Struct AVCaptureFileOutput

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

Available on crate features AVCaptureFileOutput and AVCaptureOutputBase only.

AVCaptureFileOutput is an abstract subclass of AVCaptureOutput that provides an interface for writing captured media to files.

This abstract superclass defines the interface for outputs that record media samples to files. File outputs can start recording to a new file using the startRecordingToOutputFileURL:recordingDelegate: method. On successive invocations of this method on macOS, the output file can by changed dynamically without losing media samples. A file output can stop recording using the stopRecording method. Because files are recorded in the background, applications will need to specify a delegate for each new file so that they can be notified when recorded files are finished.

On macOS, clients can also set a delegate on the file output itself that can be used to control recording along exact media sample boundaries using the captureOutput:didOutputSampleBuffer:fromConnection: method.

The concrete subclasses of AVCaptureFileOutput are AVCaptureMovieFileOutput, which records media to a QuickTime movie file, and AVCaptureAudioFileOutput, which writes audio media to a variety of audio file formats.

See also Apple’s documentation

Implementations

impl AVCaptureFileOutput

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

The receiver’s delegate.

The value of this property is an object conforming to the AVCaptureFileOutputDelegate protocol that will be able to monitor and control recording along exact sample boundaries.

pub unsafe fn setDelegate( &self, delegate: Option<&ProtocolObject<dyn AVCaptureFileOutputDelegate>>, )

Setter for delegate.

pub unsafe fn outputFileURL(&self) -> Option<Retained<NSURL>>

The file URL of the file to which the receiver is currently recording incoming buffers.

The value of this property is an NSURL object containing the file URL of the file currently being written by the receiver. Returns nil if the receiver is not recording to any file.

pub unsafe fn startRecordingToOutputFileURL_recordingDelegate( &self, output_file_url: &NSURL, delegate: &ProtocolObject<dyn AVCaptureFileOutputRecordingDelegate>, )

Tells the receiver to start recording to a new file, and specifies a delegate that will be notified when recording is finished.

Parameter outputFileURL: An NSURL object containing the URL of the output file. This method throws an NSInvalidArgumentException if the URL is not a valid file URL.

Parameter delegate: An object conforming to the AVCaptureFileOutputRecordingDelegate protocol. Clients must specify a delegate so that they can be notified when recording to the given URL is finished.

The method sets the file URL to which the receiver is currently writing output media. If a file at the given URL already exists when capturing starts, recording to the new file will fail.

Clients need not call stopRecording before calling this method while another recording is in progress. On macOS, if this method is invoked while an existing output file was already being recorded, no media samples will be discarded between the old file and the new file.

When recording is stopped either by calling stopRecording, by changing files using this method, or because of an error, the remaining data that needs to be included to the file will be written in the background. Therefore, clients must specify a delegate that will be notified when all data has been written to the file using the captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: method. The recording delegate can also optionally implement methods that inform it when data starts being written, when recording is paused and resumed, and when recording is about to be finished.

On macOS, if this method is called within the captureOutput:didOutputSampleBuffer:fromConnection: delegate method, the first samples written to the new file are guaranteed to be those contained in the sample buffer passed to that method.

Note: AVCaptureAudioFileOutput does not support -startRecordingToOutputFileURL:recordingDelegate:. Use -startRecordingToOutputFileURL:outputFileType:recordingDelegate: instead.

pub unsafe fn stopRecording(&self)

Tells the receiver to stop recording to the current file.

Clients can call this method when they want to stop recording new samples to the current file, and do not want to continue recording to another file. Clients that want to switch from one file to another should not call this method. Instead they should simply call startRecordingToOutputFileURL:recordingDelegate: with the new file URL.

When recording is stopped either by calling this method, by changing files using startRecordingToOutputFileURL:recordingDelegate:, or because of an error, the remaining data that needs to be included to the file will be written in the background. Therefore, before using the file, clients must wait until the delegate that was specified in startRecordingToOutputFileURL:recordingDelegate: is notified when all data has been written to the file using the captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: method.

On macOS, if this method is called within the captureOutput:didOutputSampleBuffer:fromConnection: delegate method, the last samples written to the current file are guaranteed to be those that were output immediately before those in the sample buffer passed to that method.

pub unsafe fn isRecording(&self) -> bool

Indicates whether the receiver is currently recording.

The value of this property is YES when the receiver currently has a file to which it is writing new samples, NO otherwise.

pub unsafe fn isRecordingPaused(&self) -> bool

Indicates whether recording to the current output file is paused.

This property indicates recording to the file returned by outputFileURL has been previously paused using the pauseRecording method. When a recording is paused, captured samples are not written to the output file, but new samples can be written to the same file in the future by calling resumeRecording.

pub unsafe fn pauseRecording(&self)

Pauses recording to the current output file.

This method causes the receiver to stop writing captured samples to the current output file returned by outputFileURL, but leaves the file open so that samples can be written to it in the future, when resumeRecording is called. This allows clients to record multiple media segments that are not contiguous in time to a single file.

On macOS, if this method is called within the captureOutput:didOutputSampleBuffer:fromConnection: delegate method, the last samples written to the current file are guaranteed to be those that were output immediately before those in the sample buffer passed to that method.

A recording can be stopped as normal, even when it’s paused.

A format or device change will result in the recording being stopped, even when it’s paused.

pub unsafe fn resumeRecording(&self)

Resumes recording to the current output file after it was previously paused using pauseRecording.

This method causes the receiver to resume writing captured samples to the current output file returned by outputFileURL, after recording was previously paused using pauseRecording. This allows clients to record multiple media segments that are not contiguous in time to a single file.

On macOS, if this method is called within the captureOutput:didOutputSampleBuffer:fromConnection: delegate method, the first samples written to the current file are guaranteed to be those contained in the sample buffer passed to that method.

pub unsafe fn recordedDuration(&self) -> CMTime

Available on crate feature objc2-core-media only.

Indicates the duration of the media recorded to the current output file.

If recording is in progress, this property returns the total time recorded so far.

pub unsafe fn recordedFileSize(&self) -> i64

Indicates the size, in bytes, of the data recorded to the current output file.

If a recording is in progress, this property returns the size in bytes of the data recorded so far.

pub unsafe fn maxRecordedDuration(&self) -> CMTime

Available on crate feature objc2-core-media only.

Specifies the maximum duration of the media that should be recorded by the receiver.

This property specifies a hard limit on the duration of recorded files. Recording is stopped when the limit is reached and the captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: delegate method is invoked with an appropriate error. The default value of this property is kCMTimeInvalid, which indicates no limit.

pub unsafe fn setMaxRecordedDuration(&self, max_recorded_duration: CMTime)

Available on crate feature objc2-core-media only.

Setter for maxRecordedDuration.

pub unsafe fn maxRecordedFileSize(&self) -> i64

Specifies the maximum size, in bytes, of the data that should be recorded by the receiver.

This property specifies a hard limit on the data size of recorded files. Recording is stopped when the limit is reached and the captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: delegate method is invoked with an appropriate error. The default value of this property is 0, which indicates no limit.

pub unsafe fn setMaxRecordedFileSize(&self, max_recorded_file_size: i64)

Setter for maxRecordedFileSize.

pub unsafe fn minFreeDiskSpaceLimit(&self) -> i64

Specifies the minimum amount of free space, in bytes, required for recording to continue on a given volume.

This property specifies a hard lower limit on the amount of free space that must remain on a target volume for recording to continue. Recording is stopped when the limit is reached and the captureOutput:didFinishRecordingToOutputFileAtURL:fromConnections:error: delegate method is invoked with an appropriate error.

pub unsafe fn setMinFreeDiskSpaceLimit(&self, min_free_disk_space_limit: i64)

Setter for minFreeDiskSpaceLimit.

impl AVCaptureFileOutput

Methods declared on superclass AVCaptureOutput.

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

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

Methods from Deref<Target = AVCaptureOutput>

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

Available on crate feature AVCaptureSession only.

The connections that describe the flow of media data to the receiver from AVCaptureInputs.

The value of this property is an NSArray of AVCaptureConnection objects, each describing the mapping between the receiver and the AVCaptureInputPorts of one or more AVCaptureInputs.

pub unsafe fn connectionWithMediaType( &self, media_type: &AVMediaType, ) -> Option<Retained<AVCaptureConnection>>

Available on crate features AVCaptureSession and AVMediaFormat only.

Returns the first connection in the connections array with an inputPort of the specified mediaType.

Parameter mediaType: An AVMediaType constant from AVMediaFormat.h, e.g. AVMediaTypeVideo.

This convenience method returns the first AVCaptureConnection in the receiver’s connections array that has an AVCaptureInputPort of the specified mediaType. If no connection with the specified mediaType is found, nil is returned.

pub unsafe fn transformedMetadataObjectForMetadataObject_connection( &self, metadata_object: &AVMetadataObject, connection: &AVCaptureConnection, ) -> Option<Retained<AVMetadataObject>>

Available on crate features AVCaptureSession and AVMetadataObject only.

Converts an AVMetadataObject’s visual properties to the receiver’s coordinates.

Parameter metadataObject: An AVMetadataObject originating from the same AVCaptureInput as the receiver.

Parameter connection: The receiver’s connection whose AVCaptureInput matches that of the metadata object to be converted.

Returns: An AVMetadataObject whose properties are in output coordinates.

AVMetadataObject bounds may be expressed as a rect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. Face metadata objects likewise express yaw and roll angles with respect to an unrotated picture. -transformedMetadataObjectForMetadataObject:connection: converts the visual properties in the coordinate space of the supplied AVMetadataObject to the coordinate space of the receiver. The conversion takes orientation, mirroring, and scaling into consideration. If the provided metadata object originates from an input source other than the preview layer’s, nil will be returned.

If an AVCaptureVideoDataOutput instance’s connection’s videoOrientation or videoMirrored properties are set to non-default values, the output applies the desired mirroring and orientation by physically rotating and or flipping sample buffers as they pass through it. AVCaptureStillImageOutput, on the other hand, does not physically rotate its buffers. It attaches an appropriate kCGImagePropertyOrientation number to captured still image buffers (see ImageIO/CGImageProperties.h) indicating how the image should be displayed on playback. Likewise, AVCaptureMovieFileOutput does not physically apply orientation/mirroring to its sample buffers – it uses a QuickTime track matrix to indicate how the buffers should be rotated and/or flipped on playback.

transformedMetadataObjectForMetadataObject:connection: alters the visual properties of the provided metadata object to match the physical rotation / mirroring of the sample buffers provided by the receiver through the indicated connection. I.e., for video data output, adjusted metadata object coordinates are rotated/mirrored. For still image and movie file output, they are not.

pub unsafe fn metadataOutputRectOfInterestForRect( &self, rect_in_output_coordinates: CGRect, ) -> CGRect

Available on crate feature objc2-core-foundation only.

Converts a rectangle in the receiver’s coordinate space to a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose capture device is providing input to the receiver.

Parameter rectInOutputCoordinates: A CGRect in the receiver’s coordinates.

Returns: A CGRect in the coordinate space of the metadata output whose capture device is providing input to the receiver.

AVCaptureMetadataOutput rectOfInterest is expressed as a CGRect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. This convenience method converts a rectangle in the coordinate space of the receiver to a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose AVCaptureDevice is providing input to the receiver. The conversion takes orientation, mirroring, and scaling into consideration. See -transformedMetadataObjectForMetadataObject:connection: for a full discussion of how orientation and mirroring are applied to sample buffers passing through the output.

pub unsafe fn rectForMetadataOutputRectOfInterest( &self, rect_in_metadata_output_coordinates: CGRect, ) -> CGRect

Available on crate feature objc2-core-foundation only.

Converts a rectangle of interest in the coordinate space of an AVCaptureMetadataOutput whose capture device is providing input to the receiver to a rectangle in the receiver’s coordinates.

Parameter rectInMetadataOutputCoordinates: A CGRect in the coordinate space of the metadata output whose capture device is providing input to the receiver.

Returns: A CGRect in the receiver’s coordinates.

AVCaptureMetadataOutput rectOfInterest is expressed as a CGRect where {0,0} represents the top left of the picture area, and {1,1} represents the bottom right on an unrotated picture. This convenience method converts a rectangle in the coordinate space of an AVCaptureMetadataOutput whose AVCaptureDevice is providing input to the coordinate space of the receiver. The conversion takes orientation, mirroring, and scaling into consideration. See -transformedMetadataObjectForMetadataObject:connection: for a full discussion of how orientation and mirroring are applied to sample buffers passing through the output.

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.

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<AVCaptureFileOutput> for AVCaptureAudioFileOutput

fn as_ref(&self) -> &AVCaptureFileOutput

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

impl AsRef<AVCaptureFileOutput> for AVCaptureFileOutput

fn as_ref(&self) -> &Self

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

impl AsRef<AVCaptureFileOutput> for AVCaptureMovieFileOutput

fn as_ref(&self) -> &AVCaptureFileOutput

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

impl AsRef<AVCaptureOutput> for AVCaptureFileOutput

fn as_ref(&self) -> &AVCaptureOutput

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

impl AsRef<AnyObject> for AVCaptureFileOutput

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVCaptureFileOutput

fn as_ref(&self) -> &NSObject

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

impl Borrow<AVCaptureFileOutput> for AVCaptureAudioFileOutput

fn borrow(&self) -> &AVCaptureFileOutput

Immutably borrows from an owned value.

impl Borrow<AVCaptureFileOutput> for AVCaptureMovieFileOutput

fn borrow(&self) -> &AVCaptureFileOutput

Immutably borrows from an owned value.

impl Borrow<AVCaptureOutput> for AVCaptureFileOutput

fn borrow(&self) -> &AVCaptureOutput

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVCaptureFileOutput

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVCaptureFileOutput

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVCaptureFileOutput

const NAME: &'static str = "AVCaptureFileOutput"

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

type Super = AVCaptureOutput

The superclass of this class.

type ThreadKind = <<AVCaptureFileOutput 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 AVCaptureFileOutput

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

Formats the value using the given formatter.

impl Deref for AVCaptureFileOutput

type Target = AVCaptureOutput

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVCaptureFileOutput

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 AVCaptureFileOutput

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVCaptureFileOutput

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 AVCaptureFileOutput

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 AVCaptureFileOutput

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

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

impl DowncastTarget for AVCaptureFileOutput

impl Eq for AVCaptureFileOutput