AVCaptureMovieFileOutput -没有活动/启用连接

Question

我正试图用AVFoundation在我的AVFoundation应用程序中录制视频。但是，每当我单击“记录”按钮时，应用程序就会崩溃。

startRecordingToOutputFileURL:recordingDelegate：-没有活动/启用的连接。

我知道同样的问题是这样问的，但没有一个答案对我有帮助。我的问题是，相同的代码完全适用于另一个应用程序，当我尝试在这个应用程序中使用完全相同的代码时-崩溃。但是照片捕捉仍然很好。。

把我的密码加在这里--请帮我，谢谢。

  -(void)viewDidLoad
  {
 [super viewDidLoad];
 self.captureSession = [[AVCaptureSession alloc] init];

   AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];

  self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
  self.audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:nil];

  self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
  NSDictionary *stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
                                          AVVideoCodecJPEG, AVVideoCodecKey, nil];
  [self.stillImageOutput setOutputSettings:stillImageOutputSettings];

  self.movieOutput = [[AVCaptureMovieFileOutput alloc] init];

  [self.captureSession addInput:self.videoInput];
  [self.captureSession addOutput:self.stillImageOutput];




   previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
   UIView *aView = self.view;
   previewLayer.frame = CGRectMake(70, 190, 270, 270);
   [aView.layer addSublayer:previewLayer];


     }




  -(NSURL *) tempFileURL
  {
    NSString *outputPath = [[NSString alloc] initWithFormat:@"%@%@", NSTemporaryDirectory(), @"output.mov"];
    NSURL *outputURL = [[NSURL alloc] initFileURLWithPath:outputPath];
   NSFileManager *manager = [[NSFileManager alloc] init];
   if ([manager fileExistsAtPath:outputPath])
    {
    [manager removeItemAtPath:outputPath error:nil];
    }


    return outputURL;
  }

  -(IBAction)capture:(id)sender
  {

    if (self.movieOutput.isRecording == YES)
    {
         [self.movieOutput stopRecording];
    }
    else
    {
         [self.movieOutput startRecordingToOutputFileURL:[self tempFileURL] recordingDelegate:self];
    }

      }





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


   BOOL recordedSuccessfully = YES;
  if ([error code] != noErr)
    {
    id value = [[error userInfo] objectForKey:AVErrorRecordingSuccessfullyFinishedKey];
    if (value)
        recordedSuccessfully = [value boolValue];
    NSLog(@"A problem occurred while recording: %@", error);
   }
  if (recordedSuccessfully) {
    ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];

    [library writeVideoAtPathToSavedPhotosAlbum:outputFileURL
                                completionBlock:^(NSURL *assetURL, NSError *error)
     {
         UIAlertView *alert;
         if (!error)
         {
             alert = [[UIAlertView alloc] initWithTitle:@"Video Saved"
                                                message:@"The movie was successfully saved to you photos library"
                                               delegate:nil
                                      cancelButtonTitle:@"OK"
                                      otherButtonTitles:nil, nil];
         }
         else
         {
             alert = [[UIAlertView alloc] initWithTitle:@"Error Saving Video"
                                                message:@"The movie was not saved to you photos library"
                                               delegate:nil
                                      cancelButtonTitle:@"OK"

                                      otherButtonTitles:nil, nil];
         }

         [alert show];
     }
     ];
    }

  }

Answer 1

我在更改videoDevice activeFormat时也遇到了同样的问题，后来我想录制视频。因为我使用的是最优质的视频，所以我不得不将sessionPreset设置为高，如下所示

_session.sessionPreset = AVCaptureSessionPresetHigh；

它对我有效！:)

Answer 2

在您的代码中缺少了几样东西：

1. 您忘了将movieOutput添加到captureSession中
2. 同样适用于您的audioInput
3. 所有会话配置都需要由[_captureSession beginConfiguration]和[_captureSession commitConfiguration]封装。
4. 对于音频记录，需要将AVAudioSession设置为正确的类别。

下面是更新的代码：

- (void)viewDidLoad
{
    [super viewDidLoad];

    NSError *error = nil;
    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryRecord
                                           error:&error];

    if(!error)
    {
        [[AVAudioSession sharedInstance] setActive:YES error:&error];

        if(error) NSLog(@"Error while activating AudioSession : %@", error);
    }
    else
    {
        NSLog(@"Error while setting category of AudioSession : %@", error);
    }

    self.captureSession = [[AVCaptureSession alloc] init];

    AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];

    self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];
    self.audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:nil];

    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
    NSDictionary *stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
                                              AVVideoCodecJPEG, AVVideoCodecKey, nil];
    [self.stillImageOutput setOutputSettings:stillImageOutputSettings];

    self.movieOutput = [[AVCaptureMovieFileOutput alloc] init];

    [self.captureSession beginConfiguration];

    [self.captureSession addInput:self.videoInput];
    [self.captureSession addInput:self.audioInput];
    [self.captureSession addOutput:self.movieOutput];
    [self.captureSession addOutput:self.stillImageOutput];

    [self.captureSession commitConfiguration];

    AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
    previewLayer.frame = CGRectMake(0, 0, 320, 500);
    [self.view.layer addSublayer:previewLayer];

    [self.captureSession startRunning];
}

- (IBAction)toggleRecording:(id)sender
{
    if(!self.movieOutput.isRecording)
    {
        [self.recordButton setTitle:@"Stop" forState:UIControlStateNormal];

        NSString *outputPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"output.mp4"];

        NSFileManager *manager = [[NSFileManager alloc] init];
        if ([manager fileExistsAtPath:outputPath])
        {
            [manager removeItemAtPath:outputPath error:nil];
        }

        [self.movieOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputPath]
                                      recordingDelegate:self];
    }
    else
    {
        [self.recordButton setTitle:@"Start recording" forState:UIControlStateNormal];

        [self.movieOutput stopRecording];
    }
}

- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error
{
    NSLog(@"Did finish recording, error %@ | path %@ | connections %@", error, [outputFileURL absoluteString], connections);
}

希望这能有所帮助

Answer 3

因为目前您没有一个活动连接记录视频文件。

在记录到输出文件之前，检查连接活动状态：

AVCaptureConnection *c = [self.movieOutput connectionWithMediaType:AVMediaTypeVideo];
if (c.active) {
  //connection is active
} else {
  //connection is not active
  //try to change self.captureSession.sessionPreset,
  //or change videoDevice.activeFormat
}

如果连接未激活，请尝试更改captureSession.sessionPreset或videoDevice.activeFormat。

重复，直到设置了有效的格式(这意味着c.active ==是的)。然后你可以录制视频到输出文件。