 113 | |
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| 114 | if (!(num_total_bits >> 3)) |
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| 115 | { |
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| 116 | /* insufficient bits accumulated to write out, append new_held_bits to |
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| 117 | * current held_bits */ |
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| 118 | /* NB, this requires that v only contains 0 in bit positions {31..n} */ |
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| 119 | m_held_bits |= next_held_bits; |
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| 120 | m_num_held_bits = next_num_held_bits; |
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| 121 | return; |
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| 122 | } |
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| 123 | |
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| 124 | /* topword serves to justify held_bits to align with the msb of uiBits */ |
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| 125 | UInt topword = (uiNumberOfBits - next_num_held_bits) & ~((1 << 3) -1); |
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| 126 | UInt write_bits = (m_held_bits << topword) | (uiBits >> next_num_held_bits); |
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| 127 | |
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| 128 | switch (num_total_bits >> 3) |
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| 129 | { |
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[1029] | 130 | case 4: m_fifo.push_back(write_bits >> 24); |
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| 131 | case 3: m_fifo.push_back(write_bits >> 16); |
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| 132 | case 2: m_fifo.push_back(write_bits >> 8); |
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| 133 | case 1: m_fifo.push_back(write_bits); |
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[313] | 134 | } |
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| 135 | |
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| 136 | m_held_bits = next_held_bits; |
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| 137 | m_num_held_bits = next_num_held_bits; |
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| 138 | } |
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| 139 | |
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| 140 | Void TComOutputBitstream::writeAlignOne() |
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| 141 | { |
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| 142 | UInt num_bits = getNumBitsUntilByteAligned(); |
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| 143 | write((1 << num_bits) - 1, num_bits); |
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| 144 | return; |
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| 145 | } |
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| 146 | |
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| 147 | Void TComOutputBitstream::writeAlignZero() |
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| 148 | { |
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| 149 | if (0 == m_num_held_bits) |
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| 150 | { |
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| 151 | return; |
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| 152 | } |
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[1029] | 153 | m_fifo.push_back(m_held_bits); |
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[313] | 154 | m_held_bits = 0; |
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| 155 | m_num_held_bits = 0; |
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| 156 | } |
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| 157 | |
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| 158 | /** |
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| 159 | - add substream to the end of the current bitstream |
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| 160 | . |
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| 161 | \param pcSubstream substream to be added |
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| 162 | */ |
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| 163 | Void TComOutputBitstream::addSubstream( TComOutputBitstream* pcSubstream ) |
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| 164 | { |
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| 165 | UInt uiNumBits = pcSubstream->getNumberOfWrittenBits(); |
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| 166 | |
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| 167 | const vector<uint8_t>& rbsp = pcSubstream->getFIFO(); |
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| 168 | for (vector<uint8_t>::const_iterator it = rbsp.begin(); it != rbsp.end();) |
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| 169 | { |
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| 170 | write(*it++, 8); |
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| 171 | } |
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| 172 | if (uiNumBits&0x7) |
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| 173 | { |
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| 174 | write(pcSubstream->getHeldBits()>>(8-(uiNumBits&0x7)), uiNumBits&0x7); |
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| 175 | } |
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| 176 | } |
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| 177 | |
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| 178 | Void TComOutputBitstream::writeByteAlignment() |
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| 179 | { |
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| 180 | write( 1, 1); |
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| 181 | writeAlignZero(); |
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| 182 | } |
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| 183 | |
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| 184 | Int TComOutputBitstream::countStartCodeEmulations() |
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| 185 | { |
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| 186 | UInt cnt = 0; |
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| 187 | vector<uint8_t>& rbsp = getFIFO(); |
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| 188 | for (vector<uint8_t>::iterator it = rbsp.begin(); it != rbsp.end();) |
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| 189 | { |
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| 190 | vector<uint8_t>::iterator found = it; |
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| 191 | do |
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| 192 | { |
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| 193 | // find the next emulated 00 00 {00,01,02,03} |
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| 194 | // NB, end()-1, prevents finding a trailing two byte sequence |
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| 195 | found = search_n(found, rbsp.end()-1, 2, 0); |
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| 196 | found++; |
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| 197 | // if not found, found == end, otherwise found = second zero byte |
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| 198 | if (found == rbsp.end()) |
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| 199 | { |
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| 200 | break; |
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| 201 | } |
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| 202 | if (*(++found) <= 3) |
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| 203 | { |
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| 204 | break; |
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| 205 | } |
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| 206 | } while (true); |
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| 207 | it = found; |
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| 208 | if (found != rbsp.end()) |
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| 209 | { |
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| 210 | cnt++; |
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| 211 | } |
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| 212 | } |
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| 213 | return cnt; |
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| 214 | } |
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| 215 | |
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| 216 | /** |
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[1260] | 217 | * read uiNumberOfBits from bitstream without updating the bitstream |
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| 218 | * state, storing the result in ruiBits. |
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[313] | 219 | * |
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[1260] | 220 | * If reading uiNumberOfBits would overrun the bitstream buffer, |
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| 221 | * the bitstream is effectively padded with sufficient zero-bits to |
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[313] | 222 | * avoid the overrun. |
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| 223 | */ |
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| 224 | Void TComInputBitstream::pseudoRead ( UInt uiNumberOfBits, UInt& ruiBits ) |
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| 225 | { |
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| 226 | UInt saved_num_held_bits = m_num_held_bits; |
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| 227 | UChar saved_held_bits = m_held_bits; |
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| 228 | UInt saved_fifo_idx = m_fifo_idx; |
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[644] | 229 | #if P0138_USE_ALT_CPB_PARAMS_FLAG |
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| 230 | UInt saved_numBitsRead = m_numBitsRead; |
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| 231 | #endif |
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[313] | 232 | |
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| 233 | UInt num_bits_to_read = min(uiNumberOfBits, getNumBitsLeft()); |
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| 234 | read(num_bits_to_read, ruiBits); |
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| 235 | ruiBits <<= (uiNumberOfBits - num_bits_to_read); |
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| 236 | |
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| 237 | m_fifo_idx = saved_fifo_idx; |
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| 238 | m_held_bits = saved_held_bits; |
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| 239 | m_num_held_bits = saved_num_held_bits; |
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[644] | 240 | #if P0138_USE_ALT_CPB_PARAMS_FLAG |
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| 241 | m_numBitsRead = saved_numBitsRead; |
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| 242 | #endif |
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[313] | 243 | } |
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| 244 | |
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| 245 | |
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| 246 | Void TComInputBitstream::read (UInt uiNumberOfBits, UInt& ruiBits) |
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| 247 | { |
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| 248 | assert( uiNumberOfBits <= 32 ); |
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[1246] | 249 | |
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[313] | 250 | m_numBitsRead += uiNumberOfBits; |
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| 251 | |
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| 252 | /* NB, bits are extracted from the MSB of each byte. */ |
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| 253 | UInt retval = 0; |
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| 254 | if (uiNumberOfBits <= m_num_held_bits) |
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| 255 | { |
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| 256 | /* n=1, len(H)=7: -VHH HHHH, shift_down=6, mask=0xfe |
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| 257 | * n=3, len(H)=7: -VVV HHHH, shift_down=4, mask=0xf8 |
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| 258 | */ |
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| 259 | retval = m_held_bits >> (m_num_held_bits - uiNumberOfBits); |
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| 260 | retval &= ~(0xff << uiNumberOfBits); |
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| 261 | m_num_held_bits -= uiNumberOfBits; |
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| 262 | ruiBits = retval; |
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| 263 | return; |
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| 264 | } |
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| 265 | |
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| 266 | /* all num_held_bits will go into retval |
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| 267 | * => need to mask leftover bits from previous extractions |
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| 268 | * => align retval with top of extracted word */ |
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| 269 | /* n=5, len(H)=3: ---- -VVV, mask=0x07, shift_up=5-3=2, |
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| 270 | * n=9, len(H)=3: ---- -VVV, mask=0x07, shift_up=9-3=6 */ |
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| 271 | uiNumberOfBits -= m_num_held_bits; |
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| 272 | retval = m_held_bits & ~(0xff << m_num_held_bits); |
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| 273 | retval <<= uiNumberOfBits; |
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| 274 | |
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| 275 | /* number of whole bytes that need to be loaded to form retval */ |
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| 276 | /* n=32, len(H)=0, load 4bytes, shift_down=0 |
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| 277 | * n=32, len(H)=1, load 4bytes, shift_down=1 |
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| 278 | * n=31, len(H)=1, load 4bytes, shift_down=1+1 |
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| 279 | * n=8, len(H)=0, load 1byte, shift_down=0 |
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| 280 | * n=8, len(H)=3, load 1byte, shift_down=3 |
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| 281 | * n=5, len(H)=1, load 1byte, shift_down=1+3 |
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| 282 | */ |
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| 283 | UInt aligned_word = 0; |
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| 284 | UInt num_bytes_to_load = (uiNumberOfBits - 1) >> 3; |
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| 285 | assert(m_fifo_idx + num_bytes_to_load < m_fifo->size()); |
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| 286 | |
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| 287 | switch (num_bytes_to_load) |
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| 288 | { |
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| 289 | case 3: aligned_word = (*m_fifo)[m_fifo_idx++] << 24; |
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| 290 | case 2: aligned_word |= (*m_fifo)[m_fifo_idx++] << 16; |
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| 291 | case 1: aligned_word |= (*m_fifo)[m_fifo_idx++] << 8; |
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| 292 | case 0: aligned_word |= (*m_fifo)[m_fifo_idx++]; |
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| 293 | } |
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| 294 | |
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| 295 | /* resolve remainder bits */ |
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| 296 | UInt next_num_held_bits = (32 - uiNumberOfBits) % 8; |
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| 297 | |
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| 298 | /* copy required part of aligned_word into retval */ |
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| 299 | retval |= aligned_word >> next_num_held_bits; |
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| 300 | |
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| 301 | /* store held bits */ |
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| 302 | m_num_held_bits = next_num_held_bits; |
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| 303 | m_held_bits = aligned_word; |
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| 304 | |
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| 305 | ruiBits = retval; |
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| 306 | } |
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| 307 | |
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| 308 | /** |
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| 309 | * insert the contents of the bytealigned (and flushed) bitstream src |
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| 310 | * into this at byte position pos. |
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| 311 | */ |
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[1029] | 312 | Void TComOutputBitstream::insertAt(const TComOutputBitstream& src, UInt pos) |
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[313] | 313 | { |
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| 314 | UInt src_bits = src.getNumberOfWrittenBits(); |
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| 315 | assert(0 == src_bits % 8); |
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| 316 | |
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[1029] | 317 | vector<uint8_t>::iterator at = m_fifo.begin() + pos; |
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| 318 | m_fifo.insert(at, src.m_fifo.begin(), src.m_fifo.end()); |
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[313] | 319 | } |
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| 320 | |
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[1029] | 321 | UInt TComInputBitstream::readOutTrailingBits () |
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[313] | 322 | { |
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[1029] | 323 | UInt count=0; |
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[313] | 324 | UInt uiBits = 0; |
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| 325 | |
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| 326 | while ( ( getNumBitsLeft() > 0 ) && (getNumBitsUntilByteAligned()!=0) ) |
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| 327 | { |
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[1029] | 328 | count++; |
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[313] | 329 | read ( 1, uiBits ); |
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| 330 | } |
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[1029] | 331 | return count; |
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[313] | 332 | } |
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[1029] | 333 | // |
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| 334 | //TComOutputBitstream& TComOutputBitstream::operator= (const TComOutputBitstream& src) |
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| 335 | //{ |
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| 336 | // vector<uint8_t>::iterator at = m_fifo.begin(); |
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| 337 | // m_fifo.insert(at, src.m_fifo.begin(), src.m_fifo.end()); |
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| 338 | // |
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| 339 | // m_num_held_bits = src.m_num_held_bits; |
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| 340 | // m_held_bits = src.m_held_bits; |
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| 341 | // |
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| 342 | // return *this; |
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| 343 | //} |
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[313] | 344 | |
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| 345 | /** |
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[1260] | 346 | Extract substream from the current bitstream. |
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| 347 | |
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[313] | 348 | \param uiNumBits number of bits to transfer |
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| 349 | */ |
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| 350 | TComInputBitstream *TComInputBitstream::extractSubstream( UInt uiNumBits ) |
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| 351 | { |
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| 352 | UInt uiNumBytes = uiNumBits/8; |
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| 353 | std::vector<uint8_t>* buf = new std::vector<uint8_t>; |
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| 354 | UInt uiByte; |
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| 355 | for (UInt ui = 0; ui < uiNumBytes; ui++) |
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| 356 | { |
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| 357 | read(8, uiByte); |
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| 358 | buf->push_back(uiByte); |
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| 359 | } |
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| 360 | if (uiNumBits&0x7) |
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| 361 | { |
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| 362 | uiByte = 0; |
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| 363 | read(uiNumBits&0x7, uiByte); |
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| 364 | uiByte <<= 8-(uiNumBits&0x7); |
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| 365 | buf->push_back(uiByte); |
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| 366 | } |
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| 367 | return new TComInputBitstream(buf); |
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| 368 | } |
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| 369 | |
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| 370 | /** |
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| 371 | - delete internal fifo |
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| 372 | */ |
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| 373 | Void TComInputBitstream::deleteFifo() |
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| 374 | { |
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| 375 | delete m_fifo; |
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| 376 | m_fifo = NULL; |
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| 377 | } |
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| 378 | |
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[1029] | 379 | UInt TComInputBitstream::readByteAlignment() |
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[313] | 380 | { |
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| 381 | UInt code = 0; |
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| 382 | read( 1, code ); |
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| 383 | assert(code == 1); |
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| 384 | |
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| 385 | UInt numBits = getNumBitsUntilByteAligned(); |
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| 386 | if(numBits) |
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| 387 | { |
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| 388 | assert(numBits <= getNumBitsLeft()); |
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| 389 | read( numBits, code ); |
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| 390 | assert(code == 0); |
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| 391 | } |
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[1029] | 392 | return numBits+1; |
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[313] | 393 | } |
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| 394 | |
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| 395 | //! \} |
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