Why Only ScreenCapture Time Interval is So long?

[jxxnnee]

I've used both AttachCamera and AttachScreen.

However, when using AttachCamera, the time interval is about 2 seconds, but when using AttachScreen, the time interval is almost 10 seconds. What reason do you suspect?

I Use Same VideoSettings at both AttachCamera and AttachScreen.

public var videoSettings: Setting<VideoCodec, VideoCodec.Option> {
    [
        .muted: false,
        .width: 336, // video output width
        .height: 598, // video output height
        .bitrate: 3000 * 1024, // video output bitrate
        .profileLevel: kVTProfileLevel_H264_Extended_AutoLevel,
        // H264 Profile require "import VideoToolbox"
        .maxKeyFrameIntervalDuration: 2, // key frame / sec
    ]
}

public var captureSettings: Setting<AVMixer, AVMixer.Option> {
    [
        .fps: 30, // FPS
        .sessionPreset: AVCaptureSession.Preset.hd1280x720,
        .preferredVideoStabilizationMode: true
    ]
}

AttachScreen

let stream = RTMPStream(connection: conn)
stream.videoSettings = self.videoSettings
                        
self.captureSession = ScreenCaptureSession(viewToCapture: self.webView)            
stream.attachScreen(self.captureSession, useScreenSize: false)

AttachCamera

let stream = RTMPStream(connection: conn)
        
stream.captureSettings = self.captureSettings
stream.videoSettings = self.videoSettings
        
let audio = AVCaptureDevice.default(for: .audio)
let camera = DeviceUtil.device(withPosition: .front)
stream.attachCamera(camera) { err in
            
}