stk::StkFrames Class Reference

An STK class to handle vectorized audio data. More...

#include <Stk.h>

Public Member Functions
	StkFrames (unsigned int nFrames=0, unsigned int nChannels=0)
	The default constructor initializes the frame data structure to size zero.
	StkFrames (const StkFloat &value, unsigned int nFrames, unsigned int nChannels)
	Overloaded constructor that initializes the frame data to the specified size with value.
virtual	~StkFrames ()
	The destructor.
StkFloat &	operator[] (size_t n)
	Subscript operator that returns a reference to element n of self.
StkFloat	operator[] (size_t n) const
	Subscript operator that returns the value at element n of self.
StkFrames	operator+ (const StkFrames &frames) const
	Sum operator.
StkFrames &	operator+= (StkFrames &f)
	Assignment by sum operator into self.
StkFrames &	operator*= (StkFrames &f)
	Assignment by product operator into self.
StkFrames	operator* (StkFloat v) const
	Scaling operator (StkFrame * StkFloat).
StkFrames &	operator*= (StkFloat v)
	Scaling operator (inline).
StkFloat &	operator() (size_t frame, unsigned int channel)
	Channel / frame subscript operator that returns a reference.
StkFloat	operator() (size_t frame, unsigned int channel) const
	Channel / frame subscript operator that returns a value.
StkFloat	interpolate (StkFloat frame, unsigned int channel=0) const
	Return an interpolated value at the fractional frame index and channel.
size_t	size () const
	Returns the total number of audio samples represented by the object.
bool	empty () const
	Returns true if the object size is zero and false otherwise.
virtual void	resize (size_t nFrames, unsigned int nChannels=1)
	Resize self to represent the specified number of channels and frames.
virtual void	resize (size_t nFrames, unsigned int nChannels, StkFloat value)
	Resize self to represent the specified number of channels and frames and perform element initialization.
StkFrames &	getChannel (unsigned int channel, StkFrames &destinationFrames, unsigned int destinationChannel) const
	Retrieves a single channel.
void	setChannel (unsigned int channel, const StkFrames &sourceFrames, unsigned int sourceChannel)
	Sets a single channel.
unsigned int	channels (void) const
	Return the number of channels represented by the data.
unsigned int	frames (void) const
	Return the number of sample frames represented by the data.
void	setDataRate (StkFloat rate)
	Set the sample rate associated with the StkFrames data.
StkFloat	dataRate (void) const
	Return the sample rate associated with the StkFrames data.

Detailed Description

An STK class to handle vectorized audio data.

This class can hold single- or multi-channel audio data. The data type is always StkFloat and the channel format is always interleaved. In an effort to maintain efficiency, no out-of-bounds checks are performed in this class unless STK_DEBUG is defined.

Internally, the data is stored in a one-dimensional C array. An indexing operator is available to set and retrieve data values. Alternately, one can use pointers to access the data, using the index operator to get an address for a particular location in the data:

StkFloat* ptr = &myStkFrames[0];

Note that this class can also be used as a table with interpolating lookup.

Possible future improvements in this class could include functions to convert to and return other data types.

by Perry R. Cook and Gary P. Scavone, 1995–2023.

Member Function Documentation

operator[]() [1/2]

StkFloat & stk::StkFrames::operator[] ( size_t  n )

inline

Subscript operator that returns a reference to element n of self.

The result can be used as an lvalue. This reference is valid until the resize function is called or the array is destroyed. The index n must be between 0 and size less one. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( n >= size_ ) {
    std::ostringstream error;
    error << "StkFrames::operator[]: invalid index (" << n << ") value!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  return data_[n];
}

operator[]() [2/2]

StkFloat stk::StkFrames::operator[] ( size_t  n ) const

inline

Subscript operator that returns the value at element n of self.

The index n must be between 0 and size less one. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( n >= size_ ) {
    std::ostringstream error;
    error << "StkFrames::operator[]: invalid index (" << n << ") value!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  return data_[n];
}

operator+()

StkFrames stk::StkFrames::operator+ ( const StkFrames &  frames ) const

inline

Sum operator.

The dimensions of the argument are expected to be the same as self. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( f.frames() != nFrames_ || f.channels() != nChannels_ ) {
    std::ostringstream error;
    error << "StkFrames::operator+: frames argument must be of equal dimensions!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
  StkFrames sum((unsigned int)nFrames_,nChannels_);
  StkFloat *sumPtr = &sum[0];
  const StkFloat *fptr = f.data_;
  const StkFloat *dPtr = data_;
  for (unsigned int i = 0; i < size_; i++) {
    *sumPtr++ = *fptr++ + *dPtr++;
  }
  return sum;
}

operator+=()

StkFrames & stk::StkFrames::operator+= ( StkFrames &  f )

inline

Assignment by sum operator into self.

The dimensions of the argument are expected to be the same as self. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( f.frames() != nFrames_ || f.channels() != nChannels_ ) {
    std::ostringstream error;
    error << "StkFrames::operator+=: frames argument must be of equal dimensions!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  StkFloat *fptr = &f[0];
  StkFloat *dptr = data_;
  for ( unsigned int i=0; i<size_; i++ )
    *dptr++ += *fptr++;
  return *this;
}

operator*=()

StkFrames & stk::StkFrames::operator*= ( StkFrames &  f )

inline

Assignment by product operator into self.

The dimensions of the argument are expected to be the same as self. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( f.frames() != nFrames_ || f.channels() != nChannels_ ) {
    std::ostringstream error;
    error << "StkFrames::operator*=: frames argument must be of equal dimensions!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  StkFloat *fptr = &f[0];
  StkFloat *dptr = data_;
  for ( unsigned int i=0; i<size_; i++ )
    *dptr++ *= *fptr++;
  return *this;
}

operator()() [1/2]

StkFloat & stk::StkFrames::operator() ( size_t  frame, unsigned int  channel  )

inline

Channel / frame subscript operator that returns a reference.

The result can be used as an lvalue. This reference is valid until the resize function is called or the array is destroyed. The frame index must be between 0 and frames() - 1. The channel index must be between 0 and channels() - 1. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( frame >= nFrames_ || channel >= nChannels_ ) {
    std::ostringstream error;
    error << "StkFrames::operator(): invalid frame (" << frame << ") or channel (" << channel << ") value!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  return data_[ frame * nChannels_ + channel ];
}

operator()() [2/2]

StkFloat stk::StkFrames::operator() ( size_t  frame, unsigned int  channel  ) const

inline

Channel / frame subscript operator that returns a value.

The frame index must be between 0 and frames() - 1. The channel index must be between 0 and channels() - 1. No range checking is performed unless STK_DEBUG is defined.

{
#if defined(_STK_DEBUG_)
  if ( frame >= nFrames_ || channel >= nChannels_ ) {
    std::ostringstream error;
    error << "StkFrames::operator(): invalid frame (" << frame << ") or channel (" << channel << ") value!";
    Stk::handleError( error.str(), StkError::MEMORY_ACCESS );
  }
#endif
 
  return data_[ frame * nChannels_ + channel ];
}

interpolate()

StkFloat stk::StkFrames::interpolate	(	StkFloat	frame,
		unsigned int	channel = 0
	)		const

Return an interpolated value at the fractional frame index and channel.

This function performs linear interpolation. The frame index must be between 0.0 and frames() - 1. The channel index must be between 0 and channels() - 1. No range checking is performed unless STK_DEBUG is defined.

resize() [1/2]

virtual void stk::StkFrames::resize ( size_t  nFrames, unsigned int  nChannels = 1  )

virtual

Resize self to represent the specified number of channels and frames.

Changes the size of self based on the number of frames and channels. No element assignment is performed. No memory deallocation occurs if the new size is smaller than the previous size. Further, no new memory is allocated when the new size is smaller or equal to a previously allocated size.

resize() [2/2]

virtual void stk::StkFrames::resize ( size_t  nFrames, unsigned int  nChannels, StkFloat  value  )

virtual

Resize self to represent the specified number of channels and frames and perform element initialization.

Changes the size of self based on the number of frames and channels, and assigns value to every element. No memory deallocation occurs if the new size is smaller than the previous size. Further, no new memory is allocated when the new size is smaller or equal to a previously allocated size.

getChannel()

StkFrames & stk::StkFrames::getChannel	(	unsigned int	channel,
		StkFrames &	destinationFrames,
		unsigned int	destinationChannel
	)		const

Retrieves a single channel.

Copies the specified channel into destinationFrames's destinationChannel. destinationChannel must be between 0 and destination.channels() - 1 and channel must be between 0 and channels() - 1. destination.frames() must be >= frames(). No range checking is performed unless STK_DEBUG is defined.

setChannel()

void stk::StkFrames::setChannel	(	unsigned int	channel,
		const StkFrames &	sourceFrames,
		unsigned int	sourceChannel
	)

Sets a single channel.

Copies the sourceChannel of sourceFrames into the channel of self. SourceFrames.frames() must be equal to frames(). No range checking is performed unless STK_DEBUG is defined.

setDataRate()

void stk::StkFrames::setDataRate ( StkFloat  rate )

inline

Set the sample rate associated with the StkFrames data.

By default, this value is set equal to the current STK sample rate at the time of instantiation.

{ dataRate_ = rate; };

dataRate()

StkFloat stk::StkFrames::dataRate ( void  ) const

inline

Return the sample rate associated with the StkFrames data.

By default, this value is set equal to the current STK sample rate at the time of instantiation.

{ return dataRate_; };

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

• Stk.h