Struct AVAudioUnitTimePitch

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pub struct AVAudioUnitTimePitch { /* private fields */ }

Available on crate features AVAudioNode and AVAudioUnit and AVAudioUnitTimeEffect and AVAudioUnitTimePitch only.

Expand description

an AVAudioUnitTimeEffect that provides good quality time stretching and pitch shifting

In this time effect, the playback rate and pitch parameters function independently of each other

Implementations§

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impl AVAudioUnitTimePitch

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pub unsafe fn rate(&self) -> c_float

playback rate of the input signal

Range: 1/32 -> 32.0 Default: 1.0 Unit: Generic

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pub unsafe fn setRate(&self, rate: c_float)

Setter for rate.

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pub unsafe fn pitch(&self) -> c_float

amount by which the input signal is pitch shifted

1 octave = 1200 cents 1 musical semitone = 100 cents

Range: -2400 -> 2400 Default: 0.0 Unit: Cents

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pub unsafe fn setPitch(&self, pitch: c_float)

Setter for pitch.

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pub unsafe fn overlap(&self) -> c_float

amount of overlap between segments of the input audio signal

A higher value results in fewer artifacts in the output signal. This parameter also impacts the amount of CPU used.

Range: 3.0 -> 32.0 Default: 8.0 Unit: Generic

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pub unsafe fn setOverlap(&self, overlap: c_float)

Setter for overlap.

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impl AVAudioUnitTimePitch

Methods declared on superclass AVAudioUnitTimeEffect.

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pub unsafe fn initWithAudioComponentDescription( this: Allocated<Self>, audio_component_description: AudioComponentDescription, ) -> Retained<Self>

Available on crate feature objc2-audio-toolbox and non-watchOS only.

create an AVAudioUnitTimeEffect object

Parameter audioComponentDescription: AudioComponentDescription of the audio unit to be initialized

The componentType must be kAudioUnitType_FormatConverter

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impl AVAudioUnitTimePitch

Methods declared on superclass NSObject.

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pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

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pub unsafe fn new() -> Retained<Self>

Methods from Deref<Target = AVAudioUnitTimeEffect>§

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pub unsafe fn bypass(&self) -> bool

bypass state of the audio unit

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pub unsafe fn setBypass(&self, bypass: bool)

Setter for bypass.

Methods from Deref<Target = AVAudioUnit>§

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pub unsafe fn loadAudioUnitPresetAtURL_error( &self, url: &NSURL, ) -> Result<(), Retained<NSError>>

Load an audio unit preset.

Parameter url: NSURL of the .aupreset file.

Parameter outError: A pointer to a NSError object

If the .aupreset file cannot be successfully loaded, an error is returned.

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pub unsafe fn audioComponentDescription(&self) -> AudioComponentDescription

Available on crate feature objc2-audio-toolbox and non-watchOS only.

AudioComponentDescription of the underlying audio unit.

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pub unsafe fn audioUnit(&self) -> AudioUnit

Available on crate feature objc2-audio-toolbox and non-watchOS only.

Reference to the underlying audio unit.

A reference to the underlying audio unit is provided so that parameters that are not exposed by AVAudioUnit subclasses can be modified using the AudioUnit C API.

No operations that may conflict with state maintained by the engine should be performed directly on the audio unit. These include changing initialization state, stream formats, channel layouts or connections to other audio units.

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pub unsafe fn AUAudioUnit(&self) -> Retained<AUAudioUnit>

Available on crate feature objc2-audio-toolbox and non-watchOS only.

An AUAudioUnit wrapping or underlying the implementation’s AudioUnit.

This provides an AUAudioUnit which either wraps or underlies the implementation’s AudioUnit, depending on how that audio unit is packaged. Applications can interact with this AUAudioUnit to control custom properties, select presets, change parameters, etc.

As with the audioUnit property, no operations that may conflict with state maintained by the engine should be performed directly on the audio unit. These include changing initialization state, stream formats, channel layouts or connections to other audio units.

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pub unsafe fn name(&self) -> Retained<NSString>

Name of the audio unit.

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pub unsafe fn manufacturerName(&self) -> Retained<NSString>

Manufacturer name of the audio unit.

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pub unsafe fn version(&self) -> NSUInteger

Version number of the audio unit.

Methods from Deref<Target = AVAudioNode>§

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pub unsafe fn reset(&self)

Clear a unit’s previous processing state.

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pub unsafe fn inputFormatForBus( &self, bus: AVAudioNodeBus, ) -> Retained<AVAudioFormat>

Available on crate features AVAudioFormat and AVAudioTypes only.

Obtain an input bus’s format.

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pub unsafe fn outputFormatForBus( &self, bus: AVAudioNodeBus, ) -> Retained<AVAudioFormat>

Available on crate features AVAudioFormat and AVAudioTypes only.

Obtain an output bus’s format.

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pub unsafe fn nameForInputBus( &self, bus: AVAudioNodeBus, ) -> Option<Retained<NSString>>

Available on crate feature AVAudioTypes only.

Return the name of an input bus.

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pub unsafe fn nameForOutputBus( &self, bus: AVAudioNodeBus, ) -> Option<Retained<NSString>>

Available on crate feature AVAudioTypes only.

Return the name of an output bus.

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pub unsafe fn installTapOnBus_bufferSize_format_block( &self, bus: AVAudioNodeBus, buffer_size: AVAudioFrameCount, format: Option<&AVAudioFormat>, tap_block: AVAudioNodeTapBlock, )

Available on crate features AVAudioBuffer and AVAudioFormat and AVAudioTime and AVAudioTypes and block2 only.

Create a “tap” to record/monitor/observe the output of the node.

Parameter bus: the node output bus to which to attach the tap

Parameter bufferSize: the requested size of the incoming buffers in sample frames. Supported range is [100, 400] ms.

Parameter format: If non-nil, attempts to apply this as the format of the specified output bus. This should only be done when attaching to an output bus which is not connected to another node; an error will result otherwise. The tap and connection formats (if non-nil) on the specified bus should be identical. Otherwise, the latter operation will override any previously set format.

Parameter tapBlock: a block to be called with audio buffers

Only one tap may be installed on any bus. Taps may be safely installed and removed while the engine is running.

Note that if you have a tap installed on AVAudioOutputNode, there could be a mismatch between the tap buffer format and AVAudioOutputNode’s output format, depending on the underlying physical device. Hence, instead of tapping the AVAudioOutputNode, it is advised to tap the node connected to it.

E.g. to capture audio from input node:

AVAudioEngine *engine = [[AVAudioEngine alloc] init];
AVAudioInputNode *input = [engine inputNode];
AVAudioFormat *format = [input outputFormatForBus: 0];
[input installTapOnBus: 0 bufferSize: 8192 format: format block: ^(AVAudioPCMBuffer *buf, AVAudioTime *when) {
// ‘buf' contains audio captured from input node at time 'when'
}];
....
// start engine

§Safety

tap_block must be a valid pointer.

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pub unsafe fn removeTapOnBus(&self, bus: AVAudioNodeBus)

Available on crate feature AVAudioTypes only.

Destroy a tap.

Parameter bus: the node output bus whose tap is to be destroyed

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pub unsafe fn engine(&self) -> Option<Retained<AVAudioEngine>>

Available on crate feature AVAudioEngine only.

The engine to which the node is attached (or nil).

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pub unsafe fn numberOfInputs(&self) -> NSUInteger

The node’s number of input busses.

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pub unsafe fn numberOfOutputs(&self) -> NSUInteger

The node’s number of output busses.

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pub unsafe fn lastRenderTime(&self) -> Option<Retained<AVAudioTime>>

Available on crate feature AVAudioTime only.

Obtain the time for which the node most recently rendered.

Will return nil if the engine is not running or if the node is not connected to an input or output node.

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pub unsafe fn AUAudioUnit(&self) -> Retained<AUAudioUnit>

Available on crate feature objc2-audio-toolbox and non-watchOS only.

An AUAudioUnit wrapping or underlying the implementation’s AudioUnit.

This provides an AUAudioUnit which either wraps or underlies the implementation’s AudioUnit, depending on how that audio unit is packaged. Applications can interact with this AUAudioUnit to control custom properties, select presets, change parameters, etc.

No operations that may conflict with state maintained by the engine should be performed directly on the audio unit. These include changing initialization state, stream formats, channel layouts or connections to other audio units.

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pub unsafe fn latency(&self) -> NSTimeInterval

The processing latency of the node, in seconds.

This property reflects the delay between when an impulse in the audio stream arrives at the input vs. output of the node. This should reflect the delay due to signal processing (e.g. filters, FFT’s, etc.), not delay or reverberation which is being applied as an effect. A value of zero indicates either no latency or an unknown latency.

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pub unsafe fn outputPresentationLatency(&self) -> NSTimeInterval

The maximum render pipeline latency downstream of the node, in seconds.

This describes the maximum time it will take for the audio at the output of a node to be presented. For instance, the output presentation latency of the output node in the engine is:

zero in manual rendering mode
the presentation latency of the device itself when rendering to an audio device (see AVAudioIONode(presentationLatency)) The output presentation latency of a node connected directly to the output node is the output node’s presentation latency plus the output node’s processing latency (see latency).

For a node which is exclusively in the input node chain (i.e. not connected to engine’s output node), this property reflects the latency for the output of this node to be presented at the output of the terminating node in the input chain.

A value of zero indicates either an unknown or no latency.

Note that this latency value can change as the engine is reconfigured (started/stopped, connections made/altered downstream of this node etc.). So it is recommended not to cache this value and fetch it whenever it’s needed.

Methods from Deref<Target = NSObject>§

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pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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pub fn class(&self) -> &'static AnyClass

Dynamically find the class of this object.

§Panics

May panic if the object is invalid (which may be the case for objects returned from unavailable init/new methods).

§Example

Check that an instance of NSObject has the precise class NSObject.

use objc2::ClassType;
use objc2::runtime::NSObject;

let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());

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pub unsafe fn get_ivar<T>(&self, name: &str) -> &T
where T: Encode,

👎Deprecated: this is difficult to use correctly, use Ivar::load instead.

Use Ivar::load instead.

§Safety

The object must have an instance variable with the given name, and it must be of type T.

See Ivar::load_ptr for details surrounding this.

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pub fn downcast_ref<T>(&self) -> Option<&T>
where T: DowncastTarget,

Attempt to downcast the object to a class of type T.

This is the reference-variant. Use Retained::downcast if you want to convert a retained object to another type.

§Mutable classes

Some classes have immutable and mutable variants, such as NSString and NSMutableString.

When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.

So using this method to convert a NSString to a NSMutableString, while not unsound, is generally frowned upon unless you created the string yourself, or the API explicitly documents the string to be mutable.

See Apple’s documentation on mutability and on isKindOfClass: for more details.

§Generic classes

Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.

You can, however, safely downcast to generic collections where all the type-parameters are AnyObject.

§Panics

This works internally by calling isKindOfClass:. That means that the object must have the instance method of that name, and an exception will be thrown (if CoreFoundation is linked) or the process will abort if that is not the case. In the vast majority of cases, you don’t need to worry about this, since both root objects NSObject and NSProxy implement this method.

§Examples

Cast an NSString back and forth from NSObject.

use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};

let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();

Try (and fail) to cast an NSObject to an NSString.

use objc2_foundation::{NSObject, NSString};

let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());

Try to cast to an array of strings.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();

This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.

Downcast when processing each element instead.

use objc2_foundation::{NSArray, NSObject, NSString};

let arr = NSArray::from_retained_slice(&[NSObject::new()]);

for elem in arr {
    if let Some(data) = elem.downcast_ref::<NSString>() {
        // handle `data`
    }
}