add virtmic patch (#127)

src/renderer/patches/index.ts

@@ -8,3 +8,4 @@
 import "./spellCheck";
 import "./platformClass";
 import "./windowsTitleBar";
+import "./screenShareAudio";

src/renderer/patches/screenShareAudio.ts

@@ -0,0 +1,41 @@
+import { isLinux } from "../utils";
+if (isLinux) {
+    const original = navigator.mediaDevices.getDisplayMedia;
+    async function getVirtmic() {
+        const getAudioDevice = async (deviceName: string|undefined) => {;
+            let devices = await navigator.mediaDevices.enumerateDevices();
+            let audioDevice = devices.find(({
+                label
+            }) => label === deviceName);
+        return audioDevice;
+        }    
+
+        var id: string|undefined;
+        try {
+            let vesktopAudioSink = await getAudioDevice('vesktop-virtmic');
+            id = vesktopAudioSink?.deviceId;
+        }
+        catch (error) {
+            id = 'error';
+        }
+    return id;
+    };
+    navigator.mediaDevices.getDisplayMedia = async function() {
+        const id = await getVirtmic();
+        const stream = await original.apply(this);
+        if (id !== 'error'){
+            const audio = await navigator.mediaDevices.getUserMedia({ 
+                audio: { 
+                    deviceId: {
+                        exact: id
+                    },
+                    autoGainControl: false,
+                    echoCancellation: false,
+                    noiseSuppression: false
+                } 
+            });
+            audio.getAudioTracks().forEach(t => stream.addTrack(t));
+        };
+        return stream;
+    };
+};