ios - startRecordingToOutputFileURL 没有事件/启用的连接 ios

Question

我想录制一个短片(30 秒)，应该在 30 秒后自动停止。我使用 AVCAPTURESESSION 启动了相机，现在我想开始自动录制视频。

这是我的代码:

AVCaptureSession *session = [[AVCaptureSession alloc] init];
session.sessionPreset = AVCaptureSessionPresetHigh;

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
[session addInput:input];

AVCaptureVideoPreviewLayer *newCaptureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
newCaptureVideoPreviewLayer.frame = self.view.bounds;

[self.view.layer addSublayer:newCaptureVideoPreviewLayer];

[session startRunning];

如何录制 30 秒的视频。

我的尝试:

NSString *documentsDirPath =[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject];
NSURL *documentsDirUrl = [NSURL fileURLWithPath:documentsDirPath isDirectory:YES];
NSURL *url = [NSURL URLWithString:@"out.mp4" relativeToURL:documentsDirUrl];
[self.movieFileOutput startRecordingToOutputFileURL:url recordingDelegate:self];



- (AVCaptureMovieFileOutput *)movieFileOutput {
    AVCaptureMovieFileOutput *_movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];
    if (!_movieFileOutput) {
        _movieFileOutput = [[AVCaptureMovieFileOutput alloc] init];

        Float64 TotalSeconds = 30;          //Total seconds
        int32_t preferredTimeScale = 30;    //Frames per second
        CMTime maxDuration = CMTimeMakeWithSeconds(TotalSeconds, preferredTimeScale);
        _movieFileOutput.maxRecordedDuration = maxDuration;
        _movieFileOutput.minFreeDiskSpaceLimit = 1024 * 1024;
    }

    return _movieFileOutput;
} 

但它给我错误，[AVCaptureMovieFileOutput startRecordingToOutputFileURL:recordingDelegate:] - 没有事件/启用的连接。'

如何录制 30 秒的视频剪辑。

Answer 1

我找到了这个错误的原因。检查你session的“setSessionPreset”设置，照片的分辨率设置与视频不同，对于iPhone5，后置摄像头的视频分辨率为1920*1080，前置摄像头为1280*720，照片的最大分辨率为3264*2488，所以如果你将错误解决方案设置为视频，连接将不会被激活。