feat: Implement an Electron-based broadcasting client with screen/window and audio source selection, including Pipewire integration, and add auto-unmute to the viewer.

client/pipewire.js

@@ -0,0 +1,148 @@
+const { exec } = require('child_process');
+const util = require('util');
+const execAsync = util.promisify(exec);
+
+const VIRT_MIC_NAME = 'simplescreenshare-audio';
+
+// Pipewire helper class to isolate application audio
+class PipewireHelper {
+    
+    // Create a virtual microphone (a null-audio-sink) that Electron can listen to
+    static async createVirtualMic() {
+        try {
+            await execAsync(`pw-cli destroy ${VIRT_MIC_NAME}`).catch(() => {}); // Cleanup old
+            
+            const cmd = `pw-cli create-node adapter '{ factory.name=support.null-audio-sink node.name=${VIRT_MIC_NAME} node.description="SimpleScreenshare Audio" media.class=Audio/Source/Virtual object.linger=1 audio.position=[FL,FR] }'`;
+            const { stdout } = await execAsync(cmd);
+            console.log("Created virtual mic:", stdout.trim());
+            
+            // Wait a moment for Pipewire to register it
+            await new Promise(resolve => setTimeout(resolve, 500));
+            return true;
+        } catch (error) {
+            console.error("Failed to create virtual mic:", error);
+            return false;
+        }
+    }
+
+    // Destroy the virtual microphone
+    static async destroyVirtualMic() {
+        try {
+            // Find node ID
+            const { stdout } = await execAsync(`pw-cli dump short Node`);
+            const lines = stdout.split('\\n');
+            for (const line of lines) {
+                if (line.includes(VIRT_MIC_NAME)) {
+                    const id = line.split(',')[0].trim();
+                    await execAsync(`pw-cli destroy ${id}`);
+                    console.log(`Destroyed virtual mic (ID: ${id})`);
+                }
+            }
+        } catch (error) {
+            console.error("Failed to destroy virtual mic:", error);
+        }
+    }
+
+    // Get all running applications currently playing audio
+    static async getAudioApplications() {
+        try {
+            // pw-dump outputs the entire graph as JSON, increase buffer!
+            const { stdout } = await execAsync('pw-dump', { maxBuffer: 1024 * 1024 * 50 });
+            const dump = JSON.parse(stdout);
+            
+            // Filter out audio output streams (applications playing sound)
+            const apps = dump.filter(node => 
+                node.info && 
+                node.info.props && 
+                node.info.props['media.class'] === 'Stream/Output/Audio' &&
+                node.info.props['application.name']
+            ).map(node => ({
+                id: node.id,
+                name: node.info.props['application.name'],
+                mediaName: node.info.props['media.name'] || 'Unknown Stream'
+            }));
+            
+            // Deduplicate by application name and return
+            const uniqueApps = [];
+            const seen = new Set();
+            for (const app of apps) {
+                if (!seen.has(app.name)) {
+                    seen.add(app.name);
+                    uniqueApps.push(app);
+                }
+            }
+            return uniqueApps;
+            
+        } catch (error) {
+            console.error("Failed to get audio applications:", error);
+            return [];
+        }
+    }
+
+    // Link a target application's output to our Virtual Microphone
+    static async linkApplicationToMic(targetAppName) {
+        try {
+            // 1. Get the dump with massive buffer
+            const { stdout: dumpOut } = await execAsync('pw-dump', { maxBuffer: 1024 * 1024 * 50 });
+            const dump = JSON.parse(dumpOut);
+            
+            // 2. Find the target application node
+            const targetNode = dump.find(node => 
+                node.info && 
+                node.info.props && 
+                node.info.props['media.class'] === 'Stream/Output/Audio' &&
+                node.info.props['application.name'] === targetAppName
+            );
+            
+            // 3. Find our virtual mic node
+            const micNode = dump.find(node => 
+                node.info && 
+                node.info.props && 
+                node.info.props['node.name'] === VIRT_MIC_NAME
+            );
+            
+            if (!targetNode || !micNode) {
+                console.error("Could not find target node or virtual mic node");
+                return false;
+            }
+
+            console.log(`Linking ${targetAppName} (ID: ${targetNode.id}) to ${VIRT_MIC_NAME} (ID: ${micNode.id})`);
+
+            // 4. Find the Ports for both nodes
+            const ports = dump.filter(n => n.type === 'PipeWire:Interface:Port');
+            
+            // Target App Output Ports
+            const targetPorts = ports.filter(p => p.info.props['node.id'] === targetNode.id && p.info.direction === 'output');
+            const targetFL = targetPorts.find(p => p.info.props['audio.channel'] === 'FL');
+            const targetFR = targetPorts.find(p => p.info.props['audio.channel'] === 'FR');
+
+            // Virtual Mic Input Ports
+            const micPorts = ports.filter(p => p.info.props['node.id'] === micNode.id && p.info.direction === 'input');
+            const micFL = micPorts.find(p => p.info.props['audio.channel'] === 'FL');
+            const micFR = micPorts.find(p => p.info.props['audio.channel'] === 'FR');
+
+            if (!targetFL || !targetFR || !micFL || !micFR) {
+                console.error("Could not find stereo ports for linking");
+                return false;
+            }
+
+            // 5. Link them using port aliases!
+            const targetFlAlias = targetFL.info.props['port.alias'] || targetFL.info.props['object.path'] || targetFL.id;
+            const targetFrAlias = targetFR.info.props['port.alias'] || targetFR.info.props['object.path'] || targetFR.id;
+            const micFlAlias = micFL.info.props['port.alias'] || micFL.info.props['object.path'] || micFL.id;
+            const micFrAlias = micFR.info.props['port.alias'] || micFR.info.props['object.path'] || micFR.id;
+
+            await execAsync(`pw-link "${targetFlAlias}" "${micFlAlias}"`).catch(e => console.log("pw-link output:", e.message));
+            await execAsync(`pw-link "${targetFrAlias}" "${micFrAlias}"`).catch(e => console.log("pw-link output:", e.message));
+            
+            console.log("Successfully linked audio.");
+            return true;
+
+        } catch (error) {
+            console.error("Failed to link application:", error);
+            return false;
+        }
+    }
+}
+
+module.exports = PipewireHelper;