Struct AVVideoOutputSpecification 

pub struct AVVideoOutputSpecification { /* private fields */ }

Available on crate feature AVPlayerOutput only.

AVVideoOutputSpecification offers a way to package CMTagCollections together with output settings. Allowing for direct association between output settings and specific tag collections, as well as default output settings which can be associated with all tag collections which do not have a specified mapping.

For more information about working with CMTagCollections and CMTags first look at <CoreMedia /CMTagCollection.h>

See also Apple’s documentation

Implementations

impl AVVideoOutputSpecification

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

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

pub unsafe fn initWithTagCollections( this: Allocated<Self>, tag_collections: &NSArray, ) -> Retained<Self>

Creates an instance of AVVideoOutputSpecification initialized with the specified tag collections.

Parameter tagCollections: Expects a non-empty array of CMTagCollections. Tag collections are given priority based on their position in the array, where position i take priority over position i+1.

This method throws an exception for the following reasons:

• tagCollections is nil or has a count of 0.
• tagCollections contains elements that are not of the type CMTagCollection.

Safety

tag_collections generic should be of the correct type.

pub unsafe fn setOutputPixelBufferAttributes_forTagCollection( &self, pixel_buffer_attributes: Option<&NSDictionary<NSString, AnyObject>>, tag_collection: &CMTagCollection, )

👎Deprecated

Available on crate feature objc2-core-media only.

Specifies a mapping between a tag collection and a set of pixel buffer attributes.

Parameter pixelBufferAttributes: The client requirements for CVPixelBuffers related to the tags in tagCollection, expressed using the constants in <CoreVideo /CVPixelBuffer.h>.

Parameter tagCollection: A single tag collection for which these pixel buffer attributes should map to.

If this method is called twice on the same tag collection, the first requested pixel buffer attributes will be overridden.

Note: Pixel buffer attributes are translated into output settings, therefore, the rules of -setOutputSettings:forTagCollection apply to this method as well. Namely, if you set pixel buffer attributes for a tag collection and then output settings for that same tag collection, your pixel buffer attributes will be overridden and vice-versa.

Safety

pixel_buffer_attributes generic should be of the correct type.

pub unsafe fn setOutputSettings_forTagCollection( &self, output_settings: Option<&NSDictionary<NSString, AnyObject>>, tag_collection: &CMTagCollection, )

Available on crate feature objc2-core-media only.

Specifies a mapping between a tag collection and a set of output settings.

Parameter outputSettings: The client requirements for output CVPixelBuffers related to the tags in tagCollection, expressed using the constants in AVVideoSettings.h. For uncompressed video output, start with kCVPixelBuffer* keys in <CoreVideo /CVPixelBuffer.h>. In addition to the keys in CVPixelBuffer.h, uncompressed video settings dictionaries may also contain the following keys:

• AVVideoAllowWideColorKey

Parameter tagCollection: A single tag collection for which these output settings should map to.

If this method is called twice on the same tag collection, the first requested output settings will be overridden.

Note: This method throws an exception for any of the following reasons:

• The settings will yield compressed output
• The settings do not honor the requirements list above for outputSettings.
• tagCollection does not match with any tag collection in -preferredTagCollections.

Safety

output_settings generic should be of the correct type.

pub unsafe fn preferredTagCollections(&self) -> Retained<NSArray>

Tag collections held by AVVideoOutputSpecification.

Returns an array of CMTagCollections.

pub unsafe fn defaultPixelBufferAttributes( &self, ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>

👎Deprecated

The default client requirements for CVPixelBuffers related to all tag collections not explicitly set with setOutputPixelBufferAttributes:forTagCollection:, expressed using the constants in <CoreVideo /CVPixelBuffer.h>.

NSDictionary where keys are of type NSString, values should match the type specified by the corresponding keys documentation in <CoreVideo /CVPixelBuffer.h>

Note: Pixel buffer attributes are translated into output settings, therefore, the rules of defaultOutputSettings apply to defaultPixelBufferAttributes as well. If defaultPixelBufferAttributes are set after setting defaultOutputSettings, the set output settings will be overridden and vice-versa.

pub unsafe fn setDefaultPixelBufferAttributes( &self, default_pixel_buffer_attributes: Option<&NSDictionary<NSString, AnyObject>>, )

👎Deprecated

Setter for defaultPixelBufferAttributes.

This is copied when set.

Safety

default_pixel_buffer_attributes generic should be of the correct type.

pub unsafe fn defaultOutputSettings( &self, ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>

The default client requirements for output CVPixelBuffers related to all tag collections not explicitly set with -setOutputSettings:forTagCollection, expressed using the constants in AVVideoSettings.h. For uncompressed video output, start with kCVPixelBuffer* keys in <CoreVideo /CVPixelBuffer.h>. In addition to the keys in CVPixelBuffer.h, uncompressed video settings dictionaries may also contain the following keys:

• AVVideoAllowWideColorKey

NSDictionary where keys are of type NSString, values should match the type specified by the corresponding keys documentation in <AVFoundation /AVVideoSettings.h> and <CoreVideo /CVPixelBuffer.h>.

Note: The setter for this property throws an exception for any of the following reasons:

• The settings will yield compressed output
• The settings do not honor the requirements list above for outputSettings.

pub unsafe fn setDefaultOutputSettings( &self, default_output_settings: Option<&NSDictionary<NSString, AnyObject>>, )

Setter for defaultOutputSettings.

This is copied when set.

Safety

default_output_settings generic should be of the correct type.

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<AVVideoOutputSpecification> for AVVideoOutputSpecification

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVVideoOutputSpecification

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVVideoOutputSpecification

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for AVVideoOutputSpecification

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVVideoOutputSpecification

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVVideoOutputSpecification

const NAME: &'static str = "AVVideoOutputSpecification"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVVideoOutputSpecification 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 CopyingHelper for AVVideoOutputSpecification

type Result = AVVideoOutputSpecification

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for AVVideoOutputSpecification

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

Formats the value using the given formatter.

impl Deref for AVVideoOutputSpecification

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVVideoOutputSpecification

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 AVVideoOutputSpecification

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSCopying for AVVideoOutputSpecification

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSObjectProtocol for AVVideoOutputSpecification

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 AVVideoOutputSpecification

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 AVVideoOutputSpecification

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

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

impl DowncastTarget for AVVideoOutputSpecification

impl Eq for AVVideoOutputSpecification