SndAudioProcessor Class Reference

A VST-like audio FX processing module base class. More...

#import <SndAudioProcessor.h>

Inheritance diagram for SndAudioProcessor:

List of all members.

Public Member Functions
(id)	- init
	Initialization method.
(id)	- initWithParamCount:name:
	Initialization method.
(id)	- initWithParameterDictionary:name:
	Initialization using a dictionary of parameters.
(id)	- reset
	Message sent when host determines the SndAudioProcessor should reinitialize its processing state. Eg, a delay processor would zero its z-buffers.
(int)	- paramCount
	Gets the number of parameters.
(float)	- paramValue:
	Gets the value of the indexed parameter.
(NSString *)	- paramName:
	Gets the name of indexed parameter.
(NSString *)	- paramLabel:
	Returns a label or extra text describing the parameters units of measurement.
(NSString *)	- paramDisplay:
	Converts an object-internal value into a more user-friendly representation.
(void)	- setParam:toValue:
	Sets the indexed parameter to the value given.
(BOOL)	- processReplacingInputBuffer:outputBuffer:
	Process the inputBuffer, and replace the results in the output buffer.
(void)	- setAudioProcessorChain:
	(Internal SndKit use only) Individual processors may want to query their enclosing processor chain, for example to get the time at the start of the buffer (nowTime). This method gets called when a processor gets added to the chain, with the id of the chain.
(SndAudioProcessorChain *)	- audioProcessorChain
	Returns the SndAudioProcessorChain to which the processor is attached.
(BOOL)	- isActive
	Processor activity status query method.
(id)	- setActive:
	Sets the active status of the processor.
(id)	- setName:
	Assigns the SndAudioProcessor instance a new name.
(NSString *)	- name
	Returns the name of the audio processor.
(NSDictionary *)	- paramDictionary
	Returns an NSDictionary holding all parameters of a SndAudioProcessor instance.
(void)	- setParamsWithDictionary:
	Sets parameters with names and values provided by the given NSDictionary.
(void)	- setParamWithKey:toValue:
	Assigns the parameter named keyName to the passed value.
(NSNumber *)	- paramObjectForIndex:
	Returns the parameter value as an NSNumber given an index.
(void)	- setParameterDelegate:
	Assigns the current parameter delegate.
(id)	- parameterDelegate
Static Public Member Functions
(void)	+ registerAudioProcessorClass:
	Registers an SndAudioProcessor class.
(NSArray *)	+ fxClasses
	Use this to get a list of all the available FX processors.
(NSArray *)	+ availableAudioProcessors
	Returns an array of names of available audio units (on MacOS X).
(id)	+ audioProcessor
	Factory method.
(SndAudioProcessor *)	+ audioProcessorNamed:
	Returns an autoreleased instance of a SndProcessor subclass named processorName.
Protected Attributes
int	numParams
SndAudioProcessorChain *	audioProcessorChain
NSString *	name
BOOL	active
id	parameterDelegate

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Detailed Description

A VST-like audio FX processing module base class.

To come

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Member Function Documentation

+ (void) registerAudioProcessorClass:

(id)

fxclass

Registers an SndAudioProcessor class.

Automatically called by the SndAudioProcessor init method, so any subclasses will automatically register themselves once instantiated.

Parameters:

fxclass

The class of an SndAudioProcessor

+ (NSArray*) fxClasses

Use this to get a list of all the available FX processors.

Returns:

An NSArray of SndAudioProcessor sub-classed Class object ids

+ (NSArray *) availableAudioProcessors

Returns an array of names of available audio units (on MacOS X).

The names returned can be assumed to be human readable and reasonably formatted. They can also be assumed to be unique and therefore can be used to create an instance using +processorNamed:.

Returns:

Returns an autoreleased NSArray of NSStrings of audio processors.

Reimplemented in SndAudioUnitProcessor.

+ (id) audioProcessor

Factory method.

To come

Returns:

Returns a freshly initialized, autoreleased SndAudioProcessor

+ (SndAudioProcessor *) audioProcessorNamed:

(NSString *)

processorName

Returns an autoreleased instance of a SndProcessor subclass named processorName.

Parameters:

processorName

The name of a SndAudioProcessor as returned previously by availableAudioProcessors.

Factory method.

Reimplemented in SndAudioUnitProcessor.

- (id) init

Initialization method.

Returns:

Returns self.

Reimplemented in SndAudioProcessorReverb.

- (id) initWithParamCount:		(const int)	count
name:		(NSString *)	name

Initialization method.

Parameters:

	count	Number of parameters.
	name	Name of sound audio processor.

Returns:

Returns self.

Reimplemented in SndAudioUnitProcessor.

- (id) initWithParameterDictionary:		(NSDictionary *)	paramDictionary
name:		(NSString *)	name

Initialization using a dictionary of parameters.

Parameters:

	paramDictionary	NSDictionary of parameters and values to initialise SndAudioProcessor instance with.
	name	Name of the SndAudioProcessor to initialise.

Returns:

Returns self.

- (id) reset

Message sent when host determines the SndAudioProcessor should reinitialize its processing state. Eg, a delay processor would zero its z-buffers.

Returns:

self

- (int) paramCount

Gets the number of parameters.

Returns:

number of parameters

- (float) paramValue:

(const int)

index

Gets the value of the indexed parameter.

Following the VST convention, this should be in the range [0,1]. No enforcement at the present time.

Parameters:

index

Index of the parameter

Returns:

parameter value

Reimplemented in SndAudioUnitProcessor, SndAudioFader, and SndAudioProcessorReverb.

- (NSString *) paramName:

(const int)

index

Gets the name of indexed parameter.

Parameters:

index

Parameter index

Returns:

NSString with parameter name

Reimplemented in SndAudioUnitProcessor, SndAudioFader, and SndAudioProcessorReverb.

- (NSString *) paramLabel:

(const int)

index

Returns a label or extra text describing the parameters units of measurement.

Parameters:

index

Parameter index

Example: if the parameter is in deciBels, an appropriate result might be to return "dB"

Returns:

Returns the label for the parameter.

Reimplemented in SndAudioUnitProcessor.

- (NSString *) paramDisplay:

(const int)

index

Converts an object-internal value into a more user-friendly representation.

Parameters:

index

Parameter index

Example: An instance variable may have a floating point range [0,1], but it represents a deciBel amount for user purposes. This method is an opportunity for the object to provide a more meaningful description of the parameter.

Returns:

Returns an NSString containing the alternative string representation of the parameter

Reimplemented in SndAudioUnitProcessor.

- (void) setParam:		(const int)	index
toValue:		(const float)	value

Sets the indexed parameter to the value given.

By VST convention, the argument v should be in the range [0,1]. If the internal parameter has a different range, this should be mapped internally.

Parameters:

	index	Index of the parameter to be set.
	value	Floating point value in the range [0,1]

Reimplemented in SndAudioUnitProcessor, SndAudioFader, and SndAudioProcessorReverb.

- (BOOL) processReplacingInputBuffer:		(SndAudioBuffer *)	inB
outputBuffer:		(SndAudioBuffer *)	outB

Process the inputBuffer, and replace the results in the output buffer.

Overide this method with your own FX processing routines. There is nothing to stop inB and outB referring to the same buffer - be warned that replacing the output values in outB may change inB in these cases.

Parameters:

	inB	The input buffer
	outB	The output buffer

Returns:

BOOL indicates whether the output is held in outB (YES), or inB (NO). Means that processors that decide not to touch their data at all don't need to spend time copying between buffers.

Reimplemented in SndAudioUnitProcessor, SndAudioFader, and SndAudioProcessorReverb.

- (void) setAudioProcessorChain:

(SndAudioProcessorChain *)

inChain

(Internal SndKit use only) Individual processors may want to query their enclosing processor chain, for example to get the time at the start of the buffer (nowTime). This method gets called when a processor gets added to the chain, with the id of the chain.

Parameters:

inChain

- (SndAudioProcessorChain *) audioProcessorChain

Returns the SndAudioProcessorChain to which the processor is attached.

Returns:

Returns a SndAudioProcessorChain instance.

- (BOOL) isActive

Processor activity status query method.

Returns:

Returns TRUE if the processor is active, ie whether the host processor chain should pass the audio stream through this processor.

- (id) setActive:

(const BOOL)

b

Sets the active status of the processor.

Parameters:

b

TRUE if the processor is to be made active.

Returns:

self

- (id) setName:

(NSString *)

aName

Assigns the SndAudioProcessor instance a new name.

Returns:

Returns self.

- (NSString *) name

Returns the name of the audio processor.

Returns:

Returns an NSString instance.

The name may or may not be unique to each instance of a SndAudioProcessor.

- (NSDictionary *) paramDictionary

Returns an NSDictionary holding all parameters of a SndAudioProcessor instance.

Returns:

An autoreleased NSDictionary.

Each element in the dictionary has a key with an NSString of the parameter name and an object which is an NSValue of the floating point parameter value.

- (void) setParamsWithDictionary:

(NSDictionary *)

paramDictionary

Sets parameters with names and values provided by the given NSDictionary.

Parameters:

paramDictionary

an NSDictionary holding NSString keys and NSValue float encoded objects.

Each element in the dictionary has a key with an NSString of the parameter name and an object which is an NSValue of the floating point parameter value.

- (void) setParamWithKey:		(NSString *)	keyName
toValue:		(NSNumber *)	value

Assigns the parameter named keyName to the passed value.

Parameters:

	keyName	An NSString case-sensitively matching a parameter name.
	value	An NSValue holding an encoded float value between 0.0 and 1.0.

- (NSNumber *) paramObjectForIndex:

(const int)

i

Returns the parameter value as an NSNumber given an index.

Returns:

Returns an NSNumber instance.

- (void) setParameterDelegate:

(id)

delegate

Assigns the current parameter delegate.

The message -parameter:ofAudioProcessor:didChangeTo: is sent to the delegate when a parameter changes.

Parameters:

delegate

An object to receive notification that a parameter changed value.

- (id) parameterDelegate

Returns:

Returns the current parameter delegate.

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Member Data Documentation

- (int) numParams [protected]

Number of parameters in the audio processor

- (SndAudioProcessorChain*) audioProcessorChain [protected]

The SndAudioProcessorChain hosting this processor

- (NSString*) name [protected]

- (BOOL) active [protected]

Indicates the processor instance will perform the processing.

- (id) parameterDelegate [protected]

Delegate object informed when a parameters value is changed.

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

• SndAudioProcessor.h