feat: add change input audio device function (#160)

Author: ao-anam

src/AnamClient.ts

@@ -549,6 +549,28 @@ export default class AnamClient {
     return this.inputAudioState;
   }
 
+  public async changeAudioInputDevice(deviceId: string): Promise<void> {
+    if (this.clientOptions?.disableInputAudio) {
+      throw new Error(
+        'AnamClient: Cannot change audio input device because input audio is disabled.',
+      );
+    }
+
+    if (!this._isStreaming) {
+      throw new Error(
+        'AnamClient: Cannot change audio input device while not streaming. Start streaming first.',
+      );
+    }
+
+    if (!this.streamingClient) {
+      throw new Error(
+        'AnamClient: Cannot change audio input device because streaming client is not available. Start streaming first.',
+      );
+    }
+
+    await this.streamingClient.changeAudioInputDevice(deviceId);
+  }
+
   public createTalkMessageStream(correlationId?: string): TalkMessageStream {
     if (!this.streamingClient) {
       throw new Error(

src/modules/StreamingClient.ts

@@ -269,6 +269,66 @@ export class StreamingClient {
     return this.peerConnection;
   }
 
+  public async changeAudioInputDevice(deviceId: string): Promise<void> {
+    if (!this.peerConnection) {
+      throw new Error(
+        'StreamingClient - changeAudioInputDevice: peer connection is not initialized. Start streaming first.',
+      );
+    }
+
+    if (deviceId === null || deviceId === undefined) {
+      throw new Error(
+        'StreamingClient - changeAudioInputDevice: deviceId is required',
+      );
+    }
+
+    // Store the current mute state to preserve it
+    const wasMuted = this.inputAudioState.isMuted;
+
+    try {
+      // Stop the current audio stream tracks
+      if (this.inputAudioStream) {
+        this.inputAudioStream.getAudioTracks().forEach((track) => {
+          track.stop();
+        });
+      }
+
+      // Request new audio stream with the new device ID
+      const audioConstraints: MediaTrackConstraints = {
+        echoCancellation: true,
+        deviceId: {
+          exact: deviceId,
+        },
+      };
+
+      this.inputAudioStream = await navigator.mediaDevices.getUserMedia({
+        audio: audioConstraints,
+      });
+
+      // Update the stored device ID
+      this.audioDeviceId = deviceId;
+
+      // Replace the audio track in the peer connection
+      await this.setupAudioTrack();
+
+      // Restore the mute state
+      if (wasMuted) {
+        this.muteAllAudioTracks();
+      }
+
+      // Emit event to notify that the device has changed
+      this.publicEventEmitter.emit(
+        AnamEvent.INPUT_AUDIO_DEVICE_CHANGED,
+        deviceId,
+      );
+    } catch (error) {
+      console.error('Failed to change audio input device:', error);
+      throw new Error(
+        `StreamingClient - changeAudioInputDevice: ${error instanceof Error ? error.message : String(error)}`,
+      );
+    }
+  }
+
   public getInputAudioStream(): MediaStream | null {
     return this.inputAudioStream;
   }

src/types/events/public/AnamEvent.ts

@@ -13,4 +13,5 @@ export enum AnamEvent {
   MIC_PERMISSION_PENDING = 'MIC_PERMISSION_PENDING',
   MIC_PERMISSION_GRANTED = 'MIC_PERMISSION_GRANTED',
   MIC_PERMISSION_DENIED = 'MIC_PERMISSION_DENIED',
+  INPUT_AUDIO_DEVICE_CHANGED = 'INPUT_AUDIO_DEVICE_CHANGED',
 }

src/types/events/public/EventCallbacks.ts

@@ -21,4 +21,5 @@ export type EventCallbacks = {
   [AnamEvent.MIC_PERMISSION_PENDING]: () => void;
   [AnamEvent.MIC_PERMISSION_GRANTED]: () => void;
   [AnamEvent.MIC_PERMISSION_DENIED]: (error: string) => void;
+  [AnamEvent.INPUT_AUDIO_DEVICE_CHANGED]: (deviceId: string) => void;
 };