Tweak AVIF tuning and preferences

2026-08-11 16:30:28 +00:00 · 2026-03-02 09:42:14 +01:00
parent 4d0c45c11c
commit c176bd92a9
12 changed files with 972 additions and 47 deletions
--- a/docs/image-mode-technical.md
+++ b/docs/image-mode-technical.md
@@ -205,7 +205,34 @@ Status line below thumbnail:
 - Receiver (pending): `🖼️ Tap to load · {w}×{h}`
 - Loading: `📥 Loading… {received}/{total}`

-## 9. Persistence
+## 9. Transmit Time Estimate (UI)
+
+Image bubbles and Message Technical Details show an **estimated transmit time** (`~... tx`).
+
+The estimate is airtime-based (LoRa packet model), not just compressed image size:
+
+- Source inputs:
+  - `total` fragments and `bytes` from `IE1` envelope
+  - `pathLen` from message metadata
+  - current radio params from `deviceInfo`: `radioBw`, `radioSf`, `radioCr`
+- Per-fragment payload model:
+  - `meshHeader(2)` + `pathLen` + `imageHeader(8)` + `fragmentBytes`
+- LoRa airtime:
+  - standard symbol-time formula (preamble + payload symbols)
+- Mesh pacing/hops:
+  - multiplied by `(1 + airtimeBudgetFactor)` where default factor is `1.0`
+  - multiplied by hop count `(pathLen + 1)`
+- Total estimate:
+  - sum over all fragments
+
+BW handling:
+
+- If `radioBw` is index `0..9`, app maps it to Hz (`7.8k` .. `500k`)
+- If `radioBw > 1000`, it is treated as Hz directly
+
+Fallback defaults are used when radio params are unavailable: `SF10`, `BW250kHz`, `CR5`.
+
+## 10. Persistence

 `ImageProvider` stores sessions in `SharedPreferences` under key
 `stored_image_sessions_v1`:
@@ -214,14 +241,14 @@ Status line below thumbnail:
 - Outgoing: fragment list + envelope text + `cachedAt` timestamp.
 - Expired outgoing sessions (> 15 min) are not restored on startup.

-## 10. Operational Constraints
+## 11. Operational Constraints

 - No firmware changes required (reuses `cmdSendRawData` / `pushRawData`).
 - On-demand fetch works only if sender app is online and has cached session.
 - Raw return path requires a valid direct route to requester.
 - Available on iOS and Android (`image_picker` + `flutter_avif`).

-## 11. High-Level Sequence
+## 12. High-Level Sequence

 ```mermaid
 sequenceDiagram
--- a/docs/voice-mode-technical.md
+++ b/docs/voice-mode-technical.md
@@ -175,19 +175,47 @@ Parser validation enforces:

 `VR1` handling verifies sender prefix matches `requesterKey6` to reduce spoofing risk.

-## 10. Operational Constraints
+## 10. Transmit Time Estimate (UI)
+
+Voice bubbles and Message Technical Details show an **estimated transmit time** (`~... tx`).
+
+The estimate is airtime-based (LoRa packet model), not file-duration-only:
+
+- Source inputs:
+  - `packetCount` and `durationMs` from `VE1` envelope, or
+  - actual received `VoicePacket.codec2Data.length` bytes when local session packets exist
+  - `pathLen` from message metadata
+  - current radio params from `deviceInfo`: `radioBw`, `radioSf`, `radioCr`
+- Per-packet payload model:
+  - `meshHeader(2)` + `pathLen` + `voiceHeader(8)` + `codec2Bytes`
+- LoRa airtime:
+  - standard symbol-time formula (preamble + payload symbols)
+- Mesh pacing/hops:
+  - multiplied by `(1 + airtimeBudgetFactor)` where default factor is `1.0`
+  - multiplied by hop count `(pathLen + 1)`
+- Total estimate:
+  - sum over all packets
+
+BW handling:
+
+- If `radioBw` is index `0..9`, app maps it to Hz (`7.8k` .. `500k`)
+- If `radioBw > 1000`, it is treated as Hz directly
+
+Fallback defaults are used when radio params are unavailable: `SF10`, `BW250kHz`, `CR5`.
+
+## 11. Operational Constraints

 - No firmware changes required.
 - On-demand fetch works only if sender app is online and has cached session.
 - Raw return path needs a currently valid direct route to requester.
 - Voice capture is available on iOS and Android (`Platform.isIOS || Platform.isAndroid`).

-## 11. Backward Compatibility
+## 12. Backward Compatibility

 - Legacy `V:` text packet parsing is still supported.
 - Message voice detection accepts both new `VE1` and legacy `V:` formats.

-## 12. High-Level Sequence
+## 13. High-Level Sequence

 ```mermaid
 sequenceDiagram
--- a/lib/screens/messages_tab.dart
+++ b/lib/screens/messages_tab.dart
@@ -450,11 +450,17 @@ class _MessagesTabState extends State<MessagesTab> {
      final maxSize = await ImagePreferences.getMaxSize();
      final compression = await ImagePreferences.getCompression();
      final grayscale = await ImagePreferences.getGrayscale();
+      final ultraMode = await ImagePreferences.getUltraMode();
+      final effectiveMaxSize = ImagePreferences.effectiveMaxSize(
+        maxSize,
+        ultraMode: ultraMode,
+      );
      final result = await ImageCodecService.compress(
        rawBytes,
-        maxDimension: maxSize,
+        maxDimension: effectiveMaxSize,
        compression: compression,
        grayscale: grayscale,
+        ultraMode: ultraMode,
      );
      if (result == null) {
        if (!mounted) return;
--- a/lib/screens/settings_screen.dart
+++ b/lib/screens/settings_screen.dart
@@ -1,5 +1,8 @@
 import 'dart:io' show Platform;
+import 'dart:typed_data';
 import 'package:flutter/material.dart';
+import 'package:flutter_avif/flutter_avif.dart';
+import 'package:image_picker/image_picker.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:package_info_plus/package_info_plus.dart';
 import 'package:provider/provider.dart';
@@ -9,12 +12,17 @@ import 'package:url_launcher/url_launcher.dart';
 import '../providers/contacts_provider.dart';
 import '../providers/messages_provider.dart';
 import '../providers/app_provider.dart';
+import '../providers/connection_provider.dart';
 import '../services/location_tracking_service.dart';
 import '../services/locale_preferences.dart';
 import '../services/update_checker_service.dart';
+import '../services/voice_codec_service.dart';
 import '../services/voice_bitrate_preferences.dart';
 import '../services/image_preferences.dart';
+import '../services/image_codec_service.dart';
 import '../utils/sample_data_generator.dart';
+import '../utils/image_message_parser.dart';
+import '../utils/voice_message_parser.dart';
 import '../theme/app_theme.dart';
 import '../l10n/app_localizations.dart';
 import '../widgets/connection_mode_selector.dart';
@@ -51,6 +59,13 @@ class _SettingsScreenState extends State<SettingsScreen> {
  int _imageMaxSize = ImagePreferences.defaultMaxSize;
  int _imageCompression = ImagePreferences.defaultQuality;
  bool _imageGrayscale = ImagePreferences.defaultGrayscale;
+  bool _imageUltraMode = ImagePreferences.defaultUltraMode;
+  Uint8List? _previewSourceBytes;
+  String? _previewSourceName;
+  Uint8List? _previewCompressedBytes;
+  bool _isPreviewLoading = false;
+  bool _showCurrentImagePreview = true;
+  final ImagePicker _imagePicker = ImagePicker();
  final LocationTrackingService _locationService = LocationTrackingService();

  @override
@@ -121,24 +136,88 @@ class _SettingsScreenState extends State<SettingsScreen> {
    final size = await ImagePreferences.getMaxSize();
    final compression = await ImagePreferences.getCompression();
    final grayscale = await ImagePreferences.getGrayscale();
+    final ultraMode = await ImagePreferences.getUltraMode();
    if (!mounted) return;
    setState(() {
-      _imageMaxSize = size;
+      _imageMaxSize = ImagePreferences.effectiveMaxSize(
+        size,
+        ultraMode: ultraMode,
+      );
      _imageCompression = compression;
      _imageGrayscale = grayscale;
+      _imageUltraMode = ultraMode;
    });
+    await _refreshImageModePreview();
  }

  Future<void> _saveImageMaxSize(int size) async {
    await ImagePreferences.setMaxSize(size);
    if (!mounted) return;
    setState(() => _imageMaxSize = size);
+    await _refreshImageModePreview();
  }

  Future<void> _saveImageCompression(int compression) async {
    await ImagePreferences.setCompression(compression);
    if (!mounted) return;
    setState(() => _imageCompression = compression);
+    await _refreshImageModePreview();
+  }
+
+  Future<void> _refreshImageModePreview() async {
+    final sourceBytes = _previewSourceBytes;
+    if (sourceBytes == null) {
+      if (!mounted) return;
+      setState(() => _previewCompressedBytes = null);
+      return;
+    }
+
+    setState(() => _isPreviewLoading = true);
+    try {
+      final result = await ImageCodecService.compress(
+        sourceBytes,
+        maxDimension: ImagePreferences.effectiveMaxSize(
+          _imageMaxSize,
+          ultraMode: _imageUltraMode,
+        ),
+        compression: _imageCompression,
+        grayscale: _imageGrayscale,
+        ultraMode: _imageUltraMode,
+      );
+      if (!mounted) return;
+      setState(() {
+        _previewCompressedBytes = result?.bytes;
+        _isPreviewLoading = false;
+      });
+    } catch (_) {
+      if (!mounted) return;
+      setState(() {
+        _previewCompressedBytes = null;
+        _isPreviewLoading = false;
+      });
+    }
+  }
+
+  Future<void> _selectPreviewImageFromGallery() async {
+    try {
+      final picked = await _imagePicker.pickImage(source: ImageSource.gallery);
+      if (picked == null) return;
+      final bytes = await picked.readAsBytes();
+      if (!mounted) return;
+      setState(() {
+        _previewSourceBytes = bytes;
+        _previewSourceName = picked.name;
+      });
+      await _refreshImageModePreview();
+    } catch (e) {
+      if (!mounted) return;
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(
+          content: Text('Failed to load preview image: $e'),
+          backgroundColor: Colors.red,
+        ),
+      );
+    }
  }

  Future<void> _initializeLocationService() async {
@@ -606,14 +685,16 @@ class _SettingsScreenState extends State<SettingsScreen> {

          // Voice Settings Section
          _buildSectionHeader('Voice'),
-          Consumer<AppProvider>(
-            builder: (context, appProvider, child) => _buildVoiceStatsCard(
-              bitrate: _voiceBitrate,
-              bandPassEnabled: appProvider.isVoiceBandPassFilterEnabled,
-              compressorEnabled: appProvider.isVoiceCompressorEnabled,
-              limiterEnabled: appProvider.isVoiceLimiterEnabled,
-              silenceTrimEnabled: appProvider.isVoiceSilenceTrimmingEnabled,
-            ),
+          Consumer2<AppProvider, ConnectionProvider>(
+            builder: (context, appProvider, connectionProvider, child) =>
+                _buildVoiceStatsCard(
+                  bitrate: _voiceBitrate,
+                  connectionProvider: connectionProvider,
+                  bandPassEnabled: appProvider.isVoiceBandPassFilterEnabled,
+                  compressorEnabled: appProvider.isVoiceCompressorEnabled,
+                  limiterEnabled: appProvider.isVoiceLimiterEnabled,
+                  silenceTrimEnabled: appProvider.isVoiceSilenceTrimmingEnabled,
+                ),
          ),
          ListTile(
            leading: const Icon(Icons.graphic_eq),
@@ -708,8 +789,28 @@ class _SettingsScreenState extends State<SettingsScreen> {
            onChanged: (value) async {
              await ImagePreferences.setGrayscale(value);
              setState(() => _imageGrayscale = value);
+              await _refreshImageModePreview();
            },
          ),
+          SwitchListTile(
+            secondary: const Icon(Icons.compress),
+            title: const Text('Ultra mode'),
+            subtitle: const Text(
+              'Extra-aggressive compression with stronger AVIF settings',
+            ),
+            value: _imageUltraMode,
+            onChanged: (value) async {
+              await ImagePreferences.setUltraMode(value);
+              setState(() {
+                _imageUltraMode = value;
+              });
+              await _refreshImageModePreview();
+            },
+          ),
+          Consumer<ConnectionProvider>(
+            builder: (context, connectionProvider, child) =>
+                _buildImageModePreviewCard(connectionProvider),
+          ),
          const Divider(),

          // Templates Section
@@ -931,8 +1032,187 @@ class _SettingsScreenState extends State<SettingsScreen> {
    );
  }

+  Widget _buildImageModePreviewCard(ConnectionProvider connectionProvider) {
+    final sourceBytes = _previewSourceBytes;
+    final fileName = _previewSourceName ?? 'No image selected';
+    final radioBw = connectionProvider.deviceInfo.radioBw;
+    final radioSf = connectionProvider.deviceInfo.radioSf;
+    final radioCr = connectionProvider.deviceInfo.radioCr;
+    final bwHz = _resolveBandwidthHz(radioBw);
+    final previewSizeBytes = _previewCompressedBytes?.length ?? 0;
+    final directChunk = safeImageDataBytesForPath(0);
+    final twoHopChunk = safeImageDataBytesForPath(2);
+    final directFragments = previewSizeBytes > 0
+        ? (previewSizeBytes + directChunk - 1) ~/ directChunk
+        : 0;
+    final twoHopFragments = previewSizeBytes > 0
+        ? (previewSizeBytes + twoHopChunk - 1) ~/ twoHopChunk
+        : 0;
+    final imageDirect = estimateImageTransmitDuration(
+      fragmentCount: directFragments,
+      sizeBytes: previewSizeBytes,
+      pathLen: 0,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    final imageTwoHop = estimateImageTransmitDuration(
+      fragmentCount: twoHopFragments,
+      sizeBytes: previewSizeBytes,
+      pathLen: 2,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+
+    return Card(
+      margin: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
+      child: Padding(
+        padding: const EdgeInsets.all(12),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            const Row(
+              children: [
+                Icon(Icons.photo_library_outlined),
+                SizedBox(width: 8),
+                Text(
+                  'Image mode preview',
+                  style: TextStyle(fontWeight: FontWeight.w700),
+                ),
+              ],
+            ),
+            const SizedBox(height: 6),
+            Row(
+              children: [
+                Expanded(
+                  child: Text(
+                    'Source image',
+                    style: Theme.of(context).textTheme.bodySmall,
+                  ),
+                ),
+                FilledButton.icon(
+                  onPressed: _isPreviewLoading
+                      ? null
+                      : _selectPreviewImageFromGallery,
+                  icon: const Icon(Icons.photo_library_outlined),
+                  label: const Text('Select from gallery'),
+                ),
+              ],
+            ),
+            const SizedBox(height: 6),
+            Text(
+              fileName,
+              style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(
+                  context,
+                ).colorScheme.onSurface.withValues(alpha: 0.8),
+              ),
+            ),
+            if (previewSizeBytes > 0) ...[
+              const SizedBox(height: 4),
+              Text(
+                'Preview tx (this image): Direct ${_formatEstimateDuration(imageDirect)} • 2-hop ${_formatEstimateDuration(imageTwoHop)}',
+                style: Theme.of(context).textTheme.bodySmall,
+              ),
+              Text(
+                'Radio BW ${_formatBandwidthLabel(bwHz)} · SF ${radioSf ?? 10} · CR ${radioCr ?? 5}',
+                style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                  color: Theme.of(
+                    context,
+                  ).colorScheme.onSurface.withValues(alpha: 0.7),
+                ),
+              ),
+            ],
+            const SizedBox(height: 10),
+            Row(
+              children: [
+                Expanded(
+                  child: Text(
+                    _showCurrentImagePreview
+                        ? 'Showing: current image mode'
+                        : 'Showing: source image',
+                    style: Theme.of(context).textTheme.bodySmall,
+                  ),
+                ),
+                Switch.adaptive(
+                  value: _showCurrentImagePreview,
+                  onChanged: (value) {
+                    setState(() => _showCurrentImagePreview = value);
+                  },
+                ),
+              ],
+            ),
+            const SizedBox(height: 6),
+            ClipRRect(
+              borderRadius: BorderRadius.circular(8),
+              child: AspectRatio(
+                aspectRatio: 1,
+                child: _showCurrentImagePreview
+                    ? (_isPreviewLoading
+                          ? const Center(
+                              child: CircularProgressIndicator(strokeWidth: 2),
+                            )
+                          : (_previewCompressedBytes != null
+                                ? AvifImage.memory(
+                                    _previewCompressedBytes!,
+                                    fit: BoxFit.cover,
+                                  )
+                                : Container(color: Colors.black12)))
+                    : (sourceBytes != null
+                          ? Image.memory(sourceBytes, fit: BoxFit.cover)
+                          : Container(color: Colors.black12)),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  String _formatEstimateDuration(Duration value) {
+    if (value.inSeconds < 60) return '~${value.inSeconds}s';
+    return '~${value.inMinutes}m ${value.inSeconds % 60}s';
+  }
+
+  static String _formatBandwidthLabel(int bwHz) {
+    if (bwHz >= 1000000) return '${(bwHz / 1000000).toStringAsFixed(2)} MHz';
+    if (bwHz >= 1000) return '${(bwHz / 1000).toStringAsFixed(1)} kHz';
+    return '$bwHz Hz';
+  }
+
+  int _resolveBandwidthHz(int? rawBw) {
+    if (rawBw == null) return 250000;
+    if (rawBw > 1000) return rawBw;
+    switch (rawBw) {
+      case 0:
+        return 7800;
+      case 1:
+        return 10400;
+      case 2:
+        return 15600;
+      case 3:
+        return 20800;
+      case 4:
+        return 31250;
+      case 5:
+        return 41700;
+      case 6:
+        return 62500;
+      case 7:
+        return 125000;
+      case 8:
+        return 250000;
+      case 9:
+        return 500000;
+      default:
+        return 250000;
+    }
+  }
+
  Widget _buildVoiceStatsCard({
    required int bitrate,
+    required ConnectionProvider connectionProvider,
    required bool bandPassEnabled,
    required bool compressorEnabled,
    required bool limiterEnabled,
@@ -949,6 +1229,33 @@ class _SettingsScreenState extends State<SettingsScreen> {
        (compressorEnabled ? 1 : 0) +
        (limiterEnabled ? 1 : 0) +
        (silenceTrimEnabled ? 1 : 0);
+    final radioBw = connectionProvider.deviceInfo.radioBw;
+    final radioSf = connectionProvider.deviceInfo.radioSf;
+    final radioCr = connectionProvider.deviceInfo.radioCr;
+    final bwHz = _resolveBandwidthHz(radioBw);
+    final voiceMode = VoiceBitratePreferences.toVoiceMode(bitrate);
+    const voicePreviewMs = 10000; // 10-second reference clip
+    final packetDurationMs = codec2ModeFor(voiceMode).packetDurationMs;
+    final voicePacketCount =
+        (voicePreviewMs + packetDurationMs - 1) ~/ packetDurationMs;
+    final voiceDirect = estimateVoiceTransmitDuration(
+      mode: voiceMode,
+      packetCount: voicePacketCount,
+      durationMs: voicePreviewMs,
+      pathLen: 0,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    final voiceTwoHop = estimateVoiceTransmitDuration(
+      mode: voiceMode,
+      packetCount: voicePacketCount,
+      durationMs: voicePreviewMs,
+      pathLen: 2,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );

    return Card(
      margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
@@ -966,6 +1273,19 @@ class _SettingsScreenState extends State<SettingsScreen> {
              'Bitrate: $bitrate bps',
              style: Theme.of(context).textTheme.bodySmall,
            ),
+            const SizedBox(height: 4),
+            Text(
+              'Preview tx (10s ${voiceMode.label}): Direct ${_formatEstimateDuration(voiceDirect)} • 2-hop ${_formatEstimateDuration(voiceTwoHop)}',
+              style: Theme.of(context).textTheme.bodySmall,
+            ),
+            Text(
+              'Radio BW ${_formatBandwidthLabel(bwHz)} · SF ${radioSf ?? 10} · CR ${radioCr ?? 5}',
+              style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(
+                  context,
+                ).colorScheme.onSurface.withValues(alpha: 0.7),
+              ),
+            ),
            const SizedBox(height: 6),
            ClipRRect(
              borderRadius: BorderRadius.circular(4),
--- a/lib/services/image_codec_service.dart
+++ b/lib/services/image_codec_service.dart
@@ -9,6 +9,9 @@ import 'package:flutter_avif/flutter_avif.dart';
 /// A typical 256×256 grayscale AVIF at quality 90 is highly compressed.
 /// → 7–20 fragments at 152 bytes each.
 class ImageCodecService {
+  static const int _normalAvifSpeed = 6;
+  static const int _ultraAvifSpeed = 4;
+
  /// Compress [rawBytes] (any decodable format: JPEG/PNG/WebP/AVIF) to a
  /// small grayscale AVIF suitable for mesh transmission.
  ///
@@ -22,8 +25,15 @@ class ImageCodecService {
    int maxDimension = 256,
    int compression = 90,
    bool grayscale = true,
+    bool ultraMode = false,
  }) async {
    try {
+      final effectiveMaxDimension = maxDimension.clamp(32, 1024);
+      final effectiveCompression = ultraMode
+          ? (compression + 12).clamp(10, 100)
+          : compression.clamp(10, 100);
+      final forceGrayscale = ultraMode ? true : grayscale;
+
      // 1a. Probe original dimensions (no resize).
      final probeCodec = await ui.instantiateImageCodec(rawBytes);
      final probeFrame = await probeCodec.getNextFrame();
@@ -35,13 +45,19 @@ class ImageCodecService {
      //     the image fits within maxDimension×maxDimension without stretching.
      int dstW = srcW;
      int dstH = srcH;
-      if (srcW > maxDimension || srcH > maxDimension) {
+      if (srcW > effectiveMaxDimension || srcH > effectiveMaxDimension) {
        if (srcW >= srcH) {
-          dstW = maxDimension;
-          dstH = (srcH * maxDimension / srcW).round().clamp(1, maxDimension);
+          dstW = effectiveMaxDimension;
+          dstH = (srcH * effectiveMaxDimension / srcW).round().clamp(
+            1,
+            effectiveMaxDimension,
+          );
        } else {
-          dstH = maxDimension;
-          dstW = (srcW * maxDimension / srcH).round().clamp(1, maxDimension);
+          dstH = effectiveMaxDimension;
+          dstW = (srcW * effectiveMaxDimension / srcH).round().clamp(
+            1,
+            effectiveMaxDimension,
+          );
        }
      }

@@ -67,7 +83,7 @@ class ImageCodecService {

      // 3. Optionally convert to grayscale in-place (luminance).
      final rgba = byteData.buffer.asUint8List();
-      if (grayscale) {
+      if (forceGrayscale) {
        for (var i = 0; i < rgba.length; i += 4) {
          final lum =
              (0.299 * rgba[i] + 0.587 * rgba[i + 1] + 0.114 * rgba[i + 2])
@@ -102,13 +118,19 @@ class ImageCodecService {
      // 5. Encode PNG → AVIF.
      //    maxQuantizer/minQuantizer: libavif CQ scale (0 = lossless, 63 = worst).
      //    compression=90 maps to maxQuantizer≈57, minQuantizer≈37.
-      final maxQ = ((compression / 100) * 63).round().clamp(0, 63);
+      final maxQ = ((effectiveCompression / 100) * 63).round().clamp(0, 63);
      final minQ = (maxQ * 0.65).round().clamp(0, maxQ);
      final avif = await encodeAvif(
        pngBytes,
+        maxThreads: 2,
        maxQuantizer: maxQ,
        minQuantizer: minQ,
-        speed: 8, // fast encode (0 = slowest/best, 10 = fastest)
+        // We force fully opaque alpha, so alpha can be quantized aggressively.
+        maxQuantizerAlpha: 63,
+        minQuantizerAlpha: 63,
+        // Slower speed improves compression efficiency at similar quality.
+        speed: ultraMode ? _ultraAvifSpeed : _normalAvifSpeed,
+        keepExif: false,
      );
      if (avif.isEmpty) return null;

--- a/lib/services/image_preferences.dart
+++ b/lib/services/image_preferences.dart
@@ -6,12 +6,14 @@ class ImagePreferences {
  // Keep the legacy key name so existing users retain their saved value.
  static const String _qualityKey = 'image_quality';
  static const String _grayscaleKey = 'image_grayscale';
+  static const String _ultraModeKey = 'image_ultra_mode';

  static const int defaultMaxSize = 256;
  static const int defaultQuality = 90;
  static const bool defaultGrayscale = true;
+  static const bool defaultUltraMode = false;

-  static const List<int> supportedSizes = [64, 128, 256];
+  static const List<int> supportedSizes = [64, 96, 128, 256];

  static Future<int> getMaxSize() async {
    final prefs = await SharedPreferences.getInstance();
@@ -44,4 +46,21 @@ class ImagePreferences {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setBool(_grayscaleKey, value);
  }
+
+  static Future<bool> getUltraMode() async {
+    final prefs = await SharedPreferences.getInstance();
+    return prefs.getBool(_ultraModeKey) ?? defaultUltraMode;
+  }
+
+  static Future<void> setUltraMode(bool value) async {
+    final prefs = await SharedPreferences.getInstance();
+    await prefs.setBool(_ultraModeKey, value);
+  }
+
+  static int effectiveMaxSize(
+    int configuredMaxSize, {
+    required bool ultraMode,
+  }) {
+    return configuredMaxSize.clamp(32, 1024);
+  }
 }
--- a/lib/utils/image_message_parser.dart
+++ b/lib/utils/image_message_parser.dart
@@ -3,6 +3,15 @@ import 'dart:typed_data';
 const int _maxCompanionFrameBytes = 172; // MeshCore MAX_FRAME_SIZE
 const int _cmdSendRawDataOverheadBytes = 2; // cmd + pathLen
 const int _maxMeshPacketPayloadBytes = 184; // MeshCore MAX_PACKET_PAYLOAD
+const int _meshPacketHeaderBytes = 2; // mesh header bytes before path/payload
+const int _imagePacketHeaderBytes = 8; // image packet binary header in payload
+const int _defaultLoRaSf = 10; // MeshCore companion defaults (SF10)
+const int _defaultLoRaCr = 5; // MeshCore companion defaults (4/5)
+const int _defaultLoRaBwHz = 250000; // MeshCore companion defaults (250kHz)
+const int _defaultLoRaPreambleSymbols = 8;
+const int _defaultLoRaCrcEnabled = 1;
+const int _defaultLoRaExplicitHeader = 1;
+const double _defaultAirtimeBudgetFactor = 1.0; // one half duty-cycle

 /// Compressed image format used in the image packet protocol.
 enum ImageFormat {
@@ -119,6 +128,118 @@ int safeImageDataBytesForPath(int pathLen) {
  return maxData.clamp(1, 255).toInt();
 }

+/// Approximate end-to-end transmit time for image fragments on MeshCore LoRa.
+///
+/// The estimate uses:
+/// - LoRa airtime math with MeshCore companion defaults (SF10/BW250/CR5),
+/// - MeshCore airtime budget pacing (default factor 1.0),
+/// - hop multiplier (`pathLen + 1`) for direct routed packets.
+Duration estimateImageTransmitDuration({
+  required int fragmentCount,
+  required int sizeBytes,
+  int pathLen = 0,
+  int? radioBw,
+  int? radioSf,
+  int? radioCr,
+}) {
+  if (fragmentCount <= 0 || sizeBytes <= 0) return Duration.zero;
+
+  final safePathLen = pathLen.clamp(0, 64);
+  final hops = safePathLen + 1;
+  final baseDataPerFragment = sizeBytes ~/ fragmentCount;
+  final extraBytes = sizeBytes % fragmentCount;
+  var totalMs = 0.0;
+
+  for (var i = 0; i < fragmentCount; i++) {
+    final fragmentDataBytes = baseDataPerFragment + (i < extraBytes ? 1 : 0);
+    final loraLen =
+        _meshPacketHeaderBytes +
+        safePathLen +
+        _imagePacketHeaderBytes +
+        fragmentDataBytes;
+    final airtimeMs = _estimateLoRaAirtimeMs(
+      loraLen,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    totalMs += airtimeMs * (1.0 + _defaultAirtimeBudgetFactor) * hops;
+  }
+
+  return Duration(milliseconds: totalMs.round());
+}
+
+double _estimateLoRaAirtimeMs(
+  int payloadLenBytes, {
+  int? radioBw,
+  int? radioSf,
+  int? radioCr,
+}) {
+  final sf = _normalizeSf(radioSf);
+  final bw = _resolveBandwidthHz(radioBw).toDouble();
+  final cr = (_normalizeCr(radioCr) - 4).clamp(1, 4);
+  final ih = _defaultLoRaExplicitHeader == 1 ? 0 : 1;
+  final de = (sf >= 11 && _defaultLoRaBwHz <= 125000) ? 1 : 0;
+
+  final symbolMs = ((1 << sf) / bw) * 1000.0;
+  final preambleMs = (_defaultLoRaPreambleSymbols + 4.25) * symbolMs;
+
+  final num =
+      (8 * payloadLenBytes) -
+      (4 * sf) +
+      28 +
+      (16 * _defaultLoRaCrcEnabled) -
+      (20 * ih);
+  final den = 4 * (sf - (2 * de));
+  final payloadSymCoeff = den <= 0 ? 0 : (num / den).ceil();
+  final payloadSymbols =
+      8 + (payloadSymCoeff < 0 ? 0 : payloadSymCoeff) * (cr + 4);
+  final payloadMs = payloadSymbols * symbolMs;
+
+  return preambleMs + payloadMs;
+}
+
+int _normalizeSf(int? value) {
+  if (value == null) return _defaultLoRaSf;
+  if (value >= 5 && value <= 12) return value;
+  return _defaultLoRaSf;
+}
+
+int _normalizeCr(int? value) {
+  if (value == null) return _defaultLoRaCr;
+  if (value >= 5 && value <= 8) return value;
+  return _defaultLoRaCr;
+}
+
+int _resolveBandwidthHz(int? rawBw) {
+  if (rawBw == null) return _defaultLoRaBwHz;
+  if (rawBw > 1000) return rawBw;
+  switch (rawBw) {
+    case 0:
+      return 7800;
+    case 1:
+      return 10400;
+    case 2:
+      return 15600;
+    case 3:
+      return 20800;
+    case 4:
+      return 31250;
+    case 5:
+      return 41700;
+    case 6:
+      return 62500;
+    case 7:
+      return 125000;
+    case 8:
+      return 250000;
+    case 9:
+      return 500000;
+    default:
+      return _defaultLoRaBwHz;
+  }
+}
+
 /// Envelope announcing image availability (control plane).
 ///
 /// Text format:
--- a/lib/utils/voice_message_parser.dart
+++ b/lib/utils/voice_message_parser.dart
@@ -1,6 +1,16 @@
 import 'dart:convert';
 import 'dart:typed_data';

+const int _meshPacketHeaderBytes = 2; // mesh header bytes before path/payload
+const int _voicePacketHeaderBytes = 8; // voice packet binary header in payload
+const int _defaultLoRaSf = 10; // MeshCore companion defaults (SF10)
+const int _defaultLoRaCr = 5; // MeshCore companion defaults (4/5)
+const int _defaultLoRaBwHz = 250000; // MeshCore companion defaults (250kHz)
+const int _defaultLoRaPreambleSymbols = 8;
+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 {
@@ -248,6 +258,160 @@ 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,
+};
+
+/// Approximate end-to-end transmit time for a voice session over MeshCore LoRa.
+///
+/// Uses envelope-level metadata (mode + duration + packet count) when only the
+/// envelope is available and packet bytes are not yet received locally.
+Duration estimateVoiceTransmitDuration({
+  required VoicePacketMode mode,
+  required int packetCount,
+  required int durationMs,
+  int pathLen = 0,
+  int? radioBw,
+  int? radioSf,
+  int? radioCr,
+}) {
+  if (packetCount <= 0 || durationMs <= 0) return Duration.zero;
+
+  final bytesPerSecond = voiceModeBytesPerSecond(mode);
+  final totalCodecBytes = (durationMs * bytesPerSecond / 1000.0).round();
+  final safePathLen = pathLen.clamp(0, 64);
+  final hops = safePathLen + 1;
+  final baseBytesPerPacket = totalCodecBytes ~/ packetCount;
+  final extraBytes = totalCodecBytes % packetCount;
+  var totalMs = 0.0;
+
+  for (var i = 0; i < packetCount; i++) {
+    final codecBytes = baseBytesPerPacket + (i < extraBytes ? 1 : 0);
+    final loraLen =
+        _meshPacketHeaderBytes +
+        safePathLen +
+        _voicePacketHeaderBytes +
+        codecBytes;
+    final airtimeMs = _estimateLoRaAirtimeMs(
+      loraLen,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    totalMs += airtimeMs * (1.0 + _defaultAirtimeBudgetFactor) * hops;
+  }
+
+  return Duration(milliseconds: totalMs.round());
+}
+
+/// Approximate transmit time using actually received voice packet sizes.
+Duration estimateVoiceTransmitDurationFromPackets({
+  required Iterable<VoicePacket?> packets,
+  int pathLen = 0,
+  int? radioBw,
+  int? radioSf,
+  int? radioCr,
+}) {
+  final safePathLen = pathLen.clamp(0, 64);
+  final hops = safePathLen + 1;
+  var totalMs = 0.0;
+
+  for (final packet in packets) {
+    if (packet == null) continue;
+    final loraLen =
+        _meshPacketHeaderBytes +
+        safePathLen +
+        _voicePacketHeaderBytes +
+        packet.codec2Data.length;
+    final airtimeMs = _estimateLoRaAirtimeMs(
+      loraLen,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    totalMs += airtimeMs * (1.0 + _defaultAirtimeBudgetFactor) * hops;
+  }
+
+  return Duration(milliseconds: totalMs.round());
+}
+
+double _estimateLoRaAirtimeMs(
+  int payloadLenBytes, {
+  int? radioBw,
+  int? radioSf,
+  int? radioCr,
+}) {
+  final sf = _normalizeSf(radioSf);
+  final bw = _resolveBandwidthHz(radioBw).toDouble();
+  final cr = (_normalizeCr(radioCr) - 4).clamp(1, 4);
+  final ih = _defaultLoRaExplicitHeader == 1 ? 0 : 1;
+  final de = (sf >= 11 && _defaultLoRaBwHz <= 125000) ? 1 : 0;
+
+  final symbolMs = ((1 << sf) / bw) * 1000.0;
+  final preambleMs = (_defaultLoRaPreambleSymbols + 4.25) * symbolMs;
+
+  final num =
+      (8 * payloadLenBytes) -
+      (4 * sf) +
+      28 +
+      (16 * _defaultLoRaCrcEnabled) -
+      (20 * ih);
+  final den = 4 * (sf - (2 * de));
+  final payloadSymCoeff = den <= 0 ? 0 : (num / den).ceil();
+  final payloadSymbols =
+      8 + (payloadSymCoeff < 0 ? 0 : payloadSymCoeff) * (cr + 4);
+  final payloadMs = payloadSymbols * symbolMs;
+
+  return preambleMs + payloadMs;
+}
+
+int _normalizeSf(int? value) {
+  if (value == null) return _defaultLoRaSf;
+  if (value >= 5 && value <= 12) return value;
+  return _defaultLoRaSf;
+}
+
+int _normalizeCr(int? value) {
+  if (value == null) return _defaultLoRaCr;
+  if (value >= 5 && value <= 8) return value;
+  return _defaultLoRaCr;
+}
+
+int _resolveBandwidthHz(int? rawBw) {
+  if (rawBw == null) return _defaultLoRaBwHz;
+  if (rawBw > 1000) return rawBw;
+  switch (rawBw) {
+    case 0:
+      return 7800;
+    case 1:
+      return 10400;
+    case 2:
+      return 15600;
+    case 3:
+      return 20800;
+    case 4:
+      return 31250;
+    case 5:
+      return 41700;
+    case 6:
+      return 62500;
+    case 7:
+      return 125000;
+    case 8:
+      return 250000;
+    case 9:
+      return 500000;
+    default:
+      return _defaultLoRaBwHz;
+  }
+}
+
 /// Direct control-plane request to fetch voice packets for a session.
 ///
 /// Text format:
--- a/lib/widgets/messages/image_message_bubble.dart
+++ b/lib/widgets/messages/image_message_bubble.dart
@@ -34,6 +34,15 @@ class _ImageMessageBubbleState extends State<ImageMessageBubble> {

  @override
  Widget build(BuildContext context) {
+    final radioBw = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioBw,
+    );
+    final radioSf = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioSf,
+    );
+    final radioCr = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioCr,
+    );
    final envelope = ImageEnvelope.tryParse(widget.message.text);
    if (envelope == null) return const SizedBox.shrink();

@@ -84,6 +93,10 @@ class _ImageMessageBubbleState extends State<ImageMessageBubble> {
                    received: received,
                    total: total,
                    envelope: envelope,
+                    pathLen: widget.message.pathLen,
+                    radioBw: radioBw,
+                    radioSf: radioSf,
+                    radioCr: radioCr,
                    error: _errorText,
                    isSentByMe: widget.isSentByMe,
                  ),
@@ -219,17 +232,40 @@ class _ImageMessageBubbleState extends State<ImageMessageBubble> {
    required int received,
    required int total,
    required ImageEnvelope envelope,
+    required int pathLen,
+    required int? radioBw,
+    required int? radioSf,
+    required int? radioCr,
    required String? error,
    required bool isSentByMe,
  }) {
+    final txEstimate = estimateImageTransmitDuration(
+      fragmentCount: envelope.total,
+      sizeBytes: envelope.sizeBytes,
+      pathLen: pathLen,
+      radioBw: radioBw,
+      radioSf: radioSf,
+      radioCr: radioCr,
+    );
+    final txEstimateLabel = _formatTransmitEstimate(txEstimate);
+
    if (error != null) return error;
-    if (isRequesting) return '📥 Loading… $received/$total';
+    if (isRequesting) return '📥 Loading… $received/$total · $txEstimateLabel';
    if (isComplete) {
      final base =
          '🖼️ ${envelope.width}×${envelope.height} ${envelope.format.label}';
-      return isSentByMe ? '$base · ${envelope.total} seg' : base;
+      return isSentByMe
+          ? '$base · ${envelope.total} seg · $txEstimateLabel'
+          : '$base · $txEstimateLabel';
    }
-    return '🖼️ Tap to load · ${envelope.width}×${envelope.height}';
+    return '🖼️ Tap to load · ${envelope.width}×${envelope.height} · $txEstimateLabel';
+  }
+
+  static String _formatTransmitEstimate(Duration value) {
+    if (value.inSeconds < 60) return '~${value.inSeconds}s tx';
+    final minutes = value.inMinutes;
+    final seconds = value.inSeconds % 60;
+    return '~${minutes}m ${seconds}s tx';
  }

  void _showFullScreen(BuildContext context, Uint8List imageBytes) {
--- a/lib/widgets/messages/message_bubble.dart
+++ b/lib/widgets/messages/message_bubble.dart
@@ -298,6 +298,9 @@ class _MessageBubbleState extends State<MessageBubble> {

  void _showTechnicalDetails(BuildContext context) {
    final connectionProvider = context.read<ConnectionProvider>();
+    final radioBw = connectionProvider.deviceInfo.radioBw;
+    final radioSf = connectionProvider.deviceInfo.radioSf;
+    final radioCr = connectionProvider.deviceInfo.radioCr;
    final contactsProvider = context.read<ContactsProvider>();
    final voiceProvider = context.read<VoiceProvider>();
    final imageProvider = context.read<ip.ImageProvider>();
@@ -350,6 +353,45 @@ class _MessageBubbleState extends State<MessageBubble> {
    final imageSession = imageEnvelope != null
        ? imageProvider.session(imageEnvelope.sessionId)
        : null;
+    final imageTxEstimate = imageEnvelope != null
+        ? estimateImageTransmitDuration(
+            fragmentCount: imageEnvelope.total,
+            sizeBytes: imageEnvelope.sizeBytes,
+            pathLen: widget.message.pathLen,
+            radioBw: radioBw,
+            radioSf: radioSf,
+            radioCr: radioCr,
+          )
+        : Duration.zero;
+    final voiceTxEstimate = voiceSession != null
+        ? estimateVoiceTransmitDurationFromPackets(
+            packets: voiceSession.packets,
+            pathLen: widget.message.pathLen,
+            radioBw: radioBw,
+            radioSf: radioSf,
+            radioCr: radioCr,
+          )
+        : envelope != null
+        ? estimateVoiceTransmitDuration(
+            mode: envelope.mode,
+            packetCount: envelope.total,
+            durationMs: envelope.durationMs,
+            pathLen: widget.message.pathLen,
+            radioBw: radioBw,
+            radioSf: radioSf,
+            radioCr: radioCr,
+          )
+        : legacyVoicePacket != null
+        ? estimateVoiceTransmitDuration(
+            mode: legacyVoicePacket.mode,
+            packetCount: legacyVoicePacket.total,
+            durationMs: legacyVoicePacket.durationMs * legacyVoicePacket.total,
+            pathLen: widget.message.pathLen,
+            radioBw: radioBw,
+            radioSf: radioSf,
+            radioCr: radioCr,
+          )
+        : Duration.zero;

    final senderPrefixHex = widget.message.senderPublicKeyPrefix
        ?.map((b) => b.toRadixString(16).padLeft(2, '0'))
@@ -431,8 +473,16 @@ class _MessageBubbleState extends State<MessageBubble> {
        rawLines.add(
          'Session estimated duration s: ${voiceSession.estimatedDurationSeconds.toStringAsFixed(2)}',
        );
+        rawLines.add(
+          'Estimated voice tx: ~${voiceTxEstimate.inSeconds}s (current radio)',
+        );
      } else {
        rawLines.add('Session present locally: no');
+        if (voiceTxEstimate > Duration.zero) {
+          rawLines.add(
+            'Estimated voice tx: ~${voiceTxEstimate.inSeconds}s (current radio)',
+          );
+        }
      }
    }

@@ -448,6 +498,9 @@ class _MessageBubbleState extends State<MessageBubble> {
      );
      rawLines.add('Fragments total (envelope): ${imageEnvelope.total}');
      rawLines.add('Compressed size (envelope): ${imageEnvelope.sizeBytes} B');
+      rawLines.add(
+        'Estimated image tx: ~${imageTxEstimate.inSeconds}s (current radio)',
+      );
      rawLines.add('Envelope senderKey6: ${imageEnvelope.senderKey6}');
      rawLines.add('Envelope ts: ${imageEnvelope.timestampSec}');
      rawLines.add('Envelope ver: ${imageEnvelope.version}');
@@ -588,7 +641,9 @@ class _MessageBubbleState extends State<MessageBubble> {
                      _detailRow(
                        context,
                        label: l10n.floodFallback,
-                        value: widget.message.usedFloodFallback ? l10n.yes : l10n.no,
+                        value: widget.message.usedFloodFallback
+                            ? l10n.yes
+                            : l10n.no,
                      ),
                    ],
                  ),
@@ -670,6 +725,59 @@ class _MessageBubbleState extends State<MessageBubble> {
                            label: l10n.complete,
                            value: voiceSession.isComplete ? l10n.yes : l10n.no,
                          ),
+                        if (voiceTxEstimate > Duration.zero)
+                          _detailRow(
+                            context,
+                            label: 'Estimated tx',
+                            value: voiceTxEstimate.inSeconds < 60
+                                ? '~${voiceTxEstimate.inSeconds}s'
+                                : '~${voiceTxEstimate.inMinutes}m ${voiceTxEstimate.inSeconds % 60}s',
+                          ),
+                      ],
+                    ),
+                  ),
+                ],
+                if (imageEnvelope != null) ...[
+                  const SizedBox(height: 12),
+                  _techSection(
+                    context,
+                    icon: Icons.image_outlined,
+                    title: 'Image',
+                    child: Column(
+                      children: [
+                        _detailRow(context, label: l10n.envelope, value: 'IE1'),
+                        _detailRow(
+                          context,
+                          label: 'Format',
+                          value: imageEnvelope.format.label,
+                        ),
+                        _detailRow(
+                          context,
+                          label: 'Dimensions',
+                          value:
+                              '${imageEnvelope.width}×${imageEnvelope.height}',
+                        ),
+                        _detailRow(
+                          context,
+                          label: 'Segments',
+                          value: imageSession != null
+                              ? '${imageSession.receivedCount}/${imageSession.total}'
+                              : '${imageEnvelope.total}',
+                        ),
+                        if (imageSession != null)
+                          _detailRow(
+                            context,
+                            label: l10n.complete,
+                            value: imageSession.isComplete ? l10n.yes : l10n.no,
+                          ),
+                        if (imageTxEstimate > Duration.zero)
+                          _detailRow(
+                            context,
+                            label: 'Estimated tx',
+                            value: imageTxEstimate.inSeconds < 60
+                                ? '~${imageTxEstimate.inSeconds}s'
+                                : '~${imageTxEstimate.inMinutes}m ${imageTxEstimate.inSeconds % 60}s',
+                          ),
                      ],
                    ),
                  ),
@@ -681,7 +789,10 @@ class _MessageBubbleState extends State<MessageBubble> {
                  visualDensity: VisualDensity.compact,
                  title: Text(
                    l10n.rawDump,
-                    style: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600),
+                    style: const TextStyle(
+                      fontSize: 12,
+                      fontWeight: FontWeight.w600,
+                    ),
                  ),
                  children: [
                    Container(
@@ -1834,7 +1945,8 @@ class _MessageBubbleState extends State<MessageBubble> {
                !widget.isCompact)
              VoiceMessageBubble(message: message, isSentByMe: isOwnMessage)
            // Image message content (IE1 envelope)
-            else if (ImageEnvelope.isEnvelope(message.text) && !widget.isCompact)
+            else if (ImageEnvelope.isEnvelope(message.text) &&
+                !widget.isCompact)
              ImageMessageBubble(message: message, isSentByMe: isOwnMessage)
            // Regular message content
            else if (!message.isDrawing || widget.isCompact)
--- a/lib/widgets/messages/voice_message_bubble.dart
+++ b/lib/widgets/messages/voice_message_bubble.dart
@@ -31,6 +31,15 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {

  @override
  Widget build(BuildContext context) {
+    final radioBw = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioBw,
+    );
+    final radioSf = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioSf,
+    );
+    final radioCr = context.select<ConnectionProvider, int?>(
+      (p) => p.deviceInfo.radioCr,
+    );
    final voiceId = widget.message.voiceId;
    if (voiceId == null) return const SizedBox.shrink();

@@ -73,6 +82,16 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {
          session: session,
          messageText: widget.message.text,
        );
+        final txEstimate = _resolveVoiceTransmitEstimate(
+          session: session,
+          envelope: envelope,
+          messageText: widget.message.text,
+          pathLen: widget.message.pathLen,
+          radioBw: radioBw,
+          radioSf: radioSf,
+          radioCr: radioCr,
+        );
+        final txEstimateLabel = _formatTransmitEstimate(txEstimate);

        return Row(
          mainAxisSize: MainAxisSize.min,
@@ -124,21 +143,21 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {
                    ),
                  )
                else
-                  _WaveformBar(
-                    isComplete: isComplete,
-                    bars: waveformBars,
-                  ),
+                  _WaveformBar(isComplete: isComplete, bars: waveformBars),
                const SizedBox(height: 4),
                Text(
                  _buildStatusText(
                    durationLabel: durationLabel,
                    modeLabel: modeLabel,
+                    txEstimateLabel: txEstimateLabel,
                    received: received,
                    total: total,
                    isComplete: isComplete,
                    isRequesting: _isRequesting,
                    errorText: _errorText,
-                    requestingLabel: AppLocalizations.of(context)!.requestingVoice,
+                    requestingLabel: AppLocalizations.of(
+                      context,
+                    )!.requestingVoice,
                  ),
                  style: TextStyle(
                    fontSize: 11,
@@ -236,6 +255,7 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {
  static String _buildStatusText({
    required String durationLabel,
    required String modeLabel,
+    required String txEstimateLabel,
    required int received,
    required int total,
    required bool isComplete,
@@ -246,12 +266,12 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {
    if (errorText != null) return errorText;
    final progress = total > 0 ? ' ($received/$total)' : '';
    if (isRequesting) {
-      return '$requestingLabel$progress';
+      return '$requestingLabel$progress · $txEstimateLabel';
    }
    if (!isComplete && total > 0) {
-      return '🎙️ $durationLabel · $modeLabel$progress';
+      return '🎙️ $durationLabel · $modeLabel$progress · $txEstimateLabel';
    }
-    return '🎙️ $durationLabel · $modeLabel';
+    return '🎙️ $durationLabel · $modeLabel · $txEstimateLabel';
  }

  List<double> _resolveWaveformBars({
@@ -271,16 +291,68 @@ class _VoiceMessageBubbleState extends State<VoiceMessageBubble> {

    return const [];
  }
+
+  Duration _resolveVoiceTransmitEstimate({
+    required VoiceSession? session,
+    required VoiceEnvelope? envelope,
+    required String messageText,
+    required int pathLen,
+    required int? radioBw,
+    required int? radioSf,
+    required int? radioCr,
+  }) {
+    if (session != null) {
+      final fromSession = estimateVoiceTransmitDurationFromPackets(
+        packets: session.packets,
+        pathLen: pathLen,
+        radioBw: radioBw,
+        radioSf: radioSf,
+        radioCr: radioCr,
+      );
+      if (fromSession > Duration.zero) return fromSession;
+    }
+
+    if (envelope != null) {
+      return estimateVoiceTransmitDuration(
+        mode: envelope.mode,
+        packetCount: envelope.total,
+        durationMs: envelope.durationMs,
+        pathLen: pathLen,
+        radioBw: radioBw,
+        radioSf: radioSf,
+        radioCr: radioCr,
+      );
+    }
+
+    final legacyPacket = VoicePacket.tryParseText(messageText);
+    if (legacyPacket != null) {
+      return estimateVoiceTransmitDuration(
+        mode: legacyPacket.mode,
+        packetCount: legacyPacket.total,
+        durationMs: legacyPacket.durationMs * legacyPacket.total,
+        pathLen: pathLen,
+        radioBw: radioBw,
+        radioSf: radioSf,
+        radioCr: radioCr,
+      );
+    }
+    return Duration.zero;
+  }
+
+  static String _formatTransmitEstimate(Duration value) {
+    if (value <= Duration.zero) return '~0s tx';
+    if (value.inSeconds < 60) return '~${value.inSeconds}s tx';
+    final minutes = value.inMinutes;
+    final seconds = value.inSeconds % 60;
+    return '~${minutes}m ${seconds}s tx';
+  }
 }

 /// Voice waveform rendered as a row of bars.
 class _WaveformBar extends StatelessWidget {
  final bool isComplete;
  final List<double> bars;
-  const _WaveformBar({
-    required this.isComplete,
-    required this.bars,
-  });
+  const _WaveformBar({required this.isComplete, required this.bars});

  @override
  Widget build(BuildContext context) {
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -173,10 +173,8 @@ flutter:

  # Enable generation of localization files
  generate: true
-  # To add assets to your application, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
+  assets:
+    - screenshots/ios/

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/to/resolution-aware-images