stk::FileLoop Class Reference

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.
void	openFile (std::string fileName, bool raw=false, bool doNormalize=true, bool doInt2FloatScaling=true)
	Open the specified file and load its data.
void	closeFile (void)
	Close a file if one is open.
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.
void	normalize (StkFloat peak)
	Normalize data to a maximum of +-peak.
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).
void	setRate (StkFloat rate)
	Set the data read rate in samples. The rate can be negative.
void	setFrequency (StkFloat frequency)
	Set the data interpolation rate based on a looping frequency.
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.
void	addPhaseOffset (StkFloat angle)
	Add a phase offset to the current read pointer.
StkFloat	lastOut (unsigned int channel=0)
	Return the specified channel value of the last computed frame.
StkFloat	tick (unsigned int channel=0)
	Compute a sample frame and return the specified channel value.
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.

Additional Inherited Members
	FileWvIn (unsigned long chunkThreshold=1000000, unsigned long chunkSize=1024)
	Default constructor.
	FileWvIn (std::string fileName, bool raw=false, bool doNormalize=true, unsigned long chunkThreshold=1000000, unsigned long chunkSize=1024, bool doInt2FloatScaling=true)
	Overloaded constructor for file input.
	~FileWvIn (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.
virtual void	closeFile (void)
	Close a file if one is open.
virtual void	reset (void)
	Clear outputs and reset time (file) pointer to zero.
virtual void	normalize (void)
	Normalize data to a maximum of +-1.0.
virtual void	normalize (StkFloat peak)
	Normalize data to a maximum of +-peak.
virtual unsigned long	getSize (void) const
	Return the file size in sample frames.
virtual StkFloat	getFileRate (void) const
	Return the input file sample rate in Hz (not the data read rate).
bool	isOpen (void)
	Query whether a file is open.
bool	isFinished (void) const
	Query whether reading is complete.
virtual void	setRate (StkFloat rate)
	Set the data read rate in samples. The rate can be negative.
virtual void	addTime (StkFloat time)
	Increment the read pointer by time samples.
void	setInterpolate (bool doInterpolate)
	Turn linear interpolation on/off.
StkFloat	lastOut (unsigned int channel=0)
	Return the specified channel value of the last computed frame.
virtual StkFloat	tick (unsigned int channel=0)
	Compute a sample frame and return the specified channel value.
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.
Protected Member Functions inherited from stk::WvIn
unsigned int	channelsOut (void) const
	Return the number of audio channels in the data or stream.
const StkFrames &	lastFrame (void) const
	Return an StkFrames reference to the last computed sample frame.
virtual StkFloat	tick (unsigned int channel=0)=0
	Compute one sample frame and return the specified channel value.
virtual StkFrames &	tick (StkFrames &frames, unsigned int channel=0)=0
	Fill the StkFrames object with computed sample frames, starting at the specified channel and return the same reference.
Protected Member Functions inherited from stk::Stk
	Stk (void)
	Default constructor.
virtual	~Stk (void)
	Class destructor.
virtual void	sampleRateChanged (StkFloat newRate, StkFloat oldRate)
	This function should be implemented in subclasses that depend on the sample rate.
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.
void	handleError (StkError::Type type) const
	Internal function for error reporting that assumes message in oStream_ variable.
void	ignoreSampleRateChange (bool ignore=true)
	A function to enable/disable the automatic updating of class data when the STK sample rate changes.
Static Protected Member Functions inherited from stk::Stk
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.
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 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, 1995–2023.

Member Function Documentation

openFile()

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.

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.

{ FileWvIn::normalize( 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.

{ 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.

{ return data_.dataRate(); };

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.

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

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.

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

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.

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

• FileLoop.h