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FileWvIn Class Reference

#include <FileWvIn.h>

Inheritance diagram for FileWvIn:

WvIn Stk WaveLoop List of all members.

Detailed Description

STK audio file input class.

This class inherits from WvIn. It provides a "tick-level" interface to the FileRead class. It also provides variable-rate "playback" functionality. Audio file support is provided by the FileRead class. Linear interpolation is used for fractional "read rates".

FileWvIn supports multi-channel data. It is important to distinguish the tick() methods, which return samples produced by averaging across sample frames, from the tickFrame() methods, which return references to multi-channel sample frames.

FileWvIn will either load the entire content of an audio file into local memory or incrementally read file data from disk in chunks. This behavior is controlled by the optional constructor arguments chunkThreshold and chunkSize. File sizes greater than chunkThreshold (in sample frames) will be read incrementally in chunks of chunkSize each (also in sample frames).

When the file end is reached, subsequent calls to the tick() functions return zero-valued data and isFinished() returns true.

See the FileRead class for a description of the supported audio file formats.

by Perry R. Cook and Gary P. Scavone, 1995 - 2007.


Public Member Functions

 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)
 Overloaded constructor for file input.
virtual ~FileWvIn ()
 Class destructor.
void openFile (std::string fileName, bool raw=false, bool doNormalize=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.
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).
bool isFinished (void) const
 Query whether reading is complete.
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.


Constructor & Destructor Documentation

FileWvIn::FileWvIn std::string  fileName,
bool  raw = false,
bool  doNormalize = true,
unsigned long  chunkThreshold = 1000000,
unsigned long  chunkSize = 1024
 

Overloaded constructor for file input.

An StkError will be thrown if the file is not found, its format is unknown, or a read error occurs.


Member Function Documentation

void FileWvIn::openFile std::string  fileName,
bool  raw = false,
bool  doNormalize = true
 

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 data is to be loaded incrementally from disk and normalization is specified, a scaling will be applied with respect to fixed-point limits. If the data format is floating-point, no scaling is performed.

Reimplemented in WaveLoop.

void FileWvIn::normalize void   ) 
 

Normalize data to a maximum of +-1.0.

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

void FileWvIn::normalize StkFloat  peak  ) 
 

Normalize data to a maximum of +-peak.

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

StkFloat FileWvIn::getFileRate void   )  const [inline]
 

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.

void FileWvIn::setRate StkFloat  rate  ) 
 

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 in WaveLoop.

virtual void FileWvIn::addTime StkFloat  time  )  [virtual]
 

Increment the read pointer by time samples.

Note that this function will not modify the interpolation flag status.

Reimplemented in WaveLoop.

void FileWvIn::setInterpolate bool  doInterpolate  )  [inline]
 

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.


The documentation for this class was generated from the following file:
The Synthesis ToolKit in C++ (STK)
©1995-2007 Perry R. Cook and Gary P. Scavone. All Rights Reserved.