Objective-C:在iOS上使用AVFoundation录制视频时将音频静音/取消静音

#import <AVFoundation/AVFoundation.h>

AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];

AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];
AVCaptureDeviceInput *audioInput = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:nil];
if ([captureSession canAddInput:audioInput]) {
    [captureSession addInput:audioInput];
}

AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
if ([captureSession canAddInput:videoInput]) {
    [captureSession addInput:videoInput];
}

AVCaptureMovieFileOutput *movieOutput = [[AVCaptureMovieFileOutput alloc] init];
if ([captureSession canAddOutput:movieOutput]) {
    [captureSession addOutput:movieOutput];
}

AVCaptureConnection *audioConnection = [movieOutput connectionWithMediaType:AVMediaTypeAudio];
[audioConnection setEnabled:NO];

AVCaptureConnection *audioConnection = [movieOutput connectionWithMediaType:AVMediaTypeAudio];
[audioConnection setEnabled:YES];

NSString *outputFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"output.mov"];
NSURL *outputFileURL = [NSURL fileURLWithPath:outputFilePath];
[movieOutput startRecordingToOutputFileURL:outputFileURL recordingDelegate:nil];