SampleHandler.swift

import ReplayKit
import Speech
import UserNotifications

class SampleHandler: RPBroadcastSampleHandler {
  var running = true
  
  override func broadcastStarted(withSetupInfo setupInfo: [String : NSObject]?) {
        // User has requested to start the broadcast. Setup info from the UI extension can be supplied but optional.
        do {
            videoWriter = try AVAssetWriter(outputURL: FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.com.thatmarcel.captions.shared")!.appendingPathComponent("movie.mov"), fileType: .mov)
        } catch {
            print(error)
        }
        assert(videoWriter != nil, "Invalid parameter not satisfying: videoWriter != nil")
        
        let videoSettings = [
            AVVideoCodecKey : AVVideoCodecType.h264,
            AVVideoWidthKey : UIScreen.main.bounds.size.width,
            AVVideoHeightKey : UIScreen.main.bounds.size.height
            ] as [String : Any]
        writerInput = AVAssetWriterInput(mediaType: .video, outputSettings: videoSettings)
        writerInput.expectsMediaDataInRealTime = true
        
        assert(videoWriter?.canAdd(writerInput) ?? false, "Invalid parameter not satisfying: videoWriter?.canAdd(writerInput) ?? false")
        videoWriter?.add(writerInput)
        DispatchQueue.main.asyncAfter(deadline: .now() + 10) {
            self.save()
        }
        // Initialize speech regonition
  }
  
  func save() {
        running = false
        writerInput.markAsFinished()
        videoWriter?.finishWriting {
            
        }
    }
  
  override func processSampleBuffer(_ sampleBuffer: CMSampleBuffer, with sampleBufferType: RPSampleBufferType) {
        switch sampleBufferType {
            case RPSampleBufferType.video:
                if videoWriter?.status == .unknown {
                    videoWriter?.startWriting()
                    videoWriter?.startSession(atSourceTime: CMSampleBufferGetPresentationTimeStamp(sampleBuffer))
                    return
                }
                if running, writerInput.isReadyForMoreMediaData {
                    writerInput.append(sampleBuffer)
                }
                break
            case RPSampleBufferType.audioApp:
                // Handle audio sample buffer for app audio
                if let _ = self.speechRecognizer, let request = self.request, let _ = self.task {
                    request.appendAudioSampleBuffer(sampleBuffer) // request is the SFSpeechAudioBufferRecognitionRequest
                }
                break
            case RPSampleBufferType.audioMic:
                // Handle audio sample buffer for mic audio
                break
        @unknown default:
            print("unknown")
        }
    }
}