Struct AVCaptureTimecodeGenerator 

pub struct AVCaptureTimecodeGenerator { /* private fields */ }

Available on crate feature AVCaptureTimecodeGenerator only.

Generates and synchronizes timecode data from various sources for precise video and audio synchronization.

The AVCaptureTimecodeGenerator class supports multiple timecode sources, including frame counting, system clock synchronization, and MIDI timecode input (MTC). Suitable for playback, recording, or other time-sensitive operations where precise timecode metadata is required.

Use the startSynchronizationWithTimecodeSource: method to set up the desired timecode source.

See also Apple’s documentation

Implementations

impl AVCaptureTimecodeGenerator

pub unsafe fn availableSources( &self, ) -> Retained<NSArray<AVCaptureTimecodeSource>>

An array of available timecode synchronization sources that can be used by the timecode generator.

This property provides a list of AVCaptureTimecodeSource objects representing the available timecode sources with which the generator can synchronize. The sources may include built-in options such as the frame counter and real-time clock, as well as dynamically detected sources such as connected MIDI or HID devices.

This array is key-value observable, allowing you to monitor changes in real-time. For example, when a new MIDI device is connected, the array is updated to include the corresponding timecode source.

• Returns: A read-only array of AVCaptureTimecodeSource objects representing the available timecode synchronization sources.

pub unsafe fn currentSource(&self) -> Retained<AVCaptureTimecodeSource>

The active timecode source used by AVCaptureTimecodeGenerator to maintain clock synchronization for accurate timecode generation.

Indicates the active timecode source, as defined in the AVCaptureTimecodeSynchronizationSourceType enum. If an AVCaptureTimecodeGenerator becomes disconnected from its source, it continues generating timecodes using historical data from its ring buffer. This approach allows the generator to maintain synchronization during brief disruptions, as is common in cinema workflows where timecode signals may experience discontinuities.

pub unsafe fn delegate( &self, ) -> Option<Retained<ProtocolObject<dyn AVCaptureTimecodeGeneratorDelegate>>>

The delegate that receives timecode updates from the timecode generator.

You can use your delegate to receive real-time timecode updates. Implement the timecodeGenerator:didReceiveUpdate: method in your delegate to handle updates.

pub unsafe fn delegateCallbackQueue(&self) -> Option<Retained<DispatchQueue>>

Available on crate feature dispatch2 only.

The dispatch queue on which delegate callbacks are invoked.

Provides the queue set in setDelegate:queue:. If no delegate is assigned, this property is nil.

pub unsafe fn setDelegate_queue( &self, delegate: Option<&ProtocolObject<dyn AVCaptureTimecodeGeneratorDelegate>>, callback_queue: Option<&DispatchQueue>, )

Available on crate feature dispatch2 only.

Assigns a delegate to receive real-time timecode updates and specifies a queue for callbacks.

• Parameter delegate: An object conforming to the AVCaptureTimecodeGeneratorDelegate protocol.
• Parameter callbackQueue: The dispatch queue on which the delegate methods are invoked. The callbackQueue parameter may not be nil, except when setting the AVCaptureTimecodeGeneratorDelegate to nil, otherwise setDelegate:queue: throws an NSInvalidArgumentException.

Use this method to configure a delegate that handles timecode updates. The specified queue ensures thread-safe invocation of delegate methods.

Safety

callback_queue possibly has additional threading requirements.

pub unsafe fn synchronizationTimeout(&self) -> NSTimeInterval

The maximum time interval allowed for source synchronization attempts before timing out.

This property specifies the duration, in seconds, that the AVCaptureTimecodeGenerator will attempt to synchronize with a timecode source before timing out if synchronization cannot be achieved. If this threshold is exceeded, the synchronization status updates to reflect a timeout, and your AVCaptureTimecodeGeneratorDelegate/timecodeGenerator:transitionedToSynchronizationStatus:forSource: delegate method fires, informing you of the event. The default value is 15 seconds.

pub unsafe fn setSynchronizationTimeout( &self, synchronization_timeout: NSTimeInterval, )

Setter for synchronizationTimeout.

pub unsafe fn timecodeAlignmentOffset(&self) -> NSTimeInterval

The time offset, in seconds, applied to the generated timecode.

This offset allows fine-tuning of time alignment for synchronization with external sources or to accommodate any intentional delay. The default value is 0 seconds.

pub unsafe fn setTimecodeAlignmentOffset( &self, timecode_alignment_offset: NSTimeInterval, )

Setter for timecodeAlignmentOffset.

pub unsafe fn timecodeFrameDuration(&self) -> CMTime

Available on crate feature objc2-core-media only.

The frame duration that the generator will use to generate timecodes.

pub unsafe fn setTimecodeFrameDuration(&self, timecode_frame_duration: CMTime)

Available on crate feature objc2-core-media only.

Setter for timecodeFrameDuration.

pub unsafe fn startSynchronizationWithTimecodeSource( &self, source: &AVCaptureTimecodeSource, )

Synchronizes the generator with the specified timecode source.

• Parameter source: The timecode source for synchronization.

pub unsafe fn generateInitialTimecode(&self) -> AVCaptureTimecode

Available on crate feature objc2-core-media only.

Generates an initial timecode intended to be the first in a sequence.

• Returns: A populated AVCaptureTimecode structure.

pub unsafe fn frameCountSource() -> Retained<AVCaptureTimecodeSource>

A frame counter timecode source that operates independently of any internal or external synchronization.

This class property represents a standalone timecode source that advances based purely on frame count, independent of any real-time or external synchronization. It is ideal for scenarios where a simple, self-contained timing reference is sufficient, without requiring alignment to system clocks or external devices.

pub unsafe fn realTimeClockSource() -> Retained<AVCaptureTimecodeSource>

A predefined timecode source synchronized to the real-time system clock.

This class property provides a default timecode source based on the real-time system clock, requiring no external device. It is ideal for live events or scenarios where alignment with the current time of day is necessary.

impl AVCaptureTimecodeGenerator

Methods declared on superclass NSObject.

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

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

Methods from Deref<Target = NSObject>

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

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());

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.

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`
    }
}

Trait Implementations

impl AsRef<AVCaptureTimecodeGenerator> for AVCaptureTimecodeGenerator

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<AnyObject> for AVCaptureTimecodeGenerator

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for AVCaptureTimecodeGenerator

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for AVCaptureTimecodeGenerator

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVCaptureTimecodeGenerator

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVCaptureTimecodeGenerator

const NAME: &'static str = "AVCaptureTimecodeGenerator"

The name of the Objective-C class that this type represents.

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVCaptureTimecodeGenerator as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for AVCaptureTimecodeGenerator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for AVCaptureTimecodeGenerator

type Target = NSObject

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for AVCaptureTimecodeGenerator

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for AVCaptureTimecodeGenerator

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVCaptureTimecodeGenerator

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for AVCaptureTimecodeGenerator

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for AVCaptureTimecodeGenerator

const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for AVCaptureTimecodeGenerator

impl Eq for AVCaptureTimecodeGenerator