iOS 8 iPad AVCaptureMovieFileOutput drops / loses / never gets audio track after 13 - 14 seconds of recording

Question

I have the following code which works for iOS 6 & 7.x.

In iOS 8.1 I have a strange issue where if you capture a session for about 13 seconds or longer, the resu

Answer 1

I had this issue and the way to fix this in Swift 4 is the following:

• Do not set movieFileOutput.maxRecordedDuration. There seems to be a bug with this where if you set this then if you are recording videos for longer than 12-13 seconds they will have no audio.

• Instead use a timer to stop the recording and set movieFragmentInterval like this:

movieFileOutput.movieFragmentInterval = CMTime.invalid

Here is a whole block of code just to show you how I did it:

var seconds = 20
var timer = Timer()
var movieFileOutput = AVCaptureMovieFileOutput()

func startRecording(){
    movieFileOutput.movieFragmentInterval = CMTime.invalid
    movieFileOutput.startRecording(to: URL(fileURLWithPath: getVideoFileLocation()), recordingDelegate: self)
    startTimer()
}

func stopRecording(){
    movieFileOutput.stopRecording()
    timer.invalidate()
}

func startTimer(){
    timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: (#selector(updateTimer)), userInfo: nil, repeats: true)
}

@objc func updateTimer(){
    seconds -= 1
    if(seconds == 0){
        stopRecording()
    }
}

func getVideoFileLocation() -> String {
    return NSTemporaryDirectory().appending("myrecording.mp4")
}


extension FTVideoReviewViewController : AVCaptureFileOutputRecordingDelegate{
    public func fileOutput(_ output: AVCaptureFileOutput, didFinishRecordingTo outputFileURL: URL, from connections: [AVCaptureConnection], error: Error?) {
        print("Finished recording: \(outputFileURL)")
        // do stuff here when recording is finished
    }
}