STK file looping / oscillator class. More...

#include <FileLoop.h>

Inheritance diagram for stk::FileLoop:

Public Member Functions
	FileLoop (unsigned long chunkThreshold=1000000, unsigned long chunkSize=1024)
	Default constructor.

	FileLoop (std::string fileName, bool raw=false, bool doNormalize=true, unsigned long chunkThreshold=1000000, unsigned long chunkSize=1024, bool doInt2FloatScaling=true)
	Class constructor that opens a specified file.

	~FileLoop (void)
	Class destructor.

virtual void	openFile (std::string fileName, bool raw=false, bool doNormalize=true, bool doInt2FloatScaling=true)
	Open the specified file and load its data. More...

virtual void	closeFile (void)
	Close a file if one is open.

virtual void	reset (void)
	Clear outputs and reset time (file) pointer to zero.

unsigned int	channelsOut (void) const
	Return the number of audio channels in the data or stream.

void	normalize (void)
	Normalize data to a maximum of +-1.0. More...

void	normalize (StkFloat peak)
	Normalize data to a maximum of +-peak. More...

unsigned long	getSize (void) const
	Return the file size in sample frames.

StkFloat	getFileRate (void) const
	Return the input file sample rate in Hz (not the data read rate). More...

void	setRate (StkFloat rate)
	Set the data read rate in samples. The rate can be negative. More...

void	setFrequency (StkFloat frequency)
	Set the data interpolation rate based on a looping frequency. More...

void	addTime (StkFloat time)
	Increment the read pointer by time samples, modulo file size.

void	addPhase (StkFloat angle)
	Increment current read pointer by angle, relative to a looping frequency. More...

void	addPhaseOffset (StkFloat angle)
	Add a phase offset to the current read pointer. More...

StkFloat	lastOut (unsigned int channel=0)
	Return the specified channel value of the last computed frame. More...

StkFloat	tick (unsigned int channel=0)
	Compute a sample frame and return the specified `channel` value. More...

virtual StkFrames &	tick (StkFrames &frames, unsigned int channel=0)
	Fill the StkFrames object with computed sample frames, starting at the specified channel and return the same reference. More...

Protected Member Functions
virtual bool	isOpen (void)
	Query whether a file is open.

virtual bool	isFinished (void) const
	Query whether reading is complete.

void	setInterpolate (bool doInterpolate)
	Turn linear interpolation on/off. More...

const StkFrames &	lastFrame (void) const
	Return an StkFrames reference to the last computed sample frame. More...

void	ignoreSampleRateChange (bool ignore=true)
	A function to enable/disable the automatic updating of class data when the STK sample rate changes. More...

void	handleError (StkError::Type type) const
	Internal function for error reporting that assumes message in `oStream_` variable.

void	addSampleRateAlert (Stk *ptr)
	Add class pointer to list for sample rate change notification.

void	removeSampleRateAlert (Stk *ptr)
	Remove class pointer from list for sample rate change notification.

Static Protected Member Functions
static StkFloat	sampleRate (void)
	Static method that returns the current STK sample rate.

static void	setSampleRate (StkFloat rate)
	Static method that sets the STK sample rate. More...

static void	clear_alertList ()
	Static method that frees memory from alertList_.

static std::string	rawwavePath (void)
	Static method that returns the current rawwave path.

static void	setRawwavePath (std::string path)
	Static method that sets the STK rawwave path.

static void	swap16 (unsigned char *ptr)
	Static method that byte-swaps a 16-bit data type.

static void	swap32 (unsigned char *ptr)
	Static method that byte-swaps a 32-bit data type.

static void	swap64 (unsigned char *ptr)
	Static method that byte-swaps a 64-bit data type.

static void	sleep (unsigned long milliseconds)
	Static cross-platform method to sleep for a number of milliseconds.

static bool	inRange (StkFloat value, StkFloat min, StkFloat max)
	Static method to check whether a value is within a specified range.

static void	handleError (const char *message, StkError::Type type)
	Static function for error reporting and handling using c-strings.

static void	handleError (std::string message, StkError::Type type)
	Static function for error reporting and handling using c++ strings.

static void	showWarnings (bool status)
	Toggle display of WARNING and STATUS messages.

static void	printErrors (bool status)
	Toggle display of error messages before throwing exceptions.

Static Protected Attributes
static const StkFormat	STK_SINT8

static const StkFormat	STK_SINT16

static const StkFormat	STK_SINT24

static const StkFormat	STK_SINT32

static const StkFormat	STK_FLOAT32

static const StkFormat	STK_FLOAT64

Detailed Description

STK file looping / oscillator class.

This class provides audio file looping functionality. Any audio file that can be loaded by FileRead can be looped using this class.

FileLoop supports multi-channel data. It is important to distinguish the tick() method that computes a single frame (and returns only the specified sample of a multi-channel frame) from the overloaded one that takes an StkFrames object for multi-channel and/or multi-frame data.

by Perry R. Cook and Gary P. Scavone, 1995–2019.

Member Function Documentation

◆ openFile()

virtual void stk::FileLoop::openFile	(	std::string	fileName,
		bool	raw = `false`,
		bool	doNormalize = `true`,
		bool	doInt2FloatScaling = `true`
	)

virtual

Open the specified file and load its data.

Data from a previously opened file will be overwritten by this function. An StkError will be thrown if the file is not found, its format is unknown, or a read error occurs. If the file length is less than the chunkThreshold limit and doNormalize is true, the file data will be normalized with respect to the maximum absolute value of the data. If the doInt2FloatScaling flag is true and the input data is fixed-point, a scaling will be applied with respect to the fixed-point limits.

Reimplemented from stk::FileWvIn.

Reimplemented in stk::MemoryLoop.

◆ normalize() [1/2]

void stk::FileLoop::normalize ( void )

inlinevirtual

Normalize data to a maximum of +-1.0.

This function has no effect when data is incrementally loaded from disk.

Reimplemented from stk::FileWvIn.

67 { FileWvIn::normalize( 1.0 ); };

stk::FileWvIn::normalize

virtual void normalize(void)

Normalize data to a maximum of +-1.0.

◆ normalize() [2/2]

void stk::FileLoop::normalize ( StkFloat peak )

inlinevirtual

Normalize data to a maximum of +-peak.

This function has no effect when data is incrementally loaded from disk.

Reimplemented from stk::FileWvIn.

74 { FileWvIn::normalize( peak ); };

◆ getFileRate()

StkFloat stk::FileLoop::getFileRate ( void ) const

inlinevirtual

Return the input file sample rate in Hz (not the data read rate).

WAV, SND, and AIF formatted files specify a sample rate in their headers. STK RAW files have a sample rate of 22050 Hz by definition. MAT-files are assumed to have a rate of 44100 Hz.

Reimplemented from stk::FileWvIn.

86 { return data_.dataRate(); };

stk::StkFrames::dataRate

StkFloat dataRate(void) const

Return the sample rate associated with the StkFrames data.

Definition: Stk.h:432

◆ setRate()

void stk::FileLoop::setRate ( StkFloat rate )

virtual

Set the data read rate in samples. The rate can be negative.

If the rate value is negative, the data is read in reverse order.

Reimplemented from stk::FileWvIn.

◆ setFrequency()

void stk::FileLoop::setFrequency ( StkFloat frequency )

inline

Set the data interpolation rate based on a looping frequency.

This function determines the interpolation rate based on the file size and the current Stk::sampleRate. The frequency value corresponds to file cycles per second. The frequency can be negative, in which case the loop is read in reverse order.

101 { this->setRate( fileSize_ * frequency / Stk::sampleRate() ); };

stk::FileLoop::setRate

void setRate(StkFloat rate)

Set the data read rate in samples. The rate can be negative.

stk::Stk::sampleRate

static StkFloat sampleRate(void)

Static method that returns the current STK sample rate.

Definition: Stk.h:156

◆ addPhase()

void stk::FileLoop::addPhase ( StkFloat angle )

Increment current read pointer by angle, relative to a looping frequency.

This function increments the read pointer based on the file size and the current Stk::sampleRate. The anAngle value is a multiple of file size.

◆ addPhaseOffset()

void stk::FileLoop::addPhaseOffset ( StkFloat angle )

Add a phase offset to the current read pointer.

This function determines a time offset based on the file size and the current Stk::sampleRate. The angle value is a multiple of file size.

◆ lastOut()

StkFloat stk::FileLoop::lastOut ( unsigned int channel = 0 )

inline

Return the specified channel value of the last computed frame.

For multi-channel files, use the lastFrame() function to get all values from the last computed frame. If no file data is loaded, the returned value is 0.0. The channel argument must be less than the number of channels in the file data (the first channel is specified by 0). However, range checking is only performed if STK_DEBUG is defined during compilation, in which case an out-of-range value will trigger an StkError exception.

132 { return FileWvIn::lastOut( channel ); };

stk::FileWvIn::lastOut

StkFloat lastOut(unsigned int channel=0)

Return the specified channel value of the last computed frame.

Definition: FileWvIn.h:194

◆ tick() [1/2]

StkFloat stk::FileLoop::tick ( unsigned int channel = 0 )

virtual

Compute a sample frame and return the specified channel value.

For multi-channel files, use the lastFrame() function to get all values from the computed frame. If no file data is loaded, the returned value is 0.0. The channel argument must be less than the number of channels in the file data (the first channel is specified by 0). However, range checking is only performed if STK_DEBUG is defined during compilation, in which case an out-of-range value will trigger an StkError exception.

Reimplemented from stk::FileWvIn.

◆ tick() [2/2]

virtual StkFrames& stk::FileLoop::tick	(	StkFrames &	frames,
		unsigned int	channel = `0`
	)

virtual

Fill the StkFrames object with computed sample frames, starting at the specified channel and return the same reference.

The channel argument plus the number of output channels must be less than the number of channels in the StkFrames argument (the first channel is specified by 0). However, range checking is only performed if STK_DEBUG is defined during compilation, in which case an out-of-range value will trigger an StkError exception.

Reimplemented from stk::FileWvIn.

◆ setInterpolate()

void stk::FileWvIn::setInterpolate ( bool doInterpolate )

inlineinherited

Turn linear interpolation on/off.

Interpolation is automatically off when the read rate is an integer value. If interpolation is turned off for a fractional rate, the time index is truncated to an integer value.

139 { interpolate_ = doInterpolate; };

◆ lastFrame()

const StkFrames& stk::WvIn::lastFrame ( void ) const

inlineinherited

Return an StkFrames reference to the last computed sample frame.

If no file data is loaded, an empty container is returned.

29 { return lastFrame_; };

◆ setSampleRate()

static void stk::Stk::setSampleRate ( StkFloat rate )

staticinherited

Static method that sets the STK sample rate.

The sample rate set using this method is queried by all STK classes that depend on its value. It is initialized to the default SRATE set in Stk.h. Many STK classes use the sample rate during instantiation. Therefore, if you wish to use a rate that is different from the default rate, it is imperative that it be set BEFORE STK objects are instantiated. A few classes that make use of the global STK sample rate are automatically notified when the rate changes so that internal class data can be appropriately updated. However, this has not been fully implemented. Specifically, classes that appropriately update their own data when either a setFrequency() or noteOn() function is called do not currently receive the automatic notification of rate change. If the user wants a specific class instance to ignore such notifications, perhaps in a multi-rate context, the function Stk::ignoreSampleRateChange() should be called.

◆ ignoreSampleRateChange()

void stk::Stk::ignoreSampleRateChange ( bool ignore = true )

inlineinherited

A function to enable/disable the automatic updating of class data when the STK sample rate changes.

This function allows the user to enable or disable class data updates in response to global sample rate changes on a class by class basis.

184 { ignoreSampleRateChange_ = ignore; };

Member Data Documentation

◆ STK_SINT8

const StkFormat stk::Stk::STK_SINT8

staticinherited

-128 to +127

◆ STK_SINT16

const StkFormat stk::Stk::STK_SINT16

staticinherited

-32768 to +32767

◆ STK_SINT24

const StkFormat stk::Stk::STK_SINT24

staticinherited

Lower 3 bytes of 32-bit signed integer.

◆ STK_SINT32

const StkFormat stk::Stk::STK_SINT32

staticinherited

-2147483648 to +2147483647.

◆ STK_FLOAT32

const StkFormat stk::Stk::STK_FLOAT32

staticinherited

Normalized between plus/minus 1.0.

◆ STK_FLOAT64

const StkFormat stk::Stk::STK_FLOAT64

staticinherited

Normalized between plus/minus 1.0.

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

FileLoop.h

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Static Protected Attributes

Detailed Description

Member Function Documentation

◆ openFile()

◆ normalize() [1/2]

◆ normalize() [2/2]

◆ getFileRate()

◆ setRate()

◆ setFrequency()

◆ addPhase()

◆ addPhaseOffset()

◆ lastOut()

◆ tick() [1/2]

◆ tick() [2/2]

◆ setInterpolate()

◆ lastFrame()

◆ setSampleRate()

◆ ignoreSampleRateChange()

Member Data Documentation

◆ STK_SINT8

◆ STK_SINT16

◆ STK_SINT24

◆ STK_SINT32

◆ STK_FLOAT32

◆ STK_FLOAT64