Add mono input channel selection to audio configuration

Agent-Logs-Url: https://github.com/andersnm/modulyzer/sessions/f1d880be-bfe5-4d9e-b778-86ded95487ee

Co-authored-by: andersnm <16575282+andersnm@users.noreply.github.com>

Author: Copilot

src/App.ts

@@ -302,6 +302,7 @@ export class Appl extends CommandHost implements IComponent {
         this.device.outputDeviceId = await this.readSetting<string>("OutputDevice") ?? null;
         this.device.inputDeviceId = await this.readSetting<string>("InputDevice") ?? null;
         this.device.latencySec = await this.readSetting<number>("Latency") ?? 125;
+        this.device.inputMode = await this.readSetting<"stereo" | "left" | "right">("InputMode") ?? "stereo";
 
         await this.executeCommand("show-audio-configuration");
     }
@@ -316,7 +317,8 @@ export class Appl extends CommandHost implements IComponent {
         await handleMap.set(key, value);
     }
 
-    async setAudioDevice(outputDeviceId: string, inputDeviceId: string, latencySec: number) {
+    async setAudioDevice(outputDeviceId: string, inputDeviceId: string, latencySec: number, inputMode: "stereo" | "left" | "right" = "stereo") {
+        this.device.inputMode = inputMode;
         await this.device.create(outputDeviceId, inputDeviceId, latencySec);
 
         this.player = new Player(this.instrumentFactories, this.device);
@@ -327,6 +329,7 @@ export class Appl extends CommandHost implements IComponent {
         await this.writeSetting("OutputDevice", outputDeviceId);
         await this.writeSetting("InputDevice", inputDeviceId);
         await this.writeSetting("Latency", latencySec);
+        await this.writeSetting("InputMode", inputMode);
     }
 
     render() {
@@ -420,17 +423,15 @@ export class Appl extends CommandHost implements IComponent {
             return;
         }
 
-        this.song.replaceWaveBuffer(this.recordWave, this.recordOffset, inputs);
-
-        for (let i = 0; i < this.recordWave.buffers.length; i++) {
-            const output = this.recordWave.buffers[i];
-            const input = inputs[i % inputs.length];
-
-            for (let j = 0; j < input.length; j++) {
-                output[this.recordOffset + j] = input[j];
-            }
+        // For mono waves, select the channel specified by inputMode
+        let effectiveInputs = inputs;
+        if (this.recordWave.buffers.length === 1) {
+            const channelIndex = this.device.inputMode === "right" && inputs.length > 1 ? 1 : 0;
+            effectiveInputs = [inputs[channelIndex]];
         }
 
+        this.song.replaceWaveBuffer(this.recordWave, this.recordOffset, effectiveInputs);
+
         this.recordOffset += inputLength;
         // notify document
     };

src/commands/Application/ShowAudioConfigurationCommand.ts

@@ -16,12 +16,13 @@ export class ShowAudioConfigurationCommand {
         audioConfiguration.cancelable = !!this.app.device.context;
         audioConfiguration.currentOutputDeviceId = this.app.device.outputDeviceId;
         audioConfiguration.currentInputDeviceId = this.app.device.inputDeviceId;
+        audioConfiguration.inputMode = this.app.device.inputMode;
 
         const result = await this.app.modalDialogContainer.showModal("Audio Configuration", audioConfiguration, false);
         if (!result) {
             return;
         }
 
-        await this.app.setAudioDevice(audioConfiguration.currentOutputDeviceId, audioConfiguration.currentInputDeviceId, audioConfiguration.latencySec);
+        await this.app.setAudioDevice(audioConfiguration.currentOutputDeviceId, audioConfiguration.currentInputDeviceId, audioConfiguration.latencySec, audioConfiguration.inputMode);
     }
 }

src/components/AudioConfiguration.ts

@@ -27,7 +27,7 @@ export class AudioConfiguration implements IComponent {
     currentInputDeviceId: string;
     currentOutputDeviceId: string;
     microphonePermission: string = "denied";
-    inputMode: string = "stereo";
+    inputMode: "stereo" | "left" | "right" = "stereo";
     currentInputSampleRate = 44100;
     currentInputChannelCount = 2;
     latencySec = 0.5;
@@ -41,6 +41,7 @@ export class AudioConfiguration implements IComponent {
     outputDevicesSelect: HTMLSelectElement;
     inputDevicesSelect: HTMLSelectElement;
     latencySelect: HTMLSelectElement;
+    inputModeSelect: HTMLSelectElement;
     buttonBar: ModalButtonBar;
 
     constructor(app: Appl) {
@@ -95,6 +96,7 @@ export class AudioConfiguration implements IComponent {
         this.bindOutputDevices(outputDevices)
         this.bindInputDevices(inputDevices)
         this.bindLatency();
+        this.bindInputMode();
         this.bindButtons();
 
         this.bind();
@@ -117,6 +119,10 @@ export class AudioConfiguration implements IComponent {
         } as DeviceInfo;
     };
 
+    bindInputMode() {
+        this.inputModeSelect.value = this.inputMode;
+    }
+
     bindLatency() {
         while (this.latencySelect.options.length > 0) this.latencySelect.options.remove(0);
 
@@ -228,11 +234,32 @@ export class AudioConfiguration implements IComponent {
 
         const latencyGroup = FormGroup("Latency", this.latencySelect);
 
+        this.inputModeSelect = document.createElement("select");
+        this.inputModeSelect.className = "w-full rounded-lg p-1 bg-neutral-800";
+        this.inputModeSelect.addEventListener("change", () => {
+            this.inputMode = this.inputModeSelect.value as "stereo" | "left" | "right";
+        });
+
+        const inputModeOptions: { value: string; label: string }[] = [
+            { value: "stereo", label: "Stereo" },
+            { value: "left", label: "Left channel (mono)" },
+            { value: "right", label: "Right channel (mono)" },
+        ];
+        for (const { value, label } of inputModeOptions) {
+            const opt = document.createElement("option");
+            opt.value = value;
+            opt.label = label;
+            this.inputModeSelect.options.add(opt);
+        }
+
+        const inputModeGroup = FormGroup("Mono Input Channel", this.inputModeSelect);
+
         this.buttonBar = new ModalButtonBar(this.app);
 
         this.configForm.appendChild(outputGroup);
         this.configForm.appendChild(inputGroup);
         this.configForm.appendChild(latencyGroup);
+        this.configForm.appendChild(inputModeGroup);
 
         this.configForm.appendChild(this.buttonBar.getDomNode());
     }