source: 3DVCSoftware/trunk/source/Lib/TLibCommon/TComBitStream.h @ 724

Last change on this file since 724 was 608, checked in by tech, 11 years ago

Merged DEV-2.0-dev0@604.

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[5]1/* The copyright in this software is being made available under the BSD
2 * License, included below. This software may be subject to other third party
3 * and contributor rights, including patent rights, and no such rights are
[56]4 * granted under this license. 
[5]5 *
[608]6 * Copyright (c) 2010-2013, ITU/ISO/IEC
[5]7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 *
12 *  * Redistributions of source code must retain the above copyright notice,
13 *    this list of conditions and the following disclaimer.
14 *  * Redistributions in binary form must reproduce the above copyright notice,
15 *    this list of conditions and the following disclaimer in the documentation
16 *    and/or other materials provided with the distribution.
[56]17 *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
[5]18 *    be used to endorse or promote products derived from this software without
19 *    specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
31 * THE POSSIBILITY OF SUCH DAMAGE.
32 */
[2]33
34/** \file     TComBitStream.h
35    \brief    class for handling bitstream (header)
36*/
37
38#ifndef __COMBITSTREAM__
39#define __COMBITSTREAM__
40
41#if _MSC_VER > 1000
42#pragma once
43#endif // _MSC_VER > 1000
44
[56]45#include <stdint.h>
46#include <vector>
[2]47#include <stdio.h>
48#include <assert.h>
49#include "CommonDef.h"
50
[56]51//! \ingroup TLibCommon
52//! \{
53
[2]54// ====================================================================================================================
55// Class definition
56// ====================================================================================================================
57
58/// pure virtual class for basic bit handling
59class TComBitIf
60{
61public:
62  virtual Void        writeAlignOne         () {};
[56]63  virtual Void        writeAlignZero        () {};
[2]64  virtual Void        write                 ( UInt uiBits, UInt uiNumberOfBits )  = 0;
65  virtual Void        resetBits             ()                                    = 0;
66  virtual UInt getNumberOfWrittenBits() const = 0;
67  virtual ~TComBitIf() {}
68};
69
[56]70/**
71 * Model of a writable bitstream that accumulates bits to produce a
72 * bytestream.
73 */
74class TComOutputBitstream : public TComBitIf
[2]75{
[56]76  /**
77   * FIFO for storage of bytes.  Use:
78   *  - fifo.push_back(x) to append words
79   *  - fifo.clear() to empty the FIFO
80   *  - &fifo.front() to get a pointer to the data array.
81   *    NB, this pointer is only valid until the next push_back()/clear()
82   */
83  std::vector<uint8_t> *m_fifo;
[2]84
[608]85  UInt m_num_held_bits; /// number of bits not flushed to bytestream.
86  UChar m_held_bits; /// the bits held and not flushed to bytestream.
[56]87                             /// this value is always msb-aligned, bigendian.
[42]88
[2]89public:
90  // create / destroy
[56]91  TComOutputBitstream();
92  ~TComOutputBitstream();
93
[2]94  // interface for encoding
[56]95  /**
96   * append uiNumberOfBits least significant bits of uiBits to
97   * the current bitstream
98   */
[2]99  Void        write           ( UInt uiBits, UInt uiNumberOfBits );
[56]100
101  /** insert one bits until the bitstream is byte-aligned */
[2]102  Void        writeAlignOne   ();
[56]103
104  /** insert zero bits until the bitstream is byte-aligned */
[2]105  Void        writeAlignZero  ();
[56]106
107  /** this function should never be called */
108  void resetBits() { assert(0); }
109
110  // utility functions
111
112  /**
113   * Return a pointer to the start of the byte-stream buffer.
114   * Pointer is valid until the next write/flush/reset call.
115   * NB, data is arranged such that subsequent bytes in the
116   * bytestream are stored in ascending addresses.
117   */
[608]118  Char* getByteStream() const;
[56]119
120  /**
121   * Return the number of valid bytes available from  getByteStream()
122   */
[608]123  UInt getByteStreamLength();
[56]124
125  /**
126   * Reset all internal state.
127   */
128  Void clear();
129
130  /**
131   * returns the number of bits that need to be written to
132   * achieve byte alignment.
133   */
134  Int getNumBitsUntilByteAligned() { return (8 - m_num_held_bits) & 0x7; }
135
136  /**
137   * Return the number of bits that have been written since the last clear()
138   */
[608]139  UInt getNumberOfWrittenBits() const { return UInt(m_fifo->size()) * 8 + m_num_held_bits; }
[56]140
[608]141  void insertAt(const TComOutputBitstream& src, UInt pos);
[56]142
143  /**
144   * Return a reference to the internal fifo
145   */
146  std::vector<uint8_t>& getFIFO() { return *m_fifo; }
147
148  UChar getHeldBits  ()          { return m_held_bits;          }
149
150  TComOutputBitstream& operator= (const TComOutputBitstream& src);
151  /** Return a reference to the internal fifo */
152  std::vector<uint8_t>& getFIFO() const { return *m_fifo; }
153
154  Void          addSubstream    ( TComOutputBitstream* pcSubstream );
[608]155  Void writeByteAlignment();
156
157  //! returns the number of start code emulations contained in the current buffer
158  Int countStartCodeEmulations();
[56]159};
160
161/**
162 * Model of an input bitstream that extracts bits from a predefined
163 * bytestream.
164 */
165class TComInputBitstream
166{
167  std::vector<uint8_t> *m_fifo; /// FIFO for storage of complete bytes
[608]168  std::vector<UInt> m_emulationPreventionByteLocation;
[56]169
170protected:
[608]171  UInt m_fifo_idx; /// Read index into m_fifo
[56]172
[608]173  UInt m_num_held_bits;
174  UChar m_held_bits;
[56]175  UInt  m_numBitsRead;
176
177public:
178  /**
179   * Create a new bitstream reader object that reads from #buf#.  Ownership
180   * of #buf# remains with the callee, although the constructed object
181   * will hold a reference to #buf#
182   */
183  TComInputBitstream(std::vector<uint8_t>* buf);
184  ~TComInputBitstream();
185
[2]186  // interface for decoding
187  Void        pseudoRead      ( UInt uiNumberOfBits, UInt& ruiBits );
188  Void        read            ( UInt uiNumberOfBits, UInt& ruiBits );
[56]189  Void        readByte        ( UInt &ruiBits )
190  {
191    assert(m_fifo_idx < m_fifo->size());
192    ruiBits = (*m_fifo)[m_fifo_idx++];
193  }
[2]194
[608]195  Void        peekPreviousByte( UInt &byte )
196  {
197    assert(m_fifo_idx > 0);
198    byte = (*m_fifo)[m_fifo_idx - 1];
199  }
200 
[56]201  Void        readOutTrailingBits ();
202  UChar getHeldBits  ()          { return m_held_bits;          }
203  TComOutputBitstream& operator= (const TComOutputBitstream& src);
204  UInt  getByteLocation              ( )                     { return m_fifo_idx                    ; }
[2]205
206  // Peek at bits in word-storage. Used in determining if we have completed reading of current bitstream and therefore slice in LCEC.
[608]207  UInt        peekBits (UInt uiBits) { UInt tmp; pseudoRead(uiBits, tmp); return tmp; }
[2]208
209  // utility functions
[608]210  UInt read(UInt numberOfBits) { UInt tmp; read(numberOfBits, tmp); return tmp; }
[56]211  UInt     readByte() { UInt tmp; readByte( tmp ); return tmp; }
[608]212  UInt getNumBitsUntilByteAligned() { return m_num_held_bits & (0x7); }
213  UInt getNumBitsLeft() { return 8*((UInt)m_fifo->size() - m_fifo_idx) + m_num_held_bits; }
[56]214  TComInputBitstream *extractSubstream( UInt uiNumBits ); // Read the nominated number of bits, and return as a bitstream.
215  Void                deleteFifo(); // Delete internal fifo of bitstream.
216  UInt  getNumBitsRead() { return m_numBitsRead; }
[608]217  Void readByteAlignment();
218
219  Void      pushEmulationPreventionByteLocation ( UInt pos )                  { m_emulationPreventionByteLocation.push_back( pos ); }
220  UInt      numEmulationPreventionBytesRead     ()                            { return (UInt) m_emulationPreventionByteLocation.size();    }
221  std::vector<UInt>  getEmulationPreventionByteLocation  ()                   { return m_emulationPreventionByteLocation;           }
222  UInt      getEmulationPreventionByteLocation  ( UInt idx )                  { return m_emulationPreventionByteLocation[ idx ];    }
223  Void      clearEmulationPreventionByteLocation()                            { m_emulationPreventionByteLocation.clear();          }
224  Void      setEmulationPreventionByteLocation  ( std::vector<UInt> vec )     { m_emulationPreventionByteLocation = vec;            }
[56]225};
[2]226
[56]227//! \}
[42]228
[2]229#endif
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