Struct VTFrameProcessor 

#[repr(C)]
pub struct VTFrameProcessor { /* private fields */ }

Available on crate features VTFrameProcessor and objc2 only.

Creates a new VTFrameProcessor for the configured video effect

The VTFrameProcessor class is the main class to perform frame processing. Users can specify a video effect by passing a VTFrameProcessorConfiguration based object to the startSessionWithConfiguration call. Once a session is created, the processWithParameters method is called in a loop to process the frames one by one. Once all the frames are processed, endSession needs to called to finish all pending processing. The caller needs to ensure that all buffers passed to the processWithParameters interface are unmodified (inclduing attachments) until the function returns or the callback is received in the case of asynchronous mode.

See also Apple’s documentation

Implementations

impl VTFrameProcessor

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

pub unsafe fn startSessionWithConfiguration_error( &self, configuration: &ProtocolObject<dyn VTFrameProcessorConfiguration>, ) -> Result<(), Retained<NSError>>

Available on crate features VTFrameProcessorConfiguration and objc2-foundation only.

Starts a new session and configures the processor pipeline.

Parameter configuration: A VTFrameProcessorConfiguration based object corresponding to the video effect that will be applied in the subsequent processWithParameters calls.

Parameter error: Will contain error information if any. You may specify NULL for this parameter if you do not want the error information.

pub unsafe fn processWithParameters_error( &self, parameters: &ProtocolObject<dyn VTFrameProcessorParameters>, ) -> Result<(), Retained<NSError>>

Available on crate features VTFrameProcessorParameters and objc2-foundation only.

Synchronously performs the effect specified in startSessionWithConfigurations.

Frame level settings and frame level input/output parameters are passed by using the respective VTFrameProcessorParameters for the effect that VTFrameProcessor is configured for.

Parameter parameters: A VTFrameProcessorParameters based object to specify additional frame based parameters to be used during processing. it needs to match the configuration type used during start session.

Parameter error: Will contain error information if any. You may specify NULL for this parameter if you do not want the error information.

pub unsafe fn processWithParameters_completionHandler( &self, parameters: &ProtocolObject<dyn VTFrameProcessorParameters>, completion_handler: &DynBlock<dyn Fn(NonNull<ProtocolObject<dyn VTFrameProcessorParameters>>, *mut NSError)>, )

Available on crate features VTFrameProcessorParameters and block2 and objc2-foundation only.

Asynchronously performs the effect specified in startSessionWithConfigurations.

Parameter parameters: A VTFrameProcessorParameters based object to specify additional frame based parameters to be used during processing. it needs to match the configuration type used during start session.

Parameter completionHandler: This completion handler will be called when frame processing in competed. The completion handler will receive the same parameters object that was provided tot he original call, as well as an NSError which will contain an error code if processing was not successful.

pub unsafe fn processWithCommandBuffer_parameters( &self, command_buffer: &ProtocolObject<dyn MTLCommandBuffer>, parameters: &ProtocolObject<dyn VTFrameProcessorParameters>, )

Available on crate features VTFrameProcessorParameters and objc2-metal only.

This API provides a Metal API friendly version of processWithParameters.

This function allows clients to add the effect to an existing Metal command buffer. This can be used by clients that have an existing Metal pipeline and want to add this effect to it. Note: this function will wait until all previously inserted tasks in the command buffer finished before running. Tasks inserted after the processWithCommandBuffer will run after the effect is applied. Processing does not happen until the commandBuffer is executed.

Parameter commandBuffer: An existing Metal command buffer where the frame processing will be inserted.

Parameter parameters: A VTFrameProcessorParameters based object to specify additional frame based parameters to be used during processing. it needs to match the configuration type used during start session.

pub unsafe fn endSession(&self)

Performs all necessary tasks to end the session. After this call completes, no new frames can be processed unless startSessionWithConfigurations is called again.

impl VTFrameProcessor

Methods declared on superclass NSObject.

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<AnyObject> for VTFrameProcessor

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for VTFrameProcessor

fn as_ref(&self) -> &NSObject

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

impl AsRef<VTFrameProcessor> for VTFrameProcessor

fn as_ref(&self) -> &Self

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

impl Borrow<AnyObject> for VTFrameProcessor

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for VTFrameProcessor

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for VTFrameProcessor

const NAME: &'static str = "VTFrameProcessor"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<VTFrameProcessor 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 VTFrameProcessor

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

Formats the value using the given formatter.

impl Deref for VTFrameProcessor

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for VTFrameProcessor

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 VTFrameProcessor

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for VTFrameProcessor

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 VTFrameProcessor

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 VTFrameProcessor

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

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

impl DowncastTarget for VTFrameProcessor

impl Eq for VTFrameProcessor