Dirac - A Video Codec

Created by the British Broadcasting Corporation.

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dirac::ByteIO Class Reference

Class ByteIO - top-level class for reading/writing bytes to a stream.

#include <byteio.h>

Inheritance diagram for dirac::ByteIO:

[legend]List of all members.

Public Member Functions

• ByteIO (bool new_stream=true)

  Default constructor.
  

• ByteIO (const ByteIO &stream_data)

  Constructor.
  

• virtual ~ByteIO ()

  Destructor.
  

• virtual void CollateByteStats (DiracByteStats &dirac_byte_stats)

  Gathers byte-stream statistics.
  

• virtual const std::string GetBytes ()

  Get bytes in Dirac-bytestream format.
  

• int GetReadBytePosition () const

  Get position of read stream pointer.
  

• virtual int GetSize () const

  Gets size (in bytes).
  

• void SetByteParams (const ByteIO &byte_io)

  Copies stream source/destination info.
  

• void ByteAlignOutput ()

  Sync input for byte-alignment.
  

• void WriteUint (unsigned int value)

  Ouputs an unsigned integer in interleaved exp Golomb format.
  

• void SetBitsLeft (int left_bits)

  Sets input size in bits.
  

• int BitsLeft (void)

  Sets input size in bits.
  

Protected Member Functions

• bool CanRead () const
• bool GetBit (unsigned char &c, int pos) const
• void SetBit (unsigned char &c, int pos) const
• void SetBits (unsigned char &c, unsigned char bits) const
• void ByteAlignInput ()

  Sync input for byte-alignment.
  

• bool ReadBool ()

  Reads boolean value.
  

• bool ReadBoolB ()

  Reads boolean value - bounded i/o.
  

• int ReadBit ()

  Reads next bit.
  

• int ReadBitB ()

  Reads next bit - bounded i/o.
  

• unsigned int ReadNBits (int count)

  Reads next 'count' bits.
  

• void InputBytes (char *data, int count)

  Reads from stream.
  

• void FlushInputB ()

  Flushes the bounde input.
  

• int ReadSint ()

  Reads a signed integer in interleaved exp-Golomb format return Signed integer read.
  

• int ReadSintB ()

  Reads a signed integer in interleaved exp-Golomb format from bounded input return Signed integer read.
  

• unsigned int ReadUint ()

  Reads an unsigned integer in interleaved exp Golomb format.
  

• unsigned int ReadUintB ()

  Reads an unsigned integer in interleaved exp Golomb format from bounded input.
  

• unsigned int ReadUintLit (const int byte_size)

  Reads a fixed length unsigned integer from the stream in big endian.
  

• unsigned char InputUnByte ()

  Reads a byte from the stream.
  

• std::string InputUnString (const int count)

  Reads a series of bytes from a stream.
  

• void WriteBit (const bool &bit)

  Outputs a bit.
  

• int WriteNBits (unsigned int val)

  Outputs an unsigned integer.
  

• void WriteNBits (unsigned int val, int count)

  Outputs an n bit integer.
  

• void OutputBytes (const std::string &bytes)

  Outputs a series of bytes.
  

• void OutputCurrentByte ()

  Outputs current byte contents.
  

• void WriteSint (int val)

  Outputs an integer in Golomb signed integer format.
  

• void WriteUintLit (const unsigned int &value, const int &length)

  Output unsigned int value in big endian format.
  

• void RemoveRedundantBytes (const int count)

  Removes portion of byte-stream no longer required.
  

• void SeekGet (const int offset, std::ios_base::seekdir dir)

Protected Attributes

• std::stringstream * mp_stream

  Input/output steam.
  

Private Attributes

• unsigned char m_current_byte

  Char used for temporary storage of op data bits.
  

• int m_current_pos

  Used to set individual bit within the current header byte.
  

• int m_num_bytes

  Number of bytes processed.
  

• bool m_new_stream

  stream alloc flag
  

• int m_bits_left

  num bits left to read
  

Friends

• class ArithCodecBase

  ArithCodec can see internals for getting/setting bits.
  

• class BandVLC

  VLC entropy coder can see internals for getting/setting bits.
  

• class IntraDCBandVLC

  VLC entropy coder can see internals for getting/setting bits.
  

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Constructor & Destructor Documentation

dirac::ByteIO::ByteIO (  bool  new_stream = true  )

Parameters: new_stream  Has Creates & owns data buffer

dirac::ByteIO::ByteIO (  const ByteIO &  stream_data  )

Parameters: stream_data  Copies data buffer details

virtual dirac::ByteIO::~ByteIO (   )  [virtual]

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Member Function Documentation

int dirac::ByteIO::BitsLeft (  void   )  [inline]

Read is limited by this

void dirac::ByteIO::ByteAlignInput (   )  [protected]

void dirac::ByteIO::ByteAlignOutput (   )

bool dirac::ByteIO::CanRead (   )  const [inline, protected]

virtual void dirac::ByteIO::CollateByteStats (  DiracByteStats &  dirac_byte_stats  )  [inline, virtual]

Parameters: dirac_byte_stats  Collates byte information Reimplemented in dirac::ComponentByteIO, dirac::EndOfSequenceByteIO, dirac::MvDataByteIO, dirac::ParseUnitByteIO, dirac::PictureByteIO, and dirac::TransformByteIO.

void dirac::ByteIO::FlushInputB (   )  [protected]

bool dirac::ByteIO::GetBit (  unsigned char &  c, int  pos )  const [inline, protected]

virtual const std::string dirac::ByteIO::GetBytes (   )  [virtual]

Reimplemented in dirac::DiracByteStream, dirac::MvDataByteIO, dirac::MvDataElementByteIO, dirac::ParseUnitByteIO, dirac::PictureByteIO, dirac::SubbandByteIO, and dirac::TransformByteIO.

int dirac::ByteIO::GetReadBytePosition (   )  const [inline]

virtual int dirac::ByteIO::GetSize (   )  const [virtual]

Reimplemented in dirac::SequenceHeaderByteIO, dirac::MvDataByteIO, dirac::MvDataElementByteIO, dirac::ParseUnitByteIO, dirac::PictureByteIO, and dirac::TransformByteIO.

void dirac::ByteIO::InputBytes (  char *  data, int  count )  [inline, protected]

Parameters: data  Start of char buffer count  Number of bytes to read

unsigned char dirac::ByteIO::InputUnByte (   )  [inline, protected]

std::string dirac::ByteIO::InputUnString (  const int  count  )  [inline, protected]

void dirac::ByteIO::OutputBytes (  const std::string &  bytes  )  [inline, protected]

void dirac::ByteIO::OutputCurrentByte (   )  [inline, protected]

int dirac::ByteIO::ReadBit (   )  [protected]

int dirac::ByteIO::ReadBitB (   )  [protected]

bool dirac::ByteIO::ReadBool (   )  [protected]

bool dirac::ByteIO::ReadBoolB (   )  [protected]

unsigned int dirac::ByteIO::ReadNBits (  int  count  )  [protected]

Parameters: count  number of bits to be read Returns: unsigned interger read

int dirac::ByteIO::ReadSint (   )  [protected]

int dirac::ByteIO::ReadSintB (   )  [protected]

unsigned int dirac::ByteIO::ReadUint (   )  [protected]

Returns: Unsigned Integer read

unsigned int dirac::ByteIO::ReadUintB (   )  [protected]

Returns: Unsigned Integer read

unsigned int dirac::ByteIO::ReadUintLit (  const int  byte_size  )  [inline, protected]

Parameters: byte_size  Number of bytes in fixed length integer Returns: Unsigned Integer read

void dirac::ByteIO::RemoveRedundantBytes (  const int  count  )  [protected]

Parameters: count  Number of bytes to be removed from beginning of stream

void dirac::ByteIO::SeekGet (  const int  offset, std::ios_base::seekdir  dir )  [inline, protected]

void dirac::ByteIO::SetBit (  unsigned char &  c, int  pos )  const [inline, protected]

void dirac::ByteIO::SetBits (  unsigned char &  c, unsigned char  bits )  const [inline, protected]

void dirac::ByteIO::SetBitsLeft (  int  left_bits  )  [inline]

Read is limited by this

void dirac::ByteIO::SetByteParams (  const ByteIO &  byte_io  )

Parameters: byte_io  Byte source/destination

void dirac::ByteIO::WriteBit (  const bool &  bit  )  [protected]

Parameters: bit  1/0 Output

void dirac::ByteIO::WriteNBits (  unsigned int  val, int  count )  [protected]

Parameters: val  Unsigned Integer to be output count  number of bits to be written

int dirac::ByteIO::WriteNBits (  unsigned int  val  )  [protected]

Parameters: val  Integer to be output Returns: number of bits written

void dirac::ByteIO::WriteSint (  int  val  )  [protected]

Parameters: val  Integer to be output

void dirac::ByteIO::WriteUint (  unsigned int  value  )

Parameters: value  Integer to be output

void dirac::ByteIO::WriteUintLit (  const unsigned int &  value, const int &  length )  [inline, protected]

Parameters: value  Integer to be output length  number of bytes in val to output

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Friends And Related Function Documentation

friend class ArithCodecBase [friend]

friend class BandVLC [friend]

friend class IntraDCBandVLC [friend]

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Member Data Documentation

int dirac::ByteIO::m_bits_left [private]

unsigned char dirac::ByteIO::m_current_byte [private]

int dirac::ByteIO::m_current_pos [private]

bool dirac::ByteIO::m_new_stream [private]

int dirac::ByteIO::m_num_bytes [private]

std::stringstream* dirac::ByteIO::mp_stream [protected]

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The documentation for this class was generated from the following file:

• byteio.h

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