From 6ac4a7ae929e81b6a4c5b87aa228b6cf3a47ffea Mon Sep 17 00:00:00 2001
From: Hiroshi Horie <548776+hiroshihorie@users.noreply.github.com>
Date: Tue, 23 Nov 2021 08:52:34 +0700
Subject: [PATCH] IPCCapturer

---
 .../LiveKit/track/capturers/IPCCapturer.swift | 72 +++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 Sources/LiveKit/track/capturers/IPCCapturer.swift

diff --git a/Sources/LiveKit/track/capturers/IPCCapturer.swift b/Sources/LiveKit/track/capturers/IPCCapturer.swift
new file mode 100644
index 000000000..5bbe26e46
--- /dev/null
+++ b/Sources/LiveKit/track/capturers/IPCCapturer.swift
@@ -0,0 +1,72 @@
+import Foundation
+import WebRTC
+import Promises
+
+/// Experimental capturer that uses inter-process-communication to receive
+/// video buffers
+class IPCCapturer: VideoCapturer {
+
+    private let capturer = RTCVideoCapturer()
+    private let ipcServer = IPCServer()
+    private let ipcName: String
+
+    init(delegate: RTCVideoCapturerDelegate, ipcName: String) {
+        self.ipcName = ipcName
+        super.init(delegate: delegate)
+        
+        ipcServer.onReceivedData = { _, messageId, data in
+            
+            guard let message = try? IPCMessage(serializedData: data) else {
+                logger.warning("Failed to decode ipc message")
+                return
+            }
+
+            if case let .buffer(bufferMessage) = message.type,
+               case let .video(videoMessage) = bufferMessage.type {
+
+                // restore pixel buffer from data
+                let pixelBuffer = CVPixelBuffer.from(bufferMessage.buffer,
+                                                     width: Int(videoMessage.width),
+                                                     height: Int(videoMessage.height),
+                                                     pixelFormat: videoMessage.format)
+
+                // TODO: handle rotation
+                
+                delegate.capturer(self.capturer,
+                                   didCapture: pixelBuffer,
+                                   timeStampNs: bufferMessage.timestampNs,
+                                   rotation: ._0)
+            }
+        }
+    }
+    
+    override func startCapture() -> Promise<Void> {
+        super.startCapture().then {
+            // start listening for ipc messages
+            self.ipcServer.listen(self.ipcName)
+        }
+    }
+    
+    override func stopCapture() -> Promise<Void> {
+        super.stopCapture().then {
+            // stop listening for ipc messages
+            self.ipcServer.close()
+        }
+    }
+}
+
+extension LocalVideoTrack {
+
+    public static func createIPCTrack(name: String = Track.screenShareName,
+                                      ipcName: String,
+                                      source: VideoTrack.Source = .screenShareVideo) -> LocalVideoTrack {
+        let videoSource = Engine.factory.videoSource()
+        let capturer = IPCCapturer(delegate: videoSource, ipcName: ipcName)
+        return LocalVideoTrack(
+            capturer: capturer,
+            videoSource: videoSource,
+            name: name,
+            source: source
+        )
+    }
+}