let back = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back)
stream.attachCamera(back)

if #available(iOS 13.0, *) {
  let front = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front)
  stream.attachMultiCamera(front)
}

import AVFoundation
let session = AVAudioSession.sharedInstance()
do {
    try session.setCategory(.playAndRecord, mode: .default, options: [.defaultToSpeaker, .allowBluetooth])
    try session.setActive(true)
} catch {
    print(error)
}

let connection = RTMPConnection()
let stream = RTMPStream(connection: rtmpConnection)
stream.attachAudio(AVCaptureDevice.default(for: .audio)) { error in
    // print(error)
}
stream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back)) { error in
    // print(error)
}

let hkView = MTHKView(frame: view.bounds)
hkView.videoGravity = AVLayerVideoGravity.resizeAspectFill
hkView.attachStream(stream)

// add ViewController#view
view.addSubview(hkView)

connection.connect("rtmp:///appName/instanceName")
stream.publish("streamName")

var stream = RTMPStream(connection: rtmpConnection)

stream.frameRate = 30
stream.sessionPreset = AVCaptureSession.Preset.medium

/// Specifies the video capture settings.
stream.videoCapture(for: 0).isVideoMirrored = false
stream.videoCapture(for: 0).preferredVideoStabilizationMode = .auto
// rtmpStream.videoCapture(for: 1).isVideoMirrored = false

// Specifies the audio codec settings.
stream.audioSettings = AudioCodecSettings(
  bitRate: 64 * 1000
)

// Specifies the video codec settings.
stream.videoSettings = VideoCodecSettings(
  videoSize: .init(width: 854, height: 480),
  profileLevel: kVTProfileLevel_H264_Baseline_3_1 as String,
  bitRate: 640 * 1000,
  maxKeyFrameIntervalDuration: 2,
  scalingMode: .trim,
  bitRateMode: .average,
  allowFrameReordering: nil,
  isHardwareEncoderEnabled: true
)

// Specifies the recording settings. 0" means the same of input.
stream.startRecording([
  AVMediaType.audio: [
    AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
    AVSampleRateKey: 0,
    AVNumberOfChannelsKey: 0,
    // AVEncoderBitRateKey: 128000,
  ],
  AVMediaType.video: [
    AVVideoCodecKey: AVVideoCodecH264,
    AVVideoHeightKey: 0,
    AVVideoWidthKey: 0,
    /*
    AVVideoCompressionPropertiesKey: [
      AVVideoMaxKeyFrameIntervalDurationKey: 2,
      AVVideoProfileLevelKey: AVVideoProfileLevelH264Baseline30,
      AVVideoAverageBitRateKey: 512000
    ]
    */
  ]
])

// 2nd arguemnt set false
stream.attachAudio(AVCaptureDevice.default(for: .audio), automaticallyConfiguresApplicationAudioSession: false)

// picrure in picrure settings.
stream.multiCamCaptureSettings = MultiCamCaptureSetting(
  mode: .pip,
  cornerRadius: 16.0,
  regionOfInterest: .init(
    origin: CGPoint(x: 16, y: 16),
    size: .init(width: 160, height: 160)
  )
)

// split settings.
stream.multiCamCaptureSettings = MultiCamCaptureSetting(
  mode: .split(direction: .east),
  cornerRadius: 0.0,
  regionOfInterest: .init(
    origin: .zero,
    size: .zero
  )
)

var connection = RTMPConnection()
connection.connect("rtmp://username:password@localhost/appName/instanceName")

// iOS
let screen = IOUIScreenCaptureUnit(shared: UIApplication.shared)
screen.delegate = stream
screen.startRunning()

// macOS
stream.attachScreen(AVCaptureScreenInput(displayID: CGMainDisplayID()))

var stream = HTTPStream()
stream.attachCamera(AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back))
stream.attachAudio(AVCaptureDevice.default(for: .audio))
stream.publish("hello")

var hkView = MTHKView(frame: view.bounds)
hkView.attachStream(httpStream)

var httpService = HLSService(domain: "", type: "_http._tcp", name: "HaishinKit", port: 8080)
httpService.addHTTPStream(stream)
httpService.startRunning()

// add ViewController#view
view.addSubview(hkView)