source: 3DVCSoftware/branches/HTM-DEV-0.1-dev/source/Lib/TLibEncoder/NALwrite.cpp @ 367

Last change on this file since 367 was 367, checked in by tech, 11 years ago

Further minor cleanups.

  • Property svn:eol-style set to native
File size: 5.2 KB
Line 
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) 2010-2013, 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#include <vector>
35#include <algorithm>
36#include <ostream>
37
38#include "TLibCommon/NAL.h"
39#include "TLibCommon/TComBitStream.h"
40#include "NALwrite.h"
41
42using namespace std;
43
44//! \ingroup TLibEncoder
45//! \{
46
47static const Char emulation_prevention_three_byte[] = {3};
48
49Void writeNalUnitHeader(ostream& out, OutputNALUnit& nalu)       // nal_unit_header()
50{
51TComOutputBitstream bsNALUHeader;
52
53  bsNALUHeader.write(0,1);                    // forbidden_zero_bit
54  bsNALUHeader.write(nalu.m_nalUnitType, 6);  // nal_unit_type
55  bsNALUHeader.write(nalu.m_reservedZero6Bits, 6);                   // nuh_reserved_zero_6bits
56  bsNALUHeader.write(nalu.m_temporalId+1, 3); // nuh_temporal_id_plus1
57
58  out.write(bsNALUHeader.getByteStream(), bsNALUHeader.getByteStreamLength());
59}
60/**
61 * write nalu to bytestream out, performing RBSP anti startcode
62 * emulation as required.  nalu.m_RBSPayload must be byte aligned.
63 */
64void write(ostream& out, OutputNALUnit& nalu)
65{
66  writeNalUnitHeader(out, nalu);
67  /* write out rsbp_byte's, inserting any required
68   * emulation_prevention_three_byte's */
69  /* 7.4.1 ...
70   * emulation_prevention_three_byte is a byte equal to 0x03. When an
71   * emulation_prevention_three_byte is present in the NAL unit, it shall be
72   * discarded by the decoding process.
73   * The last byte of the NAL unit shall not be equal to 0x00.
74   * Within the NAL unit, the following three-byte sequences shall not occur at
75   * any byte-aligned position:
76   *  - 0x000000
77   *  - 0x000001
78   *  - 0x000002
79   * Within the NAL unit, any four-byte sequence that starts with 0x000003
80   * other than the following sequences shall not occur at any byte-aligned
81   * position:
82   *  - 0x00000300
83   *  - 0x00000301
84   *  - 0x00000302
85   *  - 0x00000303
86   */
87  vector<uint8_t>& rbsp   = nalu.m_Bitstream.getFIFO();
88
89  for (vector<uint8_t>::iterator it = rbsp.begin(); it != rbsp.end();)
90  {
91    /* 1) find the next emulated 00 00 {00,01,02,03}
92     * 2a) if not found, write all remaining bytes out, stop.
93     * 2b) otherwise, write all non-emulated bytes out
94     * 3) insert emulation_prevention_three_byte
95     */
96    vector<uint8_t>::iterator found = it;
97    do
98    {
99      /* NB, end()-1, prevents finding a trailing two byte sequence */
100      found = search_n(found, rbsp.end()-1, 2, 0);
101      found++;
102      /* if not found, found == end, otherwise found = second zero byte */
103      if (found == rbsp.end())
104        break;
105      if (*(++found) <= 3)
106        break;
107    } while (true);
108
109    it = found;
110    if (found != rbsp.end())
111    {
112      it = rbsp.insert(found, emulation_prevention_three_byte[0]);
113    }
114  }
115
116  out.write((Char*)&(*rbsp.begin()), rbsp.end() - rbsp.begin());
117
118  /* 7.4.1.1
119   * ... when the last byte of the RBSP data is equal to 0x00 (which can
120   * only occur when the RBSP ends in a cabac_zero_word), a final byte equal
121   * to 0x03 is appended to the end of the data.
122   */
123  if (rbsp.back() == 0x00)
124  {
125    out.write(emulation_prevention_three_byte, 1);
126  }
127}
128
129/**
130 * Write rbsp_trailing_bits to bs causing it to become byte-aligned
131 */
132void writeRBSPTrailingBits(TComOutputBitstream& bs)
133{
134  bs.write( 1, 1 );
135  bs.writeAlignZero();
136}
137
138/**
139 * Copy NALU from naluSrc to naluDest
140 */
141void copyNaluData(OutputNALUnit& naluDest, const OutputNALUnit& naluSrc)
142{
143  naluDest.m_nalUnitType = naluSrc.m_nalUnitType;
144  naluDest.m_reservedZero6Bits  = naluSrc.m_reservedZero6Bits;
145  naluDest.m_temporalId  = naluSrc.m_temporalId;
146  naluDest.m_Bitstream   = naluSrc.m_Bitstream;
147}
148
149//! \}
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