AVCaptureSession录制带有音频的视频

Question

我有我的应用程序设置为使用AVCaptureSession从相机录制视频，但是，它没有音频。我需要做什么来录制音频，然后将其添加到文件的videoOutput中？这里是我的录制视频代码：

AVCaptureSession *session = [[AVCaptureSession alloc] init]; 
[session beginConfiguration]; 
session.sessionPreset = AVCaptureSessionPresetMedium; 

CALayer *viewLayer = self.vImagePreview.layer; 
NSLog(@"viewLayer = %@", viewLayer); 

AVCaptureVideoPreviewLayer *captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session]; 
captureVideoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill; 
captureVideoPreviewLayer.frame = self.vImagePreview.bounds; 

[self.vImagePreview.layer addSublayer:captureVideoPreviewLayer]; 

AVCaptureDevice *device = [self frontFacingCameraIfAvailable]; 

NSError *error = nil; 
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error]; 
if (!input) { 
    // Handle the error appropriately. 
    NSLog(@"ERROR: trying to open camera: %@", error); 
} 

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); 
NSString *documentsDirectoryPath = [paths objectAtIndex:0]; 

AVCaptureMovieFileOutput *movieFileOutput = [[AVCaptureMovieFileOutput alloc] init]; 

NSString *archives = [documentsDirectoryPath stringByAppendingPathComponent:@"archives"]; 
NSString *outputpathofmovie = [[archives stringByAppendingPathComponent:@"Test"] stringByAppendingString:@".mp4"]; 
NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputpathofmovie]; 

[session addInput:input]; 
[session addOutput:movieFileOutput]; 
[session commitConfiguration]; 
[session startRunning]; 
[movieFileOutput startRecordingToOutputFileURL:outputURL recordingDelegate:self]; 

我又增加了输入音频，但它不会与在背景中的MPMoviePlayerController工作。对于可以播放一个视频并同时记录来自相机的音频和视频的内容，有什么想法吗？

Answer 1

您还没有包括音频设备：

AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio]; 
AVCaptureDeviceInput * audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:nil]; 
[session addInput:audioInput] 

beginConfiguration和commitConfiguration之间。它会工作！

Answer 2

添加下面的代码beginConfiguration()和commitConfiguration()

// Add audio device to the recording 

let audioDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeAudio) 
do { 
    let audioInput = try AVCaptureDeviceInput(device: audioDevice) 
    self.captureSession.addInput(audioInput) 
} catch { 
    print("Unable to add audio device to the recording.") 
}