ChannelRemappingAudioSource Class Reference

Inheritance diagram for ChannelRemappingAudioSource:

List of all members.

---

Detailed Description

An AudioSource that takes the audio from another source, and re-maps its input and output channels to a different arrangement.

You can use this to increase or decrease the number of channels that an audio source uses, or to re-order those channels.

Call the reset() method before using it to set up a default mapping, and then the setInputChannelMapping() and setOutputChannelMapping() methods to create an appropriate mapping, otherwise no channels will be connected and it'll produce silence.

See also:

AudioSource

Public Member Functions
	ChannelRemappingAudioSource (AudioSource *const source, const bool deleteSourceWhenDeleted)
	Creates a remapping source that will pass on audio from the given input.
	~ChannelRemappingAudioSource ()
	Destructor.
void	setNumberOfChannelsToProduce (const int requiredNumberOfChannels) throw ()
	Specifies a number of channels that this audio source must produce from its getNextAudioBlock() callback.
void	clearAllMappings () throw ()
	Clears any mapped channels.
void	setInputChannelMapping (const int destChannelIndex, const int sourceChannelIndex) throw ()
	Creates an input channel mapping.
void	setOutputChannelMapping (const int sourceChannelIndex, const int destChannelIndex) throw ()
	Creates an output channel mapping.
int	getRemappedInputChannel (const int inputChannelIndex) const throw ()
	Returns the channel from our input that will be sent to channel inputChannelIndex of our input audio source.
int	getRemappedOutputChannel (const int outputChannelIndex) const throw ()
	Returns the output channel to which channel outputChannelIndex of our input audio source will be sent to.
XmlElement *	createXml () const throw ()
	Returns an XML object to encapsulate the state of the mappings.
void	restoreFromXml (const XmlElement &e) throw ()
	Restores the mappings from an XML object created by createXML().
void	prepareToPlay (int samplesPerBlockExpected, double sampleRate)
	Tells the source to prepare for playing.
void	releaseResources ()
	Allows the source to release anything it no longer needs after playback has stopped.
void	getNextAudioBlock (const AudioSourceChannelInfo &bufferToFill)
	Called repeatedly to fetch subsequent blocks of audio data.

---

Constructor & Destructor Documentation

ChannelRemappingAudioSource::ChannelRemappingAudioSource (  AudioSource *const   source, const bool  deleteSourceWhenDeleted )

Creates a remapping source that will pass on audio from the given input. Parameters: source  the input source to use. Make sure that this doesn't get deleted before the ChannelRemappingAudioSource object deleteSourceWhenDeleted  if true, the input source will be deleted when this object is deleted, if false, the caller is responsible for its deletion

ChannelRemappingAudioSource::~ChannelRemappingAudioSource (   )

Destructor.

---

Member Function Documentation

void ChannelRemappingAudioSource::setNumberOfChannelsToProduce (  const int  requiredNumberOfChannels  )  throw ()

Specifies a number of channels that this audio source must produce from its getNextAudioBlock() callback.

void ChannelRemappingAudioSource::clearAllMappings (   )  throw ()

Clears any mapped channels. After this, no channels are mapped, so this object will produce silence. Create some mappings with setInputChannelMapping() and setOutputChannelMapping().

void ChannelRemappingAudioSource::setInputChannelMapping (  const int  destChannelIndex, const int  sourceChannelIndex )  throw ()

Creates an input channel mapping. When the getNextAudioBlock() method is called, the data in channel sourceChannelIndex of the incoming data will be sent to destChannelIndex of our input source. Parameters: destChannelIndex  the index of an input channel in our input audio source (i.e. the source specified when this object was created). sourceChannelIndex  the index of the input channel in the incoming audio data buffer during our getNextAudioBlock() callback

void ChannelRemappingAudioSource::setOutputChannelMapping (  const int  sourceChannelIndex, const int  destChannelIndex )  throw ()

Creates an output channel mapping. When the getNextAudioBlock() method is called, the data returned in channel sourceChannelIndex by our input audio source will be copied to channel destChannelIndex of the final buffer. Parameters: sourceChannelIndex  the index of an output channel coming from our input audio source (i.e. the source specified when this object was created). destChannelIndex  the index of the output channel in the incoming audio data buffer during our getNextAudioBlock() callback

int ChannelRemappingAudioSource::getRemappedInputChannel (  const int  inputChannelIndex  )  const throw ()

Returns the channel from our input that will be sent to channel inputChannelIndex of our input audio source.

int ChannelRemappingAudioSource::getRemappedOutputChannel (  const int  outputChannelIndex  )  const throw ()

Returns the output channel to which channel outputChannelIndex of our input audio source will be sent to.

XmlElement* ChannelRemappingAudioSource::createXml (   )  const throw ()

Returns an XML object to encapsulate the state of the mappings. See also: restoreFromXml

void ChannelRemappingAudioSource::restoreFromXml (  const XmlElement &  e  )  throw ()

Restores the mappings from an XML object created by createXML(). See also: createXml

void ChannelRemappingAudioSource::prepareToPlay (  int  samplesPerBlockExpected, double  sampleRate )  [virtual]

Tells the source to prepare for playing. The source can use this opportunity to initialise anything it needs to. Note that this method could be called more than once in succession without a matching call to releaseResources(), so make sure your code is robust and can handle that kind of situation. Parameters: samplesPerBlockExpected  the number of samples that the source will be expected to supply each time its getNextAudioBlock() method is called. This number may vary slightly, because it will be dependent on audio hardware callbacks, and these aren't guaranteed to always use a constant block size, so the source should be able to cope with small variations. sampleRate  the sample rate that the output will be used at - this is needed by sources such as tone generators. See also: releaseResources, getNextAudioBlock Implements AudioSource.

void ChannelRemappingAudioSource::releaseResources (   )  [virtual]

Allows the source to release anything it no longer needs after playback has stopped. This will be called when the source is no longer going to have its getNextAudioBlock() method called, so it should release any spare memory, etc. that it might have allocated during the prepareToPlay() call. Note that there's no guarantee that prepareToPlay() will actually have been called before releaseResources(), and it may be called more than once in succession, so make sure your code is robust and doesn't make any assumptions about when it will be called. See also: prepareToPlay, getNextAudioBlock Implements AudioSource.

void ChannelRemappingAudioSource::getNextAudioBlock (  const AudioSourceChannelInfo &  bufferToFill  )  [virtual]

Called repeatedly to fetch subsequent blocks of audio data. After calling the prepareToPlay() method, this callback will be made each time the audio playback hardware (or whatever other destination the audio data is going to) needs another block of data. It will generally be called on a high-priority system thread, or possibly even an interrupt, so be careful not to do too much work here, as that will cause audio glitches! See also: AudioSourceChannelInfo, prepareToPlay, releaseResources Implements AudioSource.

---

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

• juce_ChannelRemappingAudioSource.h