RPScreenRecorder.shared().startCapture won't write / keeps failing

When trying to record and save audio/video with ReplayKit I keep getting errors. I'm using

Xcode: Version 11.2.1
Swift 5
iOS 13
iPhone 7+ physical device

When I set the filePath I'm already using URL(fileURLWithPath: ). The file extension and AVFileType are both .mp4. I check to see if the file already exists in the FileManager and if so I remove it: do { try FileManager.default.removeItem(at: videoURL) }. I tried to change the path itself to "Library/Caches/" like in @florianSAP answer which didn't work.

Here the 3 errors:

// 1. from recording
if !self.assetWriter.startWriting() {
print("Can't write")
return
}
// 2. from recording
if self.assetWriter.status == AVAssetWriter.Status.failed {
print("StartCapture Error Occurred, Status = \(self.assetWriter.status.rawValue), \(self.assetWriter.error?.localizedDescription) \(self.assetWriter.error?.debugDescription)")
return
}
// 3. this one is when trying to save the url in the PHAssetChangeRequest.creationRequestForAssetFromVideo completionHandler
if let error = error {
print("PHAssetChangeRequest Video Error: \(error.localizedDescription)")
return
}
// 4. this isn't an error but inside the switch rpSampleBufferType { } statement "not a video sample" kept printing out

The error messages are:

> StartCapture Error Occurred, Status = 3, The operation could not be
> completed Optional(Error Domain=AVFoundationErrorDomain Code=-11800
> "The operation could not be completed"
> UserInfo={NSLocalizedFailureReason=An unknown error occurred (-17508),
> NSLocalizedDescription=The operation could not be completed,
> NSUnderlyingError=0x2833a93b0 {Error Domain=NSOSStatusErrorDomain
> Code=-17508 "(null)"}})
>
> PHAssetChangeRequest Video Error: The operation couldn’t be completed. (PHPhotosErrorDomain
> error -1.)

Where am I going to wrong at?

Start Recording

let recorder = RPScreenRecorder.shared()
var assetWriter: AVAssetWriter!
var videoURL: URL!
var videoInput: AVAssetWriterInput!
var audioMicInput: AVAssetWriterInput!
guard let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first else { return }
videoURL = URL(fileURLWithPath: documentsPath.appending(UUID().uuidString + ".mp4"))
guard let videoURL = videoURL else { return }
do {
try FileManager.default.removeItem(at: videoURL)
} catch {}
do {
try assetWriter = AVAssetWriter(outputURL: videoURL, fileType: .mp4) // AVAssetWriter(url: videoURL, fileType: .mp4) didn't make a difference
} catch {}
let videoSettings: [String : Any] = [
AVVideoCodecKey: AVVideoCodecType.h264,
AVVideoWidthKey: view.bounds.width,
AVVideoHeightKey: view.bounds.height
]
videoInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoSettings)
videoInput.expectsMediaDataInRealTime = true
if assetWriter.canAdd(videoInput) {
assetWriter.add(videoInput)
}
let audioSettings: [String:Any] = [AVFormatIDKey : kAudioFormatMPEG4AAC,
AVNumberOfChannelsKey : 2,
AVSampleRateKey : 44100.0,
AVEncoderBitRateKey: 192000
]
audioMicInput = AVAssetWriterInput(mediaType: .audio, outputSettings: audioSettings)
audioMicInput.expectsMediaDataInRealTime = true
if assetWriter.canAdd(audioMicInput) {
assetWriter.add(audioMicInput)
}
guard recorder.isAvailable else { return }
recorder.startCapture(handler: { (cmSampleBuffer, rpSampleBufferType, err) in
if let err = err { return }
// I tried to check if this was ready and added the below code to it but it made no difference
// if CMSampleBufferDataIsReady(cmSampleBuffer) { ... the code below was put in here ... }
DispatchQueue.main.async {
switch rpSampleBufferType {
case .video:
if self.assetWriter.status == AVAssetWriter.Status.unknown {
if !self.assetWriter.startWriting() {
print("Can't write")
return
}
print("Starting writing")
self.assetWriter.startWriting()
self.assetWriter.startSession(atSourceTime:  CMSampleBufferGetPresentationTimeStamp(cmSampleBuffer))
}
if self.assetWriter.status == AVAssetWriter.Status.failed {
print("StartCapture Error Occurred, Status = \(self.assetWriter.status.rawValue), \(self.assetWriter.error?.localizedDescription) \(self.assetWriter.error?.debugDescription)")
return
}
if self.assetWriter.status == AVAssetWriter.Status.writing {
if self.videoInput.isReadyForMoreMediaData {
if self.videoInput.append(cmSampleBuffer) == false {
print("problem writing video")
}
}
}
case .audioMic:
if self.audioMicInput.isReadyForMoreMediaData {
print("audioMic data added")
self.audioMicInput.append(cmSampleBuffer)
}
default:
print("not a video sample")
}
}
}
}, completionHandler: { (error) in
if let error = error { return }
})

Stop Recording:

recorder.stopCapture { (error) in
if let error = error { return }
guard let videoInput = self.videoInput else { return }
guard let audioMicInput = self.audioMicInput else { return }
guard let assetWriter = self.assetWriter else { return }
guard let videoURL = videoURL else { return }
videoInput.markAsFinished()
audioMicInput.markAsFinished()
assetWriter.finishWriting(completionHandler: {
PHPhotoLibrary.shared().performChanges({
PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: videoUrl)
}) { (saved, error) in
if let error = error {
print("PHAssetChangeRequest Video Error: \(error.localizedDescription)")
return
}
if saved {
// ... show success message
}
}
})
}

RPScreenRecorder Delegate that never gets called:

func screenRecorder(_ screenRecorder: RPScreenRecorder, didStopRecordingWith previewViewController: RPPreviewViewController?, error: Error?) {
if let error = error {
print(error.localizedDescription)
}
}

I was able to solve this by doing 2 things:

1- The first thing I did was I change the videoURL’s filePath from:

// Old Way that was causing some sort of path error
videoURL = URL(fileURLWithPath: documentsPath.appending(UUID().uuidString + ".mp4"))
// This is what the Old Path looked like. Look at the series of numbers beginning with 506... directly after Documents
///var/mobile/Containers/Data/Application/AAEF38A2-7AF1-4A32-A612-296B1584A764/Documents506D36BA-0C27-466A-A0BA-C197481F471A.mp4

to

// New Way that got the path to work
let dirPath = "\(documentsPath)/Videos_\(UUID().uuidString).mp4"
videoURL = URL(fileURLWithPath: dirPath)
// This is what the new path looks like. After Documents there is now a forward slash, the word Videos with an underscore, and then the series of numbers beginning with 506...
///var/mobile/Containers/Data/Application/AAEF38A2-7AF1-4A32-A612-296B1584A764/Documents/Videos_506D36BA-0C27-466A-A0BA-C197481F471A.mp4

2 -The second thing I did was change the code inside the recorder.startCapture(handler: { (cmSampleBuffer, rpSampleBufferType, err):

recorder.startCapture(handler: { (cmSampleBuffer, rpSampleBufferType, err) in
if let err = err { return }
if CMSampleBufferDataIsReady(cmSampleBuffer) {
DispatchQueue.main.async {
switch rpSampleBufferType {
case .video:
print("writing sample....")
if self.assetWriter?.status == AVAssetWriter.Status.unknown {
print("Started writing")
self.assetWriter?.startWriting()
self.assetWriter?.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(cmSampleBuffer))
}
if self.assetWriter.status == AVAssetWriter.Status.failed {
print("StartCapture Error Occurred, Status = \(self.assetWriter.status.rawValue), \(self.assetWriter.error!.localizedDescription) \(self.assetWriter.error.debugDescription)")
return
}
if self.assetWriter.status == AVAssetWriter.Status.writing {
if self.videoInput.isReadyForMoreMediaData {
print("Writing a sample")
if self.videoInput.append(cmSampleBuffer) == false {
print("problem writing video")
}
}
}
case .audioMic:
if self.audioMicInput.isReadyForMoreMediaData {
print("audioMic data added")
self.audioMicInput.append(cmSampleBuffer)
}
default:
print("not a video sample")
}
}
}, completionHandler: { (error) in
if let error = error { return }
})

This has nothing to do with the actual problem I ran into but if audio isn't syncing then you have to add this code below to viewDidLoad. I got it from the comments section here.

do {
try AVAudioSession.sharedInstance().setCategory(.playAndRecord, mode: .videoRecording, options: [.defaultToSpeaker])
try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation)
} catch {
#if DEBUG
print("Setting category to AVAudioSessionCategoryPlayback failed.")
#endif
}

If you need to find the meaning of error codes you can look here https://www.osstatus.com. It helped me find 11800 for this problem but not 17508.