objc2_av_foundation/generated/
AVCaptureVideoDataOutput.rs

1//! This file has been automatically generated by `objc2`'s `header-translator`.
2//! DO NOT EDIT
3use core::ffi::*;
4use core::ptr::NonNull;
5#[cfg(feature = "dispatch2")]
6use dispatch2::*;
7use objc2::__framework_prelude::*;
8#[cfg(feature = "objc2-core-media")]
9use objc2_core_media::*;
10use objc2_foundation::*;
11
12use crate::*;
13
14extern_class!(
15    /// AVCaptureVideoDataOutput is a concrete subclass of AVCaptureOutput that can be used to process uncompressed or compressed frames from the video being captured.
16    ///
17    ///
18    /// Instances of AVCaptureVideoDataOutput produce video frames suitable for processing using other media APIs. Applications can access the frames with the captureOutput:didOutputSampleBuffer:fromConnection: delegate method.
19    ///
20    /// See also [Apple's documentation](https://developer.apple.com/documentation/avfoundation/avcapturevideodataoutput?language=objc)
21    #[unsafe(super(AVCaptureOutput, NSObject))]
22    #[derive(Debug, PartialEq, Eq, Hash)]
23    #[cfg(feature = "AVCaptureOutputBase")]
24    pub struct AVCaptureVideoDataOutput;
25);
26
27#[cfg(feature = "AVCaptureOutputBase")]
28extern_conformance!(
29    unsafe impl NSObjectProtocol for AVCaptureVideoDataOutput {}
30);
31
32#[cfg(feature = "AVCaptureOutputBase")]
33impl AVCaptureVideoDataOutput {
34    extern_methods!(
35        #[unsafe(method(init))]
36        #[unsafe(method_family = init)]
37        pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>;
38
39        #[unsafe(method(new))]
40        #[unsafe(method_family = new)]
41        pub unsafe fn new() -> Retained<Self>;
42
43        #[cfg(feature = "dispatch2")]
44        /// Sets the receiver's delegate that will accept captured buffers and dispatch queue on which the delegate will be called.
45        ///
46        ///
47        /// Parameter `sampleBufferDelegate`: An object conforming to the AVCaptureVideoDataOutputSampleBufferDelegate protocol that will receive sample buffers after they are captured.
48        ///
49        /// Parameter `sampleBufferCallbackQueue`: A dispatch queue on which all sample buffer delegate methods will be called.
50        ///
51        ///
52        /// When a new video sample buffer is captured it will be vended to the sample buffer delegate using the captureOutput:didOutputSampleBuffer:fromConnection: delegate method. All delegate methods will be called on the specified dispatch queue. If the queue is blocked when new frames are captured, those frames will be automatically dropped at a time determined by the value of the alwaysDiscardsLateVideoFrames property. This allows clients to process existing frames on the same queue without having to manage the potential memory usage increases that would otherwise occur when that processing is unable to keep up with the rate of incoming frames. If their frame processing is consistently unable to keep up with the rate of incoming frames, clients should consider using the minFrameDuration property, which will generally yield better performance characteristics and more consistent frame rates than frame dropping alone.
53        ///
54        /// Clients that need to minimize the chances of frames being dropped should specify a queue on which a sufficiently small amount of processing is being done outside of receiving sample buffers. However, if such clients migrate extra processing to another queue, they are responsible for ensuring that memory usage does not grow without bound from frames that have not been processed.
55        ///
56        /// A serial dispatch queue must be used to guarantee that video frames will be delivered in order. The sampleBufferCallbackQueue parameter may not be NULL, except when setting the sampleBufferDelegate to nil otherwise -setSampleBufferDelegate:queue: throws an NSInvalidArgumentException.
57        #[unsafe(method(setSampleBufferDelegate:queue:))]
58        #[unsafe(method_family = none)]
59        pub unsafe fn setSampleBufferDelegate_queue(
60            &self,
61            sample_buffer_delegate: Option<
62                &ProtocolObject<dyn AVCaptureVideoDataOutputSampleBufferDelegate>,
63            >,
64            sample_buffer_callback_queue: Option<&DispatchQueue>,
65        );
66
67        /// The receiver's delegate.
68        ///
69        ///
70        /// The value of this property is an object conforming to the AVCaptureVideoDataOutputSampleBufferDelegate protocol that will receive sample buffers after they are captured. The delegate is set using the setSampleBufferDelegate:queue: method.
71        #[unsafe(method(sampleBufferDelegate))]
72        #[unsafe(method_family = none)]
73        pub unsafe fn sampleBufferDelegate(
74            &self,
75        ) -> Option<Retained<ProtocolObject<dyn AVCaptureVideoDataOutputSampleBufferDelegate>>>;
76
77        #[cfg(feature = "dispatch2")]
78        /// The dispatch queue on which all sample buffer delegate methods will be called.
79        ///
80        ///
81        /// The value of this property is a dispatch_queue_t. The queue is set using the setSampleBufferDelegate:queue: method.
82        #[unsafe(method(sampleBufferCallbackQueue))]
83        #[unsafe(method_family = none)]
84        pub unsafe fn sampleBufferCallbackQueue(&self) -> Option<Retained<DispatchQueue>>;
85
86        /// Specifies the settings used to decode or re-encode video before it is output by the receiver.
87        ///
88        ///
89        /// See AVVideoSettings.h for more information on how to construct a video settings dictionary. To receive samples in their device native format, set this property to an empty dictionary (i.e. [NSDictionary dictionary]). To receive samples in a default uncompressed format, set this property to nil. Note that after this property is set to nil, subsequent querying of this property will yield a non-nil dictionary reflecting the settings used by the AVCaptureSession's current sessionPreset.
90        ///
91        /// On iOS versions prior to iOS 16.0, the only supported key is kCVPixelBufferPixelFormatTypeKey. Use -availableVideoCVPixelFormatTypes for the list of supported pixel formats. For apps linked on or after iOS 16.0, kCVPixelBufferPixelFormatTypeKey, kCVPixelBufferWidthKey, and kCVPixelBufferHeightKey are supported. The width and height must match the videoOrientation specified on the output's AVCaptureConnection or an NSInvalidArgumentException is thrown. The aspect ratio of width and height must match the aspect ratio of the source's activeFormat (corrected for the connection's videoOrientation) or an NSInvalidArgumentException is thrown. If width or height exceeds the source's activeFormat's width or height, an NSInvalidArgumentException is thrown. Changing width and height when deliversPreviewSizedOutputBuffers is set to YES is not supported and throws an NSInvalidArgumentException.
92        #[unsafe(method(videoSettings))]
93        #[unsafe(method_family = none)]
94        pub unsafe fn videoSettings(&self) -> Retained<NSDictionary<NSString, AnyObject>>;
95
96        /// Setter for [`videoSettings`][Self::videoSettings].
97        #[unsafe(method(setVideoSettings:))]
98        #[unsafe(method_family = none)]
99        pub unsafe fn setVideoSettings(
100            &self,
101            video_settings: Option<&NSDictionary<NSString, AnyObject>>,
102        );
103
104        #[cfg(feature = "AVMediaFormat")]
105        /// Specifies the recommended settings for use with an AVAssetWriterInput.
106        ///
107        ///
108        /// Parameter `outputFileType`: Specifies the UTI of the file type to be written (see AVMediaFormat.h for a list of file format UTIs).
109        ///
110        /// Returns: A fully populated dictionary of keys and values that are compatible with AVAssetWriter.
111        ///
112        ///
113        /// The value of this property is an NSDictionary containing values for compression settings keys defined in AVVideoSettings.h. This dictionary is suitable for use as the "outputSettings" parameter when creating an AVAssetWriterInput, such as,
114        ///
115        /// [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:outputSettings sourceFormatHint:hint];
116        ///
117        /// The dictionary returned contains all necessary keys and values needed by AVAssetWriter (see AVAssetWriterInput.h, -initWithMediaType:outputSettings: for a more in depth discussion). For QuickTime movie and ISO file types, the recommended video settings will produce output comparable to that of AVCaptureMovieFileOutput.
118        ///
119        /// Note that the dictionary of settings is dependent on the current configuration of the receiver's AVCaptureSession and its inputs. The settings dictionary may change if the session's configuration changes. As such, you should configure your session first, then query the recommended video settings. As of iOS 8.3, movies produced with these settings successfully import into the iOS camera roll and sync to and from like devices via iTunes.
120        #[unsafe(method(recommendedVideoSettingsForAssetWriterWithOutputFileType:))]
121        #[unsafe(method_family = none)]
122        pub unsafe fn recommendedVideoSettingsForAssetWriterWithOutputFileType(
123            &self,
124            output_file_type: &AVFileType,
125        ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>;
126
127        #[cfg(all(feature = "AVMediaFormat", feature = "AVVideoSettings"))]
128        /// Specifies the available video codecs for use with AVAssetWriter and a given file type.
129        ///
130        ///
131        /// Parameter `outputFileType`: Specifies the UTI of the file type to be written (see AVMediaFormat.h for a list of file format UTIs).
132        ///
133        /// Returns: An array of video codecs; see AVVideoSettings.h for a full list.
134        ///
135        ///
136        /// This method allows you to query the available video codecs that may be used when specifying an AVVideoCodecKey in -recommendedVideoSettingsForVideoCodecType:assetWriterOutputFileType:. When specifying an outputFileType of AVFileTypeQuickTimeMovie, video codecs are ordered identically to -[AVCaptureMovieFileOutput availableVideoCodecTypes].
137        #[unsafe(method(availableVideoCodecTypesForAssetWriterWithOutputFileType:))]
138        #[unsafe(method_family = none)]
139        pub unsafe fn availableVideoCodecTypesForAssetWriterWithOutputFileType(
140            &self,
141            output_file_type: &AVFileType,
142        ) -> Retained<NSArray<AVVideoCodecType>>;
143
144        #[cfg(all(feature = "AVMediaFormat", feature = "AVVideoSettings"))]
145        /// Specifies the recommended settings for a particular video codec type, to be used with an AVAssetWriterInput.
146        ///
147        ///
148        /// Parameter `videoCodecType`: Specifies the desired AVVideoCodecKey to be used for compression (see AVVideoSettings.h).
149        ///
150        /// Parameter `outputFileType`: Specifies the UTI of the file type to be written (see AVMediaFormat.h for a list of file format UTIs).
151        ///
152        /// Returns: A fully populated dictionary of keys and values that are compatible with AVAssetWriter.
153        ///
154        ///
155        /// The value of this property is an NSDictionary containing values for compression settings keys defined in AVVideoSettings.h. This dictionary is suitable for use as the "outputSettings" parameter when creating an AVAssetWriterInput, such as,
156        ///
157        /// [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:outputSettings sourceFormatHint:hint];
158        ///
159        /// The dictionary returned contains all necessary keys and values needed by AVAssetWriter (see AVAssetWriterInput.h, -initWithMediaType:outputSettings: for a more in depth discussion). For QuickTime movie and ISO file types, the recommended video settings will produce output comparable to that of AVCaptureMovieFileOutput.
160        ///
161        /// The videoCodecType string provided must be present in the availableVideoCodecTypesForAssetWriterWithOutputFileType: array, or an NSInvalidArgumentException is thrown.
162        ///
163        /// Note that the dictionary of settings is dependent on the current configuration of the receiver's AVCaptureSession and its inputs. The settings dictionary may change if the session's configuration changes. As such, you should configure your session first, then query the recommended video settings. As of iOS 8.3, movies produced with these settings successfully import into the iOS camera roll and sync to and from like devices via iTunes.
164        #[unsafe(method(recommendedVideoSettingsForVideoCodecType:assetWriterOutputFileType:))]
165        #[unsafe(method_family = none)]
166        pub unsafe fn recommendedVideoSettingsForVideoCodecType_assetWriterOutputFileType(
167            &self,
168            video_codec_type: &AVVideoCodecType,
169            output_file_type: &AVFileType,
170        ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>;
171
172        #[cfg(all(feature = "AVMediaFormat", feature = "AVVideoSettings"))]
173        /// Specifies the recommended settings for a particular video codec type with output file URL, to be used with an AVAssetWriterInput.
174        ///
175        ///
176        /// Parameter `videoCodecType`: Specifies the desired AVVideoCodecKey to be used for compression (see AVVideoSettings.h).
177        ///
178        /// Parameter `outputFileType`: Specifies the UTI of the file type to be written (see AVMediaFormat.h for a list of file format UTIs).
179        ///
180        /// Parameter `outputFileURL`: Specifies the output URL of the file to be written.
181        ///
182        /// If you wish to capture onto an external storage device get an externalStorageDevice of type AVExternalStorageDevice (as defined in AVExternalStorageDevice.h):
183        /// [AVExternalStorageDeviceDiscoverySession sharedSession] externalStorageDevices]
184        ///
185        /// Then use [externalStorageDevice nextAvailableURLsWithPathExtensions:pathExtensions error:
186        /// &error
187        /// ] to get the output file URL.
188        ///
189        ///
190        /// Returns: A fully populated dictionary of keys and values that are compatible with AVAssetWriter.
191        ///
192        ///
193        /// The value of this property is an NSDictionary containing values for compression settings keys defined in AVVideoSettings.h. This dictionary is suitable for use as the "outputSettings" parameter when creating an AVAssetWriterInput, such as,
194        ///
195        /// [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:outputSettings sourceFormatHint:hint];
196        ///
197        /// The dictionary returned contains all necessary keys and values needed by AVAssetWriter (see AVAssetWriterInput.h, -initWithMediaType:outputSettings: for a more in depth discussion). For QuickTime movie and ISO file types, the recommended video settings will produce output comparable to that of AVCaptureMovieFileOutput.
198        ///
199        /// The videoCodecType string provided must be present in the availableVideoCodecTypesForAssetWriterWithOutputFileType: array, or an NSInvalidArgumentException is thrown.
200        ///
201        /// Note that the dictionary of settings is dependent on the current configuration of the receiver's AVCaptureSession and its inputs. The settings dictionary may change if the session's configuration changes. As such, you should configure your session first, then query the recommended video settings. As of iOS 8.3, movies produced with these settings successfully import into the iOS camera roll and sync to and from like devices via iTunes.
202        #[unsafe(method(recommendedVideoSettingsForVideoCodecType:assetWriterOutputFileType:outputFileURL:))]
203        #[unsafe(method_family = none)]
204        pub unsafe fn recommendedVideoSettingsForVideoCodecType_assetWriterOutputFileType_outputFileURL(
205            &self,
206            video_codec_type: &AVVideoCodecType,
207            output_file_type: &AVFileType,
208            output_file_url: Option<&NSURL>,
209        ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>;
210
211        /// Indicates the supported video pixel formats that can be specified in videoSettings.
212        ///
213        ///
214        /// The value of this property is an NSArray of NSNumbers that can be used as values for the kCVPixelBufferPixelFormatTypeKey in the receiver's videoSettings property. The formats are listed in an unspecified order. This list can may change if the activeFormat of the AVCaptureDevice connected to the receiver changes.
215        #[unsafe(method(availableVideoCVPixelFormatTypes))]
216        #[unsafe(method_family = none)]
217        pub unsafe fn availableVideoCVPixelFormatTypes(&self) -> Retained<NSArray<NSNumber>>;
218
219        #[cfg(feature = "AVVideoSettings")]
220        /// Indicates the supported video codec formats that can be specified in videoSettings.
221        ///
222        ///
223        /// The value of this property is an NSArray of AVVideoCodecTypes that can be used as values for the AVVideoCodecKey in the receiver's videoSettings property.
224        #[unsafe(method(availableVideoCodecTypes))]
225        #[unsafe(method_family = none)]
226        pub unsafe fn availableVideoCodecTypes(&self) -> Retained<NSArray<AVVideoCodecType>>;
227
228        #[cfg(feature = "objc2-core-media")]
229        /// Specifies the minimum time interval between which the receiver should output consecutive video frames.
230        ///
231        ///
232        /// The value of this property is a CMTime specifying the minimum duration of each video frame output by the receiver, placing a lower bound on the amount of time that should separate consecutive frames. This is equivalent to the inverse of the maximum frame rate. A value of kCMTimeZero or kCMTimeInvalid indicates an unlimited maximum frame rate. The default value is kCMTimeInvalid. As of iOS 5.0, minFrameDuration is deprecated. Use AVCaptureConnection's videoMinFrameDuration property instead.
233        #[deprecated = "Use AVCaptureConnection's videoMinFrameDuration property instead."]
234        #[unsafe(method(minFrameDuration))]
235        #[unsafe(method_family = none)]
236        pub unsafe fn minFrameDuration(&self) -> CMTime;
237
238        #[cfg(feature = "objc2-core-media")]
239        /// Setter for [`minFrameDuration`][Self::minFrameDuration].
240        #[deprecated = "Use AVCaptureConnection's videoMinFrameDuration property instead."]
241        #[unsafe(method(setMinFrameDuration:))]
242        #[unsafe(method_family = none)]
243        pub unsafe fn setMinFrameDuration(&self, min_frame_duration: CMTime);
244
245        /// Specifies whether the receiver should always discard any video frame that is not processed before the next frame is captured.
246        ///
247        ///
248        /// When the value of this property is YES, the receiver will immediately discard frames that are captured while the dispatch queue handling existing frames is blocked in the captureOutput:didOutputSampleBuffer:fromConnection: delegate method. When the value of this property is NO, delegates will be allowed more time to process old frames before new frames are discarded, but application memory usage may increase significantly as a result. The default value is YES.
249        #[unsafe(method(alwaysDiscardsLateVideoFrames))]
250        #[unsafe(method_family = none)]
251        pub unsafe fn alwaysDiscardsLateVideoFrames(&self) -> bool;
252
253        /// Setter for [`alwaysDiscardsLateVideoFrames`][Self::alwaysDiscardsLateVideoFrames].
254        #[unsafe(method(setAlwaysDiscardsLateVideoFrames:))]
255        #[unsafe(method_family = none)]
256        pub unsafe fn setAlwaysDiscardsLateVideoFrames(
257            &self,
258            always_discards_late_video_frames: bool,
259        );
260
261        /// Indicates whether the receiver automatically configures the size of output buffers.
262        ///
263        ///
264        /// Default value is YES. In most configurations, AVCaptureVideoDataOutput delivers full-resolution buffers, that is, buffers with the same dimensions as the source AVCaptureDevice's activeFormat's videoDimensions. When this property is set to YES, the receiver is free to configure the dimensions of the buffers delivered to -captureOutput:didOutputSampleBuffer:fromConnection:, such that they are a smaller preview size (roughly the size of the screen). For instance, when the AVCaptureSession's sessionPreset is set to AVCaptureSessionPresetPhoto, it is assumed that video data output buffers are being delivered as a preview proxy. Likewise, if an AVCapturePhotoOutput is present in the session with livePhotoCaptureEnabled, it is assumed that video data output is being used for photo preview, and thus preview-sized buffers are a better choice than full-res buffers. You can query deliversPreviewSizedOutputBuffers to find out whether automatic configuration of output buffer dimensions is currently downscaling buffers to a preview size. You can also query the videoSettings property to find out the exact width and height being delivered. If you wish to manually set deliversPreviewSizedOutputBuffers, you must first set automaticallyConfiguresOutputBufferDimensions to NO.
265        #[unsafe(method(automaticallyConfiguresOutputBufferDimensions))]
266        #[unsafe(method_family = none)]
267        pub unsafe fn automaticallyConfiguresOutputBufferDimensions(&self) -> bool;
268
269        /// Setter for [`automaticallyConfiguresOutputBufferDimensions`][Self::automaticallyConfiguresOutputBufferDimensions].
270        #[unsafe(method(setAutomaticallyConfiguresOutputBufferDimensions:))]
271        #[unsafe(method_family = none)]
272        pub unsafe fn setAutomaticallyConfiguresOutputBufferDimensions(
273            &self,
274            automatically_configures_output_buffer_dimensions: bool,
275        );
276
277        /// Indicates whether the receiver is currently configured to deliver preview sized buffers.
278        ///
279        ///
280        /// If you wish to manually set deliversPreviewSizedOutputBuffers, you must first set automaticallyConfiguresOutputBufferDimensions to NO. When deliversPreviewSizedOutputBuffers is set to YES, auto focus, exposure, and white balance changes are quicker. AVCaptureVideoDataOutput assumes that the buffers are being used for on-screen preview rather than recording.
281        #[unsafe(method(deliversPreviewSizedOutputBuffers))]
282        #[unsafe(method_family = none)]
283        pub unsafe fn deliversPreviewSizedOutputBuffers(&self) -> bool;
284
285        /// Setter for [`deliversPreviewSizedOutputBuffers`][Self::deliversPreviewSizedOutputBuffers].
286        #[unsafe(method(setDeliversPreviewSizedOutputBuffers:))]
287        #[unsafe(method_family = none)]
288        pub unsafe fn setDeliversPreviewSizedOutputBuffers(
289            &self,
290            delivers_preview_sized_output_buffers: bool,
291        );
292    );
293}
294
295extern_protocol!(
296    /// Defines an interface for delegates of AVCaptureVideoDataOutput to receive captured video sample buffers and be notified of late sample buffers that were dropped.
297    ///
298    /// See also [Apple's documentation](https://developer.apple.com/documentation/avfoundation/avcapturevideodataoutputsamplebufferdelegate?language=objc)
299    pub unsafe trait AVCaptureVideoDataOutputSampleBufferDelegate: NSObjectProtocol {
300        #[cfg(all(
301            feature = "AVCaptureOutputBase",
302            feature = "AVCaptureSession",
303            feature = "objc2-core-media"
304        ))]
305        /// Called whenever an AVCaptureVideoDataOutput instance outputs a new video frame.
306        ///
307        ///
308        /// Parameter `output`: The AVCaptureVideoDataOutput instance that output the frame.
309        ///
310        /// Parameter `sampleBuffer`: A CMSampleBuffer object containing the video frame data and additional information about the frame, such as its format and presentation time.
311        ///
312        /// Parameter `connection`: The AVCaptureConnection from which the video was received.
313        ///
314        ///
315        /// Delegates receive this message whenever the output captures and outputs a new video frame, decoding or re-encoding it as specified by its videoSettings property. Delegates can use the provided video frame in conjunction with other APIs for further processing. This method will be called on the dispatch queue specified by the output's sampleBufferCallbackQueue property. This method is called periodically, so it must be efficient to prevent capture performance problems, including dropped frames.
316        ///
317        /// Clients that need to reference the CMSampleBuffer object outside of the scope of this method must CFRetain it and then CFRelease it when they are finished with it.
318        ///
319        /// Note that to maintain optimal performance, some sample buffers directly reference pools of memory that may need to be reused by the device system and other capture inputs. This is frequently the case for uncompressed device native capture where memory blocks are copied as little as possible. If multiple sample buffers reference such pools of memory for too long, inputs will no longer be able to copy new samples into memory and those samples will be dropped. If your application is causing samples to be dropped by retaining the provided CMSampleBuffer objects for too long, but it needs access to the sample data for a long period of time, consider copying the data into a new buffer and then calling CFRelease on the sample buffer if it was previously retained so that the memory it references can be reused.
320        #[optional]
321        #[unsafe(method(captureOutput:didOutputSampleBuffer:fromConnection:))]
322        #[unsafe(method_family = none)]
323        unsafe fn captureOutput_didOutputSampleBuffer_fromConnection(
324            &self,
325            output: &AVCaptureOutput,
326            sample_buffer: &CMSampleBuffer,
327            connection: &AVCaptureConnection,
328        );
329
330        #[cfg(all(
331            feature = "AVCaptureOutputBase",
332            feature = "AVCaptureSession",
333            feature = "objc2-core-media"
334        ))]
335        /// Called once for each frame that is discarded.
336        ///
337        ///
338        /// Parameter `output`: The AVCaptureVideoDataOutput instance that dropped the frame.
339        ///
340        /// Parameter `sampleBuffer`: A CMSampleBuffer object containing information about the dropped frame, such as its format and presentation time. This sample buffer will contain none of the original video data.
341        ///
342        /// Parameter `connection`: The AVCaptureConnection from which the dropped video frame was received.
343        ///
344        ///
345        /// Delegates receive this message whenever a video frame is dropped. This method is called once for each dropped frame. The CMSampleBuffer object passed to this delegate method will contain metadata about the dropped video frame, such as its duration and presentation time stamp, but will contain no actual video data. On iOS, Included in the sample buffer attachments is the kCMSampleBufferAttachmentKey_DroppedFrameReason, which indicates why the frame was dropped. This method will be called on the dispatch queue specified by the output's sampleBufferCallbackQueue property. Because this method will be called on the same dispatch queue that is responsible for outputting video frames, it must be efficient to prevent further capture performance problems, such as additional dropped video frames.
346        #[optional]
347        #[unsafe(method(captureOutput:didDropSampleBuffer:fromConnection:))]
348        #[unsafe(method_family = none)]
349        unsafe fn captureOutput_didDropSampleBuffer_fromConnection(
350            &self,
351            output: &AVCaptureOutput,
352            sample_buffer: &CMSampleBuffer,
353            connection: &AVCaptureConnection,
354        );
355    }
356);