同時AVCaptureVideoDataOutput和AVCaptureMovieFileOutput

Question

我需要能夠讓AVCaptureVideoDataOutput和AVCaptureMovieFileOutput同時工作。下面的代碼工作，但是，視頻錄製不。調用startRecordingToOutputFileURL後，直接調用didFinishRecordingToOutputFileAtURL代表。現在，如果我只需註釋掉行刪除從 AVCaptureSessionAVCaptureVideoDataOutput：

[captureSession addOutput:captureDataOutput];

的錄像作品，但隨後SampleBufferDelegate不叫（我需要）。

我怎樣才能讓AVCaptureVideoDataOutput和AVCaptureMovieFileOutput同時工作。

- (void)initCapture { 
AVCaptureDeviceInput *captureInput = [AVCaptureDeviceInput deviceInputWithDevice:[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo] error:NULL]; 

captureDataOutput = [[AVCaptureVideoDataOutput alloc] init]; 
[captureDataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()]; 

m_captureFileOutput = [[AVCaptureMovieFileOutput alloc] init]; 

NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey; 
NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_32BGRA]; 
NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key]; 

[captureDataOutput setVideoSettings:videoSettings]; 

captureSession = [[AVCaptureSession alloc] init]; 

[captureSession addInput:captureInput]; 
[captureSession addOutput:m_captureFileOutput]; 
[captureSession addOutput:captureDataOutput]; 

[captureSession beginConfiguration]; 
[captureSession setSessionPreset:AVCaptureSessionPresetLow]; 
[captureSession commitConfiguration]; 

[self performSelector:@selector(startRecording) withObject:nil afterDelay:10.0]; 
[self performSelector:@selector(stopRecording) withObject:nil afterDelay:15.0]; 

[captureSession startRunning]; 
} 


- (void) startRecording 
{ 
    [m_captureFileOutput startRecordingToOutputFileURL:[self tempFileURL] recordingDelegate:self]; 

} 

- (void) stopRecording 
{ 
    if([m_captureFileOutput isRecording]) 
[m_captureFileOutput stopRecording]; 

} 


- (NSURL *) tempFileURL 
{ 
NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"camera.mov"]; 
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath]; 
NSFileManager *fileManager = [NSFileManager defaultManager]; 
if ([fileManager fileExistsAtPath:outputPath]) { 
    [[NSFileManager defaultManager] removeItemAtPath:outputPath error:nil]; 
[outputPath release]; 
return [outputURL autorelease]; 
} 



- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didStartRecordingToOutputFileAtURL:(NSURL *)fileURL fromConnections:(NSArray *)connections 
{ 
NSLog(@"start record video"); 
} 

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error 
{ 
NSLog(@"end record"); 
} 


- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection 
{ 
     // do stuff with sampleBuffer 
} 

我要補充我得到的錯誤：

Error Domain=NSOSStatusErrorDomain Code=-12780 "The operation couldn’t be completed. (OSStatus error -12780.)" UserInfo=0x23fcd0 {AVErrorRecordingSuccessfullyFinishedKey=false} 

從

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error 

乾杯

Answer 1

我在蘋果公司的支持接觸的工程師，他告訴我，同時AVCaptureVideoDataOutput + AVCaptureMovieFileOutput不支持使用。我不知道他們將來是否會支持它，但他使用了「此時不支持」這個詞。

我鼓勵你填寫一個bug報告/功能請求，就像我一樣（bugreport.apple.com），因爲它們衡量人們想要什麼東西的難度，我們也許可以在不久的將來看到這一點。

Answer 2

雖然你不能使用AVCaptureVideoDataOutput，您可以同時使用AVCaptureVideoPreviewLayer與AVCaptureMovieFileOutput。請參閱Apple網站上的「AVCam」示例。

在Xamarin.iOS，代碼如下所示：

var session = new AVCaptureSession(); 

var camera = AVCaptureDevice.DefaultDeviceWithMediaType(AVMediaType.Video); 
var mic = AVCaptureDevice.DefaultDeviceWithMediaType(AVMediaType.Audio); 
if(camera == null || mic == null){ 
    throw new Exception("Can't find devices"); 
} 

if(session.CanAddInput(camera)){ 
    session.AddInput(camera); 
} 
if(session.CanAddInput(mic)){ 
    session.AddInput(mic); 
} 

var layer = new AVCaptureVideoPreviewLayer(session); 
layer.LayerVideoGravity = AVLayerVideoGravity.ResizeAspectFill; 
layer.VideoGravity = AVCaptureVideoPreviewLayer.GravityResizeAspectFill; 

cameraView = new UIView(); 
cameraView.Layer.AddSublayer(layer); 

var filePath = System.IO.Path.Combine(Path.GetTempPath(), "temporary.mov"); 
var fileUrl = NSUrl.FromFilename(filePath); 

var movieFileOutput = new AVCaptureMovieFileOutput(); 
var recordingDelegate = new MyRecordingDelegate(); 
session.AddOutput(movieFileOutput); 

movieFileOutput.StartRecordingToOutputFile(fileUrl, recordingDelegate);