Default mic settings (#37)

lib/src/track/local_audio_track.dart

@@ -21,14 +21,11 @@ class LocalAudioTrack extends AudioTrack with LocalTrack {
   /// Creates a new audio track from the default audio input device.
   static Future<LocalAudioTrack> create(
       [LocalAudioTrackOptions? options]) async {
-    // TODO: have back up incase the options fail
+    final audioConstraints = options?.toMediaConstraintsMap() ??
+        const LocalAudioTrackOptions().toMediaConstraintsMap();
     final stream =
         await rtc.navigator.mediaDevices.getUserMedia(<String, dynamic>{
-      // 'audio': <String, dynamic>{
-      // 'echoCancellation': true,
-      // 'noiseSuppression': true,
-      // },
-      'audio': true,
+      'audio': audioConstraints,
       'video': false,
     });
 

lib/src/track/options.dart

@@ -236,5 +236,32 @@ class VideoParameters {
 
 /// Options when creating an LocalAudioTrack. Placeholder for now.
 class LocalAudioTrackOptions {
-  const LocalAudioTrackOptions();
+  final bool noiseSuppression;
+  final bool echoCancellation;
+  final bool autoGainControl;
+  final bool highPassFilter;
+  final bool typingNoiseDetection;
+
+  const LocalAudioTrackOptions({
+    this.noiseSuppression = true,
+    this.echoCancellation = true,
+    this.autoGainControl = true,
+    this.highPassFilter = false,
+    this.typingNoiseDetection = true,
+  });
+
+  Map<String, dynamic> toMediaConstraintsMap() => <String, dynamic>{
+        'optional': <Map<String, dynamic>>[
+          <String, dynamic>{'echoCancellation': echoCancellation},
+          <String, dynamic>{'googDAEchoCancellation': echoCancellation},
+          <String, dynamic>{'googEchoCancellation': echoCancellation},
+          <String, dynamic>{'googEchoCancellation2': echoCancellation},
+          <String, dynamic>{'noiseSuppression': noiseSuppression},
+          <String, dynamic>{'googNoiseSuppression': noiseSuppression},
+          <String, dynamic>{'googNoiseSuppression2': noiseSuppression},
+          <String, dynamic>{'googAutoGainControl': autoGainControl},
+          <String, dynamic>{'googHighpassFilter': highPassFilter},
+          <String, dynamic>{'googTypingNoiseDetection': typingNoiseDetection},
+        ],
+      };
 }