如何在webrtc ios中录制远程视频

Question

我使用webrtc-ios和swiftui成功地在屏幕上实时播放了远程视频。但我也想要实时录制视频。我知道如何将RTCVideooframe更改为CMsamplebuffer，并且我知道我必须使用Avassetwriter保存它。但我不确定在哪里可以实时提取RTCVideoFrame。

这是我的代码。

struct VideoView: UIViewRepresentable {

    let videoTrack: RTCVideoTrack?
    @Binding var refreshVideoTrack: Bool

    //RTCNSGLVideoView
    //RTCMTLNSVideoView
    func makeUIView(context: Context) -> RTCEAGLVideoView {
        let view = RTCEAGLVideoView(frame: .zero)
        view.contentMode = .scaleAspectFill
        return view
    }

    func updateUIView(_ view: RTCEAGLVideoView, context: Context) {

        if(refreshVideoTrack){
            videoTrack?.add(view)
            refreshVideoTrack = false
        }
    }
} 

VideoView(videoTrack: homeViewModel.remoteVideoTrack, refreshVideoTrack: Binding<Bool>(get: {return homeViewModel.refreshRemoteVideoTrack},
                                                                                                                                                          set: { p in homeViewModel.refreshRemoteVideoTrack = p}))

我使用RTCPeerConnectionDelegate获取remoteVideoTrack

func peerConnection(_ peerConnection: RTCPeerConnection, didAdd stream: RTCMediaStream) {
        dLog("")

        remoteVideoTrack = stream.videoTracks.first
        remoteVideoTrack?.isEnabled = true
        refreshRemoteVideoTrack = true
}

Answer 1

要获取RTCVideoFrame，您可以创建一个中间RTCVideoRenderer

class FrameRenderer : NSObject, RTCVideoRenderer {
    func setSize(_ size: CGSize) {}
    func renderFrame(_ frame: RTCVideoFrame?) {}
}

videoTrack?.add(FrameRenderer())