Add LPCNet voice mode support

2026-08-11 16:30:28 +00:00 · 2026-03-11 21:16:08 +01:00
parent 1b6ff59af3
commit ca872f2049
15 changed files with 329 additions and 124 deletions
--- a/lib/providers/contacts_provider.dart
+++ b/lib/providers/contacts_provider.dart
@@ -516,8 +516,8 @@ class ContactsProvider with ChangeNotifier {
      return null;
    }

-    final firstHopHex = routeBytes
-        .sublist(0, routeHashSize)
+    final lastHopHex = routeBytes
+        .sublist(routeBytes.length - routeHashSize)
        .map((byte) => byte.toRadixString(16).padLeft(2, '0'))
        .join();
    final repeaterCandidates = _contacts.values.where((candidate) {
@@ -526,7 +526,7 @@ class ContactsProvider with ChangeNotifier {
        return false;
      }
      final location = candidate.displayLocation;
-      return location != null && candidate.publicKeyHex.startsWith(firstHopHex);
+      return location != null && candidate.publicKeyHex.startsWith(lastHopHex);
    }).toList()..sort((a, b) => b.lastAdvert.compareTo(a.lastAdvert));
    if (repeaterCandidates.isEmpty) {
      return null;
--- a/lib/providers/voice_provider.dart
+++ b/lib/providers/voice_provider.dart
@@ -303,7 +303,7 @@ class VoiceProvider with ChangeNotifier {
      debugPrint('🎙️ [VoiceProvider] decoded ${pcm.length} PCM samples');
      _playingSessionId = sessionId;
      notifyListeners();
-      await _player.play(pcm);
+      await _player.play(pcm, sampleRateHz: session.mode.sampleRateHz);
    } catch (e, st) {
      debugPrint('❌ [VoiceProvider] Playback error: $e\n$st');
      if (_playingSessionId == sessionId) {
--- a/lib/screens/messages_tab.dart
+++ b/lib/screens/messages_tab.dart
@@ -24,6 +24,7 @@ import '../widgets/messages/messages_content.dart';
 import '../widgets/common/contact_avatar.dart';
 import '../services/message_destination_preferences.dart';
 import '../services/voice_bitrate_preferences.dart';
+import '../services/voice_codec_preferences.dart';
 import '../services/voice_recorder_service.dart';
 import '../services/voice_codec_service.dart';
 import '../utils/toast_logger.dart';
@@ -81,6 +82,7 @@ class _MessagesTabState extends State<MessagesTab> {
  final List<Int16List> _recordedChunks = [];
  VoicePacketMode? _activeVoiceMode;
  int _selectedVoiceBitrate = VoiceBitratePreferences.defaultBitrate;
+  VoiceCodecKind _selectedVoiceCodec = VoiceCodecPreferences.defaultCodec;

  @override
  void initState() {
@@ -88,17 +90,19 @@ class _MessagesTabState extends State<MessagesTab> {
    _textController.addListener(_updateCharacterCount);
    // Load saved message destination
    _loadSavedDestination();
-    _loadVoiceBitrate();
+    _loadVoiceSettings();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      _checkForNavigationRequest();
    });
  }

-  Future<void> _loadVoiceBitrate() async {
+  Future<void> _loadVoiceSettings() async {
    final bitrate = await VoiceBitratePreferences.getBitrate();
+    final codec = await VoiceCodecPreferences.getCodec();
    if (!mounted) return;
    setState(() {
      _selectedVoiceBitrate = bitrate;
+      _selectedVoiceCodec = codec;
    });
  }

@@ -817,14 +821,17 @@ class _MessagesTabState extends State<MessagesTab> {
  Future<void> _startVoiceRecording() async {
    if (_isSendingVoice || _isRecording) return;
    debugPrint('🎙️ [Voice] _startVoiceRecording called');
-    // Read fresh bitrate preference so settings changes apply immediately.
+    // Read fresh voice preferences so settings changes apply immediately.
    final selectedBitrate = await VoiceBitratePreferences.getBitrate();
+    final selectedCodec = await VoiceCodecPreferences.getCodec();
    if (mounted) {
      setState(() {
        _selectedVoiceBitrate = selectedBitrate;
+        _selectedVoiceCodec = selectedCodec;
      });
    } else {
      _selectedVoiceBitrate = selectedBitrate;
+      _selectedVoiceCodec = selectedCodec;
    }
    final hasPermission = await _voiceRecorder.requestPermission();
    debugPrint('🎙️ [Voice] hasPermission=$hasPermission');
@@ -852,11 +859,11 @@ class _MessagesTabState extends State<MessagesTab> {
      (_) => rng.nextInt(256),
    ).map((b) => b.toRadixString(16).padLeft(2, '0')).join();

-    _activeVoiceMode = VoiceBitratePreferences.toVoiceMode(
-      _selectedVoiceBitrate,
-    );
+    _activeVoiceMode = _selectedVoiceCodec == VoiceCodecKind.lpcnet
+        ? VoicePacketMode.lpcnet1600
+        : VoiceBitratePreferences.toVoiceMode(_selectedVoiceBitrate);
    final packetDuration = Duration(
-      milliseconds: codec2ModeFor(_activeVoiceMode!).packetDurationMs,
+      milliseconds: _activeVoiceMode!.packetDurationMs,
    );

    debugPrint(
@@ -869,6 +876,7 @@ class _MessagesTabState extends State<MessagesTab> {
    try {
      final stream = _voiceRecorder.startCapture(
        chunkDuration: packetDuration,
+        sampleRateHz: _activeVoiceMode!.sampleRateHz,
        enableBandPassFilter: appProvider.isVoiceBandPassFilterEnabled,
        enableCompressor: appProvider.isVoiceCompressorEnabled,
        enableLimiter: appProvider.isVoiceLimiterEnabled,
--- a/lib/screens/settings_screen.dart
+++ b/lib/screens/settings_screen.dart
@@ -18,8 +18,8 @@ import '../services/location_tracking_service.dart';
 import '../services/locale_preferences.dart';
 import '../services/mesh_map_nodes_service.dart';
 import '../services/update_checker_service.dart';
-import '../services/voice_codec_service.dart';
 import '../services/voice_bitrate_preferences.dart';
+import '../services/voice_codec_preferences.dart';
 import '../services/image_preferences.dart';
 import '../services/route_hash_preferences.dart';
 import '../services/image_codec_service.dart';
@@ -60,6 +60,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
  bool _showRxTxIndicators = true;
  bool _isCheckingForUpdates = false;
  int _voiceBitrate = VoiceBitratePreferences.defaultBitrate;
+  VoiceCodecKind _voiceCodec = VoiceCodecPreferences.defaultCodec;
  int _routeHashSize = RouteHashPreferences.defaultHashSize;
  int _imageMaxSize = ImagePreferences.defaultMaxSize;
  int _imageCompression = ImagePreferences.defaultQuality;
@@ -88,7 +89,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
    _loadPackageInfo();
    _initializeLocationService();
    _loadRxTxPreference();
-    _loadVoiceBitratePreference();
+    _loadVoicePreferences();
    _loadRouteHashSizePreference();
    _loadImagePreferences();
    _loadFastLocationSettings();
@@ -178,11 +179,13 @@ class _SettingsScreenState extends State<SettingsScreen> {
    await prefs.setBool('show_rx_tx_indicators', value);
  }

-  Future<void> _loadVoiceBitratePreference() async {
+  Future<void> _loadVoicePreferences() async {
    final value = await VoiceBitratePreferences.getBitrate();
+    final codec = await VoiceCodecPreferences.getCodec();
    if (!mounted) return;
    setState(() {
      _voiceBitrate = value;
+      _voiceCodec = codec;
    });
  }

@@ -194,10 +197,27 @@ class _SettingsScreenState extends State<SettingsScreen> {
    });
  }

+  Future<void> _saveVoiceCodecPreference(VoiceCodecKind value) async {
+    await VoiceCodecPreferences.setCodec(value);
+    if (!mounted) return;
+    setState(() {
+      _voiceCodec = value;
+    });
+  }
+
  String _voiceBitrateSubtitle(int bitrate) {
+    if (_voiceCodec == VoiceCodecKind.lpcnet) {
+      return 'Fixed 1600 bps';
+    }
    return '$bitrate bps';
  }

+  String _voiceCodecSubtitle() {
+    return _voiceCodec == VoiceCodecKind.codec2
+        ? 'Selectable low-bitrate modes'
+        : 'Fixed 16 kHz / 1.6 kbps mode';
+  }
+
  Future<void> _loadRouteHashSizePreference() async {
    final value = await RouteHashPreferences.getHashSize();
    if (!mounted) return;
@@ -1159,6 +1179,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
          Consumer2<AppProvider, ConnectionProvider>(
            builder: (context, appProvider, connectionProvider, child) =>
                _buildVoiceStatsCard(
+                  codec: _voiceCodec,
                  bitrate: _voiceBitrate,
                  connectionProvider: connectionProvider,
                  bandPassEnabled: appProvider.isVoiceBandPassFilterEnabled,
@@ -1168,12 +1189,22 @@ class _SettingsScreenState extends State<SettingsScreen> {
                ),
          ),
          _buildSettingsCard([
+            ListTile(
+              leading: const Icon(Icons.record_voice_over),
+              title: const Text('Voice codec'),
+              subtitle: Text(_voiceCodecSubtitle()),
+              trailing: const Icon(Icons.chevron_right),
+              onTap: _showVoiceCodecDialog,
+            ),
            ListTile(
              leading: const Icon(Icons.graphic_eq),
              title: const Text('Voice bitrate'),
              subtitle: Text(_voiceBitrateSubtitle(_voiceBitrate)),
              trailing: const Icon(Icons.chevron_right),
-              onTap: _showVoiceBitrateDialog,
+              enabled: _voiceCodec == VoiceCodecKind.codec2,
+              onTap: _voiceCodec == VoiceCodecKind.codec2
+                  ? _showVoiceBitrateDialog
+                  : null,
            ),
            Consumer<AppProvider>(
              builder: (context, appProvider, child) => SwitchListTile(
@@ -1724,6 +1755,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
  }

  Widget _buildVoiceStatsCard({
+    required VoiceCodecKind codec,
    required int bitrate,
    required ConnectionProvider connectionProvider,
    required bool bandPassEnabled,
@@ -1746,9 +1778,11 @@ class _SettingsScreenState extends State<SettingsScreen> {
    final radioSf = connectionProvider.deviceInfo.radioSf;
    final radioCr = connectionProvider.deviceInfo.radioCr;
    final bwHz = _resolveBandwidthHz(radioBw);
-    final voiceMode = VoiceBitratePreferences.toVoiceMode(bitrate);
+    final voiceMode = codec == VoiceCodecKind.lpcnet
+        ? VoicePacketMode.lpcnet1600
+        : VoiceBitratePreferences.toVoiceMode(bitrate);
    const voicePreviewMs = 10000; // 10-second reference clip
-    final packetDurationMs = codec2ModeFor(voiceMode).packetDurationMs;
+    final packetDurationMs = voiceMode.packetDurationMs;
    final voicePacketCount =
        (voicePreviewMs + packetDurationMs - 1) ~/ packetDurationMs;
    final voiceDirect = estimateVoiceTransmitDuration(
@@ -1783,7 +1817,7 @@ class _SettingsScreenState extends State<SettingsScreen> {
            ),
            const SizedBox(height: 8),
            Text(
-              'Bitrate: $bitrate bps',
+              'Codec: ${voiceMode.label}${codec == VoiceCodecKind.codec2 ? ' · $bitrate bps' : ' · 1600 bps'}',
              style: Theme.of(context).textTheme.bodySmall,
            ),
            const SizedBox(height: 4),
@@ -2112,6 +2146,47 @@ class _SettingsScreenState extends State<SettingsScreen> {
    );
  }

+  void _showVoiceCodecDialog() {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('Voice codec'),
+        content: SingleChildScrollView(
+          child: RadioGroup<VoiceCodecKind>(
+            groupValue: _voiceCodec,
+            onChanged: (value) {
+              if (value != null) {
+                _saveVoiceCodecPreference(value);
+              }
+              Navigator.pop(context);
+            },
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                RadioListTile<VoiceCodecKind>(
+                  value: VoiceCodecKind.codec2,
+                  title: const Text('Codec2'),
+                  subtitle: const Text('Selectable ultra-low bitrate modes'),
+                ),
+                RadioListTile<VoiceCodecKind>(
+                  value: VoiceCodecKind.lpcnet,
+                  title: const Text('LPCNet'),
+                  subtitle: const Text('Fixed 16 kHz / 1.6 kbps neural mode'),
+                ),
+              ],
+            ),
+          ),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(context),
+            child: Text(AppLocalizations.of(context)!.cancel),
+          ),
+        ],
+      ),
+    );
+  }
+
  void _showAboutDialog() {
    showDialog(
      context: context,
--- a/lib/services/voice_codec_preferences.dart
+++ b/lib/services/voice_codec_preferences.dart
@@ -0,0 +1,21 @@
+import 'package:shared_preferences/shared_preferences.dart';
+import '../utils/voice_message_parser.dart';
+
+class VoiceCodecPreferences {
+  static const String _codecKey = 'voice_codec';
+  static const VoiceCodecKind defaultCodec = VoiceCodecKind.codec2;
+
+  static Future<VoiceCodecKind> getCodec() async {
+    final prefs = await SharedPreferences.getInstance();
+    final raw = prefs.getString(_codecKey);
+    return VoiceCodecKind.values.firstWhere(
+      (codec) => codec.name == raw,
+      orElse: () => defaultCodec,
+    );
+  }
+
+  static Future<void> setCodec(VoiceCodecKind codec) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setString(_codecKey, codec.name);
+  }
+}
--- a/lib/services/voice_codec_service_io.dart
+++ b/lib/services/voice_codec_service_io.dart
@@ -1,20 +1,27 @@
 import 'dart:typed_data';
 import 'package:codec2_flutter/codec2_flutter.dart';
+import 'package:lpcnet_flutter/lpcnet_flutter.dart';
 import 'package:flutter/foundation.dart';
 import '../utils/voice_message_parser.dart';

-export 'package:codec2_flutter/codec2_flutter.dart' show Codec2Mode;
-
-/// Maps [VoicePacketMode] to the [Codec2Mode] enum from the FFI plugin.
 Codec2Mode codec2ModeFor(VoicePacketMode pktMode) {
  switch (pktMode) {
-    case VoicePacketMode.mode3200: return Codec2Mode.mode3200;
-    case VoicePacketMode.mode1600: return Codec2Mode.mode1600;
-    case VoicePacketMode.mode1400: return Codec2Mode.mode1400;
-    case VoicePacketMode.mode700c: return Codec2Mode.mode700c;
-    case VoicePacketMode.mode1200: return Codec2Mode.mode1200;
-    case VoicePacketMode.mode1300: return Codec2Mode.mode1300;
-    case VoicePacketMode.mode2400: return Codec2Mode.mode2400;
+    case VoicePacketMode.mode3200:
+      return Codec2Mode.mode3200;
+    case VoicePacketMode.mode1600:
+      return Codec2Mode.mode1600;
+    case VoicePacketMode.mode1400:
+      return Codec2Mode.mode1400;
+    case VoicePacketMode.mode700c:
+      return Codec2Mode.mode700c;
+    case VoicePacketMode.mode1200:
+      return Codec2Mode.mode1200;
+    case VoicePacketMode.mode1300:
+      return Codec2Mode.mode1300;
+    case VoicePacketMode.mode2400:
+      return Codec2Mode.mode2400;
+    case VoicePacketMode.lpcnet1600:
+      throw ArgumentError('LPCNet mode does not map to Codec2');
  }
 }

@@ -39,17 +46,24 @@ class VoiceCodecService {
    }
  }

-  /// Encode [pcm] (Int16 samples, 8000 Hz mono) with [mode].
-  /// Returns the raw Codec2-encoded bytes.
  Future<Uint8List> encode(Int16List pcm, VoicePacketMode mode) {
    _ensureCodec2Supported();
-    return Codec2.encodeInIsolate(pcm, codec2ModeFor(mode));
+    switch (mode.codec) {
+      case VoiceCodecKind.codec2:
+        return Codec2.encodeInIsolate(pcm, codec2ModeFor(mode));
+      case VoiceCodecKind.lpcnet:
+        return LpcNet.encodeInIsolate(pcm);
+    }
  }

-  /// Decode [codec2Bytes] back to Int16 PCM (8000 Hz mono) with [mode].
  Future<Int16List> decode(Uint8List codec2Bytes, VoicePacketMode mode) {
    _ensureCodec2Supported();
-    return Codec2.decodeInIsolate(codec2Bytes, codec2ModeFor(mode));
+    switch (mode.codec) {
+      case VoiceCodecKind.codec2:
+        return Codec2.decodeInIsolate(codec2Bytes, codec2ModeFor(mode));
+      case VoiceCodecKind.lpcnet:
+        return LpcNet.decodeInIsolate(codec2Bytes);
+    }
  }

  /// Decode and concatenate multiple [packets] into a single PCM Int16List.
@@ -59,24 +73,14 @@ class VoiceCodecService {
    VoicePacketMode mode,
  ) async {
    _ensureCodec2Supported();
-    final c2Mode = codec2ModeFor(mode);
-    final c2 = Codec2.create(c2Mode);
-    final spf = c2.samplesPerFrame;
-    c2.destroy();
-
-    // Estimate total samples (use actual data or silence per missing packet)
    final all = <Int16List>[];
    for (final pkt in packets) {
      if (pkt == null || pkt.codec2Data.isEmpty) {
-        // Silence for missing packet — duration approximated by mode
-        final silenceSamples = (codec2ModeFor(mode).framesPerSecond) * spf;
-        all.add(Int16List(silenceSamples));
+        all.add(Int16List(mode.samplesPerPacket));
      } else {
-        final decoded = await Codec2.decodeInIsolate(pkt.codec2Data, c2Mode);
-        all.add(decoded);
+        all.add(await decode(pkt.codec2Data, mode));
      }
    }
-
    final total = all.fold<int>(0, (sum, l) => sum + l.length);
    final result = Int16List(total);
    var offset = 0;
--- a/lib/services/voice_codec_service_stub.dart
+++ b/lib/services/voice_codec_service_stub.dart
@@ -1,7 +1,6 @@
 import 'dart:typed_data';
 import '../utils/voice_message_parser.dart';

-/// Web/unsupported platform stub — Codec2 FFI is not available.
 enum Codec2Mode {
  mode3200(0),
  mode2400(1),
@@ -19,13 +18,20 @@ enum Codec2Mode {

  int get bytesPerSecond {
    switch (this) {
-      case mode3200: return 400;
-      case mode700c: return 100;
-      case mode1200: return 150;
-      case mode1300: return 175;
-      case mode1400: return 175;
-      case mode1600: return 200;
-      case mode2400: return 300;
+      case mode3200:
+        return 400;
+      case mode700c:
+        return 100;
+      case mode1200:
+        return 150;
+      case mode1300:
+        return 175;
+      case mode1400:
+        return 175;
+      case mode1600:
+        return 200;
+      case mode2400:
+        return 300;
    }
  }

@@ -40,13 +46,22 @@ enum Codec2Mode {

 Codec2Mode codec2ModeFor(VoicePacketMode pktMode) {
  switch (pktMode) {
-    case VoicePacketMode.mode3200: return Codec2Mode.mode3200;
-    case VoicePacketMode.mode1600: return Codec2Mode.mode1600;
-    case VoicePacketMode.mode1400: return Codec2Mode.mode1400;
-    case VoicePacketMode.mode700c: return Codec2Mode.mode700c;
-    case VoicePacketMode.mode1200: return Codec2Mode.mode1200;
-    case VoicePacketMode.mode1300: return Codec2Mode.mode1300;
-    case VoicePacketMode.mode2400: return Codec2Mode.mode2400;
+    case VoicePacketMode.mode3200:
+      return Codec2Mode.mode3200;
+    case VoicePacketMode.mode1600:
+      return Codec2Mode.mode1600;
+    case VoicePacketMode.mode1400:
+      return Codec2Mode.mode1400;
+    case VoicePacketMode.mode700c:
+      return Codec2Mode.mode700c;
+    case VoicePacketMode.mode1200:
+      return Codec2Mode.mode1200;
+    case VoicePacketMode.mode1300:
+      return Codec2Mode.mode1300;
+    case VoicePacketMode.mode2400:
+      return Codec2Mode.mode2400;
+    case VoicePacketMode.lpcnet1600:
+      throw ArgumentError('LPCNet mode does not map to Codec2');
  }
 }

@@ -66,6 +81,5 @@ class VoiceCodecService {
  Future<Int16List> decodePackets(
    List<VoicePacket?> packets,
    VoicePacketMode mode,
-  ) =>
-      Future.error(UnsupportedError('Voice not supported on web'));
+  ) => Future.error(UnsupportedError('Voice not supported on web'));
 }
--- a/lib/services/voice_player_service.dart
+++ b/lib/services/voice_player_service.dart
@@ -5,7 +5,7 @@ import 'package:audioplayers/audioplayers.dart';
 import 'package:flutter/foundation.dart';
 import 'package:path_provider/path_provider.dart';

-/// Plays decoded 8000 Hz / 16-bit mono PCM samples by writing a WAV file
+/// Plays decoded mono PCM samples by writing a WAV file
 /// to the system temp directory and using [AudioPlayer].
 class VoicePlayerService {
  final AudioPlayer _player = AudioPlayer();
@@ -49,16 +49,17 @@ class VoicePlayerService {
    });
  }

-  /// Play [pcmSamples] (Int16, 8000 Hz, mono).
-  Future<void> play(Int16List pcmSamples) async {
+  Future<void> play(Int16List pcmSamples, {required int sampleRateHz}) async {
    debugPrint('🔊 [VoicePlayer] play() called, ${pcmSamples.length} samples');
    if (_isPlaying) await stop();
    _position = Duration.zero;
-    _duration = Duration(milliseconds: (pcmSamples.length * 1000) ~/ 8000);
+    _duration = Duration(
+      milliseconds: (pcmSamples.length * 1000) ~/ sampleRateHz,
+    );
    _playbackStartedAt = DateTime.now();
    _events.add(null);

-    final wavBytes = _buildWav(pcmSamples, sampleRate: 8000);
+    final wavBytes = _buildWav(pcmSamples, sampleRate: sampleRateHz);
    final tmpDir = await getTemporaryDirectory();
    final file = File('${tmpDir.path}/vc_voice.wav');
    await file.writeAsBytes(wavBytes);
--- a/lib/services/voice_recorder_service.dart
+++ b/lib/services/voice_recorder_service.dart
@@ -4,7 +4,7 @@ import 'dart:typed_data';
 import 'package:flutter/foundation.dart';
 import 'package:record/record.dart';

-/// Captures raw PCM audio at 8000 Hz, 16-bit mono.
+/// Captures raw PCM audio at a codec-selected sample rate, 16-bit mono.
 ///
 /// [startCapture] returns a [Stream<Int16List>] that emits chunks of PCM
 /// samples every [chunkDuration].  Call [stopCapture] to end recording.
@@ -27,9 +27,10 @@ class VoiceRecorderService {
  /// [enableBandPassFilter] applies voice-tuned band-pass filtering when true.
  /// [enableCompressor] normalizes speech dynamics before encoding.
  /// [enableLimiter] protects against clipping peaks before encoding.
-  /// The returned stream emits [Int16List] chunks that are ready for Codec2 encoding.
+  /// The returned stream emits [Int16List] chunks that are ready for voice encoding.
  Stream<Int16List> startCapture({
    Duration chunkDuration = const Duration(seconds: 1),
+    int sampleRateHz = 8000,
    bool enableBandPassFilter = true,
    bool enableCompressor = true,
    bool enableLimiter = true,
@@ -43,6 +44,7 @@ class VoiceRecorderService {

    _startRecording(
      chunkDuration,
+      sampleRateHz: sampleRateHz,
      enableBandPassFilter: enableBandPassFilter,
      enableCompressor: enableCompressor,
      enableLimiter: enableLimiter,
@@ -52,13 +54,14 @@ class VoiceRecorderService {

  Future<void> _startRecording(
    Duration chunkDuration, {
+    required int sampleRateHz,
    required bool enableBandPassFilter,
    required bool enableCompressor,
    required bool enableLimiter,
  }) async {
-    final config = const RecordConfig(
+    final config = RecordConfig(
      encoder: AudioEncoder.pcm16bits,
-      sampleRate: 8000,
+      sampleRate: sampleRateHz,
      numChannels: 1,
      bitRate: 128000, // ignored for PCM, but required by API
    );
@@ -66,16 +69,17 @@ class VoiceRecorderService {
    try {
      final stream = await _recorder.startStream(config);
      final voiceFilter = _VoiceBandPassFilter(
-        sampleRate: 8000,
+        sampleRate: sampleRateHz,
        lowCutHz: 250.0,
        highCutHz: 3400.0,
      );
      final dynamics = _VoiceDynamicsProcessor(
-        sampleRate: 8000,
+        sampleRate: sampleRateHz,
        enableCompressor: enableCompressor,
        enableLimiter: enableLimiter,
      );
-      final chunkBytes = 8000 * 2 * chunkDuration.inMilliseconds ~/ 1000;
+      final chunkBytes =
+          sampleRateHz * 2 * chunkDuration.inMilliseconds ~/ 1000;
      final buffer = <int>[];

      _sub = stream.listen(
--- a/lib/utils/voice_message_parser.dart
+++ b/lib/utils/voice_message_parser.dart
@@ -11,20 +11,43 @@ const int _defaultLoRaCrcEnabled = 1;
 const int _defaultLoRaExplicitHeader = 1;
 const double _defaultAirtimeBudgetFactor = 1.0; // one half duty-cycle

-/// Identifies which Codec2 mode was used for a voice packet.
-/// Matches the modeId byte in the text/binary packet header.
-enum VoicePacketMode {
-  mode700c(0, '700C'),
-  mode1200(1, '1200'),
-  mode2400(2, '2400'),
-  mode1300(3, '1300'),
-  mode1400(4, '1400'),
-  mode1600(5, '1600'),
-  mode3200(6, '3200');
+enum VoiceCodecKind {
+  codec2(0, 'Codec2'),
+  lpcnet(1, 'LPCNet');

-  const VoicePacketMode(this.id, this.label);
+  const VoiceCodecKind(this.id, this.label);
  final int id;
  final String label;
+}
+
+/// Identifies which voice codec/mode was used for a packet.
+/// Matches the modeId byte in the text/binary packet header.
+enum VoicePacketMode {
+  mode700c(0, '700C', VoiceCodecKind.codec2, 8000, 100, 1600),
+  mode1200(1, '1200', VoiceCodecKind.codec2, 8000, 150, 1040),
+  mode2400(2, '2400', VoiceCodecKind.codec2, 8000, 300, 520),
+  mode1300(3, '1300', VoiceCodecKind.codec2, 8000, 175, 880),
+  mode1400(4, '1400', VoiceCodecKind.codec2, 8000, 175, 880),
+  mode1600(5, '1600', VoiceCodecKind.codec2, 8000, 200, 800),
+  mode3200(6, '3200', VoiceCodecKind.codec2, 8000, 400, 400),
+  lpcnet1600(7, 'LPCNet', VoiceCodecKind.lpcnet, 16000, 200, 40);
+
+  const VoicePacketMode(
+    this.id,
+    this.label,
+    this.codec,
+    this.sampleRateHz,
+    this.bytesPerSecond,
+    this.packetDurationMs,
+  );
+  final int id;
+  final String label;
+  final VoiceCodecKind codec;
+  final int sampleRateHz;
+  final int bytesPerSecond;
+  final int packetDurationMs;
+
+  int get samplesPerPacket => sampleRateHz * packetDurationMs ~/ 1000;

  static VoicePacketMode fromId(int id) => VoicePacketMode.values.firstWhere(
    (m) => m.id == id,
@@ -153,23 +176,15 @@ class VoicePacket {

  /// Estimated audio duration of this packet in milliseconds.
  int get durationMs {
-    // bytesPerSecond for each mode
-    final bps = switch (mode) {
-      VoicePacketMode.mode700c => 100,
-      VoicePacketMode.mode1200 => 150,
-      VoicePacketMode.mode1300 => 175,
-      VoicePacketMode.mode1400 => 175,
-      VoicePacketMode.mode1600 => 200,
-      VoicePacketMode.mode2400 => 300,
-      VoicePacketMode.mode3200 => 400,
-    };
-    if (bps == 0) return 0;
-    return (codec2Data.length * 1000 ~/ bps).clamp(0, 1500);
+    if (mode.bytesPerSecond == 0) return 0;
+    return (codec2Data.length * 1000 ~/ mode.bytesPerSecond).clamp(0, 1500);
  }

  @override
  String toString() {
-    final suffix = total > 0 ? ' ${mode.label} [$index/${total - 1}]' : ' [$index]';
+    final suffix = total > 0
+        ? ' ${mode.label} [$index/${total - 1}]'
+        : ' [$index]';
    return 'VoicePacket($sessionId$suffix ${codec2Data.length}B)';
  }
 }
@@ -242,13 +257,7 @@ class VoiceEnvelope {
 }

 int voiceModeBytesPerSecond(VoicePacketMode mode) => switch (mode) {
-  VoicePacketMode.mode700c => 100,
-  VoicePacketMode.mode1200 => 150,
-  VoicePacketMode.mode1300 => 175,
-  VoicePacketMode.mode1400 => 175,
-  VoicePacketMode.mode1600 => 200,
-  VoicePacketMode.mode2400 => 300,
-  VoicePacketMode.mode3200 => 400,
+  _ => mode.bytesPerSecond,
 };

 /// Approximate end-to-end transmit time for a voice session over MeshCore LoRa.
@@ -419,8 +428,7 @@ class VoiceFetchRequest {
    this.version = 3,
  });

-  static bool isVoiceFetchRequestText(String text) =>
-      text.startsWith(_prefix);
+  static bool isVoiceFetchRequestText(String text) => text.startsWith(_prefix);
  static bool isVoiceFetchRequestBinary(Uint8List payload) =>
      payload.isNotEmpty && payload[0] == _binaryMagic;

@@ -473,9 +481,7 @@ class VoiceFetchRequest {
      final requesterKey6 = parts[2];
      final normalizedWant = wantToken == 'a'
          ? 'all'
-          : ((wantToken.startsWith('m'))
-                ? 'missing'
-                : wantToken);
+          : ((wantToken.startsWith('m')) ? 'missing' : wantToken);

      if (sid == null) {
        return null;
@@ -602,7 +608,11 @@ String _toBase36(int value) => value.toRadixString(36);

 String _encodeSessionId(String sessionIdHex) {
  if (!RegExp(r'^[0-9a-fA-F]{8}$').hasMatch(sessionIdHex)) {
-    throw ArgumentError.value(sessionIdHex, 'sessionIdHex', 'Expected 8 hex chars');
+    throw ArgumentError.value(
+      sessionIdHex,
+      'sessionIdHex',
+      'Expected 8 hex chars',
+    );
  }
  final value = int.parse(sessionIdHex, radix: 16);
  return value.toRadixString(36);
@@ -616,10 +626,7 @@ String? _decodeSessionId(String token) {
 }

 String _encodeMissingIndicesCompact(List<int> indices) {
-  final sorted = indices
-      .where((v) => v >= 0 && v <= 254)
-      .toSet()
-      .toList()
+  final sorted = indices.where((v) => v >= 0 && v <= 254).toSet().toList()
    ..sort();
  if (sorted.isEmpty) return '';
  final chunks = <String>[];
@@ -632,7 +639,9 @@ String _encodeMissingIndicesCompact(List<int> indices) {
      continue;
    }
    chunks.add(
-      start == prev ? _toBase36(start) : '${_toBase36(start)}-${_toBase36(prev)}',
+      start == prev
+          ? _toBase36(start)
+          : '${_toBase36(start)}-${_toBase36(prev)}',
    );
    start = curr;
    prev = curr;
--- a/lib/widgets/messages/message_trace_sheet.dart
+++ b/lib/widgets/messages/message_trace_sheet.dart
@@ -10,6 +10,7 @@ import '../../models/ble_packet_log.dart';
 import '../../models/message.dart';
 import '../../providers/connection_provider.dart';
 import '../../providers/contacts_provider.dart';
+import '../../providers/messages_provider.dart';
 import '../../services/mesh_map_nodes_service.dart';
 import '../../services/route_hash_preferences.dart';
 import '../../utils/log_rx_route_decoder.dart';
@@ -35,11 +36,17 @@ class _MessageTraceSheetState extends State<MessageTraceSheet> {
  Future<_TraceResult> _loadTrace() async {
    final connectionProvider = context.read<ConnectionProvider>();
    final contactsProvider = context.read<ContactsProvider>();
+    final messagesProvider = context.read<MessagesProvider>();
    final preferredHashSize = await RouteHashPreferences.getHashSize();
-    final packetPath = _extractPathFromPacketLogs(
-      logs: connectionProvider.bleService.packetLogs,
-      message: widget.message,
-    );
+    final storedPath =
+        messagesProvider.getMessageReceptionDetails(widget.message.id)?.pathBytes;
+    final packetPath =
+        (storedPath != null && storedPath.isNotEmpty)
+        ? storedPath
+        : _extractPathFromPacketLogs(
+            logs: connectionProvider.bleService.packetLogs,
+            message: widget.message,
+          );

    final senderPrefix = _toPrefixHex(widget.message.senderPublicKeyPrefix);
    final recipientPrefix = widget.message.recipientPublicKey != null
@@ -456,7 +463,7 @@ class _MessageTraceSheetState extends State<MessageTraceSheet> {
      final hopHashes = LogRxRouteDecoder.splitHopHashes(
        packetPath,
        hashSize: hashSize,
-      );
+      ).reversed.toList();
      final matched = _matchNodesFromPathHashes(
        nodes: nodes,
        pathHashes: hopHashes,
@@ -568,6 +575,12 @@ class _MessageTraceSheetState extends State<MessageTraceSheet> {
            .toList();
        if (senderMatches.isNotEmpty) filtered = senderMatches;
      }
+      if (i == pathHashes.length - 1 && recipientPrefix != null) {
+        final recipientMatches = filtered
+            .where((n) => n.publicKey.startsWith(recipientPrefix))
+            .toList();
+        if (recipientMatches.isNotEmpty) filtered = recipientMatches;
+      }

      filtered.sort((a, b) => b.updatedAtMs.compareTo(a.updatedAtMs));
      result.add(filtered.first);