# Dirac - A Video Codec

Created by the British Broadcasting Corporation.

band_vlc.h
Go to the documentation of this file.
1 /* ***** BEGIN LICENSE BLOCK *****
2 *
3 * $Id: band_vlc.h,v 1.8 2009/02/09 09:44:56 asuraparaju Exp $ $Name: Dirac_1_0_2 $
4 *
5 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 *
7 * The contents of this file are subject to the Mozilla Public License
8 * Version 1.1 (the "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
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12 * Software distributed under the License is distributed on an "AS IS" basis,
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15 *
16 * The Original Code is BBC Research and Development code.
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18 * The Initial Developer of the Original Code is the British Broadcasting
19 * Corporation.
20 * Portions created by the Initial Developer are Copyright (C) 2004.
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23 * Contributor(s): Thomas Davies (Original Author),
24 * Scott R Ladd,
25 * Steve Bearcroft
26 * Andrew Kennedy
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40
41 #ifndef _BAND_VLC_H
42 #define _BAND_VLC_H
43
44 #include <libdirac_common/wavelet_utils.h>
45 #include <libdirac_common/band_codec.h>
46
47
48 namespace dirac
49 {
50
51 class SubbandByteIO;
52 class ByteIO;
53
55 class ArithCodecToVLCAdapter
56 {
57 public:
59 ArithCodecToVLCAdapter(SubbandByteIO* subband_byteio, size_t number_of_contexts);
60
62 virtual ~ArithCodecToVLCAdapter(){}
63
64 /* Compresses the input and returns the number of bits written */
65 int Compress (CoeffArray &in_data);
66
67 /* Decompresses the bitstream */
68 void Decompress (CoeffArray& out_data, int num_bytes);
69
70 /* Encodes a symbol and writes to the output */
71 void EncodeSymbol(bool val, int /*context_num*/)
72 {
73 m_byteio->WriteBit(val);
74 }
75
76 /* Decodes a symbol */
77 bool DecodeSymbol(int /*context_num*/)
78 {
79 return m_byteio->ReadBoolB();
80 }
81
83 virtual void DoWorkCode(CoeffArray &in_data) = 0;
84
86 virtual void DoWorkDecode(CoeffArray &out_data) = 0;
87
88 protected:
90 ByteIO *m_byteio;
91
92 private:
94 ArithCodecToVLCAdapter(const ArithCodecToVLCAdapter& cpy);
96 ArithCodecToVLCAdapter& operator=(const ArithCodecToVLCAdapter& rhs);
97 };
98
99
101
104 typedef GenericBandCodec<ArithCodecToVLCAdapter> BandVLC;
105
107 //Finally,special class incorporating prediction for the DC band of intra frames//
109
111
115 class IntraDCBandVLC: public GenericIntraDCBandCodec<ArithCodecToVLCAdapter>
116 {
117 public:
119
124 IntraDCBandVLC(SubbandByteIO* subband_byteio,
125 const SubbandList& band_list);
126 private:
128 void CodeCoeff(CoeffArray& in_data, const int xpos, const int ypos);
129
130 private:
132 IntraDCBandVLC (const IntraDCBandVLC& cpy);
133
135 IntraDCBandVLC& operator=(const IntraDCBandVLC& rhs);
136 };
137
138
139 }// end namespace dirac
140 #endif
dirac::ArithCodecToVLCAdapter::m_byteio
ByteIO * m_byteio
Definition: band_vlc.h:90
dirac::ArithCodecToVLCAdapter::operator=
ArithCodecToVLCAdapter & operator=(const ArithCodecToVLCAdapter &rhs)
Private, bodyless copy operator=: class should not be assigned.
dirac::ArithCodecToVLCAdapter
Definition: band_vlc.h:55
band_codec.h
dirac::CoeffArray
A class for wavelet coefficient data.
Definition: wavelet_utils.h:622
dirac::IntraDCBandVLC
A class specially for coding the DC subband of Intra frames.
Definition: band_vlc.h:115
dirac::BandVLC
GenericBandCodec< ArithCodecToVLCAdapter > BandVLC
A general class for coding and decoding wavelet subband data using variable length coding...
Definition: band_vlc.h:104
dirac::ArithCodecToVLCAdapter::~ArithCodecToVLCAdapter
virtual ~ArithCodecToVLCAdapter()
Definition: band_vlc.h:62
dirac::SubbandList
A class encapulating all the subbands produced by a transform.
Definition: wavelet_utils.h:279
dirac::IntraDCBandVLC::CodeCoeff
void CodeCoeff(CoeffArray &in_data, const int xpos, const int ypos)
Encode a single coefficient using error-feedback DC quantization.
dirac::ArithCodecToVLCAdapter::DoWorkCode
virtual void DoWorkCode(CoeffArray &in_data)=0
dirac::ArithCodecToVLCAdapter::EncodeSymbol
void EncodeSymbol(bool val, int)
Definition: band_vlc.h:71
dirac::ArithCodecToVLCAdapter::ArithCodecToVLCAdapter
ArithCodecToVLCAdapter(SubbandByteIO *subband_byteio, size_t number_of_contexts)
wavelet_utils.h
dirac::ArithCodecToVLCAdapter::DecodeSymbol
bool DecodeSymbol(int)
Definition: band_vlc.h:77
dirac::SubbandByteIO
Subband Dirac-bytestream input/output.
Definition: subband_byteio.h:56
dirac::GenericIntraDCBandCodec
A template class specially for coding the DC subband of Intra frames.
Definition: band_codec.h:171
dirac::IntraDCBandVLC::operator=
IntraDCBandVLC & operator=(const IntraDCBandVLC &rhs)
Private, bodyless copy operator=: class should not be assigned.
dirac::ArithCodecToVLCAdapter::Decompress
void Decompress(CoeffArray &out_data, int num_bytes)
dirac::ArithCodecToVLCAdapter::Compress
int Compress(CoeffArray &in_data)
dirac
Definition of class SequenceHeaderByteIO.
Definition: accessunit_byteio.h:51
dirac::ArithCodecToVLCAdapter::DoWorkDecode
virtual void DoWorkDecode(CoeffArray &out_data)=0
dirac::ByteIO
Class ByteIO - top-level class for reading/writing bytes to a stream.
Definition: byteio.h:72
dirac::ByteIO::ReadBoolB
bool ReadBoolB()
Reads boolean value - bounded i/o.
dirac::IntraDCBandVLC::IntraDCBandVLC
IntraDCBandVLC(SubbandByteIO *subband_byteio, const SubbandList &band_list)
Constructor.
dirac::ByteIO::WriteBit
void WriteBit(const bool &bit)
Outputs a bit.
dirac::GenericBandCodec< ArithCodecToVLCAdapter >

© 2004 British Broadcasting Corporation. Dirac code licensed under the Mozilla Public License (MPL) Version 1.1.
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