Checks whether the audio true-peaks below specific level. More...

#include <hart_true_peaks_below.hpp>

Inheritance diagram for TruePeaksBelow< SampleType >:

Public Types
enum	FilterQuality { low = 12 , medium = 24 , high = 96 }
	Number of taps of the internal poly-phase IIR filter. More...

enum class	Strictness { relaxed , strict }
	Strictness to when it comes to decision on whether the signal is below a specific dB TP target. More...

Public Member Functions
	TruePeaksBelow (double thresholdDbTP, Oversampling oversamplingRatio=Oversampling::x4, FilterQuality filterQuality=FilterQuality::low, Strictness strictness=Strictness::relaxed, double numericToleranceLinear=1e-3)
	Creates a matcher for a specific true peak level.

void	prepare (double sampleRateHz, size_t, size_t numOutputChannels, size_t) override
	Prepare for processing It is guaranteed that all subsequent process() calls will be in line with the arguments received in this callback. This callback is guaranteed to be called after canOperatePerBlock() If any of the values supplied by this callback are not supported by the matcher, it is expected to act as if the match has failed when match() gets called.

void	reset () override
	Resets the matcher to its initial state.

bool	match (AnalysisContext< SampleType > context) override
	Tells the host if the piece of audio satisfies Matcher's condition or not.

bool	canOperatePerBlock () const override
	Tells the host if it can operate on a block-by-block basis.

MatcherFailureDetails	getFailureDetails () const override
	Returns a description of why the match has failed.

void	represent (std::ostream &stream) const override
	Makes a text representation of this Matcher for test failure outputs.

Public Member Functions inherited from Matcher< SampleType, TruePeaksBelow< SampleType > >
virtual std::unique_ptr< MatcherBase< SampleType > >	copy () const override
	Returns a smart pointer with a copy of this object.

virtual std::unique_ptr< MatcherBase< SampleType > >	move () override
	Returns a smart pointer with a moved instance of this object.

TruePeaksBelow< SampleType > &	atChannels (std::initializer_list< size_t > channelsToMatch) &
	Makes this matcher check only specific channels, and ignore the rest.

TruePeaksBelow< SampleType > &&	atChannels (std::initializer_list< size_t > channelsToMatch) &&
	Makes this matcher check only specific channels, and ignore the rest.

TruePeaksBelow< SampleType > &	atChannel (size_t channelToMatch) &
	Makes this matcher check only one specific channel, and ignore the rest.

TruePeaksBelow< SampleType > &&	atChannel (size_t channelToMatch) &&
	Makes this matcher check only one specific channel, and ignore the rest.

TruePeaksBelow< SampleType > &	atAllChannels () &
	Makes this matcher check all channels.

TruePeaksBelow< SampleType > &&	atAllChannels () &&
	Makes this matcher check all channels.

TruePeaksBelow< SampleType > &	atAllChannelsExcept (std::initializer_list< size_t > channelsToSkip) &
	Makes this matcher check only specific channels, and ignore the rest.

TruePeaksBelow< SampleType > &&	atAllChannelsExcept (std::initializer_list< size_t > channelsToSkip) &&
	Makes this matcher check only specific channels, and ignore the rest.

Public Member Functions inherited from MatcherBase< SampleType >
virtual	~MatcherBase ()=default

	HART_DEPRECATED ("This method is deprecated. Switch to the one that uses AnalysisContext instead.") virtual bool match(const AudioBuffer< SampleType > &inputAudio
	Tells the host if the piece of audio satisfies Matcher's condition or not.

return	match (analysisContext)

virtual bool	supportsChannelLayout (size_t, size_t) const
	Tells the host whether this Matcher is capable of operating on audio with a specific number of channels.

virtual bool	supportsSampleRate (double) const
	Tells whether this Matcher supports given sample rate.

void	prepareWithActiveChannels (double sampleRateHz, size_t numInputChannels, size_t numOutputChannels, size_t maxBlockSizeFrames)
	Prepare for processing, meant to be called by a host.

void	representWithActiveChannels (std::ostream &stream) const
	Makes a text representation of this Matcher with optional "atChannels" appendix.

Friends
std::ostream &	operator<< (std::ostream &os, Strictness strictness)

std::ostream &	operator<< (std::ostream &os, FilterQuality filterQuality)

Additional Inherited Members
Public Attributes inherited from MatcherBase< SampleType >
const AudioBuffer< SampleType > &	observedOutputAudio

Protected Member Functions inherited from MatcherBase< SampleType >
bool	appliesToChannel (size_t channel)
	Indicates whether this matcher should check a specific channel.

ChannelFlags	getChannelFlags () const
	Returns flags for the channels that the matcher should apply to.

Protected Attributes inherited from MatcherBase< SampleType >
ChannelFlags	m_channelsToMatch {true}

Related Symbols inherited from Matcher< SampleType, TruePeaksBelow< SampleType > >
std::ostream &	operator<< (std::ostream &stream, const MatcherBase< SampleType > &matcher)
	Prints readable text representation of the Matcher object into the I/O stream.

Detailed Description

template<typename SampleType>
class hart::TruePeaksBelow< SampleType >

Checks whether the audio true-peaks below specific level.

It checks inter-sample peaks by observing oversampled signal, following ITU-R BS.1770-5 guidelines. Some of the implementation choices are exposed by ctor, such as oversampling factor and number of taps in the internal poly-phase IIR filter, as the standard does not specify the exact values. Also, you may pick whether to leave enough headroom due to potential measuring under-shoot via setting Strictness option.

For more versatile expressions, you may also check truePeak() metric.

Definition at line 30 of file hart_true_peaks_below.hpp.

Member Enumeration Documentation

◆ FilterQuality

template<typename SampleType >

enum FilterQuality

Number of taps of the internal poly-phase IIR filter.

Enumerator
low	12 taps
medium	24 taps
high	96 taps

Definition at line 35 of file hart_true_peaks_below.hpp.

◆ Strictness

template<typename SampleType >

enum class Strictness

strong

Strictness to when it comes to decision on whether the signal is below a specific dB TP target.

Enumerator
relaxed	Numeric tolerance only.
strict	Numeric tolerance + estimated under-read.

Definition at line 43 of file hart_true_peaks_below.hpp.

Constructor & Destructor Documentation

◆ TruePeaksBelow()

template<typename SampleType >

TruePeaksBelow	(	double	thresholdDbTP,
		Oversampling	oversamplingRatio = `Oversampling::x4`,
		FilterQuality	filterQuality = `FilterQuality::low`,
		Strictness	strictness = `Strictness::relaxed`,
		double	numericToleranceLinear = `1e-3`
	)

inline

Creates a matcher for a specific true peak level.

Parameters

thresholdDbTP	Expected true peak threshold in decibels true peak ("dB TP")
oversampling	Oversampling ratio, see Oversampling
filterQuality	Resolution of the internal IIR filters. "low" is in line with ITU-R BS.1770 measuring recommendations, "high" a bit closer to what mass-produced DACs implement (although still a rough approximate), "medium" is somewhere in between.
strictness	Whether to take estimated true peaks at face value, or also take potential under-read in consideration. Under-read estimation is calculated according to ITU-R BS.1770-5, Annex 2, Attachement 1 (See page 21 here). For "strict" setting, worst case will be assumed, and additional headroom equal to maximum under-shoot at $$f_norm = 0.45$$ will be required for the audio to pass this matcher's requirement.
numericToleranceLinear	Absolute tolerance for comparing frames, in linear domain (not decibels)

Definition at line 62 of file hart_true_peaks_below.hpp.

Member Function Documentation

◆ prepare()

template<typename SampleType >

void prepare	(	double	sampleRateHz,
		size_t	numInputChannels,
		size_t	numOutputChannels,
		size_t	maxBlockSizeFrames
	)

inlineoverridevirtual

Prepare for processing It is guaranteed that all subsequent process() calls will be in line with the arguments received in this callback. This callback is guaranteed to be called after canOperatePerBlock() If any of the values supplied by this callback are not supported by the matcher, it is expected to act as if the match has failed when match() gets called.

Parameters

sampleRateHz	sample rate at which the audio should be interpreted
numInputChannels	Number of channels in the input (reference) audio
numOutputChannels	Number of channels in the output (observed) audio
maxBlockSizeFrames	Maximum block size in frames (samples)

Implements MatcherBase< SampleType >.

Definition at line 80 of file hart_true_peaks_below.hpp.

◆ reset()

template<typename SampleType >

void reset ( )

inlineoverridevirtual

Resets the matcher to its initial state.

Reimplemented from MatcherBase< SampleType >.

Definition at line 90 of file hart_true_peaks_below.hpp.

◆ match()

template<typename SampleType >

bool match ( AnalysisContext< SampleType > analysisContext )

inlineoverridevirtual

Tells the host if the piece of audio satisfies Matcher's condition or not.

It is guaranteed to be called only after prepare(), or not be called at all. It is guaranteed to be handed a pair of AudioBuffers in line with values set by the last prepare() call. If canOperatePerBlock() has returned false, this callback is guaranteed to be handed a full piece of audio to check. Otherwise, it may still get a full piece of audio, or get data on a block-by-block basis.

Parameters

analysisContext Carries everything matcher should know about the input and output audio.

Returns: true if the audio satisfies the Matcher's condition, false otherwise

Reimplemented from MatcherBase< SampleType >.

Definition at line 96 of file hart_true_peaks_below.hpp.

◆ canOperatePerBlock()

template<typename SampleType >

bool canOperatePerBlock ( ) const

inlineoverridevirtual

Tells the host if it can operate on a block-by-block basis.

Some types of conditions absolutely require having a full piece of audio to produce an appropriate response. For example, hart::PeaksAt matcher. Those types of matchers will return false on this callback. Matcher is guaranteed to receive a full piece of audio if this callback has returned false. Otherwise, it may receive audio either block-by-block basis, or still get a full piece of audio, if the host decides to do so.

Implements MatcherBase< SampleType >.

Definition at line 121 of file hart_true_peaks_below.hpp.

◆ getFailureDetails()

template<typename SampleType >

MatcherFailureDetails getFailureDetails ( ) const

inlineoverridevirtual

Returns a description of why the match has failed.

It is guaranteed to be called strictly after calling match(), or not called at all

Note: This method is a callback for the test host, so you probably don't need to call it yourself ever. If you're making a custom matcher, use it to communicate the data with test host.

Return values

MatcherFailureDetails::frame	Index of frame at which the match has failed
MatcherFailureDetails::channel	Index of channel at which the failure was detected
MatcherFailureDetails::description	Readable description of why the match has failed. Do not include the value of observed frame value or its timing in the description, as well as any of values printed by represent(), as all of this will be added to the output anyway. Also, query hart::CLIConfig for number of displayed decimal places, whenever applicable.

See also: MatcherFailureDetails

Implements MatcherBase< SampleType >.

Definition at line 128 of file hart_true_peaks_below.hpp.

◆ represent()

template<typename SampleType >

void represent ( std::ostream & stream ) const

inlineoverridevirtual

Makes a text representation of this Matcher for test failure outputs.

It is strongly encouraged to follow python's repr() conventions for returned text - basically, put something like "MyClass(value1, value2)" (with no quotes) into the stream whenever possible, or "<Readable info in angled brackets>" otherwise. Also, use built-in stream manipulators like hart::dbPrecision wherever applicable. Use HART_DEFINE_GENERIC_REPRESENT() to get a basic implementation for this method.

Parameters

[out] stream Output stream to write to

Implements MatcherBase< SampleType >.

Definition at line 156 of file hart_true_peaks_below.hpp.

Friends And Related Symbol Documentation

◆ operator<< [1/2]

template<typename SampleType >

std::ostream & operator<<	(	std::ostream &	os,
		Strictness	strictness
	)

friend

Definition at line 166 of file hart_true_peaks_below.hpp.

◆ operator<< [2/2]

template<typename SampleType >

std::ostream & operator<<	(	std::ostream &	os,
		FilterQuality	filterQuality
	)

friend

Definition at line 171 of file hart_true_peaks_below.hpp.

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

include/matchers/hart_true_peaks_below.hpp

Public Types

Public Member Functions

Friends

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ FilterQuality

◆ Strictness

Constructor & Destructor Documentation

◆ TruePeaksBelow()

Member Function Documentation

◆ prepare()

◆ reset()

◆ match()

◆ canOperatePerBlock()

◆ getFailureDetails()

◆ represent()

Friends And Related Symbol Documentation

◆ operator<< [1/2]

◆ operator<< [2/2]