Dirac - A Video Codec

Created by the British Broadcasting Corporation.

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dirac::RateController Class Reference

A clas for allocation the bits to each and every types of frames in a GOP.

#include <rate_control.h>

Collaboration diagram for dirac::RateController:

[legend]List of all members.

Public Member Functions

• RateController (int trate, SourceParams &srcp, EncoderParams &encp)

  Default constructor.
  

• void CalcNextQualFactor (const PictureParams &fparams, int num_bits)

  Calculate the Quality factor of the next frame to encode.
  

• void CalcNextIntraQualFactor ()

  Calculate the Quality factor of the next I frame to encode.
  

• void SetCutPictureQualFactor ()

  Use the long-term average intra quality factor.
  

• double IntraQualFactor ()

  Return I frame qf.
  

• double QualFactor ()

  Return qf.
  

• void Report ()

  Report the allocation to picture types.
  

Private Member Functions

• double TargetSubgroupRate ()
• double ProjectedSubgroupRate ()
• void Allocate (const int fnum)

  Allocate the bits to each type of frame in a GOP.
  

• void CalcTotalBits (const SourceParams &sourceparams)

  Calculate the total number of bits in a GOP.
  

• void SetIntraQualFactor (double value)

  Set the value of Current IQF.
  

• void SetFrameDistribution ()

  Set the number of I, L1 and L2 frames in the GOP.
  

• float ReviewQualityFactor (const float qfac, const long int num_bits)

  Review the quality factor to make sure it's being set sensibly.
  

• float ClipQualityFactor (const float qfac)

  Clip the quality factor to something sensible.
  

• void UpdateBuffer (const long int num_bits)

  Update the internal decoder buffer model.
  

Private Attributes

• double m_qf

  Current Quality Factor.
  

• double m_I_qf

  I frame Quality Factor.
  

• double m_I_qf_long_term

  Long-term average of I frame Quality Factor.
  

• const int m_target_rate

  Target bit rate in kbps.
  

• long int m_Iframe_bits

  Number of bits for I frame.
  

• long int m_L1frame_bits

  Number of bits for L1 frame.
  

• long int m_L2frame_bits

  Number of bits for L2 frame.
  

• int m_num_Iframe

  Number of I frames.
  

• int m_num_L1frame

  Number of L1 frames.
  

• int m_num_L2frame

  Number of L2 frames.
  

• long int m_total_GOP_bits

  Total Number of bits in a GOP.
  

• long int m_picture_bits

  Mean number of bits in a picture.
  

• const long int m_buffer_size

  Size of the decoded bit buffer.
  

• long int m_buffer_bits

  Number of bits in the buffer.
  

• long int m_old_buffer_bits

  The old buffer occupancy.
  

• double m_buffer_rate_of_change

  The rate of change of buffer occupancy.
  

• long int m_GOP_target

  The target number of bits for the current GOP.
  

• double m_GOP_duration

  The duration of a GOP.
  

• EncoderParams & m_encparams

  A reference to the encoder parameters.
  

• FrameComplexity m_frame_complexity

  A class to hold the frame complexity object.
  

• int m_fcount

  A frame counter, giving the position within a subgroup.
  

• bool m_intra_only
• int m_L2_complexity_sum

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Constructor & Destructor Documentation

dirac::RateController::RateController (  int  trate, SourceParams &  srcp, EncoderParams &  encp )

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Member Function Documentation

void dirac::RateController::Allocate (  const int  fnum  )  [private]

void dirac::RateController::CalcNextIntraQualFactor (   )

void dirac::RateController::CalcNextQualFactor (  const PictureParams &  fparams, int  num_bits )

void dirac::RateController::CalcTotalBits (  const SourceParams &  sourceparams  )  [private]

float dirac::RateController::ClipQualityFactor (  const float  qfac  )  [private]

double dirac::RateController::IntraQualFactor (   )  [inline]

double dirac::RateController::ProjectedSubgroupRate (   )  [private]

double dirac::RateController::QualFactor (   )  [inline]

void dirac::RateController::Report (   )

float dirac::RateController::ReviewQualityFactor (  const float  qfac, const long int  num_bits )  [private]

void dirac::RateController::SetCutPictureQualFactor (   )

void dirac::RateController::SetFrameDistribution (   )  [private]

void dirac::RateController::SetIntraQualFactor (  double  value  )  [inline, private]

double dirac::RateController::TargetSubgroupRate (   )  [private]

void dirac::RateController::UpdateBuffer (  const long int  num_bits  )  [private]

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Member Data Documentation

long int dirac::RateController::m_buffer_bits [private]

double dirac::RateController::m_buffer_rate_of_change [private]

const long int dirac::RateController::m_buffer_size [private]

EncoderParams& dirac::RateController::m_encparams [private]

int dirac::RateController::m_fcount [private]

FrameComplexity dirac::RateController::m_frame_complexity [private]

double dirac::RateController::m_GOP_duration [private]

long int dirac::RateController::m_GOP_target [private]

double dirac::RateController::m_I_qf [private]

double dirac::RateController::m_I_qf_long_term [private]

long int dirac::RateController::m_Iframe_bits [private]

bool dirac::RateController::m_intra_only [private]

long int dirac::RateController::m_L1frame_bits [private]

int dirac::RateController::m_L2_complexity_sum [private]

long int dirac::RateController::m_L2frame_bits [private]

int dirac::RateController::m_num_Iframe [private]

int dirac::RateController::m_num_L1frame [private]

int dirac::RateController::m_num_L2frame [private]

long int dirac::RateController::m_old_buffer_bits [private]

long int dirac::RateController::m_picture_bits [private]

double dirac::RateController::m_qf [private]

const int dirac::RateController::m_target_rate [private]

long int dirac::RateController::m_total_GOP_bits [private]

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

• rate_control.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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