[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.h |
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| 35 | \brief class for handling bitstream (header) |
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| 36 | */ |
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| 37 | |
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[1029] | 38 | #ifndef __TCOMBITSTREAM__ |
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| 39 | #define __TCOMBITSTREAM__ |
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[313] | 40 | |
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| 41 | #if _MSC_VER > 1000 |
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| 42 | #pragma once |
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| 43 | #endif // _MSC_VER > 1000 |
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| 44 | |
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| 45 | #include <stdint.h> |
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| 46 | #include <vector> |
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| 47 | #include <stdio.h> |
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| 48 | #include "CommonDef.h" |
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| 49 | |
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| 50 | //! \ingroup TLibCommon |
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| 51 | //! \{ |
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| 52 | |
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| 53 | // ==================================================================================================================== |
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| 54 | // Class definition |
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| 55 | // ==================================================================================================================== |
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| 56 | |
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| 57 | /// pure virtual class for basic bit handling |
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| 58 | class TComBitIf |
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| 59 | { |
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| 60 | public: |
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| 61 | virtual Void writeAlignOne () {}; |
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| 62 | virtual Void writeAlignZero () {}; |
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| 63 | virtual Void write ( UInt uiBits, UInt uiNumberOfBits ) = 0; |
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| 64 | virtual Void resetBits () = 0; |
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| 65 | virtual UInt getNumberOfWrittenBits() const = 0; |
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| 66 | virtual ~TComBitIf() {} |
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| 67 | }; |
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| 68 | |
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| 69 | /** |
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| 70 | * Model of a writable bitstream that accumulates bits to produce a |
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| 71 | * bytestream. |
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| 72 | */ |
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| 73 | class TComOutputBitstream : public TComBitIf |
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| 74 | { |
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| 75 | /** |
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| 76 | * FIFO for storage of bytes. Use: |
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| 77 | * - fifo.push_back(x) to append words |
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| 78 | * - fifo.clear() to empty the FIFO |
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| 79 | * - &fifo.front() to get a pointer to the data array. |
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| 80 | * NB, this pointer is only valid until the next push_back()/clear() |
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| 81 | */ |
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[1029] | 82 | std::vector<uint8_t> m_fifo; |
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[313] | 83 | |
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| 84 | UInt m_num_held_bits; /// number of bits not flushed to bytestream. |
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| 85 | UChar m_held_bits; /// the bits held and not flushed to bytestream. |
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| 86 | /// this value is always msb-aligned, bigendian. |
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| 87 | public: |
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| 88 | // create / destroy |
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| 89 | TComOutputBitstream(); |
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| 90 | ~TComOutputBitstream(); |
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| 91 | |
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| 92 | // interface for encoding |
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| 93 | /** |
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| 94 | * append uiNumberOfBits least significant bits of uiBits to |
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| 95 | * the current bitstream |
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| 96 | */ |
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| 97 | Void write ( UInt uiBits, UInt uiNumberOfBits ); |
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| 98 | |
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| 99 | /** insert one bits until the bitstream is byte-aligned */ |
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| 100 | Void writeAlignOne (); |
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| 101 | |
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| 102 | /** insert zero bits until the bitstream is byte-aligned */ |
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| 103 | Void writeAlignZero (); |
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| 104 | |
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| 105 | /** this function should never be called */ |
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[1029] | 106 | Void resetBits() { assert(0); } |
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[313] | 107 | |
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| 108 | // utility functions |
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| 109 | |
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| 110 | /** |
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| 111 | * Return a pointer to the start of the byte-stream buffer. |
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| 112 | * Pointer is valid until the next write/flush/reset call. |
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| 113 | * NB, data is arranged such that subsequent bytes in the |
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| 114 | * bytestream are stored in ascending addresses. |
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| 115 | */ |
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| 116 | Char* getByteStream() const; |
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| 117 | |
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| 118 | /** |
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| 119 | * Return the number of valid bytes available from getByteStream() |
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| 120 | */ |
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| 121 | UInt getByteStreamLength(); |
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| 122 | |
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| 123 | /** |
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| 124 | * Reset all internal state. |
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| 125 | */ |
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| 126 | Void clear(); |
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| 127 | |
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| 128 | /** |
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| 129 | * returns the number of bits that need to be written to |
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| 130 | * achieve byte alignment. |
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| 131 | */ |
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| 132 | Int getNumBitsUntilByteAligned() { return (8 - m_num_held_bits) & 0x7; } |
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| 133 | |
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| 134 | /** |
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| 135 | * Return the number of bits that have been written since the last clear() |
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| 136 | */ |
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[1029] | 137 | UInt getNumberOfWrittenBits() const { return UInt(m_fifo.size()) * 8 + m_num_held_bits; } |
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[313] | 138 | |
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[1029] | 139 | Void insertAt(const TComOutputBitstream& src, UInt pos); |
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[313] | 140 | |
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| 141 | /** |
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| 142 | * Return a reference to the internal fifo |
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| 143 | */ |
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[1029] | 144 | std::vector<uint8_t>& getFIFO() { return m_fifo; } |
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[313] | 145 | |
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| 146 | UChar getHeldBits () { return m_held_bits; } |
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| 147 | |
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[1029] | 148 | //TComOutputBitstream& operator= (const TComOutputBitstream& src); |
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[313] | 149 | /** Return a reference to the internal fifo */ |
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[1029] | 150 | const std::vector<uint8_t>& getFIFO() const { return m_fifo; } |
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[313] | 151 | |
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| 152 | Void addSubstream ( TComOutputBitstream* pcSubstream ); |
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| 153 | Void writeByteAlignment(); |
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| 154 | |
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| 155 | //! returns the number of start code emulations contained in the current buffer |
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| 156 | Int countStartCodeEmulations(); |
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| 157 | }; |
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| 158 | |
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| 159 | /** |
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| 160 | * Model of an input bitstream that extracts bits from a predefined |
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| 161 | * bytestream. |
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| 162 | */ |
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| 163 | class TComInputBitstream |
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| 164 | { |
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| 165 | std::vector<uint8_t> *m_fifo; /// FIFO for storage of complete bytes |
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| 166 | std::vector<UInt> m_emulationPreventionByteLocation; |
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| 167 | |
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| 168 | protected: |
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| 169 | UInt m_fifo_idx; /// Read index into m_fifo |
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| 170 | |
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| 171 | UInt m_num_held_bits; |
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| 172 | UChar m_held_bits; |
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| 173 | UInt m_numBitsRead; |
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| 174 | |
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| 175 | public: |
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| 176 | /** |
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[1260] | 177 | * Create a new bitstream reader object that reads from buf. Ownership |
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| 178 | * of buf remains with the callee, although the constructed object |
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| 179 | * will hold a reference to buf |
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[313] | 180 | */ |
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| 181 | TComInputBitstream(std::vector<uint8_t>* buf); |
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| 182 | ~TComInputBitstream(); |
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| 183 | |
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| 184 | // interface for decoding |
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| 185 | Void pseudoRead ( UInt uiNumberOfBits, UInt& ruiBits ); |
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| 186 | Void read ( UInt uiNumberOfBits, UInt& ruiBits ); |
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| 187 | Void readByte ( UInt &ruiBits ) |
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| 188 | { |
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| 189 | assert(m_fifo_idx < m_fifo->size()); |
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| 190 | ruiBits = (*m_fifo)[m_fifo_idx++]; |
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| 191 | } |
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| 192 | |
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| 193 | Void peekPreviousByte( UInt &byte ) |
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| 194 | { |
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| 195 | assert(m_fifo_idx > 0); |
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| 196 | byte = (*m_fifo)[m_fifo_idx - 1]; |
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| 197 | } |
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[1246] | 198 | |
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[1029] | 199 | UInt readOutTrailingBits (); |
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[313] | 200 | UChar getHeldBits () { return m_held_bits; } |
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| 201 | TComOutputBitstream& operator= (const TComOutputBitstream& src); |
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| 202 | UInt getByteLocation ( ) { return m_fifo_idx ; } |
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| 203 | |
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| 204 | // Peek at bits in word-storage. Used in determining if we have completed reading of current bitstream and therefore slice in LCEC. |
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| 205 | UInt peekBits (UInt uiBits) { UInt tmp; pseudoRead(uiBits, tmp); return tmp; } |
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| 206 | |
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| 207 | // utility functions |
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| 208 | UInt read(UInt numberOfBits) { UInt tmp; read(numberOfBits, tmp); return tmp; } |
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| 209 | UInt readByte() { UInt tmp; readByte( tmp ); return tmp; } |
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| 210 | UInt getNumBitsUntilByteAligned() { return m_num_held_bits & (0x7); } |
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| 211 | UInt getNumBitsLeft() { return 8*((UInt)m_fifo->size() - m_fifo_idx) + m_num_held_bits; } |
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| 212 | TComInputBitstream *extractSubstream( UInt uiNumBits ); // Read the nominated number of bits, and return as a bitstream. |
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| 213 | Void deleteFifo(); // Delete internal fifo of bitstream. |
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| 214 | UInt getNumBitsRead() { return m_numBitsRead; } |
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[1029] | 215 | UInt readByteAlignment(); |
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[313] | 216 | |
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| 217 | Void pushEmulationPreventionByteLocation ( UInt pos ) { m_emulationPreventionByteLocation.push_back( pos ); } |
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| 218 | UInt numEmulationPreventionBytesRead () { return (UInt) m_emulationPreventionByteLocation.size(); } |
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| 219 | std::vector<UInt> getEmulationPreventionByteLocation () { return m_emulationPreventionByteLocation; } |
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| 220 | UInt getEmulationPreventionByteLocation ( UInt idx ) { return m_emulationPreventionByteLocation[ idx ]; } |
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| 221 | Void clearEmulationPreventionByteLocation() { m_emulationPreventionByteLocation.clear(); } |
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| 222 | Void setEmulationPreventionByteLocation ( std::vector<UInt> vec ) { m_emulationPreventionByteLocation = vec; } |
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[1235] | 223 | |
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| 224 | const std::vector<uint8_t> *getFifo() const { return m_fifo; } |
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[313] | 225 | }; |
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| 226 | |
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| 227 | //! \} |
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| 228 | |
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| 229 | #endif |
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