Async::SampleFifo Class Reference

A FIFO class for handling audio samples. More...

#include <AsyncSampleFifo.h>

List of all members.

Public Member Functions

• SampleFifo (int fifo_size)

  Default constuctor.
  

• ~SampleFifo (void)

  Destructor.
  

• int addSamples (short *samples, int count)

  Add samples to the FIFO.
  

• void stopOutput (bool stop)

  Stop automatic audio output via the writeSamples signal.
  

• bool empty (void) const

  Check if the FIFO is empty.
  

• bool full (void) const

  Check if the FIFO is full.
  

• unsigned samplesInFifo (void) const

  Find out how many samples there are in the FIFO.
  

• void writeBufferFull (bool is_full)

  Indicate to the FIFO if the receiver is ready or not to accept more samples.
  

• void setOverwrite (bool overwrite)

  Set the overwrite mode.
  

• bool overwrite (void) const

  Check the overwrite mode.
  

• int readSamples (short *samples, int count)

  Read samples from the FIFO.
  

• void clear (void)

  Clear all samples from the FIFO.
  

• void setPrebufSamples (unsigned prebuf_samples)

  Set the number of samples that must be in the fifo before any samples are written out from it.
  

• void flushSamples (void)

  Flush out the samples in the buffer.
  

• void setDebugName (const std::string &name)

  Set a name for this FIFO used for debugging.
  

Public Attributes

• SigC::Signal1< void, bool > fifoFull

  A signal that is emitted when the FIFO is full.
  

• SigC::Signal2< int, short *,
  int > writeSamples

  A signal that is emitted when the FIFO want to output samples.
  

• SigC::Signal0< void > allSamplesWritten

  A signal that is emitted when the FIFO has been emptied.
  

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Detailed Description

A FIFO class for handling audio samples.

Author:

Tobias Blomberg / SM0SVX

Date:

2004-03-07

This class implements a FIFO for handling audio samples.

Definition at line 116 of file AsyncSampleFifo.h.

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Constructor & Destructor Documentation

Async::SampleFifo::SampleFifo (  int  fifo_size  )  [explicit]

Default constuctor.

Async::SampleFifo::~SampleFifo (  void   )

Destructor.

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Member Function Documentation

int Async::SampleFifo::addSamples (  short *  samples, int  count )

Add samples to the FIFO. Parameters: samples  A buffer containing samples to put into the FIFO count  The number of samples to put into the FIFO Returns: Return the number of samples that have been put into the FIFO

void Async::SampleFifo::clear (  void   )  [inline]

Clear all samples from the FIFO. Definition at line 234 of file AsyncSampleFifo.h. References allSamplesWritten.

bool Async::SampleFifo::empty (  void   )  const [inline]

Check if the FIFO is empty. Returns: Returns true if the FIFO is empty or else false Definition at line 156 of file AsyncSampleFifo.h.

void Async::SampleFifo::flushSamples (  void   )

Flush out the samples in the buffer.

bool Async::SampleFifo::full (  void   )  const

Check if the FIFO is full. Returns: Returns true if the FIFO is full or else false This function is used to check if the FIFO is full or not. The FIFO can only reach the buffer full condition if overwrite is false. The overwrite mode is set by the setOverwrite function.

bool Async::SampleFifo::overwrite (  void   )  const [inline]

Check the overwrite mode. Returns: Returns true if overwrite is enabled or else false The FIFO can operate in overwrite or normal mode. When in normal mode, it will not be possible to add any more samples to the FIFO when it is full. Samples has to be removed first. When overwrite is set, newly added samples will overwrite the oldest samples in the buffer so the FIFO will never get full but instead samples are lost. Use this function the check the current overwrite mode. Use the setOverwrite function to set the overwrite mode. Definition at line 215 of file AsyncSampleFifo.h.

int Async::SampleFifo::readSamples (  short *  samples, int  count )

Read samples from the FIFO. Parameters: samples  A buffer to put the read samples into count  The number of samples to read. This value must not be larger than the size of the "samples" buffer given in the first argument. Returns: Returns the number of samples actually read This function can be used to read samples from the FIFO if the automatic output of samples is not enabled. Automatic output of samples and this function must not be used at the sample time.

unsigned Async::SampleFifo::samplesInFifo (  void   )  const

Find out how many samples there are in the FIFO. Returns: Returns the number of samples in the FIFO

void Async::SampleFifo::setDebugName (  const std::string &  name  )  [inline]

Set a name for this FIFO used for debugging. Parameters: name  The name to use for this FIFO Definition at line 252 of file AsyncSampleFifo.h.

void Async::SampleFifo::setOverwrite (  bool  overwrite  )  [inline]

Set the overwrite mode. Parameters: overwrite  Set to true to overwrite or else false The FIFO can operate in overwrite or normal mode. When in normal mode, it will not be possible to add any more samples to the FIFO when it is full. Samples has to be removed first. When overwrite is set, newly added samples will overwrite the oldest samples in the buffer so the FIFO will never get full but instead samples are lost. Use this function to set the overwrite mode. Definition at line 201 of file AsyncSampleFifo.h.

void Async::SampleFifo::setPrebufSamples (  unsigned  prebuf_samples  )

Set the number of samples that must be in the fifo before any samples are written out from it. Parameters: prebuf_samples  The number of samples

void Async::SampleFifo::stopOutput (  bool  stop  )

Stop automatic audio output via the writeSamples signal. Parameters: stop  Set to true to stop audio output or else false This FIFO has the ability to automatically output audio samples using the writeSamples signal. The samples are output as fast as the receiver can handle them. Flow control is handled by the receiver setting the return value from the writeSamples signal and by calling the writeBufferFull method. When the FIFO run out of samples, the allSamplesWritten signal is emitted. Use this function to enable/disable the automatic output of samples. By default, automatic output is enabled.

void Async::SampleFifo::writeBufferFull (  bool  is_full  )

Indicate to the FIFO if the receiver is ready or not to accept more samples. Parameters: is_full  Set to false if more samples can be accepted or true if not. This FIFO has the ability to automatically output audio samples using the writeSamples signal. The samples are output as fast as the receiver can handle them. Flow control is handled by the receiver setting the return value from the writeSamples signal and by calling this function. When the FIFO run out of samples, the allSamplesWritten signal is emitted. Use this function to stop or start the output of samples.

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Member Data Documentation

SigC::Signal0<void> Async::SampleFifo::allSamplesWritten

A signal that is emitted when the FIFO has been emptied. This FIFO has the ability to automatically output audio samples using the the writeSamples signal. The samples are output as fast as the receiver can handle them. Flow control is handled by the receiver setting the return value from the writeSamples signal and by calling the writeBufferFull function. When the FIFO run out of samples, this signal is emitted. Definition at line 293 of file AsyncSampleFifo.h. Referenced by clear().

SigC::Signal1<void, bool> Async::SampleFifo::fifoFull

A signal that is emitted when the FIFO is full. Parameters: is_full  Set to true if the buffer is full or false if the buffer full condition has been cleared Definition at line 260 of file AsyncSampleFifo.h.

SigC::Signal2<int, short *, int> Async::SampleFifo::writeSamples

A signal that is emitted when the FIFO want to output samples. Parameters: samples  A buffer containing the samples to output count  The number of samples in the output buffer Returns: Return the number of samples actually read by the receiver This FIFO has the ability to automatically output audio samples using the this signal. The samples are output as fast as the receiver can handle them. Flow control is handled by the receiver setting the return value from this signal and by calling the writeBufferFull method. When the FIFO run out of samples, the allSamplesWritten signal is emitted. If the value returned by the connected slot (receiver) differs from the value of the second argument of this signal (count), output will be stopped until the writeBufferFull function is called. This is how the flow control is handled. Definition at line 281 of file AsyncSampleFifo.h.

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

• AsyncSampleFifo.h

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