juce::AudioProcessor Class Reference

Base class for audio processing classes or plugins. More...

#include <juce_AudioProcessor.h>

Inheritance diagram for juce::AudioProcessor:

Collaboration diagram for juce::AudioProcessor:

Classes
class	Bus
	Describes the layout and properties of an audio bus. More...
struct	BusesLayout
	Represents the bus layout state of a plug-in. More...
struct	BusesProperties
	Structure used for AudioProcessor Callbacks. More...
struct	BusProperties
	Structure used for AudioProcessor Callbacks. More...
struct	CurveData
	Some plug-ins support sharing response curve data with the host so that it can display this curve on a console or in the mixer panel. More...
struct	InOutChannelPair
struct	TrackProperties
	A struct containing information about the DAW track inside which your AudioProcessor is loaded. More...

Public Types
enum	ProcessingPrecision {   singlePrecision,   doublePrecision }
enum	WrapperType {   wrapperType_Undefined = 0,   wrapperType_VST,   wrapperType_VST3,   wrapperType_AudioUnit,   wrapperType_AudioUnitv3,   wrapperType_RTAS,   wrapperType_AAX,   wrapperType_Standalone,   wrapperType_Unity }
	Flags to indicate the type of plugin context in which a processor is being used. More...

Public Member Functions
virtual	~AudioProcessor ()
	Destructor. More...
virtual bool	acceptsMidi () const =0
	Returns true if the processor wants MIDI messages. More...
bool	addBus (bool isInput)
	Dynamically request an additional bus. More...
virtual void	addListener (AudioProcessorListener *newListener)
	Adds a listener that will be called when an aspect of this processor changes. More...
void	addParameter (AudioProcessorParameter *)
	Adds a parameter to the AudioProcessor. More...
void	addParameterGroup (std::unique_ptr< AudioProcessorParameterGroup >)
	Adds a group of parameters to the AudioProcessor. More...
void	beginParameterChangeGesture (int parameterIndex)
	Sends a signal to the host to tell it that the user is about to start changing this parameter. More...
virtual bool	canAddBus (bool isInput) const
	Callback to query if a bus can currently be added. More...
virtual bool	canRemoveBus (bool isInput) const
	Callback to query if the last bus can currently be removed. More...
virtual void	changeProgramName (int index, const String &newName)=0
	Called by the host to rename a program. More...
bool	checkBusesLayoutSupported (const BusesLayout &) const
	Returns true if the Audio processor is likely to support a given layout. More...
virtual AudioProcessorEditor *	createEditor ()=0
	Creates the processor's GUI. More...
AudioProcessorEditor *	createEditorIfNeeded ()
	Returns the active editor, or if there isn't one, it will create one. More...
bool	disableNonMainBuses ()
	Disables all non-main buses (aux and sidechains). More...
void	editorBeingDeleted (AudioProcessorEditor *) noexcept
	Not for public use - this is called before deleting an editor component. More...
bool	enableAllBuses ()
	Enables all buses. More...
void	endParameterChangeGesture (int parameterIndex)
	Tells the host that the user has finished changing this parameter. More...
virtual int32	getAAXPluginIDForMainBusConfig (const AudioChannelSet &mainInputLayout, const AudioChannelSet &mainOutputLayout, bool idForAudioSuite) const
	AAX plug-ins need to report a unique "plug-in id" for every audio layout configuration that your AudioProcessor supports on the main bus. More...
AudioProcessorEditor *	getActiveEditor () const noexcept
	Returns the active editor, if there is one. More...
virtual StringArray	getAlternateDisplayNames () const
	Returns a list of alternative names to use for this processor. More...
int	getBlockSize () const noexcept
	Returns the current typical block size that is being used. More...
Bus *	getBus (bool isInput, int busIndex) noexcept
	Returns the audio bus with a given index and direction. More...
const Bus *	getBus (bool isInput, int busIndex) const noexcept
	Returns the audio bus with a given index and direction. More...
template<typename FloatType >
AudioBuffer< FloatType >	getBusBuffer (AudioBuffer< FloatType > &processBlockBuffer, bool isInput, int busIndex) const
	Returns an AudioBuffer containing a set of channel pointers for a specific bus. More...
int	getBusCount (bool isInput) const noexcept
	Returns the number of buses on the input or output side. More...
BusesLayout	getBusesLayout () const
	Provides the current channel layouts of this audio processor. More...
virtual AudioProcessorParameter *	getBypassParameter () const
	Returns the parameter that controls the AudioProcessor's bypass state. More...
const CriticalSection &	getCallbackLock () const noexcept
	This returns a critical section that will automatically be locked while the host is calling the processBlock() method. More...
int	getChannelCountOfBus (bool isInput, int busIndex) const noexcept
	Provides the number of channels of the bus with a given index and direction. More...
int	getChannelIndexInProcessBlockBuffer (bool isInput, int busIndex, int channelIndex) const noexcept
	Returns the position of a bus's channels within the processBlock buffer. More...
AudioChannelSet	getChannelLayoutOfBus (bool isInput, int busIndex) const noexcept
	Provides the channel layout of the bus with a given index and direction. More...
virtual int	getCurrentProgram ()=0
	Returns the number of the currently active program. More...
virtual void	getCurrentProgramStateInformation (juce::MemoryBlock &destData)
	The host will call this method if it wants to save the state of just the processor's current program. More...
int	getLatencySamples () const noexcept
	This returns the number of samples delay that the processor imposes on the audio passing through it. More...
int	getMainBusNumInputChannels () const noexcept
	Returns the number of input channels on the main bus. More...
int	getMainBusNumOutputChannels () const noexcept
	Returns the number of output channels on the main bus. More...
virtual const String	getName () const =0
	Returns the name of this processor. More...
template<int numLayouts>
BusesLayout	getNextBestLayoutInLayoutList (const BusesLayout &layouts, const short(&channelLayoutList) [numLayouts][2])
	Returns the next best layout which is contained in a channel layout map. More...
virtual int	getNumParameters ()
	This must return the correct value immediately after the object has been created, and mustn't change the number of parameters later. More...
virtual int	getNumPrograms ()=0
	Returns the number of preset programs the processor supports. More...
int	getOffsetInBusBufferForAbsoluteChannelIndex (bool isInput, int absoluteChannelIndex, int &busIndex) const noexcept
	Returns the offset in a bus's buffer from an absolute channel indes. More...
virtual float	getParameter (int parameterIndex)
	Called by the host to find out the value of one of the processor's parameters. More...
virtual AudioProcessorParameter::Category	getParameterCategory (int parameterIndex) const
	Should return the parameter's category. More...
virtual float	getParameterDefaultValue (int parameterIndex)
	Returns the default value for the parameter. More...
virtual String	getParameterID (int index)
	Returns the ID of a particular parameter. More...
virtual String	getParameterLabel (int index) const
	Some plugin types may be able to return a label string for a parameter's units. More...
virtual const String	getParameterName (int parameterIndex)
	Returns the name of a particular parameter. More...
virtual String	getParameterName (int parameterIndex, int maximumStringLength)
	Returns the name of a parameter as a text string with a preferred maximum length. More...
virtual int	getParameterNumSteps (int parameterIndex)
	Returns the number of discrete steps that this parameter can represent. More...
const OwnedArray< AudioProcessorParameter > &	getParameters () const noexcept
	Returns the current list of parameters. More...
virtual const String	getParameterText (int parameterIndex)
	Returns the value of a parameter as a text string. More...
virtual String	getParameterText (int parameterIndex, int maximumStringLength)
	Returns the value of a parameter as a text string with a preferred maximum length. More...
const AudioProcessorParameterGroup &	getParameterTree ()
	Returns the group of parameters managed by this AudioProcessor. More...
AudioPlayHead *	getPlayHead () const noexcept
	Returns the current AudioPlayHead object that should be used to find out the state and position of the playhead. More...
ProcessingPrecision	getProcessingPrecision () const noexcept
	Returns the precision-mode of the processor. More...
virtual const String	getProgramName (int index)=0
	Must return the name of a given program. More...
virtual CurveData	getResponseCurve (CurveData::Type) const
double	getSampleRate () const noexcept
	Returns the current sample rate. More...
virtual void	getStateInformation (juce::MemoryBlock &destData)=0
	The host will call this method when it wants to save the processor's internal state. More...
virtual double	getTailLengthSeconds () const =0
	Returns the length of the processor's tail, in seconds. More...
int	getTotalNumInputChannels () const noexcept
	Returns the total number of input channels. More...
int	getTotalNumOutputChannels () const noexcept
	Returns the total number of output channels. More...
virtual bool	hasEditor () const =0
	Your processor subclass must override this and return true if it can create an editor component. More...
virtual bool	isMetaParameter (int parameterIndex) const
	Should return true if this parameter is a "meta" parameter. More...
virtual bool	isMidiEffect () const
	Returns true if this is a MIDI effect plug-in and does no audio processing. More...
bool	isNonRealtime () const noexcept
	Returns true if the processor is being run in an offline mode for rendering. More...
virtual bool	isParameterAutomatable (int parameterIndex) const
	Returns true if the host can automate this parameter. More...
virtual bool	isParameterDiscrete (int parameterIndex) const
	Returns true if the parameter should take discrete, rather than continuous values. More...
virtual bool	isParameterOrientationInverted (int index) const
	This can be overridden to tell the host that particular parameters operate in the reverse direction. More...
bool	isSuspended () const noexcept
	Returns true if processing is currently suspended. More...
bool	isUsingDoublePrecision () const noexcept
	Returns true if the current precision is set to doublePrecision. More...
virtual void	memoryWarningReceived ()
	Called by the host to indicate that you should reduce your memory footprint. More...
virtual void	numBusesChanged ()
	This method is called when the number of buses is changed. More...
virtual void	numChannelsChanged ()
	This method is called when the total number of input or output channels is changed. More...
virtual void	prepareToPlay (double sampleRate, int maximumExpectedSamplesPerBlock)=0
	Called before playback starts, to let the processor prepare itself. More...
virtual void	processBlock (AudioBuffer< float > &buffer, MidiBuffer &midiMessages)=0
	Renders the next block. More...
virtual void	processBlock (AudioBuffer< double > &buffer, MidiBuffer &midiMessages)
	Renders the next block. More...
virtual void	processBlockBypassed (AudioBuffer< float > &buffer, MidiBuffer &midiMessages)
	Renders the next block when the processor is being bypassed. More...
virtual void	processBlockBypassed (AudioBuffer< double > &buffer, MidiBuffer &midiMessages)
	Renders the next block when the processor is being bypassed. More...
virtual void	processorLayoutsChanged ()
	This method is called when the layout of the audio processor changes. More...
virtual bool	producesMidi () const =0
	Returns true if the processor produces MIDI messages. More...
virtual void	releaseResources ()=0
	Called after playback has stopped, to let the object free up any resources it no longer needs. More...
bool	removeBus (bool isInput)
	Dynamically remove the latest added bus. More...
virtual void	removeListener (AudioProcessorListener *listenerToRemove)
	Removes a previously added listener. More...
virtual void	reset ()
	A plugin can override this to be told when it should reset any playing voices. More...
bool	setBusesLayout (const BusesLayout &)
	Set the channel layouts of this audio processor. More...
bool	setBusesLayoutWithoutEnabling (const BusesLayout &)
	Set the channel layouts of this audio processor without changing the enablement state of the buses. More...
bool	setChannelLayoutOfBus (bool isInput, int busIndex, const AudioChannelSet &layout)
	Set the channel layout of the bus with a given index and direction. More...
virtual void	setCurrentProgram (int index)=0
	Called by the host to change the current program. More...
virtual void	setCurrentProgramStateInformation (const void *data, int sizeInBytes)
	The host will call this method if it wants to restore the state of just the processor's current program. More...
void	setLatencySamples (int newLatency)
	Your processor subclass should call this to set the number of samples delay that it introduces. More...
virtual void	setNonRealtime (bool isNonRealtime) noexcept
	Called by the host to tell this processor whether it's being used in a non-realtime capacity for offline rendering or bouncing. More...
virtual void	setParameter (int parameterIndex, float newValue)
	The host will call this method to change the value of one of the processor's parameters. More...
void	setParameterNotifyingHost (int parameterIndex, float newValue)
	Your processor can call this when it needs to change one of its parameters. More...
void	setPlayConfigDetails (int numIns, int numOuts, double sampleRate, int blockSize)
	This is called by the processor to specify its details before being played. More...
virtual void	setPlayHead (AudioPlayHead *newPlayHead)
	Tells the processor to use this playhead object. More...
void	setProcessingPrecision (ProcessingPrecision newPrecision) noexcept
	Changes the processing precision of the receiver. More...
void	setRateAndBufferSizeDetails (double sampleRate, int blockSize) noexcept
	This is called by the processor to specify its details before being played. More...
virtual void	setStateInformation (const void *data, int sizeInBytes)=0
	This must restore the processor's state from a block of data previously created using getStateInformation(). More...
virtual bool	supportsDoublePrecisionProcessing () const
	Returns true if the Audio processor supports double precision floating point processing. More...
virtual bool	supportsMPE () const
	Returns true if the processor supports MPE. More...
void	suspendProcessing (bool shouldBeSuspended)
	Enables and disables the processing callback. More...
void	updateHostDisplay ()
	The processor can call this when something (apart from a parameter value) has changed. More...
virtual void	updateTrackProperties (const TrackProperties &properties)
	Informs the AudioProcessor that track properties such as the track's name or colour has been changed. More...

Static Public Member Functions
static bool	containsLayout (const BusesLayout &layouts, const std::initializer_list< const short[2]> &channelLayoutList)
	Returns true if the channel layout map contains a certain layout. More...
template<int numLayouts>
static bool	containsLayout (const BusesLayout &layouts, const short(&channelLayoutList) [numLayouts][2])
static void	copyXmlToBinary (const XmlElement &xml, juce::MemoryBlock &destData)
	Helper function that just converts an xml element into a binary blob. More...
static int	getDefaultNumParameterSteps () noexcept
	Returns the default number of steps for a parameter. More...
static const char *	getWrapperTypeDescription (AudioProcessor::WrapperType) noexcept
	Returns a textual description of a WrapperType value. More...
static XmlElement *	getXmlFromBinary (const void *data, int sizeInBytes)
	Retrieves an XML element that was stored as binary with the copyXmlToBinary() method. More...
static void	setTypeOfNextNewPlugin (WrapperType)

Public Attributes
WrapperType	wrapperType
	When loaded by a plugin wrapper, this flag will be set to indicate the type of plugin within which the processor is running. More...

Protected Member Functions
	AudioProcessor ()
	Constructor. More...
	AudioProcessor (const BusesProperties &ioLayouts)
	Constructor for multi-bus AudioProcessors. More...
	AudioProcessor (const std::initializer_list< const short[2]> &channelLayoutList)
	Constructor for AudioProcessors which use layout maps If your AudioProcessor uses layout maps then use this constructor. More...
virtual bool	canApplyBusCountChange (bool isInput, bool isAddingBuses, BusProperties &outNewBusProperties)
	Callback to query if adding/removing buses currently possible. More...
virtual bool	canApplyBusesLayout (const BusesLayout &layouts) const
	Callback to check if a certain bus layout can now be applied. More...
virtual bool	isBusesLayoutSupported (const BusesLayout &) const
	Callback to query if the AudioProcessor supports a specific layout. More...
void	sendParamChangeMessageToListeners (int parameterIndex, float newValue)

Protected Attributes
AudioPlayHead *	playHead = nullptr

Private Member Functions
void	addParameterInternal (AudioProcessorParameter *)
bool	applyBusLayouts (const BusesLayout &)
void	audioIOChanged (bool busNumberChanged, bool channelNumChanged)
void	checkForDupedParamIDs ()
void	createBus (bool isInput, const BusProperties &)
AudioProcessorListener *	getListenerLocked (int) const noexcept
void	getNextBestLayout (const BusesLayout &, BusesLayout &) const
BusesLayout	getNextBestLayoutInList (const BusesLayout &, const Array< InOutChannelPair > &) const
AudioProcessorParameter *	getParamChecked (int) const noexcept
template<typename floatType >
void	processBypassed (AudioBuffer< floatType > &, MidiBuffer &)
void	updateSpeakerFormatStrings ()

Static Private Member Functions
static BusesProperties	busesPropertiesFromLayoutArray (const Array< InOutChannelPair > &)
static bool	containsLayout (const BusesLayout &, const Array< InOutChannelPair > &)
template<int numLayouts>
static Array< InOutChannelPair >	layoutListToArray (const short(&configuration) [numLayouts][2])
static Array< InOutChannelPair >	layoutListToArray (const std::initializer_list< const short[2]> &configuration)

Private Attributes
Component::SafePointer< AudioProcessorEditor >	activeEditor
int	blockSize = 0
String	cachedInputSpeakerArrString
String	cachedOutputSpeakerArrString
int	cachedTotalIns = 0
int	cachedTotalOuts = 0
CriticalSection	callbackLock
BigInteger	changingParams
double	currentSampleRate = 0
OwnedArray< Bus >	inputBuses
int	latencySamples = 0
CriticalSection	listenerLock
Array< AudioProcessorListener * >	listeners
OwnedArray< AudioProcessorParameter >	managedParameters
bool	nonRealtime = false
OwnedArray< Bus >	outputBuses
AudioProcessorParameterGroup	parameterTree { {}, {}, {} }
ProcessingPrecision	processingPrecision = singlePrecision
bool	shouldCheckParamsForDupeIDs = false
bool	suspended = false
bool	textRecursionCheck = false

Friends
class	AudioProcessorParameter
class	AudioUnitPluginInstance
class	Bus
class	JuceVST3Component
class	JuceVST3EditController
class	LADSPAPluginInstance
class	VST3PluginInstance

Detailed Description

Base class for audio processing classes or plugins.

This is intended to act as a base class of audio processor that is general enough to be wrapped as a VST, AU, RTAS, etc, or used internally.

It is also used by the plugin hosting code as the wrapper around an instance of a loaded plugin.

You should derive your own class from this base class, and if you're building a plugin, you should implement a global function called createPluginFilter() which creates and returns a new instance of your subclass.

{Audio}

Member Enumeration Documentation

ProcessingPrecision

enum juce::AudioProcessor::ProcessingPrecision

Enumerator
singlePrecision
doublePrecision

WrapperType

enum juce::AudioProcessor::WrapperType

Flags to indicate the type of plugin context in which a processor is being used.

Enumerator
wrapperType_Undefined
wrapperType_VST
wrapperType_VST3
wrapperType_AudioUnit
wrapperType_AudioUnitv3
wrapperType_RTAS
wrapperType_AAX
wrapperType_Standalone
wrapperType_Unity

Constructor & Destructor Documentation

AudioProcessor() [1/3]

juce::AudioProcessor::AudioProcessor ( )

protected

Constructor.

This constructor will create a main input and output bus which are diabled by default. If you need more fine-grained control then use the other constructors.

AudioProcessor() [2/3]

juce::AudioProcessor::AudioProcessor ( const BusesProperties &  ioLayouts )

protected

Constructor for multi-bus AudioProcessors.

If your AudioProcessor supports multiple buses than use this constructor to initialise the bus layouts and bus names of your plug-in.

AudioProcessor() [3/3]

juce::AudioProcessor::AudioProcessor ( const std::initializer_list< const short[2]> &  channelLayoutList )

inlineprotected

Constructor for AudioProcessors which use layout maps If your AudioProcessor uses layout maps then use this constructor.

~AudioProcessor()

virtual juce::AudioProcessor::~AudioProcessor ( )

virtual

Destructor.

Member Function Documentation

acceptsMidi()

virtual bool juce::AudioProcessor::acceptsMidi ( ) const

pure virtual

Returns true if the processor wants MIDI messages.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

addBus()

bool juce::AudioProcessor::addBus

(

bool

isInput

)

Dynamically request an additional bus.

Request an additional bus from the audio processor. If the audio processor does not support adding additional buses then this method will return false.

Most audio processors will not allow you to dynamically add/remove audio buses and will return false.

This method will invoke the canApplyBusCountChange callback to probe if a bus can be added and, if yes, will use the supplied bus properties of the canApplyBusCountChange callback to create a new bus.

See also

canApplyBusCountChange, removeBus

addListener()

virtual void juce::AudioProcessor::addListener ( AudioProcessorListener *  newListener )

virtual

Adds a listener that will be called when an aspect of this processor changes.

addParameter()

void juce::AudioProcessor::addParameter

(

AudioProcessorParameter *

)

Adds a parameter to the AudioProcessor.

The parameter object will be managed and deleted automatically by the AudioProcessor when no longer needed.

addParameterGroup()

void juce::AudioProcessor::addParameterGroup

(

std::unique_ptr< AudioProcessorParameterGroup >

)

Adds a group of parameters to the AudioProcessor.

All the parameter objects contained within the group will be managed and deleted automatically by the AudioProcessor when no longer needed.

See also

addParameter

addParameterInternal()

void juce::AudioProcessor::addParameterInternal ( AudioProcessorParameter *  )

private

applyBusLayouts()

bool juce::AudioProcessor::applyBusLayouts ( const BusesLayout &  )

private

audioIOChanged()

void juce::AudioProcessor::audioIOChanged ( bool  busNumberChanged, bool  channelNumChanged  )

private

beginParameterChangeGesture()

void juce::AudioProcessor::beginParameterChangeGesture

(

int

parameterIndex

)

Sends a signal to the host to tell it that the user is about to start changing this parameter.

This allows the host to know when a parameter is actively being held by the user, and it may use this information to help it record automation.

If you call this, it must be matched by a later call to endParameterChangeGesture().

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::beginChangeGesture() instead.deprecated

busesPropertiesFromLayoutArray()

static BusesProperties juce::AudioProcessor::busesPropertiesFromLayoutArray ( const Array< InOutChannelPair > &  )

staticprivate

canAddBus()

virtual bool juce::AudioProcessor::canAddBus ( bool  isInput ) const

inlinevirtual

Callback to query if a bus can currently be added.

This callback probes if a bus can currently be added. You should override this callback if you want to support dynamically adding/removing buses by the host. This is useful for mixer audio processors.

The default implementation will always return false.

See also

addBus

References juce::ignoreUnused().

canApplyBusCountChange()

virtual bool juce::AudioProcessor::canApplyBusCountChange ( bool  isInput, bool  isAddingBuses, BusProperties &  outNewBusProperties  )

protectedvirtual

Callback to query if adding/removing buses currently possible.

This callback is called when the host calls addBus or removeBus. Similar to canApplyBusesLayout, this callback is only called while the AudioProcessor is stopped and gives the processor a last chance to reject a requested bus change. It can also be used to apply the bus count change to an underlying wrapped plug-in.

When adding a bus, isAddingBuses will be true and the plug-in is expected to fill out outNewBusProperties with the properties of the bus which will be created just after the successful return of this callback.

Implementations of AudioProcessor will rarely need to override this method. Only override this method if your processor supports adding and removing buses and if it needs more fine grain control over the naming of new buses or may reject bus number changes although canAddBus or canRemoveBus returned true.

The default implementation will return false if canAddBus/canRemoveBus returns false (the default behavior). Otherwise, this method returns "Input #busIndex" for input buses and "Output #busIndex" for output buses where busIndex is the index for newly created buses. The default layout in this case will be the layout of the previous bus of the same direction.

canApplyBusesLayout()

virtual bool juce::AudioProcessor::canApplyBusesLayout ( const BusesLayout &  layouts ) const

inlineprotectedvirtual

Callback to check if a certain bus layout can now be applied.

Most subclasses will not need to override this method and should instead override the isBusesLayoutSupported callback to reject certain layout changes.

This callback is called when the user requests a layout change. It will only be called if processing of the AudioProcessor has been stopped by a previous call to releaseResources or after the construction of the AudioProcessor. It will be called just before the actual layout change. By returning false you will abort the layout change and setBusesLayout will return false indicating that the layout change was not successful.

The default implementation will simply call isBusesLayoutSupported.

You only need to override this method if there is a chance that your AudioProcessor may not accept a layout although you have previously claimed to support it via the isBusesLayoutSupported callback. This can occur if your AudioProcessor's supported layouts depend on other plug-in parameters which may have changed since the last call to isBusesLayoutSupported, such as the format of an audio file which can be selected by the user in the AudioProcessor's editor. This callback gives the AudioProcessor a last chance to reject a layout if conditions have changed as it is always called just before the actual layout change.

As it is never called while the AudioProcessor is processing audio, it can also be used for AudioProcessors which wrap other plug-in formats to apply the current layout to the underlying plug-in. This callback gives such AudioProcessors a chance to reject the layout change should an error occur with the underlying plug-in during the layout change.

See also

isBusesLayoutSupported, setBusesLayout

canRemoveBus()

virtual bool juce::AudioProcessor::canRemoveBus ( bool  isInput ) const

inlinevirtual

Callback to query if the last bus can currently be removed.

This callback probes if the last bus can currently be removed. You should override this callback if you want to support dynamically adding/removing buses by the host. This is useful for mixer audio processors.

If you return true in this callback then the AudioProcessor will go ahead and delete the bus.

The default implementation will always return false.

References juce::ignoreUnused().

changeProgramName()

virtual void juce::AudioProcessor::changeProgramName ( int  index, const String &  newName  )

pure virtual

Called by the host to rename a program.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

checkBusesLayoutSupported()

bool juce::AudioProcessor::checkBusesLayoutSupported

(

const BusesLayout &

)

const

Returns true if the Audio processor is likely to support a given layout.

This can be called regardless if the processor is currently running.

checkForDupedParamIDs()

void juce::AudioProcessor::checkForDupedParamIDs ( )

private

containsLayout() [1/3]

static bool juce::AudioProcessor::containsLayout ( const BusesLayout &  layouts, const std::initializer_list< const short[2]> &  channelLayoutList  )

inlinestatic

Returns true if the channel layout map contains a certain layout.

You can use this method to help you implement the checkBusesLayoutSupported method. For example

bool checkBusesLayoutSupported (const BusesLayout& layouts) override
{
    return containsLayout (layouts, {{1,1},{2,2}});
}

containsLayout() [2/3]

template<int numLayouts>

static bool juce::AudioProcessor::containsLayout ( const BusesLayout &  layouts, const short(&)  channelLayoutList[numLayouts][2]  )

inlinestatic

containsLayout() [3/3]

static bool juce::AudioProcessor::containsLayout ( const BusesLayout &  , const Array< InOutChannelPair > &    )

staticprivate

copyXmlToBinary()

static void juce::AudioProcessor::copyXmlToBinary ( const XmlElement &  xml, juce::MemoryBlock &  destData  )

static

Helper function that just converts an xml element into a binary blob.

Use this in your processor's getStateInformation() method if you want to store its state as xml.

Then use getXmlFromBinary() to reverse this operation and retrieve the XML from a binary blob.

createBus()

void juce::AudioProcessor::createBus ( bool  isInput, const BusProperties &    )

private

createEditor()

virtual AudioProcessorEditor* juce::AudioProcessor::createEditor ( )

pure virtual

Creates the processor's GUI.

This can return nullptr if you want a GUI-less processor, in which case the host may create a generic UI that lets the user twiddle the parameters directly.

If you do want to pass back a component, the component should be created and set to the correct size before returning it. If you implement this method, you must also implement the hasEditor() method and make it return true.

Remember not to do anything silly like allowing your processor to keep a pointer to the component that gets created - it could be deleted later without any warning, which would make your pointer into a dangler. Use the getActiveEditor() method instead.

The correct way to handle the connection between an editor component and its processor is to use something like a ChangeBroadcaster so that the editor can register itself as a listener, and be told when a change occurs. This lets them safely unregister themselves when they are deleted.

Here are a few things to bear in mind when writing an editor:

• Initially there won't be an editor, until the user opens one, or they might not open one at all. Your processor mustn't rely on it being there.
• An editor object may be deleted and a replacement one created again at any time.
• It's safe to assume that an editor will be deleted before its processor.

See also

hasEditor

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

createEditorIfNeeded()

AudioProcessorEditor* juce::AudioProcessor::createEditorIfNeeded

(

)

Returns the active editor, or if there isn't one, it will create one.

This may call createEditor() internally to create the component.

disableNonMainBuses()

bool juce::AudioProcessor::disableNonMainBuses

(

)

Disables all non-main buses (aux and sidechains).

editorBeingDeleted()

void juce::AudioProcessor::editorBeingDeleted ( AudioProcessorEditor *  )

noexcept

Not for public use - this is called before deleting an editor component.

enableAllBuses()

bool juce::AudioProcessor::enableAllBuses

(

)

Enables all buses.

endParameterChangeGesture()

void juce::AudioProcessor::endParameterChangeGesture

(

int

parameterIndex

)

Tells the host that the user has finished changing this parameter.

This allows the host to know when a parameter is actively being held by the user, and it may use this information to help it record automation.

A call to this method must follow a call to beginParameterChangeGesture().

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::endChangeGesture() instead.deprecated

getAAXPluginIDForMainBusConfig()

virtual int32 juce::AudioProcessor::getAAXPluginIDForMainBusConfig ( const AudioChannelSet &  mainInputLayout, const AudioChannelSet &  mainOutputLayout, bool  idForAudioSuite  ) const

virtual

AAX plug-ins need to report a unique "plug-in id" for every audio layout configuration that your AudioProcessor supports on the main bus.

Override this function if you want your AudioProcessor to use a custom "plug-in id" (for example to stay backward compatible with older versions of JUCE).

The default implementation will compute a unique integer from the input and output layout and add this value to the 4 character code 'jcaa' (for native AAX) or 'jyaa' (for AudioSuite plug-ins).

getActiveEditor()

AudioProcessorEditor* juce::AudioProcessor::getActiveEditor ( ) const

inlinenoexcept

Returns the active editor, if there is one.

Bear in mind this can return nullptr, even if an editor has previously been opened.

References JUCE_DEPRECATED.

getAlternateDisplayNames()

virtual StringArray juce::AudioProcessor::getAlternateDisplayNames ( ) const

virtual

Returns a list of alternative names to use for this processor.

Some hosts truncate the name of your AudioProcessor when there isn't enough space in the GUI to show the full name. Overriding this method, allows the host to choose an alternative name (such as an abbreviation) to better fit the available space.

getBlockSize()

int juce::AudioProcessor::getBlockSize ( ) const

inlinenoexcept

Returns the current typical block size that is being used.

This can be called from your processBlock() method - it's not guaranteed to be valid at any other time.

Remember it's not the ONLY block size that may be used when calling processBlock, it's just the normal one. The actual block sizes used may be larger or smaller than this, and will vary between successive calls.

getBus() [1/2]

Bus* juce::AudioProcessor::getBus ( bool  isInput, int  busIndex  )

inlinenoexcept

Returns the audio bus with a given index and direction.

If busIndex is invalid then this method will return a nullptr.

getBus() [2/2]

const Bus* juce::AudioProcessor::getBus ( bool  isInput, int  busIndex  ) const

inlinenoexcept

Returns the audio bus with a given index and direction.

If busIndex is invalid then this method will return a nullptr.

getBusBuffer()

template<typename FloatType >

AudioBuffer<FloatType> juce::AudioProcessor::getBusBuffer ( AudioBuffer< FloatType > &  processBlockBuffer, bool  isInput, int  busIndex  ) const

inline

Returns an AudioBuffer containing a set of channel pointers for a specific bus.

This can be called in processBlock to get a buffer containing a sub-group of the master AudioBuffer which contains all the plugin channels.

References juce::AudioBuffer< Type >::getArrayOfWritePointers(), and juce::AudioBuffer< Type >::getNumSamples().

getBusCount()

int juce::AudioProcessor::getBusCount ( bool  isInput ) const

inlinenoexcept

Returns the number of buses on the input or output side.

getBusesLayout()

BusesLayout juce::AudioProcessor::getBusesLayout

(

)

const

Provides the current channel layouts of this audio processor.

getBypassParameter()

virtual AudioProcessorParameter* juce::AudioProcessor::getBypassParameter ( ) const

inlinevirtual

Returns the parameter that controls the AudioProcessor's bypass state.

If this method returns a nullptr then you can still control the bypass by calling processBlockBypassed instead of processBlock. On the other hand, if this method returns a non-null value, you should never call processBlockBypassed but use the returned parameter to conrol the bypass state instead.

A plug-in can override this function to return a parameter which control's your plug-in's bypass. You should always check the value of this parameter in your processBlock callback and bypass any effects if it is non-zero.

getCallbackLock()

const CriticalSection& juce::AudioProcessor::getCallbackLock ( ) const

inlinenoexcept

This returns a critical section that will automatically be locked while the host is calling the processBlock() method.

Use it from your UI or other threads to lock access to variables that are used by the process callback, but obviously be careful not to keep it locked for too long, because that could cause stuttering playback. If you need to do something that'll take a long time and need the processing to stop while it happens, use the suspendProcessing() method instead.

See also

suspendProcessing

getChannelCountOfBus()

int juce::AudioProcessor::getChannelCountOfBus ( bool  isInput, int  busIndex  ) const

inlinenoexcept

Provides the number of channels of the bus with a given index and direction.

If the index, direction combination is invalid then this will return zero.

getChannelIndexInProcessBlockBuffer()

int juce::AudioProcessor::getChannelIndexInProcessBlockBuffer ( bool  isInput, int  busIndex, int  channelIndex  ) const

noexcept

Returns the position of a bus's channels within the processBlock buffer.

This can be called in processBlock to figure out which channel of the master AudioBuffer maps onto a specific bus's channel.

getChannelLayoutOfBus()

AudioChannelSet juce::AudioProcessor::getChannelLayoutOfBus ( bool  isInput, int  busIndex  ) const

noexcept

Provides the channel layout of the bus with a given index and direction.

If the index, direction combination is invalid then this will return an AudioChannelSet with no channels.

getCurrentProgram()

virtual int juce::AudioProcessor::getCurrentProgram ( )

pure virtual

Returns the number of the currently active program.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getCurrentProgramStateInformation()

virtual void juce::AudioProcessor::getCurrentProgramStateInformation ( juce::MemoryBlock &  destData )

virtual

The host will call this method if it wants to save the state of just the processor's current program.

Unlike getStateInformation, this should only return the current program's state.

Not all hosts support this, and if you don't implement it, the base class method just calls getStateInformation() instead. If you do implement it, be sure to also implement getCurrentProgramStateInformation.

See also

getStateInformation, setCurrentProgramStateInformation

getDefaultNumParameterSteps()

static int juce::AudioProcessor::getDefaultNumParameterSteps ( )

staticnoexcept

Returns the default number of steps for a parameter.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getNumSteps() instead.

See also

getParameterNumSteps

Referenced by juce::RangedAudioParameter::getNumSteps().

getLatencySamples()

int juce::AudioProcessor::getLatencySamples ( ) const

inlinenoexcept

This returns the number of samples delay that the processor imposes on the audio passing through it.

The host will call this to find the latency - the processor itself should set this value by calling setLatencySamples() as soon as it can during its initialisation.

getListenerLocked()

AudioProcessorListener* juce::AudioProcessor::getListenerLocked ( int  ) const

privatenoexcept

getMainBusNumInputChannels()

int juce::AudioProcessor::getMainBusNumInputChannels ( ) const

inlinenoexcept

Returns the number of input channels on the main bus.

getMainBusNumOutputChannels()

int juce::AudioProcessor::getMainBusNumOutputChannels ( ) const

inlinenoexcept

Returns the number of output channels on the main bus.

getName()

virtual const String juce::AudioProcessor::getName ( ) const

pure virtual

Returns the name of this processor.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getNextBestLayout()

void juce::AudioProcessor::getNextBestLayout ( const BusesLayout &  , BusesLayout &    ) const

private

getNextBestLayoutInLayoutList()

template<int numLayouts>

BusesLayout juce::AudioProcessor::getNextBestLayoutInLayoutList ( const BusesLayout &  layouts, const short(&)  channelLayoutList[numLayouts][2]  )

inline

Returns the next best layout which is contained in a channel layout map.

You can use this mehtod to help you implement getNextBestLayout. For example:

BusesLayout getNextBestLayout (const BusesLayout& layouts) override
{
    return getNextBestLayoutInLayoutList (layouts, {{1,1},{2,2}});
}

getNextBestLayoutInList()

BusesLayout juce::AudioProcessor::getNextBestLayoutInList ( const BusesLayout &  , const Array< InOutChannelPair > &    ) const

private

getNumParameters()

virtual int juce::AudioProcessor::getNumParameters ( )

virtual

This must return the correct value immediately after the object has been created, and mustn't change the number of parameters later.

NOTE! This method will eventually be deprecated! It's recommended that you use the AudioProcessorParameter class instead to manage your parameters.deprecated

getNumPrograms()

virtual int juce::AudioProcessor::getNumPrograms ( )

pure virtual

Returns the number of preset programs the processor supports.

The value returned must be valid as soon as this object is created, and must not change over its lifetime.

This value shouldn't be less than 1.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getOffsetInBusBufferForAbsoluteChannelIndex()

int juce::AudioProcessor::getOffsetInBusBufferForAbsoluteChannelIndex ( bool  isInput, int  absoluteChannelIndex, int &  busIndex  ) const

noexcept

Returns the offset in a bus's buffer from an absolute channel indes.

This method returns the offset in a bus's buffer given an absolute channel index. It also provides the bus index. For example, this method would return one for a processor with two stereo buses when given the absolute channel index.

getParamChecked()

AudioProcessorParameter* juce::AudioProcessor::getParamChecked ( int  ) const

privatenoexcept

getParameter()

virtual float juce::AudioProcessor::getParameter ( int  parameterIndex )

virtual

Called by the host to find out the value of one of the processor's parameters.

The host will expect the value returned to be between 0 and 1.0.

This could be called quite frequently, so try to make your code efficient. It's also likely to be called by non-UI threads, so the code in here should be thread-aware.

NOTE! This method will eventually be deprecated! It's recommended that you use the AudioProcessorParameter class instead to manage your parameters.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterCategory()

virtual AudioProcessorParameter::Category juce::AudioProcessor::getParameterCategory ( int  parameterIndex ) const

virtual

Should return the parameter's category.

By default, this returns the "generic" category.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getCategory() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterDefaultValue()

virtual float juce::AudioProcessor::getParameterDefaultValue ( int  parameterIndex )

virtual

Returns the default value for the parameter.

By default, this just returns 0. The value that is returned may or may not be used, depending on the host.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getDefaultValue() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterID()

virtual String juce::AudioProcessor::getParameterID ( int  index )

virtual

Returns the ID of a particular parameter.

The ID is used to communicate the value or mapping of a particular parameter with the host. By default this method will simply return a string representation of index.

NOTE! This method will eventually be deprecated! It's recommended that you use the AudioProcessorParameterWithID class instead to manage your parameters.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterLabel()

virtual String juce::AudioProcessor::getParameterLabel ( int  index ) const

virtual

Some plugin types may be able to return a label string for a parameter's units.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getLabel() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterName() [1/2]

virtual const String juce::AudioProcessor::getParameterName ( int  parameterIndex )

virtual

Returns the name of a particular parameter.

NOTE! This method will eventually be deprecated! It's recommended that you use the AudioProcessorParameter class instead to manage your parameters.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterName() [2/2]

virtual String juce::AudioProcessor::getParameterName ( int  parameterIndex, int  maximumStringLength  )

virtual

Returns the name of a parameter as a text string with a preferred maximum length.

If you want to provide customised short versions of your parameter names that will look better in constrained spaces (e.g. the displays on hardware controller devices or mixing desks) then you should implement this method. If you don't override it, the default implementation will call getParameterName(int), and truncate the result.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getName() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterNumSteps()

virtual int juce::AudioProcessor::getParameterNumSteps ( int  parameterIndex )

virtual

Returns the number of discrete steps that this parameter can represent.

The default return value if you don't implement this method is AudioProcessor::getDefaultNumParameterSteps().

If your parameter is boolean, then you may want to make this return 2.

If you want the host to display stepped automation values, rather than a continuous interpolation between successive values, you should ensure that isParameterDiscrete returns true.

The value that is returned may or may not be used, depending on the host.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getNumSteps() instead.

See also

isParameterDiscretedeprecated

Reimplemented in juce::AudioPluginInstance.

getParameters()

const OwnedArray<AudioProcessorParameter>& juce::AudioProcessor::getParameters ( ) const

noexcept

Returns the current list of parameters.

getParameterText() [1/2]

virtual const String juce::AudioProcessor::getParameterText ( int  parameterIndex )

virtual

Returns the value of a parameter as a text string.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getText() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterText() [2/2]

virtual String juce::AudioProcessor::getParameterText ( int  parameterIndex, int  maximumStringLength  )

virtual

Returns the value of a parameter as a text string with a preferred maximum length.

If you want to provide customised short versions of your parameter values that will look better in constrained spaces (e.g. the displays on hardware controller devices or mixing desks) then you should implement this method. If you don't override it, the default implementation will call getParameterText(int), and truncate the result.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::getText() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

getParameterTree()

const AudioProcessorParameterGroup& juce::AudioProcessor::getParameterTree

(

)

Returns the group of parameters managed by this AudioProcessor.

getPlayHead()

AudioPlayHead* juce::AudioProcessor::getPlayHead ( ) const

inlinenoexcept

Returns the current AudioPlayHead object that should be used to find out the state and position of the playhead.

You can ONLY call this from your processBlock() method! Calling it at other times will produce undefined behaviour, as the host may not have any context in which a time would make sense, and some hosts will almost certainly have multithreading issues if it's not called on the audio thread.

The AudioPlayHead object that is returned can be used to get the details about the time of the start of the block currently being processed. But do not store this pointer or use it outside of the current audio callback, because the host may delete or re-use it.

If the host can't or won't provide any time info, this will return nullptr.

getProcessingPrecision()

ProcessingPrecision juce::AudioProcessor::getProcessingPrecision ( ) const

inlinenoexcept

Returns the precision-mode of the processor.

Depending on the result of this method you MUST call the corresponding version of processBlock. The default processing precision is single precision.

See also

setProcessingPrecision, supportsDoublePrecisionProcessing

getProgramName()

virtual const String juce::AudioProcessor::getProgramName ( int  index )

pure virtual

Must return the name of a given program.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getResponseCurve()

virtual CurveData juce::AudioProcessor::getResponseCurve ( CurveData::Type  ) const

inlinevirtual

getSampleRate()

double juce::AudioProcessor::getSampleRate ( ) const

inlinenoexcept

Returns the current sample rate.

This can be called from your processBlock() method - it's not guaranteed to be valid at any other time, and may return 0 if it's unknown.

getStateInformation()

virtual void juce::AudioProcessor::getStateInformation ( juce::MemoryBlock &  destData )

pure virtual

The host will call this method when it wants to save the processor's internal state.

This must copy any info about the processor's state into the block of memory provided, so that the host can store this and later restore it using setStateInformation().

Note that there's also a getCurrentProgramStateInformation() method, which only stores the current program, not the state of the entire processor.

See also the helper function copyXmlToBinary() for storing settings as XML.

See also

getCurrentProgramStateInformation

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getTailLengthSeconds()

virtual double juce::AudioProcessor::getTailLengthSeconds ( ) const

pure virtual

Returns the length of the processor's tail, in seconds.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

getTotalNumInputChannels()

int juce::AudioProcessor::getTotalNumInputChannels ( ) const

inlinenoexcept

Returns the total number of input channels.

This method will return the total number of input channels by accumulating the number of channels on each input bus. The number of channels of the buffer passed to your processBlock callback will be equivalent to either getTotalNumInputChannels or getTotalNumOutputChannels - which ever is greater.

Note that getTotalNumInputChannels is equivalent to getMainBusNumInputChannels if your processor does not have any sidechains or aux buses.

getTotalNumOutputChannels()

int juce::AudioProcessor::getTotalNumOutputChannels ( ) const

inlinenoexcept

Returns the total number of output channels.

This method will return the total number of output channels by accumulating the number of channels on each output bus. The number of channels of the buffer passed to your processBlock callback will be equivalent to either getTotalNumInputChannels or getTotalNumOutputChannels - which ever is greater.

Note that getTotalNumOutputChannels is equivalent to getMainBusNumOutputChannels if your processor does not have any sidechains or aux buses.

getWrapperTypeDescription()

static const char* juce::AudioProcessor::getWrapperTypeDescription ( AudioProcessor::WrapperType  )

staticnoexcept

Returns a textual description of a WrapperType value.

getXmlFromBinary()

static XmlElement* juce::AudioProcessor::getXmlFromBinary ( const void *  data, int  sizeInBytes  )

static

Retrieves an XML element that was stored as binary with the copyXmlToBinary() method.

This might return nullptr if the data's unsuitable or corrupted. Otherwise it will return an XmlElement object that the caller must delete when no longer needed.

hasEditor()

virtual bool juce::AudioProcessor::hasEditor ( ) const

pure virtual

Your processor subclass must override this and return true if it can create an editor component.

See also

createEditor

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

isBusesLayoutSupported()

virtual bool juce::AudioProcessor::isBusesLayoutSupported ( const BusesLayout &  ) const

inlineprotectedvirtual

Callback to query if the AudioProcessor supports a specific layout.

This callback is called when the host probes the supported bus layouts via the checkBusesLayoutSupported method. You should override this callback if you would like to limit the layouts that your AudioProcessor supports. The default implementation will accept any layout. JUCE does basic sanity checks so that the provided layouts parameter will have the same number of buses as your AudioProcessor.

See also

checkBusesLayoutSupported

isMetaParameter()

virtual bool juce::AudioProcessor::isMetaParameter ( int  parameterIndex ) const

virtual

Should return true if this parameter is a "meta" parameter.

A meta-parameter is a parameter that changes other params. It is used by some hosts (e.g. AudioUnit hosts). By default this returns false.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::isMetaParameter() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

isMidiEffect()

virtual bool juce::AudioProcessor::isMidiEffect ( ) const

inlinevirtual

Returns true if this is a MIDI effect plug-in and does no audio processing.

isNonRealtime()

bool juce::AudioProcessor::isNonRealtime ( ) const

inlinenoexcept

Returns true if the processor is being run in an offline mode for rendering.

If the processor is being run live on realtime signals, this returns false. If the mode is unknown, this will assume it's realtime and return false.

This value may be unreliable until the prepareToPlay() method has been called, and could change each time prepareToPlay() is called.

See also

setNonRealtime()

isParameterAutomatable()

virtual bool juce::AudioProcessor::isParameterAutomatable ( int  parameterIndex ) const

virtual

Returns true if the host can automate this parameter.

By default, this returns true for all parameters.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::isAutomatable() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

isParameterDiscrete()

virtual bool juce::AudioProcessor::isParameterDiscrete ( int  parameterIndex ) const

virtual

Returns true if the parameter should take discrete, rather than continuous values.

If the parameter is boolean, this should return true (with getParameterNumSteps returning 2).

The value that is returned may or may not be used, depending on the host.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::isDiscrete() instead.

See also

getParameterNumStepsdeprecated

Reimplemented in juce::AudioPluginInstance.

isParameterOrientationInverted()

virtual bool juce::AudioProcessor::isParameterOrientationInverted ( int  index ) const

virtual

This can be overridden to tell the host that particular parameters operate in the reverse direction.

(Not all plugin formats or hosts will actually use this information).

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::isOrientationInverted() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

isSuspended()

bool juce::AudioProcessor::isSuspended ( ) const

inlinenoexcept

Returns true if processing is currently suspended.

See also

suspendProcessing

isUsingDoublePrecision()

bool juce::AudioProcessor::isUsingDoublePrecision ( ) const

inlinenoexcept

Returns true if the current precision is set to doublePrecision.

layoutListToArray() [1/2]

template<int numLayouts>

static Array<InOutChannelPair> juce::AudioProcessor::layoutListToArray ( const short(&)  configuration[numLayouts][2] )

inlinestaticprivate

References juce::Array< ElementType, TypeOfCriticalSectionToUse, minimumAllocatedSize >::add().

layoutListToArray() [2/2]

static Array<InOutChannelPair> juce::AudioProcessor::layoutListToArray ( const std::initializer_list< const short[2]> &  configuration )

inlinestaticprivate

References juce::Array< ElementType, TypeOfCriticalSectionToUse, minimumAllocatedSize >::add().

memoryWarningReceived()

virtual void juce::AudioProcessor::memoryWarningReceived ( )

inlinevirtual

Called by the host to indicate that you should reduce your memory footprint.

You should override this method to free up some memory gracefully, if possible, otherwise the host may forcibly unload your AudioProcessor.

At the moment this method is only called when your AudioProcessor is an AUv3 plug-in running on iOS.

References jassertfalse.

numBusesChanged()

virtual void juce::AudioProcessor::numBusesChanged ( )

virtual

This method is called when the number of buses is changed.

numChannelsChanged()

virtual void juce::AudioProcessor::numChannelsChanged ( )

virtual

This method is called when the total number of input or output channels is changed.

prepareToPlay()

virtual void juce::AudioProcessor::prepareToPlay ( double  sampleRate, int  maximumExpectedSamplesPerBlock  )

pure virtual

Called before playback starts, to let the processor prepare itself.

The sample rate is the target sample rate, and will remain constant until playback stops.

You can call getTotalNumInputChannels and getTotalNumOutputChannels or query the busLayout member variable to find out the number of channels your processBlock callback must process.

The maximumExpectedSamplesPerBlock value is a strong hint about the maximum number of samples that will be provided in each block. You may want to use this value to resize internal buffers. You should program defensively in case a buggy host exceeds this value. The actual block sizes that the host uses may be different each time the callback happens: completely variable block sizes can be expected from some hosts.

See also

busLayout, getTotalNumInputChannels, getTotalNumOutputChannels

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

processBlock() [1/2]

virtual void juce::AudioProcessor::processBlock ( AudioBuffer< float > &  buffer, MidiBuffer &  midiMessages  )

pure virtual

Renders the next block.

When this method is called, the buffer contains a number of channels which is at least as great as the maximum number of input and output channels that this processor is using. It will be filled with the processor's input data and should be replaced with the processor's output.

So for example if your processor has a total of 2 input channels and 4 output channels, then the buffer will contain 4 channels, the first two being filled with the input data. Your processor should read these, do its processing, and replace the contents of all 4 channels with its output.

Or if your processor has a total of 5 inputs and 2 outputs, the buffer will have 5 channels, all filled with data, and your processor should overwrite the first 2 of these with its output. But be VERY careful not to write anything to the last 3 channels, as these might be mapped to memory that the host assumes is read-only!

If your plug-in has more than one input or output buses then the buffer passed to the processBlock methods will contain a bundle of all channels of each bus. Use getBusBuffer to obtain an audio buffer for a particular bus.

Note that if you have more outputs than inputs, then only those channels that correspond to an input channel are guaranteed to contain sensible data - e.g. in the case of 2 inputs and 4 outputs, the first two channels contain the input, but the last two channels may contain garbage, so you should be careful not to let this pass through without being overwritten or cleared.

Also note that the buffer may have more channels than are strictly necessary, but you should only read/write from the ones that your processor is supposed to be using.

The number of samples in these buffers is NOT guaranteed to be the same for every callback, and may be more or less than the estimated value given to prepareToPlay(). Your code must be able to cope with variable-sized blocks, or you're going to get clicks and crashes!

Also note that some hosts will occasionally decide to pass a buffer containing zero samples, so make sure that your algorithm can deal with that!

If the processor is receiving a MIDI input, then the midiMessages array will be filled with the MIDI messages for this block. Each message's timestamp will indicate the message's time, as a number of samples from the start of the block.

Any messages left in the MIDI buffer when this method has finished are assumed to be the processor's MIDI output. This means that your processor should be careful to clear any incoming messages from the array if it doesn't want them to be passed-on.

If you have implemented the getBypassParameter method, then you need to check the value of this parameter in this callback and bypass your processing if the parameter has a non-zero value.

Note that when calling this method as a host, the result may still be bypassed as the parameter that controls the bypass may be non-zero.

Be very careful about what you do in this callback - it's going to be called by the audio thread, so any kind of interaction with the UI is absolutely out of the question. If you change a parameter in here and need to tell your UI to update itself, the best way is probably to inherit from a ChangeBroadcaster, let the UI components register as listeners, and then call sendChangeMessage() inside the processBlock() method to send out an asynchronous message. You could also use the AsyncUpdater class in a similar way.

See also

getBusBuffer

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

processBlock() [2/2]

virtual void juce::AudioProcessor::processBlock ( AudioBuffer< double > &  buffer, MidiBuffer &  midiMessages  )

virtual

Renders the next block.

When this method is called, the buffer contains a number of channels which is at least as great as the maximum number of input and output channels that this processor is using. It will be filled with the processor's input data and should be replaced with the processor's output.

So for example if your processor has a combined total of 2 input channels and 4 output channels, then the buffer will contain 4 channels, the first two being filled with the input data. Your processor should read these, do its processing, and replace the contents of all 4 channels with its output.

Or if your processor has 5 inputs and 2 outputs, the buffer will have 5 channels, all filled with data, and your processor should overwrite the first 2 of these with its output. But be VERY careful not to write anything to the last 3 channels, as these might be mapped to memory that the host assumes is read-only!

If your plug-in has more than one input or output buses then the buffer passed to the processBlock methods will contain a bundle of all channels of each bus. Use getBusBuffer to obtain a audio buffer for a particular bus.

Note that if you have more outputs than inputs, then only those channels that correspond to an input channel are guaranteed to contain sensible data - e.g. in the case of 2 inputs and 4 outputs, the first two channels contain the input, but the last two channels may contain garbage, so you should be careful not to let this pass through without being overwritten or cleared.

Also note that the buffer may have more channels than are strictly necessary, but you should only read/write from the ones that your processor is supposed to be using.

If your plugin uses buses, then you should use getBusBuffer() or getChannelIndexInProcessBlockBuffer() to find out which of the input and output channels correspond to which of the buses.

The number of samples in these buffers is NOT guaranteed to be the same for every callback, and may be more or less than the estimated value given to prepareToPlay(). Your code must be able to cope with variable-sized blocks, or you're going to get clicks and crashes!

Also note that some hosts will occasionally decide to pass a buffer containing zero samples, so make sure that your algorithm can deal with that!

If the processor is receiving a MIDI input, then the midiMessages array will be filled with the MIDI messages for this block. Each message's timestamp will indicate the message's time, as a number of samples from the start of the block.

Any messages left in the MIDI buffer when this method has finished are assumed to be the processor's MIDI output. This means that your processor should be careful to clear any incoming messages from the array if it doesn't want them to be passed-on.

If you have implemented the getBypassParameter method, then you need to check the value of this parameter in this callback and bypass your processing if the parameter has a non-zero value.

Note that when calling this method as a host, the result may still be bypassed as the parameter that controls the bypass may be non-zero.

Be very careful about what you do in this callback - it's going to be called by the audio thread, so any kind of interaction with the UI is absolutely out of the question. If you change a parameter in here and need to tell your UI to update itself, the best way is probably to inherit from a ChangeBroadcaster, let the UI components register as listeners, and then call sendChangeMessage() inside the processBlock() method to send out an asynchronous message. You could also use the AsyncUpdater class in a similar way.

See also

getBusBuffer

Reimplemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

processBlockBypassed() [1/2]

virtual void juce::AudioProcessor::processBlockBypassed ( AudioBuffer< float > &  buffer, MidiBuffer &  midiMessages  )

virtual

Renders the next block when the processor is being bypassed.

The default implementation of this method will pass-through any incoming audio, but you may override this method e.g. to add latency compensation to the data to match the processor's latency characteristics. This will avoid situations where bypassing will shift the signal forward in time, possibly creating pre-echo effects and odd timings. Another use for this method would be to cross-fade or morph between the wet (not bypassed) and dry (bypassed) signals.

processBlockBypassed() [2/2]

virtual void juce::AudioProcessor::processBlockBypassed ( AudioBuffer< double > &  buffer, MidiBuffer &  midiMessages  )

virtual

Renders the next block when the processor is being bypassed.

The default implementation of this method will pass-through any incoming audio, but you may override this method e.g. to add latency compensation to the data to match the processor's latency characteristics. This will avoid situations where bypassing will shift the signal forward in time, possibly creating pre-echo effects and odd timings. Another use for this method would be to cross-fade or morph between the wet (not bypassed) and dry (bypassed) signals.

processBypassed()

template<typename floatType >

void juce::AudioProcessor::processBypassed ( AudioBuffer< floatType > &  , MidiBuffer &    )

private

processorLayoutsChanged()

virtual void juce::AudioProcessor::processorLayoutsChanged ( )

virtual

This method is called when the layout of the audio processor changes.

producesMidi()

virtual bool juce::AudioProcessor::producesMidi ( ) const

pure virtual

Returns true if the processor produces MIDI messages.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

releaseResources()

virtual void juce::AudioProcessor::releaseResources ( )

pure virtual

Called after playback has stopped, to let the object free up any resources it no longer needs.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

removeBus()

bool juce::AudioProcessor::removeBus

(

bool

isInput

)

Dynamically remove the latest added bus.

Request the removal of the last bus from the audio processor. If the audio processor does not support removing buses then this method will return false.

Most audio processors will not allow you to dynamically add/remove audio buses and will return false.

The default implementation will return false.

This method will invoke the canApplyBusCountChange callback to probe if a bus can currently be removed and, if yes, will go ahead and remove it.

See also

addBus, canRemoveBus

removeListener()

virtual void juce::AudioProcessor::removeListener ( AudioProcessorListener *  listenerToRemove )

virtual

Removes a previously added listener.

reset()

virtual void juce::AudioProcessor::reset ( )

virtual

A plugin can override this to be told when it should reset any playing voices.

The default implementation does nothing, but a host may call this to tell the plugin that it should stop any tails or sounds that have been left running.

Reimplemented in juce::AudioProcessorGraph.

sendParamChangeMessageToListeners()

void juce::AudioProcessor::sendParamChangeMessageToListeners ( int  parameterIndex, float  newValue  )

protected

setBusesLayout()

bool juce::AudioProcessor::setBusesLayout

(

const BusesLayout &

)

Set the channel layouts of this audio processor.

If the layout is not supported by this audio processor then this method will return false. You can use the checkBusesLayoutSupported and getNextBestLayout methods to probe which layouts this audio processor supports.

setBusesLayoutWithoutEnabling()

bool juce::AudioProcessor::setBusesLayoutWithoutEnabling

(

const BusesLayout &

)

Set the channel layouts of this audio processor without changing the enablement state of the buses.

If the layout is not supported by this audio processor then this method will return false. You can use the checkBusesLayoutSupported methods to probe which layouts this audio processor supports.

setChannelLayoutOfBus()

bool juce::AudioProcessor::setChannelLayoutOfBus	(	bool	isInput,
		int	busIndex,
		const AudioChannelSet &	layout
	)

Set the channel layout of the bus with a given index and direction.

If the index, direction combination is invalid or the layout is not supported by the audio processor then this method will return false.

setCurrentProgram()

virtual void juce::AudioProcessor::setCurrentProgram ( int  index )

pure virtual

Called by the host to change the current program.

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

setCurrentProgramStateInformation()

virtual void juce::AudioProcessor::setCurrentProgramStateInformation ( const void *  data, int  sizeInBytes  )

virtual

The host will call this method if it wants to restore the state of just the processor's current program.

Not all hosts support this, and if you don't implement it, the base class method just calls setStateInformation() instead. If you do implement it, be sure to also implement getCurrentProgramStateInformation.

See also

setStateInformation, getCurrentProgramStateInformation

setLatencySamples()

void juce::AudioProcessor::setLatencySamples

(

int

newLatency

)

Your processor subclass should call this to set the number of samples delay that it introduces.

The processor should call this as soon as it can during initialisation, and can call it later if the value changes.

setNonRealtime()

virtual void juce::AudioProcessor::setNonRealtime ( bool  isNonRealtime )

virtualnoexcept

Called by the host to tell this processor whether it's being used in a non-realtime capacity for offline rendering or bouncing.

Reimplemented in juce::AudioProcessorGraph.

setParameter()

virtual void juce::AudioProcessor::setParameter ( int  parameterIndex, float  newValue  )

virtual

The host will call this method to change the value of one of the processor's parameters.

The host may call this at any time, including during the audio processing callback, so the processor has to process this very fast and avoid blocking.

If you want to set the value of a parameter internally, e.g. from your editor component, then don't call this directly - instead, use the setParameterNotifyingHost() method, which will also send a message to the host telling it about the change. If the message isn't sent, the host won't be able to automate your parameters properly.

The value passed will be between 0 and 1.0.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::setValue() instead.deprecated

Reimplemented in juce::AudioPluginInstance.

setParameterNotifyingHost()

void juce::AudioProcessor::setParameterNotifyingHost	(	int	parameterIndex,
		float	newValue
	)

Your processor can call this when it needs to change one of its parameters.

This could happen when the editor or some other internal operation changes a parameter. This method will call the setParameter() method to change the value, and will then send a message to the host telling it about the change.

Note that to make sure the host correctly handles automation, you should call the beginParameterChangeGesture() and endParameterChangeGesture() methods to tell the host when the user has started and stopped changing the parameter.

NOTE! This method will eventually be deprecated! It's recommended that you use AudioProcessorParameter::setValueNotifyingHost() instead.

setPlayConfigDetails()

void juce::AudioProcessor::setPlayConfigDetails	(	int	numIns,
		int	numOuts,
		double	sampleRate,
		int	blockSize
	)

This is called by the processor to specify its details before being played.

Use this version of the function if you are not interested in any sidechain and/or aux buses and do not care about the layout of channels. Otherwise use setRateAndBufferSizeDetails.

setPlayHead()

virtual void juce::AudioProcessor::setPlayHead ( AudioPlayHead *  newPlayHead )

virtual

Tells the processor to use this playhead object.

The processor will not take ownership of the object, so the caller must delete it when it is no longer being used.

setProcessingPrecision()

void juce::AudioProcessor::setProcessingPrecision ( ProcessingPrecision  newPrecision )

noexcept

Changes the processing precision of the receiver.

A client of the AudioProcessor calls this function to indicate which version of processBlock (single or double precision) it intends to call. The client MUST call this function before calling the prepareToPlay method so that the receiver can do any necessary allocations in the prepareToPlay() method. An implementation of prepareToPlay() should call getProcessingPrecision() to determine with which precision it should allocate it's internal buffers.

Note that setting the processing precision to double floating point precision on a receiver which does not support double precision processing (i.e. supportsDoublePrecisionProcessing() returns false) will result in an assertion.

See also

getProcessingPrecision, supportsDoublePrecisionProcessing

setRateAndBufferSizeDetails()

void juce::AudioProcessor::setRateAndBufferSizeDetails ( double  sampleRate, int  blockSize  )

noexcept

This is called by the processor to specify its details before being played.

You should call this function after having informed the processor about the channel and bus layouts via setBusesLayout.

See also

setBusesLayout

setStateInformation()

virtual void juce::AudioProcessor::setStateInformation ( const void *  data, int  sizeInBytes  )

pure virtual

This must restore the processor's state from a block of data previously created using getStateInformation().

Note that there's also a setCurrentProgramStateInformation() method, which tries to restore just the current program, not the state of the entire processor.

See also the helper function getXmlFromBinary() for loading settings as XML.

See also

setCurrentProgramStateInformation

Implemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

setTypeOfNextNewPlugin()

static void juce::AudioProcessor::setTypeOfNextNewPlugin ( WrapperType  )

static

Referenced by juce::StandalonePluginHolder::createPlugin().

supportsDoublePrecisionProcessing()

virtual bool juce::AudioProcessor::supportsDoublePrecisionProcessing ( ) const

virtual

Returns true if the Audio processor supports double precision floating point processing.

The default implementation will always return false. If you return true here then you must override the double precision versions of processBlock. Additionally, you must call getProcessingPrecision() in your prepareToPlay method to determine the precision with which you need to allocate your internal buffers.

See also

getProcessingPrecision, setProcessingPrecision

Reimplemented in juce::AudioProcessorGraph, and juce::AudioProcessorGraph::AudioGraphIOProcessor.

supportsMPE()

virtual bool juce::AudioProcessor::supportsMPE ( ) const

inlinevirtual

Returns true if the processor supports MPE.

suspendProcessing()

void juce::AudioProcessor::suspendProcessing

(

bool

shouldBeSuspended

)

Enables and disables the processing callback.

If you need to do something time-consuming on a thread and would like to make sure the audio processing callback doesn't happen until you've finished, use this to disable the callback and re-enable it again afterwards.

E.g.

void loadNewPatch()
{
    suspendProcessing (true);

    ..do something that takes ages..

    suspendProcessing (false);
}

If the host tries to make an audio callback while processing is suspended, the processor will return an empty buffer, but won't block the audio thread like it would do if you use the getCallbackLock() critical section to synchronise access.

Any code that calls processBlock() should call isSuspended() before doing so, and if the processor is suspended, it should avoid the call and emit silence or whatever is appropriate.

See also

getCallbackLock

updateHostDisplay()

void juce::AudioProcessor::updateHostDisplay

(

)

The processor can call this when something (apart from a parameter value) has changed.

It sends a hint to the host that something like the program, number of parameters, etc, has changed, and that it should update itself.

updateSpeakerFormatStrings()

void juce::AudioProcessor::updateSpeakerFormatStrings ( )

private

updateTrackProperties()

virtual void juce::AudioProcessor::updateTrackProperties ( const TrackProperties &  properties )

virtual

Informs the AudioProcessor that track properties such as the track's name or colour has been changed.

If you are hosting this AudioProcessor then use this method to inform the AudioProcessor about which track the AudioProcessor is loaded on. This method may only be called on the message thread.

If you are implemeting an AudioProcessor then you can override this callback to do something useful with the track properties such as changing the colour of your AudioProcessor's editor. It's entirely up to the host when and how often this callback will be called.

The default implementation of this callback will do nothing.

Friends And Related Function Documentation

AudioProcessorParameter

friend class AudioProcessorParameter

friend

AudioUnitPluginInstance

friend class AudioUnitPluginInstance

friend

Bus

friend class Bus

friend

JuceVST3Component

friend class JuceVST3Component

friend

JuceVST3EditController

friend class JuceVST3EditController

friend

LADSPAPluginInstance

friend class LADSPAPluginInstance

friend

VST3PluginInstance

friend class VST3PluginInstance

friend

Member Data Documentation

activeEditor

Component::SafePointer<AudioProcessorEditor> juce::AudioProcessor::activeEditor

private

blockSize

int juce::AudioProcessor::blockSize = 0

private

cachedInputSpeakerArrString

String juce::AudioProcessor::cachedInputSpeakerArrString

private

cachedOutputSpeakerArrString

String juce::AudioProcessor::cachedOutputSpeakerArrString

private

cachedTotalIns

int juce::AudioProcessor::cachedTotalIns = 0

private

cachedTotalOuts

int juce::AudioProcessor::cachedTotalOuts = 0

private

callbackLock

CriticalSection juce::AudioProcessor::callbackLock

private

changingParams

BigInteger juce::AudioProcessor::changingParams

private

currentSampleRate

double juce::AudioProcessor::currentSampleRate = 0

private

inputBuses

OwnedArray<Bus> juce::AudioProcessor::inputBuses

mutableprivate

latencySamples

int juce::AudioProcessor::latencySamples = 0

private

listenerLock

CriticalSection juce::AudioProcessor::listenerLock

private

listeners

Array<AudioProcessorListener*> juce::AudioProcessor::listeners

private

managedParameters

OwnedArray<AudioProcessorParameter> juce::AudioProcessor::managedParameters

private

nonRealtime

bool juce::AudioProcessor::nonRealtime = false

private

outputBuses

OwnedArray<Bus> juce::AudioProcessor::outputBuses

mutableprivate

parameterTree

AudioProcessorParameterGroup juce::AudioProcessor::parameterTree { {}, {}, {} }

private

playHead

AudioPlayHead* juce::AudioProcessor::playHead = nullptr

protected

processingPrecision

ProcessingPrecision juce::AudioProcessor::processingPrecision = singlePrecision

private

shouldCheckParamsForDupeIDs

bool juce::AudioProcessor::shouldCheckParamsForDupeIDs = false

private

suspended

bool juce::AudioProcessor::suspended = false

private

textRecursionCheck

bool juce::AudioProcessor::textRecursionCheck = false

private

wrapperType

WrapperType juce::AudioProcessor::wrapperType

When loaded by a plugin wrapper, this flag will be set to indicate the type of plugin within which the processor is running.

---

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

• juce_AudioProcessor.h