swift - 放大时 avfoundation 录音不起作用

Question

我正在编写一个相机应用程序，我试图在 avfoundation 上实现缩放。我的代码在这里


func beginSessionWithBackCameraAndMic(){



<pre><code> captureSession.sessionPreset = AVCaptureSessionPresetHigh

captureSession.beginConfiguration()

var err:NSError?

videoInput = AVCaptureDeviceInput(device: self.cameraWithPosition(AVCaptureDevicePosition.Back), error: &err)

if(self.captureSession.canAddInput(videoInput)){
self.captureSession.addInput(videoInput);
}

audioInput = AVCaptureDeviceInput(device: audio, error: &err)

if(self.captureSession.canAddInput(audioInput)){
self.captureSession.addInput(audioInput);
}

if (captureSession.canAddOutput(movieFileOutput)){
captureSession.addOutput(movieFileOutput)
}



var captureconneciton = movieFileOutput.connectionWithMediaType(AVMediaTypeVideo)

var orientation = getOrientation()

captureconneciton.videoOrientation = orientation



previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)

previewLayer?.connection.videoOrientation = orientation

previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill

previewLayer?.frame = self.v.bounds

self.v.layer.addSublayer(previewLayer)



captureSession.commitConfiguration()

self.captureSession.startRunning()







}
</code></pre>

<p>@IBAction func record(sender: AnyObject) {</p>

<pre><code> var e = NSErrorPointer()

video.lockForConfiguration(e);

video.activeFormat = video.formats[15] as AVCaptureDeviceFormat

video.videoZoomFactor = 5


video.unlockForConfiguration()
</code></pre>

<p>var outputpath = NSTemporaryDirectory()+"output.mov";</p>

<pre><code> var outputURL = NSURL(fileURLWithPath: outputpath)

var fileManager = NSFileManager.defaultManager()

if fileManager.fileExistsAtPath(outputpath){
var error:NSError? = nil;
if (fileManager.removeItemAtPath(outputpath, error:&error) == false)
{
print("error saving temp file")
}
}

movieFileOutput.startRecordingToOutputFileURL(outputURL, recordingDelegate: self)
</code></pre>

<p>}</p>

<pre><code>func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!) {
</code></pre>

<p>//Here I am doing the necessary works saving works to my internal memory</p>

<p>}</p>



在录制功能上我更改了支持缩放的事件视频格式但是当我像这样崩溃时
2015-02-17 04:16:22.308 Ourdrum[1379:159045] <strong>* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*</strong> -[AVCaptureMovieFileOutput startRecordingToOutputFileURL:recordingDelegate:] - no active/enabled connections.'


如果我只注释这两行

video.activeFormat = video.formats[15] 作为 AVCaptureDeviceFormat

video.videoZoomFactor = 5

录音效果很好。不过，我使用了 SessionPresetHigh。

谁能帮帮我!

谢谢

Answer 1

尝试移动那些故障线

video.lockForConfiguration(e);

video.activeFormat = video.formats[15] as AVCaptureDeviceFormat

video.videoZoomFactor = 5

video.unlockForConfiguration()

在您的 beginSessionWithBackCameraAndMic 方法行之前:

self.captureSession.startRunning()

如果您锁定配置，您可以随时更改缩放系数，但我认为您必须在启动之前设置视频格式。