一起使用AVCaptureSession和AVAudioPlayer

我能够录制video并正确输出电影到文件。 但是，在尝试使用AVAudioPlayer播放某些audio时，我遇到了录像问题（无video输出）。 这是否意味着我不能同时使用AVCaptureSession和AVAudioPlayer？ 这里是我的代码来创build捕获会话和播放audio。 video捕捉首先启动，然后在捕捉过程中，我想播放一些audio。 非常感谢您的帮助。

创build捕获会话以loggingvideo（带audio）的代码 – 输出到.mov文件：

- (void)addVideoInput AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio]; //... also some code for setting up videoDevice/frontCamera NSError *error; AVCaptureDeviceInput *videoIn = [AVCaptureDeviceInput deviceInputWithDevice:frontCamera error:&error]; AVCaptureDeviceInput *audioIn = [AVCaptureDeviceInput deviceInputWithDevice:audioDevice error:&error]; if (!error) { if ([captureSession canAddInput:audioIn]) [captureSession addInput:audioIn]; else NSLog(@"Couldn't add audio input."); if ([captureSession canAddInput:videoIn]) [captureSession addInput:videoIn]; else NSLog(@"Couldn't add video input."); } - (void)addVideoOutput { AVCaptureMovieFileOutput *m_captureFileOutput = [[AVCaptureMovieFileOutput alloc] init]; [captureSession addOutput:m_captureFileOutput]; [captureSession startRunning]; NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]; NSMutableString *filePath = [NSMutableString stringWithString:@"Movie.mov"]; NSString* fileRoot = [docDir stringByAppendingPathComponent:filePath]; NSURL *fileURL = [NSURL fileURLWithPath:fileRoot]; AVCaptureConnection *videoConnection = NULL; for ( AVCaptureConnection *connection in [m_captureFileOutput connections] ) { for ( AVCaptureInputPort *port in [connection inputPorts] ) { if ( [[port mediaType] isEqual:AVMediaTypeVideo] ) { videoConnection = connection; } } } [videoConnection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight]; [m_captureFileOutput startRecordingToOutputFileURL:fileURL recordingDelegate:self]; [m_captureFileOutput release]; } 

代码播放audio，这个function是在video捕捉过程中调用的。 如果我不调用这个function，video被logging下来，我可以保存到.mov文件。 但是，如果我调用这个函数，没有输出.mov文件。

 - (void)playAudio { NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"AudioFile" ofType:@"mp3"]; NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:soundFilePath]; AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil]; [fileURL release]; self.audioPlayer = newPlayer; [newPlayer release]; [audioPlayer setDelegate:self]; [audioPlayer prepareToPlay]; [audioPlayer play]; } 

Answer 1

我通过设置audio会话解决了这个问题。 在创buildaudio播放器对象播放audio之前，我调用了以下函数。 这样，我就能够录制video（带audio）并同时播放audio。

 - (void)setupAudioSession { static BOOL audioSessionSetup = NO; if (audioSessionSetup) { return; } [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryPlayback error: nil]; UInt32 doSetProperty = 1; AudioSessionSetProperty (kAudioSessionProperty_OverrideCategoryMixWithOthers, sizeof(doSetProperty), &doSetProperty); [[AVAudioSession sharedInstance] setActive: YES error: nil]; audioSessionSetup = YES; } - (void)playAudio { [self setupAudioSession]; NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"AudioFile" ofType:@"mp3"]; NSURL *fileURL = [[NSURL alloc] initFileURLWithPath:soundFilePath]; AVAudioPlayer *newPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileURL error:nil]; [fileURL release]; self.audioPlayer = newPlayer; [newPlayer release]; [audioPlayer setDelegate:self]; [audioPlayer prepareToPlay]; [audioPlayer play]; }