A class that converts samples from an input stream to a set output sample rate. More...

#include <omSoundResampler.h>

Inheritance diagram for om::sound::filters::Resampler:

Public Types
enum	Type { BEST = 0, FASTEST = 1, INTERPOLATE = 2, INTERPOLATE_FILTERED = 3 }

Public Member Functions
	Resampler ()
	Create a default sample rate converter with the best conversion type and 44.1 kHz output sample rate. More...

	Resampler (Type newConversionType)
	Create a sample rate converter with the specified conversion type and 44.1 kHz output sample rate. More...

	Resampler (Type newConversionType, SampleRate newOutputSampleRate)
	Create a sample rate converter with the specified conversion type and output sample rate. More...

	Resampler (const Resampler &other)
	Create an exact copy of the specified sample rate converter. More...

	~Resampler ()
	Destroy this sample rate converter and release all associated resources. More...

Resampler &	operator= (const Resampler &other)
	Assign the state of the specified sample rate converter to this one. More...

SampleRate	getOutputSampleRate () const
	Return the sampling rate to which all input audio is being converted. More...

void	setOutputSampleRate (SampleRate newOutputSampleRate)
	Set the sampling rate to which all input audio should be converted. More...

Type	getType () const
	Return the type of sample rate conversion that is being performed. More...

void	setType (Type newSampleRateConversionType)
	Set the type of sample rate conversion that is being performed. More...

virtual UTF8String	getName () const
	Return a human-readable name for this sample rate converter. More...

virtual UTF8String	getManufacturer () const
	Return the manufacturer name of this sample rate converter. More...

virtual FilterVersion	getVersion () const
	Return an object representing the version of this sample rate converter. More...

virtual FilterCategory	getCategory () const
	Return an object that describes the category of effect that this filter implements. More...

virtual Size	getParameterCount () const
	Return the total number of generic accessible parameters this sample rate converter has. More...

virtual Bool	getParameterInfo (Index parameterIndex, FilterParameterInfo &info) const
	Get information about the sample rate converter parameter at the specified index. More...

virtual Bool	getParameterValueName (Index parameterIndex, const FilterParameter &value, UTF8String &name) const
	Get any special name associated with the specified value of an indexed parameter. More...

Public Member Functions inherited from om::sound::filters::SoundFilter
virtual	~SoundFilter ()
	Destroy this sound filter object. More...

SoundResult	read (SoundBuffer &outputBuffer, Size numSamples)
	Fill the specified output buffer with the requested number of samples, based on internal filter state. More...

SoundResult	read (SoundFrame &outputFrame, Size numSamples)
	Fill the specified output frame with the requested number of samples, based on internal filter state. More...

SoundResult	write (const SoundBuffer &inputBuffer, Size numSamples)
	Process the specified input buffer samples and do something with them. More...

SoundResult	write (const SoundFrame &inputFrame, Size numSamples)
	Process the specified input frame samples and do something with them. More...

SoundResult	process (const SoundBuffer &inputBuffer, SoundBuffer &outputBuffer, Size numSamples)
	Apply this filter to the specified input buffer data, placing the result in the output buffer. More...

SoundResult	process (const SoundBuffer &inputBuffer, SoundFrame &outputFrame, Size numSamples)
	Apply this filter to the specified input buffer data, placing the result in the output frame. More...

SoundResult	process (const SoundFrame &inputFrame, SoundFrame &outputFrame, Size numSamples)
	Apply this filter to the specified input frame data, placing the result in the output frame. More...

SoundResult	process (const SoundFrame &inputBuffer, SoundBuffer &outputBuffer, Size numSamples)
	Apply this filter to the specified input frame data, placing the result in the output buffer. More...

void	reset ()
	Signal to the filter that the audio stream is restarting. More...

UInt64	getFrameIndex () const
	Return the index of the next frame to be processed (or the current one if currently processing). More...

Size	getInputCount () const
	Return the current number of audio inputs that this filter has. More...

virtual UTF8String	getInputName (Index inputIndex) const
	Return a human-readable name of the filter audio input at the specified index. More...

Size	getOutputCount () const
	Return the current number of audio outputs that this filter has. More...

virtual UTF8String	getOutputName (Index outputIndex) const
	Return a human-readable name of the filter audio output at the specified index. More...

Size	getMIDIInputCount () const
	Return the current number of MIDI inputs that this filter has. More...

virtual UTF8String	getMIDIInputName (Index inputIndex) const
	Return a human-readable name of the filter MIDI input at the specified index. More...

Size	getMIDIOutputCount () const
	Return the current number of MIDI outputs that this filter has. More...

virtual UTF8String	getMIDIOutputName (Index outputIndex) const
	Return a human-readable name of the filter MIDI output at the specified index. More...

virtual Time	getLatency () const
	Return a Time value indicating the latency of this sound filter in seconds. More...

virtual Bool	getParameterIndex (const UTF8String &parameterName, Index &parameterIndex) const
	Query the index of the parameter with the specified name. More...

Bool	getParameter (Index parameterIndex, FilterParameter &value) const
	Place the value of the parameter at the specified index in the output parameter. More...

Bool	getParameter (Index parameterIndex, Bool &value) const
	Place the value of the parameter at the specified index in the output parameter. More...

Bool	getParameter (Index parameterIndex, Int64 &value) const
	Place the value of the parameter at the specified index in the output parameter. More...

Bool	getParameter (Index parameterIndex, Float32 &value) const
	Place the value of the parameter at the specified index in the output parameter. More...

Bool	getParameter (Index parameterIndex, Float64 &value) const
	Place the value of the parameter at the specified index in the output parameter. More...

template<typename ParameterType >
Bool	getParameter (const UTF8String &name, ParameterType &value) const
	Place the value of the parameter with the specified name in the output parameter. More...

template<typename ParameterType >
Bool	getParameter (const char *name, ParameterType &value) const
	Place the value of the parameter with the specified name in the output parameter. More...

Bool	setParameter (Index parameterIndex, const FilterParameter &value)
	Attempt to set the parameter value at the specified index. More...

Bool	setParameter (Index parameterIndex, Bool value)
	Attempt to set the parameter value at the specified index. More...

Bool	setParameter (Index parameterIndex, Int64 value)
	Attempt to set the parameter value at the specified index. More...

Bool	setParameter (Index parameterIndex, Float32 value)
	Attempt to set the parameter value at the specified index. More...

Bool	setParameter (Index parameterIndex, Float64 value)
	Attempt to set the parameter value at the specified index. More...

template<typename ParameterType >
Bool	setParameter (const UTF8String &name, ParameterType value)
	Attempt to set the parameter value with the specified name. More...

template<typename ParameterType >
Bool	setParameter (const char *name, ParameterType value)
	Attempt to set the parameter value with the specified name. More...

virtual Bool	writeState (DataOutputStream &stream) const
	Write the current state of this sound filter to a data output stream. More...

virtual Bool	readState (DataInputStream &stream)
	Read a previously saved filter state from the specified data input stream and replace the filter's state. More...

virtual Size	getPresetCount () const
	Return the number of standard configuration presets that this sound filter has. More...

virtual Bool	getPreset (Index presetIndex, FilterPreset &preset) const
	Get the standard preset for this sound filter with the specified index. More...

Bool	getIsSynchronized () const
	Return whether or not this sound filter performs thread synchronization. More...

void	setIsSynchronized (Bool newIsSynchronized)
	Set whether or not this sound filter performs thread synchronization. More...

virtual Bool	allowsInPlaceProcessing () const
	Return whether or not this sound filter can process audio data in-place. More...

Static Public Attributes
static const UTF8String	NAME
	A string indicating the human-readable name of this sample rate converter. More...

static const UTF8String	MANUFACTURER
	A string indicating the manufacturer name of this sample rate converter. More...

static const FilterVersion	VERSION
	An object indicating the version of this sample rate converter. More...

Static Public Attributes inherited from om::sound::filters::SoundFilter
static const om::resources::ResourceType	RESOURCE_TYPE
	The resource type for a sound filter. More...

Additional Inherited Members
Static Public Member Functions inherited from om::sound::filters::SoundFilter
static Size	getMaximumNumberOfInputs ()
	Return the maximum number of audio inputs that a SoundFilter can support. More...

static Size	getMaximumNumberOfOutputs ()
	Return the maximum number of audio outputs that a SoundFilter can support. More...

static Size	getMaximumNumberOfMIDIInputs ()
	Return the maximum number of MIDI inputs that a SoundFilter can support. More...

static Size	getMaximumNumberOfMIDIOutputs ()
	Return the maximum number of MIDI outputs that a SoundFilter can support. More...

Protected Member Functions inherited from om::sound::filters::SoundFilter
	SoundFilter ()
	Create a new sound filter with 1 audio input and output, and no MIDI inputs or outputs. More...

	SoundFilter (Size numInputs, Size numOutputs)
	Create a new sound filter with the specified number of audio inputs and outputs. More...

	SoundFilter (Size numInputs, Size numOutputs, Size numMIDIInputs, Size numMIDIOutputs)
	Create a new sound filter with the specified number of audio inputs and outputs. More...

void	setInputCount (Size newNumInputs)
	Set the number of inputs that this filter should have. More...

void	setOutputCount (Size newNumOutputs)
	Set the number of outputs that this filter should have. More...

void	setMIDIInputCount (Size newNumMIDIInputs)
	Set the number of MIDI inputs that this filter should have. More...

void	setMIDIOutputCount (Size newNumMIDIOutputs)
	Set the number of MIDI outputs that this filter should have. More...

Bool	isFirstFrame () const
	Return whether or not the filter's next frame to be processed is also its first frame. More...

void	lockMutex () const
	Acquire a mutex which handles subclass rendering parameter synchronization. More...

void	unlockMutex () const
	Release a mutex which handles subclass rendering parameter synchronization. More...

Detailed Description

A class that converts samples from an input stream to a set output sample rate.

This class should be used wherever a mismatched sample rate could occur and needs to be corrected for. For instance: sound file I/O, sound device I/O, mixing.

Several different methods of sample rate conversion are part of the class which provide a range of quality-speed tradeoffs.

Member Enumeration Documentation

enum om::sound::filters::Resampler::Type

Enumerator
BEST	The best quality sample rate conversion available. If this conversion type enum value is supplied, the converter chooses the best available sample rate converter and uses that algorithm.
FASTEST	The fastest sample rate conversion available. If this conversion type enum value is supplied, the converter chooses the fastest available sample rate converter and uses that algorithm.
INTERPOLATE	The sample rate converter does a simple interpolation of the input samples. This is the fastest way to do sample rate conversion but it also has the worst quality. There may be audible artifacts in the output audio if this conversion type is used.
INTERPOLATE_FILTERED	The sample rate converter does an interpolation of the input samples with antialiasing. This is the second fastest way to do sample rate conversion and has better quality for downsampling than INTERPOLATE because it applies a steep low pass filter at the Nyquist frequency of the output sample rate. This filter helps avoid aliasing artifacts when downsampling and corrects for added noise when upsampling.

Constructor & Destructor Documentation

om::sound::filters::Resampler::Resampler ( )

Create a default sample rate converter with the best conversion type and 44.1 kHz output sample rate.

om::sound::filters::Resampler::Resampler ( Type newConversionType )

Create a sample rate converter with the specified conversion type and 44.1 kHz output sample rate.

om::sound::filters::Resampler::Resampler	(	Type	newConversionType,
		SampleRate	newOutputSampleRate
	)

Create a sample rate converter with the specified conversion type and output sample rate.

om::sound::filters::Resampler::Resampler ( const Resampler & other )

Create an exact copy of the specified sample rate converter.

om::sound::filters::Resampler::~Resampler ( )

Destroy this sample rate converter and release all associated resources.

Member Function Documentation

Resampler& om::sound::filters::Resampler::operator= ( const Resampler & other )

Assign the state of the specified sample rate converter to this one.

SampleRate om::sound::filters::Resampler::getOutputSampleRate ( ) const

inline

Return the sampling rate to which all input audio is being converted.

void om::sound::filters::Resampler::setOutputSampleRate ( SampleRate newOutputSampleRate )

inline

Set the sampling rate to which all input audio should be converted.

If the sample rate of 0 is supplied, no sample rate conversion will be done in the filter's processing method. Otherwise, the input audio will be resampled to the desired sampling rate.

Type om::sound::filters::Resampler::getType ( ) const

inline

Return the type of sample rate conversion that is being performed.

Some types of sample rate conversion are faster or have better quality than others. This value allows the user to specify which conversion algorithm to use based on the application.

void om::sound::filters::Resampler::setType ( Type newSampleRateConversionType )

inline

Set the type of sample rate conversion that is being performed.

Some types of sample rate conversion are faster or have better quality than others. This value allows the user to specify which conversion algorithm to use based on the application.

virtual UTF8String om::sound::filters::Resampler::getName ( ) const

virtual

Return a human-readable name for this sample rate converter.

The method returns the string "Sample Rate Converter".

Reimplemented from om::sound::filters::SoundFilter.

virtual UTF8String om::sound::filters::Resampler::getManufacturer ( ) const

virtual

Return the manufacturer name of this sample rate converter.

The method returns the string "Om Sound".

Reimplemented from om::sound::filters::SoundFilter.

virtual FilterVersion om::sound::filters::Resampler::getVersion ( ) const

virtual