source: 3DVCSoftware/branches/HTM-7.0-Fix/source/Lib/TLibCommon/TComBitStream.h @ 458

Last change on this file since 458 was 296, checked in by tech, 11 years ago

Reintegrated branch 5.1-dev0 rev. 295.

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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
4 * granted under this license. 
5 *
6 * Copyright (c) 2010-2012, ITU/ISO/IEC
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.
17 *  * Neither the name of the ITU/ISO/IEC nor the names of its contributors may
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 */
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
45#include <stdint.h>
46#include <vector>
47#include <stdio.h>
48#include <assert.h>
49#include "CommonDef.h"
50
51//! \ingroup TLibCommon
52//! \{
53
54// ====================================================================================================================
55// Class definition
56// ====================================================================================================================
57
58/// pure virtual class for basic bit handling
59class TComBitIf
60{
61public:
62  virtual Void        writeAlignOne         () {};
63  virtual Void        writeAlignZero        () {};
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
70/**
71 * Model of a writable bitstream that accumulates bits to produce a
72 * bytestream.
73 */
74class TComOutputBitstream : public TComBitIf
75{
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;
84
85  unsigned int m_num_held_bits; /// number of bits not flushed to bytestream.
86  unsigned char m_held_bits; /// the bits held and not flushed to bytestream.
87                             /// this value is always msb-aligned, bigendian.
88  UInt m_uiTileMarkerLocationCount;
89  UInt *m_puiTileMarkerLocation;
90
91public:
92  // create / destroy
93  TComOutputBitstream();
94  ~TComOutputBitstream();
95
96  // interface for encoding
97  /**
98   * append uiNumberOfBits least significant bits of uiBits to
99   * the current bitstream
100   */
101  Void        write           ( UInt uiBits, UInt uiNumberOfBits );
102
103  /** insert one bits until the bitstream is byte-aligned */
104  Void        writeAlignOne   ();
105
106  /** insert zero bits until the bitstream is byte-aligned */
107  Void        writeAlignZero  ();
108
109  /** this function should never be called */
110  void resetBits() { assert(0); }
111
112  // utility functions
113
114  /**
115   * Return a pointer to the start of the byte-stream buffer.
116   * Pointer is valid until the next write/flush/reset call.
117   * NB, data is arranged such that subsequent bytes in the
118   * bytestream are stored in ascending addresses.
119   */
120  char* getByteStream() const;
121
122  /**
123   * Return the number of valid bytes available from  getByteStream()
124   */
125  unsigned int getByteStreamLength();
126
127  /**
128   * Reset all internal state.
129   */
130  Void clear();
131
132  /**
133   * returns the number of bits that need to be written to
134   * achieve byte alignment.
135   */
136  Int getNumBitsUntilByteAligned() { return (8 - m_num_held_bits) & 0x7; }
137
138  /**
139   * Return the number of bits that have been written since the last clear()
140   */
141  unsigned getNumberOfWrittenBits() const { return unsigned(m_fifo->size()) * 8 + m_num_held_bits; }
142
143  void insertAt(const TComOutputBitstream& src, unsigned pos);
144
145  /**
146   * Return a reference to the internal fifo
147   */
148  std::vector<uint8_t>& getFIFO() { return *m_fifo; }
149
150  UChar getHeldBits  ()          { return m_held_bits;          }
151
152  TComOutputBitstream& operator= (const TComOutputBitstream& src);
153  UInt  getTileMarkerLocationCount   ( )                     { return m_uiTileMarkerLocationCount   ; }
154  Void  setTileMarkerLocationCount   ( UInt i )              { m_uiTileMarkerLocationCount = i      ; } 
155  UInt  getTileMarkerLocation        ( UInt i)               { return m_puiTileMarkerLocation[i]    ; }
156  Void  setTileMarkerLocation        ( UInt i, UInt uiLOC )  { m_puiTileMarkerLocation[i] = uiLOC   ; }
157  /** Return a reference to the internal fifo */
158  std::vector<uint8_t>& getFIFO() const { return *m_fifo; }
159
160  Void          addSubstream    ( TComOutputBitstream* pcSubstream );
161};
162
163/**
164 * Model of an input bitstream that extracts bits from a predefined
165 * bytestream.
166 */
167class TComInputBitstream
168{
169  std::vector<uint8_t> *m_fifo; /// FIFO for storage of complete bytes
170
171protected:
172  unsigned int m_fifo_idx; /// Read index into m_fifo
173
174  unsigned int m_num_held_bits;
175  unsigned char m_held_bits;
176  UInt m_uiTileMarkerLocationCount;
177  UInt *m_puiTileMarkerLocation;
178  UInt  m_numBitsRead;
179
180public:
181  /**
182   * Create a new bitstream reader object that reads from #buf#.  Ownership
183   * of #buf# remains with the callee, although the constructed object
184   * will hold a reference to #buf#
185   */
186  TComInputBitstream(std::vector<uint8_t>* buf);
187  ~TComInputBitstream();
188
189  // interface for decoding
190  Void        pseudoRead      ( UInt uiNumberOfBits, UInt& ruiBits );
191  Void        read            ( UInt uiNumberOfBits, UInt& ruiBits );
192#if !OL_FLUSH_ALIGN
193  Void        readByte        ( UInt &ruiBits )
194  {
195    // More expensive, but reads "bytes" that are not aligned.
196    read(8, ruiBits);
197  }
198#else
199  Void        readByte        ( UInt &ruiBits )
200  {
201    assert(m_fifo_idx < m_fifo->size());
202    ruiBits = (*m_fifo)[m_fifo_idx++];
203  }
204#endif // OL_FLUSH && !OL_FLUSH_ALIGN
205
206  Void        readOutTrailingBits ();
207  UChar getHeldBits  ()          { return m_held_bits;          }
208  TComOutputBitstream& operator= (const TComOutputBitstream& src);
209  UInt  getTileMarkerLocationCount   ( )                     { return m_uiTileMarkerLocationCount   ; }
210  Void  setTileMarkerLocationCount   ( UInt i )              { m_uiTileMarkerLocationCount = i      ; } 
211  UInt  getTileMarkerLocation        ( UInt i)               { return m_puiTileMarkerLocation[i]    ; }
212  Void  setTileMarkerLocation        ( UInt i, UInt uiLOC )  { m_puiTileMarkerLocation[i] = uiLOC   ; }
213  UInt  getByteLocation              ( )                     { return m_fifo_idx                    ; }
214
215  // Peek at bits in word-storage. Used in determining if we have completed reading of current bitstream and therefore slice in LCEC.
216  UInt        peekBits (UInt uiBits) { unsigned tmp; pseudoRead(uiBits, tmp); return tmp; }
217
218  // utility functions
219  unsigned read(unsigned numberOfBits) { UInt tmp; read(numberOfBits, tmp); return tmp; }
220  UInt     readByte() { UInt tmp; readByte( tmp ); return tmp; }
221  unsigned getNumBitsUntilByteAligned() { return m_num_held_bits & (0x7); }
222  unsigned getNumBitsLeft() { return 8*((unsigned)m_fifo->size() - m_fifo_idx) + m_num_held_bits; }
223  TComInputBitstream *extractSubstream( UInt uiNumBits ); // Read the nominated number of bits, and return as a bitstream.
224  Void                deleteFifo(); // Delete internal fifo of bitstream.
225#if !OL_FLUSH_ALIGN
226  Void                backupByte() { m_fifo_idx--; }
227#endif
228  UInt  getNumBitsRead() { return m_numBitsRead; }
229};
230
231//! \}
232
233#endif
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