JUCE  v5.4.1-191-g0ab5e696f
JUCE API
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juce::AudioPluginInstance Class Referenceabstract

Base class for an active instance of a plugin. More...

#include <juce_AudioPluginInstance.h>

Inheritance diagram for juce::AudioPluginInstance:
Collaboration diagram for juce::AudioPluginInstance:

Classes

struct  Parameter
 Structure used to describe plugin parameters. 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

 ~AudioPluginInstance () override
 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 AudioProcessorEditorcreateEditor ()=0
 Creates the processor's GUI. More...
 
AudioProcessorEditorcreateEditorIfNeeded ()
 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 void fillInPluginDescription (PluginDescription &description) const =0
 Fills-in the appropriate parts of this plugin description object. 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...
 
AudioProcessorEditorgetActiveEditor () 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...
 
BusgetBus (bool isInput, int busIndex) noexcept
 Returns the audio bus with a given index and direction. More...
 
const BusgetBus (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 AudioProcessorParametergetBypassParameter () const
 Returns the parameter that controls the AudioProcessor's bypass state. More...
 
const CriticalSectiongetCallbackLock () 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...
 
float getParameter (int parameterIndex) override
 deprecated More...
 
AudioProcessorParameter::Category getParameterCategory (int parameterIndex) const override
 deprecated More...
 
float getParameterDefaultValue (int parameterIndex) override
 deprecated More...
 
String getParameterID (int index) override
 deprecated More...
 
String getParameterLabel (int parameterIndex) const override
 deprecated More...
 
const String getParameterName (int parameterIndex) override
 deprecated More...
 
String getParameterName (int parameterIndex, int maximumStringLength) override
 deprecated More...
 
int getParameterNumSteps (int parameterIndex) override
 deprecated More...
 
const OwnedArray< AudioProcessorParameter > & getParameters () const noexcept
 Returns the current list of parameters. More...
 
const String getParameterText (int parameterIndex) override
 deprecated More...
 
String getParameterText (int parameterIndex, int maximumStringLength) override
 deprecated More...
 
const AudioProcessorParameterGroupgetParameterTree ()
 Returns the group of parameters managed by this AudioProcessor. More...
 
virtual void * getPlatformSpecificData ()
 Returns a pointer to some kind of platform-specific data about the plugin. More...
 
AudioPlayHeadgetPlayHead () const noexcept
 Returns the current AudioPlayHead object that should be used to find out the state and position of the playhead. More...
 
PluginDescription getPluginDescription () const
 Returns a PluginDescription for this plugin. 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...
 
bool isMetaParameter (int parameterIndex) const override
 deprecated 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...
 
bool isParameterAutomatable (int parameterIndex) const override
 deprecated More...
 
bool isParameterDiscrete (int parameterIndex) const override
 deprecated More...
 
bool isParameterOrientationInverted (int parameterIndex) const override
 deprecated 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 refreshParameterList ()
 For some formats (currently AudioUnit), this forces a reload of the list of available parameters. 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...
 
void setParameter (int parameterIndex, float newValue) override
 deprecated 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 XmlElementgetXmlFromBinary (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

 AudioPluginInstance ()
 
 AudioPluginInstance (const BusesProperties &ioLayouts)
 
template<int numLayouts>
 AudioPluginInstance (const short channelLayoutList[numLayouts][2])
 
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

AudioPlayHeadplayHead = nullptr
 

Private Member Functions

void assertOnceOnDeprecatedMethodUse () const noexcept
 

Static Private Attributes

static bool deprecationAssertiontriggered
 

Detailed Description

Base class for an active instance of a plugin.

This derives from the AudioProcessor class, and adds some extra functionality that helps when wrapping dynamically loaded plugins.

This class is not needed when writing plugins, and you should never need to derive your own sub-classes from it. The plugin hosting classes use it internally and will return AudioPluginInstance objects which wrap external plugins.

See also
AudioProcessor, AudioPluginFormat

{Audio}

Member Enumeration Documentation

◆ ProcessingPrecision

Enumerator
singlePrecision 
doublePrecision 

◆ 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

◆ ~AudioPluginInstance()

juce::AudioPluginInstance::~AudioPluginInstance ( )
inlineoverride

Destructor.

Make sure that you delete any UI components that belong to this plugin before deleting the plugin.

◆ AudioPluginInstance() [1/3]

juce::AudioPluginInstance::AudioPluginInstance ( )
inlineprotected

◆ AudioPluginInstance() [2/3]

juce::AudioPluginInstance::AudioPluginInstance ( const BusesProperties ioLayouts)
inlineprotected

◆ AudioPluginInstance() [3/3]

template<int numLayouts>
juce::AudioPluginInstance::AudioPluginInstance ( const short  channelLayoutList[numLayouts][2])
inlineprotected

Member Function Documentation

◆ acceptsMidi()

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

Returns true if the processor wants MIDI messages.

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

◆ addBus()

bool juce::AudioProcessor::addBus ( bool  isInput)
inherited

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)
virtualinherited

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

◆ addParameter()

void juce::AudioProcessor::addParameter ( AudioProcessorParameter )
inherited

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 )
inherited

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

◆ assertOnceOnDeprecatedMethodUse()

void juce::AudioPluginInstance::assertOnceOnDeprecatedMethodUse ( ) const
privatenoexcept

◆ beginParameterChangeGesture()

void juce::AudioProcessor::beginParameterChangeGesture ( int  parameterIndex)
inherited

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

◆ canAddBus()

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

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 
)
protectedvirtualinherited

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
inlineprotectedvirtualinherited

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
inlinevirtualinherited

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 virtualinherited

Called by the host to rename a program.

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

◆ checkBusesLayoutSupported()

bool juce::AudioProcessor::checkBusesLayoutSupported ( const BusesLayout ) const
inherited

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

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

◆ containsLayout() [1/2]

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

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() [2/2]

template<int numLayouts>
static bool juce::AudioProcessor::containsLayout ( const BusesLayout layouts,
const short(&)  channelLayoutList[numLayouts][2] 
)
inlinestaticinherited

◆ copyXmlToBinary()

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

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.

◆ createEditor()

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

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 ( )
inherited

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 ( )
inherited

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

◆ editorBeingDeleted()

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

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

◆ enableAllBuses()

bool juce::AudioProcessor::enableAllBuses ( )
inherited

Enables all buses.

◆ endParameterChangeGesture()

void juce::AudioProcessor::endParameterChangeGesture ( int  parameterIndex)
inherited

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

◆ fillInPluginDescription()

virtual void juce::AudioPluginInstance::fillInPluginDescription ( PluginDescription description) const
pure virtual

Fills-in the appropriate parts of this plugin description object.

Implemented in juce::AudioProcessorGraph::AudioGraphIOProcessor.

◆ getAAXPluginIDForMainBusConfig()

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

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
inlinenoexceptinherited

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
virtualinherited

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
inlinenoexceptinherited

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 
)
inlinenoexceptinherited

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
inlinenoexceptinherited

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
inlineinherited

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
inlinenoexceptinherited

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

◆ getBusesLayout()

BusesLayout juce::AudioProcessor::getBusesLayout ( ) const
inherited

Provides the current channel layouts of this audio processor.

◆ getBypassParameter()

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

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
inlinenoexceptinherited

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
inlinenoexceptinherited

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
noexceptinherited

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
noexceptinherited

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 virtualinherited

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)
virtualinherited

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 ( )
staticnoexceptinherited

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
inlinenoexceptinherited

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.

◆ getMainBusNumInputChannels()

int juce::AudioProcessor::getMainBusNumInputChannels ( ) const
inlinenoexceptinherited

Returns the number of input channels on the main bus.

◆ getMainBusNumOutputChannels()

int juce::AudioProcessor::getMainBusNumOutputChannels ( ) const
inlinenoexceptinherited

Returns the number of output channels on the main bus.

◆ getName()

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

Returns the name of this processor.

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

◆ getNextBestLayoutInLayoutList()

template<int numLayouts>
BusesLayout juce::AudioProcessor::getNextBestLayoutInLayoutList ( const BusesLayout layouts,
const short(&)  channelLayoutList[numLayouts][2] 
)
inlineinherited

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}});
}

◆ getNumParameters()

virtual int juce::AudioProcessor::getNumParameters ( )
virtualinherited

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 virtualinherited

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
noexceptinherited

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.

◆ getParameter()

float juce::AudioPluginInstance::getParameter ( int  parameterIndex)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterCategory()

AudioProcessorParameter::Category juce::AudioPluginInstance::getParameterCategory ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterDefaultValue()

float juce::AudioPluginInstance::getParameterDefaultValue ( int  parameterIndex)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterID()

String juce::AudioPluginInstance::getParameterID ( int  index)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterLabel()

String juce::AudioPluginInstance::getParameterLabel ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterName() [1/2]

const String juce::AudioPluginInstance::getParameterName ( int  parameterIndex)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterName() [2/2]

String juce::AudioPluginInstance::getParameterName ( int  parameterIndex,
int  maximumStringLength 
)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterNumSteps()

int juce::AudioPluginInstance::getParameterNumSteps ( int  parameterIndex)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameters()

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

Returns the current list of parameters.

◆ getParameterText() [1/2]

const String juce::AudioPluginInstance::getParameterText ( int  parameterIndex)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterText() [2/2]

String juce::AudioPluginInstance::getParameterText ( int  parameterIndex,
int  maximumStringLength 
)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ getParameterTree()

const AudioProcessorParameterGroup& juce::AudioProcessor::getParameterTree ( )
inherited

Returns the group of parameters managed by this AudioProcessor.

◆ getPlatformSpecificData()

virtual void* juce::AudioPluginInstance::getPlatformSpecificData ( )
inlinevirtual

Returns a pointer to some kind of platform-specific data about the plugin.

E.g. For a VST, this value can be cast to an AEffect*. For an AudioUnit, it can be cast to an AudioUnit handle.

◆ getPlayHead()

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

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.

◆ getPluginDescription()

PluginDescription juce::AudioPluginInstance::getPluginDescription ( ) const

Returns a PluginDescription for this plugin.

This is just a convenience method to avoid calling fillInPluginDescription.

◆ getProcessingPrecision()

ProcessingPrecision juce::AudioProcessor::getProcessingPrecision ( ) const
inlinenoexceptinherited

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 virtualinherited

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
inlinevirtualinherited

◆ getSampleRate()

double juce::AudioProcessor::getSampleRate ( ) const
inlinenoexceptinherited

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 virtualinherited

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 virtualinherited

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

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

◆ getTotalNumInputChannels()

int juce::AudioProcessor::getTotalNumInputChannels ( ) const
inlinenoexceptinherited

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
inlinenoexceptinherited

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  )
staticnoexceptinherited

Returns a textual description of a WrapperType value.

◆ getXmlFromBinary()

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

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 virtualinherited

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
inlineprotectedvirtualinherited

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()

bool juce::AudioPluginInstance::isMetaParameter ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ isMidiEffect()

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

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

◆ isNonRealtime()

bool juce::AudioProcessor::isNonRealtime ( ) const
inlinenoexceptinherited

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()

bool juce::AudioPluginInstance::isParameterAutomatable ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ isParameterDiscrete()

bool juce::AudioPluginInstance::isParameterDiscrete ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ isParameterOrientationInverted()

bool juce::AudioPluginInstance::isParameterOrientationInverted ( int  parameterIndex) const
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ isSuspended()

bool juce::AudioProcessor::isSuspended ( ) const
inlinenoexceptinherited

Returns true if processing is currently suspended.

See also
suspendProcessing

◆ isUsingDoublePrecision()

bool juce::AudioProcessor::isUsingDoublePrecision ( ) const
inlinenoexceptinherited

Returns true if the current precision is set to doublePrecision.

◆ memoryWarningReceived()

virtual void juce::AudioProcessor::memoryWarningReceived ( )
inlinevirtualinherited

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 ( )
virtualinherited

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

◆ numChannelsChanged()

virtual void juce::AudioProcessor::numChannelsChanged ( )
virtualinherited

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 virtualinherited

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 virtualinherited

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 
)
virtualinherited

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 
)
virtualinherited

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 
)
virtualinherited

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.

◆ processorLayoutsChanged()

virtual void juce::AudioProcessor::processorLayoutsChanged ( )
virtualinherited

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

◆ producesMidi()

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

Returns true if the processor produces MIDI messages.

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

◆ refreshParameterList()

virtual void juce::AudioPluginInstance::refreshParameterList ( )
inlinevirtual

For some formats (currently AudioUnit), this forces a reload of the list of available parameters.

References JUCE_DEPRECATED.

◆ releaseResources()

virtual void juce::AudioProcessor::releaseResources ( )
pure virtualinherited

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)
inherited

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)
virtualinherited

Removes a previously added listener.

◆ reset()

virtual void juce::AudioProcessor::reset ( )
virtualinherited

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 
)
protectedinherited

◆ setBusesLayout()

bool juce::AudioProcessor::setBusesLayout ( const BusesLayout )
inherited

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 )
inherited

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 
)
inherited

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 virtualinherited

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 
)
virtualinherited

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)
inherited

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)
virtualnoexceptinherited

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()

void juce::AudioPluginInstance::setParameter ( int  parameterIndex,
float  newValue 
)
overridevirtual

deprecated

Reimplemented from juce::AudioProcessor.

◆ setParameterNotifyingHost()

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

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 
)
inherited

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)
virtualinherited

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)
noexceptinherited

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 
)
noexceptinherited

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 virtualinherited

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  )
staticinherited

◆ supportsDoublePrecisionProcessing()

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

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
inlinevirtualinherited

Returns true if the processor supports MPE.

◆ suspendProcessing()

void juce::AudioProcessor::suspendProcessing ( bool  shouldBeSuspended)
inherited

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()
{
..do something that takes ages..
}

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 ( )
inherited

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.

◆ updateTrackProperties()

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

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.

Member Data Documentation

◆ deprecationAssertiontriggered

bool juce::AudioPluginInstance::deprecationAssertiontriggered
staticprivate

◆ playHead

AudioPlayHead* juce::AudioProcessor::playHead = nullptr
protectedinherited

◆ wrapperType

WrapperType juce::AudioProcessor::wrapperType
inherited

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: