#include "GuessLambdaModifiers.h"
#include <limits>
#include <cassert>
#include <cmath>

Include dependency graph for GuessLambdaModifiers.cpp:

Functions
double	polateLambdaModifier (double targetBitrate, const Point &point1, const Point &point2)

double	guessLambdaModifier (double initialAdjustmentParameter, double targetBitrate, const std::list< Point > &pointList, double interDampeningFactor)

std::vector< double >	guessLambdaModifiers (double initialAdjustmentParameter, const std::vector< double > &targetBitrateVector, const std::list< MetaLogEntry< std::vector< double > > > &metaLogEntryList)

void	guessLambdaModifiers (std::ostream &o, std::istream &initialAdjustmentParameterIstream, std::istream &targetsIstream, std::istream &metaLogIstream)

Function Documentation

double guessLambdaModifier	(	double	initialAdjustmentParameter,
		double	targetBitrate,
		const std::list< Point > &	pointList,
		double	interDampeningFactor
	)

Guesses a single Lambda-modifier

Parameters

initialAdjustmentParameter	If interpolation/extrapolation cannot be performed, then this parameter is used in the "increment" process.
targetBitrate	The target bitrate value that this Lambda-modifier is trying to reach
pointList	The list of points that correspond with this index
interDampeningFactor	This factor is obtained based on guessed Lambda-modifiers for previous temporal layers. In some cases, this factor will scale down the change of this Lambda-modifier so that we are not making too many severe Lambda-modifier changes for a single encoder run.

Returns: The Lambda-modifier guess

Precondition: pointList cannot be empty; interDampeningFactor must be greater than zero and less than or equal to 1 (0 < interDampeningFactor <= 1)

Definition at line 118 of file GuessLambdaModifiers.cpp.

std::vector< double > guessLambdaModifiers	(	double	initialAdjustmentParameter,
		const std::vector< double > &	targetBitrateVector,
		const std::list< MetaLogEntry< std::vector< double > > > &	metaLogEntryList
	)

Guesses all of the Lambda-modifiers

Parameters

initialAdjustmentParameter	If interpolation/extrapolation cannot be performed, then this parameter is used in the "increment" process.
targetBitrateVector	The target bitrate values that we are trying to reach
metaLogEntryList	All of the previously run Lambda-modifiers and their corresponding bitrates from the meta-log

Returns: Vector containing all of the guessed Lambda-modifiers

Precondition: targetBitrateVector cannot be empty; metaLogEntryList cannot be empty; The size of targetBitrateVector must be the same as the size of bitrateVector in every item in metaLogEntryList; The size of targetBitrateVector must be the same as the size of lambdaModifiers in every item in metaLogEntryList

Definition at line 203 of file GuessLambdaModifiers.cpp.

void guessLambdaModifiers	(	std::ostream &	o,
		std::istream &	initialAdjustmentParameterIstream,
		std::istream &	targetsIstream,
		std::istream &	metaLogIstream
	)

Guesses all of the Lambda-modifiers This function performs all of the necessary input parsing. It ends up calling the other guessLambdaModifiers overload to perform the actual calculations.

Parameters

o	The output stream to write the guessed Lambda-modifiers to
initialAdjustmentParameterIstream	The input stream that contains the initial adjustment parameter
targetsIstream	The input stream that contains the target bitrates
metaLogIstream	The input stream that contains the meta-log

Exceptions

InitialAdjustmentParameterParseException	if there is an error parsing the initial adjustment parameter
TargetsParseException	if there is an error parsing the target bitrates
MetaLogParseException	if there is an error parsing the meta-log
MismatchedIndexesException	if there is a mismatch in the vector sizes or the Lambda-modifier indexes

Definition at line 362 of file GuessLambdaModifiers.cpp.

double polateLambdaModifier	(	double	targetBitrate,
		const Point &	point1,
		const Point &	point2
	)

Performs interpolation/extrapolation to guess a single Lambda-modifier

Parameters

targetBitrate	The target bitrate value that this Lambda-modifier is trying to reach
point1	One of the two previously tried points where first is the Lambda-modifier and second is the obtained bitrate
point2	One of the two previously tried points where first is the Lambda-modifier and second is the obtained bitrate

Returns: The interpolated Lambda-modifier guess

Precondition: Both given points must contain only positive non-zero values for first and second; The given points must have different first values and different second values. If either the first values are the same or the second values are the same, then we have either a vertical or horizontal slope, and thus, interpolation cannot be performed.

Definition at line 102 of file GuessLambdaModifiers.cpp.

Functions

Function Documentation