live session auto voice detection.

lib/modules/copilot/controller/copilot_provider.dart

@@ -54,18 +54,28 @@ class CopilotProvider extends ChangeNotifier {
   DateTime? _pttSpeechCandidateAt;
   DateTime? _pttLastAudioChunkAt;
   DateTime? _pttCalibrationStartedAt;
+  DateTime? _pttLastLoudAt;
+  DateTime? _pttLastLevelLogAt;
+  DateTime? _pttListeningStartedAt;
   Timer? _pttSilenceTimer;
   bool _pttAutoStopTriggered = false;
   bool _pttHasDetectedSpeech = false;
   bool _pttDetectorActive = false;
   bool _pttCalibrated = false;
   double _pttNoiseFloor = 0.0;
-  double _pttCalibrationSum = 0.0;
+  final List<double> _pttCalibrationLevels = [];
-  int _pttCalibrationSamples = 0;
+  static const Duration _silenceHoldDuration = Duration(milliseconds: 1500);
-  static const Duration _silenceHoldDuration = Duration(seconds: 3);
   static const Duration _minimumSpeechDuration = Duration(milliseconds: 300);
+  // Short dips between syllables/words shorter than this don't reset speech detection.
+  static const Duration _speechGapTolerance = Duration(milliseconds: 250);
+  // Bounds for the measured background noise level (RMS, 0..1).
+  static const double _minNoiseFloor = 0.001;
+  static const double _maxNoiseFloor = 0.2;
+  // Safety net: send what was recorded if noise keeps the user "speaking" this long.
+  static const Duration _maxUtteranceDuration = Duration(seconds: 15);
   static const Duration _calibrationDuration = Duration(milliseconds: 700);
   static const Duration _audioChunkTimeout = Duration(seconds: 2);
+  static const Duration _noSpeechTimeout = Duration(seconds: 8);
   CopilotMessage? _pttCurrentAssistantMsg;
   final audioplayers.AudioPlayer _livePlayer = audioplayers.AudioPlayer();
   final List<Uint8List> _liveAudioQueue = [];
@@ -719,6 +729,11 @@ class CopilotProvider extends ChangeNotifier {
         codec: sound.Codec.pcm16,
         numChannels: 1,
         sampleRate: 48000,
+        // OS-level noise suppression / echo cancellation / gain control before audio is sent for transcription.
+        audioSource: sound.AudioSource.voice_communication, // Android: voice-tuned mic with platform NS/AEC/AGC
+        enableNoiseSuppression: true, // Android: NoiseSuppressor effect on the PCM stream
+        enableEchoCancellation: true, // Android: removes the bot's own voice if picked up
+        enableVoiceProcessing: true, // iOS: Apple voice processing (NS/AEC/AGC)
       );
     } catch (_) {
       _stopSilenceDetection();
@@ -740,9 +755,11 @@ class CopilotProvider extends ChangeNotifier {
     _pttSpeechCandidateAt = null;
     _pttLastAudioChunkAt = null;
     _pttNoiseFloor = 0;
-    _pttCalibrationSum = 0;
+    _pttCalibrationLevels.clear();
-    _pttCalibrationSamples = 0;
     _pttCalibrationStartedAt = null;
+    _pttLastLoudAt = null;
+    _pttLastLevelLogAt = null;
+    _pttListeningStartedAt = DateTime.now();
 
     _pttSilenceTimer = Timer.periodic(
       const Duration(milliseconds: 100),
@@ -760,6 +777,9 @@ class CopilotProvider extends ChangeNotifier {
     _pttSpeechCandidateAt = null;
     _pttLastAudioChunkAt = null;
     _pttCalibrationStartedAt = null;
+    _pttLastLoudAt = null;
+    _pttLastLevelLogAt = null;
+    _pttListeningStartedAt = null;
   }
 
   void _processSilenceDetection(Uint8List chunk) {
@@ -774,12 +794,15 @@ class CopilotProvider extends ChangeNotifier {
 
     if (!_pttCalibrated) {
       _pttCalibrationStartedAt ??= now;
-      _pttCalibrationSum += rms;
+      _pttCalibrationLevels.add(rms);
-      _pttCalibrationSamples++;
       if (now.difference(_pttCalibrationStartedAt!) < _calibrationDuration) {
         return;
       }
-      _pttNoiseFloor = (_pttCalibrationSum / _pttCalibrationSamples).clamp(0.001, 0.15).toDouble();
+      // A quiet percentile (not the mean): steady background noise sets the baseline,
+      // while the user starting to talk during calibration doesn't inflate it.
+      final levels = [..._pttCalibrationLevels]..sort();
+      _pttNoiseFloor = levels[(levels.length * 0.3).floor()].clamp(_minNoiseFloor, _maxNoiseFloor).toDouble();
+      _pttLog('live: calibrated noiseFloor=${_pttNoiseFloor.toStringAsFixed(4)}');
       _pttCalibrated = true;
       return;
     }
@@ -787,38 +810,65 @@ class CopilotProvider extends ChangeNotifier {
     final speechThreshold = max(0.008, _pttNoiseFloor * 2.5);
     final isSpeechCandidate = rms > speechThreshold;
 
+    if (_pttLastLevelLogAt == null || now.difference(_pttLastLevelLogAt!) >= const Duration(seconds: 1)) {
+      _pttLastLevelLogAt = now;
+      _pttLog('live: rms=${rms.toStringAsFixed(4)} threshold=${speechThreshold.toStringAsFixed(4)} speechDetected=$_pttHasDetectedSpeech');
+    }
+
     if (isSpeechCandidate) {
+      _pttLastLoudAt = now;
       _pttSpeechCandidateAt ??= now;
-      if (now.difference(_pttSpeechCandidateAt!) >= _minimumSpeechDuration) {
+      if (_pttHasDetectedSpeech || now.difference(_pttSpeechCandidateAt!) >= _minimumSpeechDuration) {
         _pttHasDetectedSpeech = true;
         _pttLastSpeechAt = now;
       }
       return;
     }
 
+    // A brief dip between syllables is still part of the same utterance.
+    if (_pttLastLoudAt != null && now.difference(_pttLastLoudAt!) < _speechGapTolerance) return;
+
     _pttSpeechCandidateAt = null;
-    if (!_pttHasDetectedSpeech) {
+    // Follow the background on quiet chunks: drop fast if it got quieter, rise slowly if louder.
-      _pttNoiseFloor = (_pttNoiseFloor * 0.95 + rms * 0.05).clamp(0.001, 0.15).toDouble();
+    final rate = rms < _pttNoiseFloor ? 0.2 : 0.05;
-    }
+    _pttNoiseFloor = (_pttNoiseFloor * (1 - rate) + rms * rate).clamp(_minNoiseFloor, _maxNoiseFloor).toDouble();
   }
 
   void _checkSpeechSilence() {
-    if (!_pttDetectorActive || _pttAutoStopTriggered || !_pttHasDetectedSpeech || pttStatus != PttStatus.recording || !liveSessionActive) {
+    if (!_pttDetectorActive || _pttAutoStopTriggered || pttStatus != PttStatus.recording || !liveSessionActive) {
       return;
     }
 
     final now = DateTime.now();
+    if (!_pttHasDetectedSpeech) {
+      // User hasn't spoken since listening started: end the session instead of recording forever.
+      final startedAt = _pttListeningStartedAt;
+      if (startedAt != null && now.difference(startedAt) >= _noSpeechTimeout) {
+        _pttLog('live: no speech detected, stopping session');
+        _pttAutoStopTriggered = true;
+        liveSessionActive = false;
+        _stopLivePlayback();
+        cancelPushToTalk().then((_) {
+          pttErrorMessage = "Can't hear you, so the session was stopped. Tap the button to start again.";
+          notifyListeners();
+        }).catchError((_) {});
+      }
+      return;
+    }
+
     final lastChunk = _pttLastAudioChunkAt;
     if (lastChunk == null || now.difference(lastChunk) > _audioChunkTimeout) return;
 
     final lastSpeech = _pttLastSpeechAt;
-    if (lastSpeech == null || now.difference(lastSpeech) < _silenceHoldDuration) return;
+    final startedAt = _pttListeningStartedAt;
+    final tooLong = startedAt != null && now.difference(startedAt) >= _maxUtteranceDuration;
+    if (!tooLong && (lastSpeech == null || now.difference(lastSpeech) < _silenceHoldDuration)) return;
 
     _pttAutoStopTriggered = true;
     _pttDetectorActive = false;
     _pttSilenceTimer?.cancel();
     _pttSilenceTimer = null;
-    _pttLog('live: silence after speech, auto-stopping recording');
+    _pttLog('live: ${tooLong ? 'max utterance length reached' : 'silence after speech'}, auto-stopping recording');
     endPushToTalk().catchError((_) {});
   }
 

lib/modules/copilot/screens/copilot_live_talk_page.dart

@@ -1,10 +1,12 @@
 import 'package:flutter/material.dart';
+import 'package:permission_handler/permission_handler.dart';
 import 'package:provider/provider.dart';
 import 'package:test_sa/border_beam/src/beam_style.dart';
 import 'package:test_sa/border_beam/src/border_beam.dart';
 import 'package:test_sa/controllers/providers/api/user_provider.dart';
 import 'package:test_sa/extensions/context_extension.dart';
 import 'package:test_sa/extensions/int_extensions.dart';
+import 'package:test_sa/extensions/string_extensions.dart';
 import 'package:test_sa/extensions/text_extensions.dart';
 import 'package:test_sa/extensions/widget_extensions.dart';
 import 'package:test_sa/new_views/app_style/app_color.dart';
@@ -33,6 +35,18 @@ class _CopilotLiveTalkPageState extends State<CopilotLiveTalkPage> with WidgetsB
   @override
   void initState() {
     super.initState();
+    makeConnection();
+  }
+
+  /// Microphone is only needed once the user starts the session, so ask on button tap.
+  Future<bool> _ensureMicPermission() async {
+    if (await Permission.microphone.isGranted) return true;
+    if ((await Permission.microphone.request()).isGranted) return true;
+    "Microphone permission denied. Please allow microphone access to use Live Session.".showToast;
+    return false;
+  }
+
+  void makeConnection() {
     WidgetsBinding.instance.addObserver(this);
     WidgetsBinding.instance.addPostFrameCallback((_) {
       final provider = context.read<CopilotProvider>();
@@ -89,14 +103,15 @@ class _CopilotLiveTalkPageState extends State<CopilotLiveTalkPage> with WidgetsB
     }
   }
 
-  void _onMainButtonTap(CopilotProvider provider) {
+  /// The button only starts/stops the whole session. Within a session the provider
-    // The button only starts/stops the whole session (never per-utterance), and
+  /// auto-sends when the user stops speaking, plays the answer, then listens again.
-    // stopping must work at any point (listening / thinking / speaking).
+  Future<void> _onMainButtonTap(CopilotProvider provider) async {
     if (provider.liveSessionActive) {
       provider.stopLiveTalk().catchError((_) {});
-    } else {
+      return;
-      provider.startLiveTalk(context.settingProvider.language!).catchError((_) {});
     }
+    if (!await _ensureMicPermission() || !mounted) return;
+    provider.startLiveTalk(context.settingProvider.language!).catchError((_) {});
   }
 
   Widget _buildConnectionPlaceholder(BuildContext context, CopilotProvider provider) {
@@ -128,7 +143,7 @@ class _CopilotLiveTalkPageState extends State<CopilotLiveTalkPage> with WidgetsB
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      appBar: const DefaultAppBar(title: "Live Session"),
+      appBar: const DefaultAppBar(title: "Live Session", showCopilot: false),
       body: Column(
         children: [
           Expanded(
@@ -254,4 +269,3 @@ class _CopilotLiveTalkPageState extends State<CopilotLiveTalkPage> with WidgetsB
     );
   }
 }
-