feat(extensions): embed full metadata and cover after extension downloads

Replace duplicate genre/label-only embedding with a shared post-download
step that writes complete FLAC tags and optional cover art when the output
file is available locally.

apps.json

@@ -7,12 +7,12 @@
       "name": "SpotiFLAC Mobile",
       "bundleIdentifier": "com.zarzet.spotiflac",
       "developerName": "zarzet",
-      "version": "4.6.0",
+      "version": "4.7.0",
-      "versionDate": "2026-06-13",
+      "versionDate": "2026-06-30",
-      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v4.6.0/SpotiFLAC-v4.6.0-ios-unsigned.ipa",
+      "downloadURL": "https://github.com/zarzet/SpotiFLAC-Mobile/releases/download/v4.7.0/SpotiFLAC-v4.7.0-ios-unsigned.ipa",
       "localizedDescription": "SpotiFLAC Mobile is written in Flutter. Download tracks in true FLAC from Tidal, Qobuz, & Amazon Music.",
       "iconURL": "https://raw.githubusercontent.com/zarzet/SpotiFLAC-Mobile/main/assets/images/logo.png",
-      "size": 34347687
+      "size": 37442462
     }
   ]
 }

go_backend/ac4_config.go

@@ -87,22 +87,26 @@ func findBoxBySignature(data []byte, start, end int64, typ string) (mp4Box, bool
 }
 
 // audioSampleEntryHeaderLen returns the byte length of the fixed audio sample
-// entry header (from the box body start) before child boxes begin.
+// entry header (from the box body start) before child boxes begin. ok is false
-func audioSampleEntryHeaderLen(data []byte, entry mp4Box) int64 {
+// for malformed/truncated entries whose declared header is not fully present.
+func audioSampleEntryHeaderLen(data []byte, entry mp4Box) (hdrLen int64, ok bool) {
 	// 6 bytes reserved + 2 bytes data_reference_index, then the audio fields.
 	base := entry.body()
 	if base+10 > entry.end() {
-		return 8 + 20
+		return 0, false
 	}
 	version := binary.BigEndian.Uint16(data[base+8 : base+10])
+	hdrLen = 8 + 20
 	switch version {
 	case 1:
-		return 8 + 20 + 16
+		hdrLen += 16
 	case 2:
-		return 8 + 20 + 36
+		hdrLen += 36
-	default:
-		return 8 + 20
 	}
+	if base+hdrLen > entry.end() {
+		return 0, false
+	}
+	return hdrLen, true
 }
 
 type ac4Location struct {
@@ -232,13 +236,16 @@ func normalizeQuickTimeAudioToMP4(data []byte) []byte {
 		return data // already v0 (or v2, left untouched)
 	}
 
-	binary.BigEndian.PutUint16(data[verPos:verPos+2], 0)
 	// The v1 QuickTime sound extension is the 16 bytes following the 20-byte v0
 	// audio fields (samplesPerPacket, bytesPerPacket, bytesPerFrame, bytesPerSample).
 	extStart := entry.body() + 8 + 20
 	extEnd := extStart + 16
+	if extEnd > entry.end() {
+		return data
+	}
 	delta := int64(-16)
 
+	binary.BigEndian.PutUint16(data[verPos:verPos+2], 0)
 	shiftChunkOffsets(data, loc.chain[0], extStart, delta)
 	for _, b := range loc.chain {
 		growBoxSize(data, b, delta)
@@ -273,7 +280,10 @@ func EnsureAC4ConfigBox(decryptedPath, sourcePath string) error {
 		return nil
 	}
 
-	hdrLen := audioSampleEntryHeaderLen(dst, loc.entry)
+	hdrLen, ok := audioSampleEntryHeaderLen(dst, loc.entry)
+	if !ok {
+		return fmt.Errorf("malformed ac-4 sample entry")
+	}
 	childStart := loc.entry.body() + hdrLen
 	if _, has := findChildMP4(dst, childStart, loc.entry.end(), "dac4"); has {
 		// Already has dac4; still persist any normalization changes.

go_backend/ac4_config_test.go

@@ -0,0 +1,76 @@
+package gobackend
+
+import (
+	"bytes"
+	"encoding/binary"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func mp4TestBox(typ string, body []byte) []byte {
+	out := make([]byte, 8+len(body))
+	binary.BigEndian.PutUint32(out[:4], uint32(len(out)))
+	copy(out[4:8], typ)
+	copy(out[8:], body)
+	return out
+}
+
+func mp4TestAC4Tree(entryBody []byte) []byte {
+	entry := mp4TestBox("ac-4", entryBody)
+	stsdBody := append([]byte{
+		0, 0, 0, 0, // version/flags
+		0, 0, 0, 1, // entry_count
+	}, entry...)
+	stsd := mp4TestBox("stsd", stsdBody)
+	stbl := mp4TestBox("stbl", stsd)
+	minf := mp4TestBox("minf", stbl)
+	mdia := mp4TestBox("mdia", minf)
+	trak := mp4TestBox("trak", mdia)
+	moov := mp4TestBox("moov", trak)
+	return moov
+}
+
+func shortAC4SampleEntryBody(version uint16) []byte {
+	body := make([]byte, 10)
+	binary.BigEndian.PutUint16(body[8:10], version)
+	return body
+}
+
+func TestNormalizeQuickTimeAudioToMP4IgnoresTruncatedAC4Entry(t *testing.T) {
+	input := mp4TestAC4Tree(shortAC4SampleEntryBody(1))
+
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("normalizeQuickTimeAudioToMP4 panicked: %v", r)
+		}
+	}()
+
+	got := normalizeQuickTimeAudioToMP4(append([]byte{}, input...))
+	if !bytes.Equal(got, input) {
+		t.Fatal("truncated QuickTime AC-4 entry should be left unchanged")
+	}
+}
+
+func TestEnsureAC4ConfigBoxRejectsTruncatedAC4Entry(t *testing.T) {
+	dir := t.TempDir()
+	decryptedPath := filepath.Join(dir, "decrypted.mp4")
+	sourcePath := filepath.Join(dir, "source.mp4")
+
+	if err := os.WriteFile(decryptedPath, mp4TestAC4Tree(shortAC4SampleEntryBody(2)), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(sourcePath, mp4TestBox("moov", mp4TestBox("dac4", []byte{1, 2, 3, 4})), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	defer func() {
+		if r := recover(); r != nil {
+			t.Fatalf("EnsureAC4ConfigBox panicked: %v", r)
+		}
+	}()
+
+	if err := EnsureAC4ConfigBox(decryptedPath, sourcePath); err == nil {
+		t.Fatal("expected malformed AC-4 sample entry error")
+	}
+}

go_backend/exports.go

@@ -3287,7 +3287,7 @@ func InvokeExtensionActionJSON(extensionID, actionName string) (string, error) {
 }
 
 func GetExtensionPendingAuthJSON(extensionID string) (string, error) {
-	req := GetPendingAuthRequest(extensionID)
+	req := ensureExtensionPendingAuthRequest(extensionID)
 	if req == nil {
 		return "", nil
 	}
@@ -3306,6 +3306,40 @@ func GetExtensionPendingAuthJSON(extensionID string) (string, error) {
 	return string(jsonBytes), nil
 }
 
+func ensureExtensionPendingAuthRequest(extensionID string) *PendingAuthRequest {
+	extensionID = strings.TrimSpace(extensionID)
+	if extensionID == "" {
+		return nil
+	}
+
+	if req := GetPendingAuthRequest(extensionID); req != nil {
+		return req
+	}
+
+	manager := getExtensionManager()
+	ext, err := manager.GetExtension(extensionID)
+	if err != nil || ext == nil || !ext.Enabled || ext.Manifest == nil || ext.Manifest.SignedSession == nil {
+		return nil
+	}
+
+	if err := ext.ensureRuntimeReady(); err != nil || ext.runtime == nil {
+		return nil
+	}
+
+	config := signedSessionConfigWithDefaults(ext.Manifest.SignedSession)
+	if config.Namespace == "" || config.BaseURL == "" {
+		return nil
+	}
+	if record, err := ext.runtime.loadSignedSession(config); err == nil {
+		record.SessionID = ""
+		record.SessionSecret = ""
+		record.ExpiresAt = ""
+		_ = ext.runtime.saveSignedSession(config, record)
+	}
+	ext.runtime.startSignedSessionVerification(config, "pending-auth-request")
+	return GetPendingAuthRequest(extensionID)
+}
+
 func SetExtensionAuthCodeByID(extensionID, authCode string) {
 	SetExtensionAuthCode(extensionID, authCode)
 }

go_backend/extension_providers.go

@@ -2602,15 +2602,7 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 					resp.Composer = req.Composer
 				}
 
-				if !alreadyExists && req.EmbedMetadata && (req.Genre != "" || req.Label != "") && canEmbedGenreLabel(normalizedResult.FilePath) {
+				embedExtensionDownloadMetadata(resp, req, alreadyExists)
-					if err := EmbedGenreLabel(normalizedResult.FilePath, req.Genre, req.Label); err != nil {
-						GoLog("[DownloadWithExtensionFallback] Warning: failed to embed genre/label: %v\n", err)
-					} else {
-						GoLog("[DownloadWithExtensionFallback] Embedded genre=%q label=%q\n", req.Genre, req.Label)
-					}
-				} else if !alreadyExists && req.EmbedMetadata && (req.Genre != "" || req.Label != "") {
-					GoLog("[DownloadWithExtensionFallback] Skipping genre/label embed for non-local output path: %q\n", normalizedResult.FilePath)
-				}
 
 				if !alreadyExists && !isFDOutput(req.OutputFD) && strings.TrimSpace(req.OutputDir) != "" {
 					indexISRC := strings.TrimSpace(resp.ISRC)
@@ -2808,15 +2800,7 @@ func DownloadWithExtensionFallback(req DownloadRequest) (*DownloadResponse, erro
 				}
 				applyExtensionRequestFallbacks(&resp, req)
 
-				if !alreadyExists && req.EmbedMetadata && (req.Genre != "" || req.Label != "") && canEmbedGenreLabel(normalizedResult.FilePath) {
+				embedExtensionDownloadMetadata(resp, req, alreadyExists)
-					if err := EmbedGenreLabel(normalizedResult.FilePath, req.Genre, req.Label); err != nil {
-						GoLog("[DownloadWithExtensionFallback] Warning: failed to embed genre/label: %v\n", err)
-					} else {
-						GoLog("[DownloadWithExtensionFallback] Embedded genre=%q label=%q\n", req.Genre, req.Label)
-					}
-				} else if !alreadyExists && req.EmbedMetadata && (req.Genre != "" || req.Label != "") {
-					GoLog("[DownloadWithExtensionFallback] Skipping genre/label embed for non-local output path: %q\n", normalizedResult.FilePath)
-				}
 
 				if !alreadyExists && !isFDOutput(req.OutputFD) && strings.TrimSpace(req.OutputDir) != "" {
 					indexISRC := strings.TrimSpace(resp.ISRC)
@@ -3008,6 +2992,78 @@ func canEmbedGenreLabel(filePath string) bool {
 	return err == nil && !info.IsDir() && info.Size() > 0
 }
 
+func embedExtensionDownloadMetadata(resp DownloadResponse, req DownloadRequest, alreadyExists bool) {
+	if alreadyExists || !req.EmbedMetadata {
+		return
+	}
+
+	filePath := strings.TrimSpace(resp.FilePath)
+	if !canEmbedGenreLabel(filePath) {
+		if req.Genre != "" || req.Label != "" || resp.CoverURL != "" || req.CoverURL != "" {
+			GoLog("[DownloadWithExtensionFallback] Skipping metadata/cover embed for non-local FLAC output path: %q\n", filePath)
+		}
+		return
+	}
+
+	coverURL := firstNonEmptyTrimmed(resp.CoverURL, req.CoverURL)
+	var coverData []byte
+	if coverURL != "" {
+		data, err := downloadCoverToMemory(coverURL, req.EmbedMaxQualityCover)
+		if err != nil {
+			GoLog("[DownloadWithExtensionFallback] Warning: failed to download cover for metadata embed: %v\n", err)
+		} else if len(data) > 0 {
+			coverData = data
+		}
+	}
+
+	metadata := Metadata{
+		Title:         firstNonEmptyTrimmed(resp.Title, req.TrackName),
+		Artist:        firstNonEmptyTrimmed(resp.Artist, req.ArtistName),
+		Album:         firstNonEmptyTrimmed(resp.Album, req.AlbumName),
+		AlbumArtist:   firstNonEmptyTrimmed(resp.AlbumArtist, req.AlbumArtist),
+		ArtistTagMode: req.ArtistTagMode,
+		Date:          firstNonEmptyTrimmed(resp.ReleaseDate, req.ReleaseDate),
+		TrackNumber:   firstPositiveInt(resp.TrackNumber, req.TrackNumber),
+		TotalTracks:   firstPositiveInt(resp.TotalTracks, req.TotalTracks),
+		DiscNumber:    firstPositiveInt(resp.DiscNumber, req.DiscNumber),
+		TotalDiscs:    firstPositiveInt(resp.TotalDiscs, req.TotalDiscs),
+		ISRC:          firstNonEmptyTrimmed(resp.ISRC, req.ISRC),
+		Genre:         firstNonEmptyTrimmed(resp.Genre, req.Genre),
+		Label:         firstNonEmptyTrimmed(resp.Label, req.Label),
+		Copyright:     firstNonEmptyTrimmed(resp.Copyright, req.Copyright),
+		Composer:      firstNonEmptyTrimmed(resp.Composer, req.Composer),
+	}
+	if req.EmbedLyrics {
+		metadata.Lyrics = resp.LyricsLRC
+	}
+
+	var err error
+	if len(coverData) > 0 {
+		err = EmbedMetadataWithCoverData(filePath, metadata, coverData)
+	} else {
+		err = EmbedMetadata(filePath, metadata, "")
+	}
+	if err != nil {
+		GoLog("[DownloadWithExtensionFallback] Warning: failed to embed metadata/cover: %v\n", err)
+		return
+	}
+
+	if len(coverData) > 0 {
+		GoLog("[DownloadWithExtensionFallback] Embedded metadata and cover from %q\n", coverURL)
+	} else {
+		GoLog("[DownloadWithExtensionFallback] Embedded metadata without cover\n")
+	}
+}
+
+func firstPositiveInt(values ...int) int {
+	for _, value := range values {
+		if value > 0 {
+			return value
+		}
+	}
+	return 0
+}
+
 func (p *extensionProviderWrapper) CustomSearch(query string, options map[string]interface{}) ([]ExtTrackMetadata, error) {
 	return p.customSearch(query, options, "", "")
 }

go_backend/extension_signed_session.go

@@ -236,6 +236,7 @@ func (r *extensionRuntime) signedSessionClear(call goja.FunctionCall) goja.Value
 	if err := r.saveSignedSession(config, record); err != nil {
 		return r.vm.ToValue(map[string]interface{}{"success": false, "error": err.Error()})
 	}
+	ClearPendingAuthRequest(r.extensionID)
 	return r.vm.ToValue(map[string]interface{}{"success": true})
 }
 
@@ -256,6 +257,7 @@ func (r *extensionRuntime) signedSessionCompleteGrant(call goja.FunctionCall) go
 	if err := r.exchangeSignedSessionGrant(grant); err != nil {
 		return r.vm.ToValue(map[string]interface{}{"success": false, "error": err.Error()})
 	}
+	ClearPendingAuthRequest(r.extensionID)
 	return r.vm.ToValue(map[string]interface{}{"success": true})
 }
 

lib/app.dart

@@ -7,6 +7,7 @@ import 'package:spotiflac_android/screens/main_shell.dart';
 import 'package:spotiflac_android/screens/setup_screen.dart';
 import 'package:spotiflac_android/screens/tutorial_screen.dart';
 import 'package:spotiflac_android/providers/settings_provider.dart';
+import 'package:spotiflac_android/services/app_navigation_service.dart';
 import 'package:spotiflac_android/theme/dynamic_color_wrapper.dart';
 import 'package:spotiflac_android/l10n/app_localizations.dart';
 
@@ -28,6 +29,7 @@ final _routerProvider = Provider<GoRouter>((ref) {
   }
 
   return GoRouter(
+    navigatorKey: AppNavigationService.rootNavigatorKey,
     initialLocation: initialLocation,
     routes: [
       GoRoute(path: '/', builder: (context, state) => const MainShell()),

lib/constants/app_info.dart

@@ -1,8 +1,8 @@
 import 'package:flutter/foundation.dart';
 
 class AppInfo {
-  static const String version = '4.7.0';
+  static const String version = '4.7.1';
-  static const String buildNumber = '136';
+  static const String buildNumber = '137';
   static const String fullVersion = '$version+$buildNumber';
 
   static String get displayVersion => kDebugMode ? 'Internal' : version;

lib/l10n/app_localizations.dart

@@ -7607,6 +7607,48 @@ abstract class AppLocalizations {
   /// **'Lossless'**
   String get trackConvertLosslessSuffix;
 
+  /// Section label for lossless conversion dithering options
+  ///
+  /// In en, this message translates to:
+  /// **'Dithering'**
+  String get trackConvertDithering;
+
+  /// Section label for lossless conversion resampler options
+  ///
+  /// In en, this message translates to:
+  /// **'Resampler'**
+  String get trackConvertResampler;
+
+  /// Lossless conversion dither option with no dithering applied
+  ///
+  /// In en, this message translates to:
+  /// **'None'**
+  String get trackConvertDitherNone;
+
+  /// Lossless conversion triangular probability density function dither option
+  ///
+  /// In en, this message translates to:
+  /// **'TPDF'**
+  String get trackConvertDitherTriangular;
+
+  /// Lossless conversion high-pass triangular dither option
+  ///
+  /// In en, this message translates to:
+  /// **'Triangular HP'**
+  String get trackConvertDitherTriangularHp;
+
+  /// Lossless conversion default FFmpeg swresample resampler option
+  ///
+  /// In en, this message translates to:
+  /// **'SWR'**
+  String get trackConvertResamplerSwr;
+
+  /// Lossless conversion SoX resampler option
+  ///
+  /// In en, this message translates to:
+  /// **'SoXr'**
+  String get trackConvertResamplerSoxr;
+
   /// Fallback changelog text when release notes cannot be parsed
   ///
   /// In en, this message translates to:
@@ -7750,6 +7792,84 @@ abstract class AppLocalizations {
   /// In en, this message translates to:
   /// **'Kosovo'**
   String get regionCountryXK;
+
+  /// Settings option title for extension verification browser preference
+  ///
+  /// In en, this message translates to:
+  /// **'Verification browser'**
+  String get extensionVerificationBrowserTitle;
+
+  /// Subtitle when external browser is preferred for extension verification
+  ///
+  /// In en, this message translates to:
+  /// **'Open challenges in the default browser first'**
+  String get extensionVerificationBrowserSubtitleExternal;
+
+  /// Subtitle when in-app browser is preferred for extension verification
+  ///
+  /// In en, this message translates to:
+  /// **'Open challenges in the in-app browser first'**
+  String get extensionVerificationBrowserSubtitleInApp;
+
+  /// Chip label for external browser verification mode
+  ///
+  /// In en, this message translates to:
+  /// **'External'**
+  String get extensionVerificationBrowserExternal;
+
+  /// Chip label for in-app browser verification mode
+  ///
+  /// In en, this message translates to:
+  /// **'In-app'**
+  String get extensionVerificationBrowserInApp;
+
+  /// Dialog title when automatic browser launch for verification fails
+  ///
+  /// In en, this message translates to:
+  /// **'Open verification manually'**
+  String get extensionVerificationHelpTitleManual;
+
+  /// Dialog title when verification is taking longer than expected
+  ///
+  /// In en, this message translates to:
+  /// **'Verification still waiting'**
+  String get extensionVerificationHelpTitleWaiting;
+
+  /// Dialog message when automatic browser launch for verification fails
+  ///
+  /// In en, this message translates to:
+  /// **'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.'**
+  String get extensionVerificationHelpMessageManual;
+
+  /// Dialog message when verification may need manual browser help
+  ///
+  /// In en, this message translates to:
+  /// **'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.'**
+  String get extensionVerificationHelpMessageWaiting;
+
+  /// Button to dismiss the extension verification help dialog
+  ///
+  /// In en, this message translates to:
+  /// **'Close'**
+  String get extensionVerificationClose;
+
+  /// Button to copy the extension verification URL
+  ///
+  /// In en, this message translates to:
+  /// **'Copy link'**
+  String get extensionVerificationCopyLink;
+
+  /// Snackbar after copying the extension verification URL
+  ///
+  /// In en, this message translates to:
+  /// **'Verification link copied'**
+  String get extensionVerificationLinkCopied;
+
+  /// Button to open the extension verification URL in a browser
+  ///
+  /// In en, this message translates to:
+  /// **'Open browser'**
+  String get extensionVerificationOpenBrowser;
 }
 
 class _AppLocalizationsDelegate

lib/l10n/app_localizations_ar.dart

@@ -4625,6 +4625,27 @@ class AppLocalizationsAr extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4704,4 +4725,49 @@ class AppLocalizationsAr extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_de.dart

@@ -4674,6 +4674,27 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4753,4 +4774,49 @@ class AppLocalizationsDe extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_en.dart

@@ -4625,6 +4625,27 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4704,4 +4725,49 @@ class AppLocalizationsEn extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_es.dart

@@ -4619,6 +4619,27 @@ class AppLocalizationsEs extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4698,6 +4719,51 @@ class AppLocalizationsEs extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }
 
 /// The translations for Spanish Castilian, as used in Spain (`es_ES`).

lib/l10n/app_localizations_fr.dart

@@ -4739,6 +4739,27 @@ class AppLocalizationsFr extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4818,4 +4839,49 @@ class AppLocalizationsFr extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_hi.dart

@@ -4625,6 +4625,27 @@ class AppLocalizationsHi extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4704,4 +4725,49 @@ class AppLocalizationsHi extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_id.dart

@@ -4609,6 +4609,27 @@ class AppLocalizationsId extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'Tidak ada';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'Lihat catatan rilis untuk detail.';
 
@@ -4688,4 +4709,49 @@ class AppLocalizationsId extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Browser verifikasi';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Buka tantangan di browser default terlebih dahulu';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Buka tantangan di browser dalam aplikasi terlebih dahulu';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'Eksternal';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'Dalam aplikasi';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Buka verifikasi secara manual';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verifikasi masih menunggu';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile tidak dapat membuka browser secara otomatis. Buka tautan ini di browser Anda, atau salin secara manual.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'Jika browser tidak terbuka, atau verifikasi selesai tetapi tidak kembali ke SpotiFLAC Mobile, buka tautan ini lagi atau salin secara manual.';
+
+  @override
+  String get extensionVerificationClose => 'Tutup';
+
+  @override
+  String get extensionVerificationCopyLink => 'Salin tautan';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Tautan verifikasi disalin';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Buka browser';
 }

lib/l10n/app_localizations_ja.dart

@@ -4612,6 +4612,27 @@ class AppLocalizationsJa extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4691,4 +4712,49 @@ class AppLocalizationsJa extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_ko.dart

@@ -4610,6 +4610,27 @@ class AppLocalizationsKo extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4689,4 +4710,49 @@ class AppLocalizationsKo extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_nl.dart

@@ -4625,6 +4625,27 @@ class AppLocalizationsNl extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4704,4 +4725,49 @@ class AppLocalizationsNl extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_pt.dart

@@ -4619,6 +4619,27 @@ class AppLocalizationsPt extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4698,6 +4719,51 @@ class AppLocalizationsPt extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }
 
 /// The translations for Portuguese, as used in Portugal (`pt_PT`).

lib/l10n/app_localizations_ru.dart

@@ -4681,6 +4681,27 @@ class AppLocalizationsRu extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4760,4 +4781,49 @@ class AppLocalizationsRu extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_tr.dart

@@ -4656,6 +4656,27 @@ class AppLocalizationsTr extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4735,4 +4756,49 @@ class AppLocalizationsTr extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_uk.dart

@@ -4678,6 +4678,27 @@ class AppLocalizationsUk extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4757,4 +4778,49 @@ class AppLocalizationsUk extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }

lib/l10n/app_localizations_zh.dart

@@ -4619,6 +4619,27 @@ class AppLocalizationsZh extends AppLocalizations {
   @override
   String get trackConvertLosslessSuffix => 'Lossless';
 
+  @override
+  String get trackConvertDithering => 'Dithering';
+
+  @override
+  String get trackConvertResampler => 'Resampler';
+
+  @override
+  String get trackConvertDitherNone => 'None';
+
+  @override
+  String get trackConvertDitherTriangular => 'TPDF';
+
+  @override
+  String get trackConvertDitherTriangularHp => 'Triangular HP';
+
+  @override
+  String get trackConvertResamplerSwr => 'SWR';
+
+  @override
+  String get trackConvertResamplerSoxr => 'SoXr';
+
   @override
   String get updateSeeReleaseNotes => 'See release notes for details.';
 
@@ -4698,6 +4719,51 @@ class AppLocalizationsZh extends AppLocalizations {
 
   @override
   String get regionCountryXK => 'Kosovo';
+
+  @override
+  String get extensionVerificationBrowserTitle => 'Verification browser';
+
+  @override
+  String get extensionVerificationBrowserSubtitleExternal =>
+      'Open challenges in the default browser first';
+
+  @override
+  String get extensionVerificationBrowserSubtitleInApp =>
+      'Open challenges in the in-app browser first';
+
+  @override
+  String get extensionVerificationBrowserExternal => 'External';
+
+  @override
+  String get extensionVerificationBrowserInApp => 'In-app';
+
+  @override
+  String get extensionVerificationHelpTitleManual =>
+      'Open verification manually';
+
+  @override
+  String get extensionVerificationHelpTitleWaiting =>
+      'Verification still waiting';
+
+  @override
+  String get extensionVerificationHelpMessageManual =>
+      'SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.';
+
+  @override
+  String get extensionVerificationHelpMessageWaiting =>
+      'If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.';
+
+  @override
+  String get extensionVerificationClose => 'Close';
+
+  @override
+  String get extensionVerificationCopyLink => 'Copy link';
+
+  @override
+  String get extensionVerificationLinkCopied => 'Verification link copied';
+
+  @override
+  String get extensionVerificationOpenBrowser => 'Open browser';
 }
 
 /// The translations for Chinese, as used in China (`zh_CN`).

lib/l10n/arb/app_en.arb

@@ -6006,6 +6006,34 @@
   "@trackConvertLosslessSuffix": {
     "description": "Suffix used in converted lossless quality labels"
   },
+  "trackConvertDithering": "Dithering",
+  "@trackConvertDithering": {
+    "description": "Section label for lossless conversion dithering options"
+  },
+  "trackConvertResampler": "Resampler",
+  "@trackConvertResampler": {
+    "description": "Section label for lossless conversion resampler options"
+  },
+  "trackConvertDitherNone": "None",
+  "@trackConvertDitherNone": {
+    "description": "Lossless conversion dither option with no dithering applied"
+  },
+  "trackConvertDitherTriangular": "TPDF",
+  "@trackConvertDitherTriangular": {
+    "description": "Lossless conversion triangular probability density function dither option"
+  },
+  "trackConvertDitherTriangularHp": "Triangular HP",
+  "@trackConvertDitherTriangularHp": {
+    "description": "Lossless conversion high-pass triangular dither option"
+  },
+  "trackConvertResamplerSwr": "SWR",
+  "@trackConvertResamplerSwr": {
+    "description": "Lossless conversion default FFmpeg swresample resampler option"
+  },
+  "trackConvertResamplerSoxr": "SoXr",
+  "@trackConvertResamplerSoxr": {
+    "description": "Lossless conversion SoX resampler option"
+  },
   "updateSeeReleaseNotes": "See release notes for details.",
   "@updateSeeReleaseNotes": {
     "description": "Fallback changelog text when release notes cannot be parsed"
@@ -6124,5 +6152,57 @@
   "regionCountryXK": "Kosovo",
   "@regionCountryXK": {
     "description": "Country name for SongLink region picker"
+  },
+  "extensionVerificationBrowserTitle": "Verification browser",
+  "@extensionVerificationBrowserTitle": {
+    "description": "Settings option title for extension verification browser preference"
+  },
+  "extensionVerificationBrowserSubtitleExternal": "Open challenges in the default browser first",
+  "@extensionVerificationBrowserSubtitleExternal": {
+    "description": "Subtitle when external browser is preferred for extension verification"
+  },
+  "extensionVerificationBrowserSubtitleInApp": "Open challenges in the in-app browser first",
+  "@extensionVerificationBrowserSubtitleInApp": {
+    "description": "Subtitle when in-app browser is preferred for extension verification"
+  },
+  "extensionVerificationBrowserExternal": "External",
+  "@extensionVerificationBrowserExternal": {
+    "description": "Chip label for external browser verification mode"
+  },
+  "extensionVerificationBrowserInApp": "In-app",
+  "@extensionVerificationBrowserInApp": {
+    "description": "Chip label for in-app browser verification mode"
+  },
+  "extensionVerificationHelpTitleManual": "Open verification manually",
+  "@extensionVerificationHelpTitleManual": {
+    "description": "Dialog title when automatic browser launch for verification fails"
+  },
+  "extensionVerificationHelpTitleWaiting": "Verification still waiting",
+  "@extensionVerificationHelpTitleWaiting": {
+    "description": "Dialog title when verification is taking longer than expected"
+  },
+  "extensionVerificationHelpMessageManual": "SpotiFLAC Mobile could not open the browser automatically. Open this link in your browser, or copy it manually.",
+  "@extensionVerificationHelpMessageManual": {
+    "description": "Dialog message when automatic browser launch for verification fails"
+  },
+  "extensionVerificationHelpMessageWaiting": "If the browser did not open, or verification finished but did not return to SpotiFLAC Mobile, open this link again or copy it manually.",
+  "@extensionVerificationHelpMessageWaiting": {
+    "description": "Dialog message when verification may need manual browser help"
+  },
+  "extensionVerificationClose": "Close",
+  "@extensionVerificationClose": {
+    "description": "Button to dismiss the extension verification help dialog"
+  },
+  "extensionVerificationCopyLink": "Copy link",
+  "@extensionVerificationCopyLink": {
+    "description": "Button to copy the extension verification URL"
+  },
+  "extensionVerificationLinkCopied": "Verification link copied",
+  "@extensionVerificationLinkCopied": {
+    "description": "Snackbar after copying the extension verification URL"
+  },
+  "extensionVerificationOpenBrowser": "Open browser",
+  "@extensionVerificationOpenBrowser": {
+    "description": "Button to open the extension verification URL in a browser"
   }
 }

lib/l10n/arb/app_id.arb

@@ -5850,6 +5850,34 @@
   "@trackConvertLosslessSuffix": {
     "description": "Suffix used in converted lossless quality labels"
   },
+  "trackConvertDithering": "Dithering",
+  "@trackConvertDithering": {
+    "description": "Section label for lossless conversion dithering options"
+  },
+  "trackConvertResampler": "Resampler",
+  "@trackConvertResampler": {
+    "description": "Section label for lossless conversion resampler options"
+  },
+  "trackConvertDitherNone": "Tidak ada",
+  "@trackConvertDitherNone": {
+    "description": "Lossless conversion dither option with no dithering applied"
+  },
+  "trackConvertDitherTriangular": "TPDF",
+  "@trackConvertDitherTriangular": {
+    "description": "Lossless conversion triangular probability density function dither option"
+  },
+  "trackConvertDitherTriangularHp": "Triangular HP",
+  "@trackConvertDitherTriangularHp": {
+    "description": "Lossless conversion high-pass triangular dither option"
+  },
+  "trackConvertResamplerSwr": "SWR",
+  "@trackConvertResamplerSwr": {
+    "description": "Lossless conversion default FFmpeg swresample resampler option"
+  },
+  "trackConvertResamplerSoxr": "SoXr",
+  "@trackConvertResamplerSoxr": {
+    "description": "Lossless conversion SoX resampler option"
+  },
   "updateSeeReleaseNotes": "Lihat catatan rilis untuk detail.",
   "@updateSeeReleaseNotes": {
     "description": "Fallback changelog text when release notes cannot be parsed"
@@ -5968,5 +5996,57 @@
   "regionCountryXK": "Kosovo",
   "@regionCountryXK": {
     "description": "Country name for SongLink region picker"
+  },
+  "extensionVerificationBrowserTitle": "Browser verifikasi",
+  "@extensionVerificationBrowserTitle": {
+    "description": "Settings option title for extension verification browser preference"
+  },
+  "extensionVerificationBrowserSubtitleExternal": "Buka tantangan di browser default terlebih dahulu",
+  "@extensionVerificationBrowserSubtitleExternal": {
+    "description": "Subtitle when external browser is preferred for extension verification"
+  },
+  "extensionVerificationBrowserSubtitleInApp": "Buka tantangan di browser dalam aplikasi terlebih dahulu",
+  "@extensionVerificationBrowserSubtitleInApp": {
+    "description": "Subtitle when in-app browser is preferred for extension verification"
+  },
+  "extensionVerificationBrowserExternal": "Eksternal",
+  "@extensionVerificationBrowserExternal": {
+    "description": "Chip label for external browser verification mode"
+  },
+  "extensionVerificationBrowserInApp": "Dalam aplikasi",
+  "@extensionVerificationBrowserInApp": {
+    "description": "Chip label for in-app browser verification mode"
+  },
+  "extensionVerificationHelpTitleManual": "Buka verifikasi secara manual",
+  "@extensionVerificationHelpTitleManual": {
+    "description": "Dialog title when automatic browser launch for verification fails"
+  },
+  "extensionVerificationHelpTitleWaiting": "Verifikasi masih menunggu",
+  "@extensionVerificationHelpTitleWaiting": {
+    "description": "Dialog title when verification is taking longer than expected"
+  },
+  "extensionVerificationHelpMessageManual": "SpotiFLAC Mobile tidak dapat membuka browser secara otomatis. Buka tautan ini di browser Anda, atau salin secara manual.",
+  "@extensionVerificationHelpMessageManual": {
+    "description": "Dialog message when automatic browser launch for verification fails"
+  },
+  "extensionVerificationHelpMessageWaiting": "Jika browser tidak terbuka, atau verifikasi selesai tetapi tidak kembali ke SpotiFLAC Mobile, buka tautan ini lagi atau salin secara manual.",
+  "@extensionVerificationHelpMessageWaiting": {
+    "description": "Dialog message when verification may need manual browser help"
+  },
+  "extensionVerificationClose": "Tutup",
+  "@extensionVerificationClose": {
+    "description": "Button to dismiss the extension verification help dialog"
+  },
+  "extensionVerificationCopyLink": "Salin tautan",
+  "@extensionVerificationCopyLink": {
+    "description": "Button to copy the extension verification URL"
+  },
+  "extensionVerificationLinkCopied": "Tautan verifikasi disalin",
+  "@extensionVerificationLinkCopied": {
+    "description": "Snackbar after copying the extension verification URL"
+  },
+  "extensionVerificationOpenBrowser": "Buka browser",
+  "@extensionVerificationOpenBrowser": {
+    "description": "Button to open the extension verification URL in a browser"
   }
 }

lib/models/settings.dart

@@ -43,14 +43,15 @@ class AppSettings {
   final String singleFilenameFormat;
   final String albumFolderStructure;
   final bool showExtensionStore;
+  final String
+  extensionVerificationBrowserMode; // 'external_first' or 'in_app_first'
   final String locale;
   final String lyricsMode;
   final String
   tidalHighFormat; // Legacy key for 320kbps lossy output format: 'mp3_320', 'aac_320', 'opus_256', or 'opus_128'
   final bool
   useAllFilesAccess; // Android 13+ only: enable MANAGE_EXTERNAL_STORAGE
-  final bool
+  final bool autoExportFailedDownloads;
-  autoExportFailedDownloads;
   final String
   downloadNetworkMode; // 'any' = WiFi + Mobile, 'wifi_only' = WiFi only
   final bool
@@ -66,16 +67,13 @@ class AppSettings {
   final String localLibraryPath;
   final String
   localLibraryBookmark; // Base64-encoded iOS security-scoped bookmark
-  final bool
+  final bool localLibraryShowDuplicates;
-  localLibraryShowDuplicates;
   final String
   localLibraryAutoScan; // Auto-scan mode: 'off', 'on_open', 'daily', 'weekly'
 
-  final bool
+  final bool hasCompletedTutorial;
-  hasCompletedTutorial;
 
-  final List<String>
+  final List<String> lyricsProviders;
-  lyricsProviders;
   final bool
   lyricsIncludeTranslationNetease; // Append translated lyrics (Netease)
   final bool
@@ -90,8 +88,7 @@ class AppSettings {
   final String
   lastSeenVersion; // Last app version the user has acknowledged (e.g. '3.7.0')
 
-  final bool
+  final bool deduplicateDownloads;
-  deduplicateDownloads;
   final bool saveDownloadHistory;
 
   final String playerMode;
@@ -132,6 +129,7 @@ class AppSettings {
     this.singleFilenameFormat = '{title} - {artist}',
     this.albumFolderStructure = 'artist_album',
     this.showExtensionStore = true,
+    this.extensionVerificationBrowserMode = 'in_app_first',
     this.locale = 'system',
     this.lyricsMode = 'embed',
     this.tidalHighFormat = 'mp3_320',
@@ -199,6 +197,7 @@ class AppSettings {
     String? singleFilenameFormat,
     String? albumFolderStructure,
     bool? showExtensionStore,
+    String? extensionVerificationBrowserMode,
     String? locale,
     String? lyricsMode,
     String? tidalHighFormat,
@@ -274,6 +273,9 @@ class AppSettings {
       singleFilenameFormat: singleFilenameFormat ?? this.singleFilenameFormat,
       albumFolderStructure: albumFolderStructure ?? this.albumFolderStructure,
       showExtensionStore: showExtensionStore ?? this.showExtensionStore,
+      extensionVerificationBrowserMode:
+          extensionVerificationBrowserMode ??
+          this.extensionVerificationBrowserMode,
       locale: locale ?? this.locale,
       lyricsMode: lyricsMode ?? this.lyricsMode,
       tidalHighFormat: tidalHighFormat ?? this.tidalHighFormat,

lib/models/settings.g.dart

@@ -48,6 +48,8 @@ AppSettings _$AppSettingsFromJson(Map<String, dynamic> json) => AppSettings(
   albumFolderStructure:
       json['albumFolderStructure'] as String? ?? 'artist_album',
   showExtensionStore: json['showExtensionStore'] as bool? ?? true,
+  extensionVerificationBrowserMode:
+      json['extensionVerificationBrowserMode'] as String? ?? 'in_app_first',
   locale: json['locale'] as String? ?? 'system',
   lyricsMode: json['lyricsMode'] as String? ?? 'embed',
   tidalHighFormat: json['tidalHighFormat'] as String? ?? 'mp3_320',
@@ -125,6 +127,7 @@ Map<String, dynamic> _$AppSettingsToJson(
   'singleFilenameFormat': instance.singleFilenameFormat,
   'albumFolderStructure': instance.albumFolderStructure,
   'showExtensionStore': instance.showExtensionStore,
+  'extensionVerificationBrowserMode': instance.extensionVerificationBrowserMode,
   'locale': instance.locale,
   'lyricsMode': instance.lyricsMode,
   'tidalHighFormat': instance.tidalHighFormat,

lib/providers/download_queue_provider.dart

@@ -2096,13 +2096,31 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           ),
         );
 
-    final opened = await openPendingExtensionVerification(
+    final browserMode = ref
-      normalizedExtensionId,
+        .read(settingsProvider)
-    );
+        .extensionVerificationBrowserMode;
-    if (!opened) return false;
+    Uri? authUri;
+    Timer? helpDialogTimer;
 
-    final event = await grantEventFuture;
+    try {
-    return event.success;
+      final opened = await openPendingExtensionVerification(
+        normalizedExtensionId,
+        browserMode: browserMode,
+        onAuthUri: (uri) => authUri = uri,
+      );
+      if (!opened) return false;
+
+      helpDialogTimer = scheduleExtensionVerificationHelpDialog(
+        normalizedExtensionId,
+        authUri,
+        browserMode: browserMode,
+      );
+
+      final event = await grantEventFuture;
+      return event.success;
+    } finally {
+      helpDialogTimer?.cancel();
+    }
   }
 
   Future<bool> _handleVerificationRequiredDownload(
@@ -6069,15 +6087,40 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         if (status == 'skipped') {
           updateItemStatus(itemId, DownloadStatus.skipped);
         } else {
-          final errorType = result is Map
+          final resultMap = result is Map
-              ? _downloadErrorTypeFromBackend(
+              ? Map<String, dynamic>.from(result)
-                  Map<String, dynamic>.from(result)['error_type']?.toString(),
+              : null;
-                )
+          final errorMsg = (error == null || error.isEmpty)
-              : DownloadErrorType.unknown;
+              ? (resultMap?['error']?.toString() ?? 'Download failed')
+              : error;
+          final backendErrorType = resultMap == null
+              ? DownloadErrorType.unknown
+              : _downloadErrorTypeFromBackend(
+                  resultMap['error_type']?.toString(),
+                );
+          final errorType = backendErrorType == DownloadErrorType.unknown
+              ? _downloadErrorTypeFromMessage(errorMsg)
+              : backendErrorType;
+          if (errorType == DownloadErrorType.verificationRequired) {
+            _log.i(
+              'Android native worker requires verification for ${current.track.name}; switching back to interactive queue',
+            );
+            try {
+              await PlatformBridge.cancelNativeDownloadWorker();
+            } catch (e) {
+              _log.w('Failed to cancel native worker before verification: $e');
+            }
+            await _handleVerificationRequiredDownload(
+              current,
+              errorMsg,
+              _nativeWorkerVerificationService(resultMap, context),
+            );
+            continue;
+          }
           updateItemStatus(
             itemId,
             DownloadStatus.failed,
-            error: error == null || error.isEmpty ? 'Download failed' : error,
+            error: errorMsg,
             errorType: errorType,
           );
           _failedInSession++;
@@ -6901,6 +6944,24 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
     }
   }
 
+  String _nativeWorkerVerificationService(
+    Map<String, dynamic>? result,
+    _NativeWorkerRequestContext context,
+  ) {
+    if (result != null) {
+      for (final key in const [
+        'service',
+        'verification_service',
+        'provider',
+        'source',
+      ]) {
+        final value = result[key]?.toString().trim() ?? '';
+        if (value.isNotEmpty) return value;
+      }
+    }
+    return context.item.service;
+  }
+
   DownloadErrorType _downloadErrorTypeFromMessage(String errorMsg) {
     final lowerMsg = errorMsg.toLowerCase();
     if (isExtensionVerificationRequired(errorMsg)) {

lib/providers/settings_provider.dart

@@ -28,6 +28,10 @@ class SettingsNotifier extends Notifier<AppSettings> {
     'album',
     'playlist',
   };
+  static const Set<String> _extensionVerificationBrowserModeValues = {
+    'external_first',
+    'in_app_first',
+  };
 
   final Future<SharedPreferences> _prefs = SharedPreferences.getInstance();
   final FlutterSecureStorage _secureStorage = const FlutterSecureStorage();
@@ -79,6 +83,10 @@ class SettingsNotifier extends Notifier<AppSettings> {
           defaultSearchTab: sanitizedDefaultSearchTab,
           defaultService: loaded.defaultService,
           searchProvider: loaded.searchProvider,
+          extensionVerificationBrowserMode:
+              _normalizeExtensionVerificationBrowserMode(
+                loaded.extensionVerificationBrowserMode,
+              ),
         );
 
         await _runMigrations(prefs);
@@ -270,6 +278,14 @@ class SettingsNotifier extends Notifier<AppSettings> {
     return 'all';
   }
 
+  String _normalizeExtensionVerificationBrowserMode(String value) {
+    final normalized = value.trim().toLowerCase();
+    if (_extensionVerificationBrowserModeValues.contains(normalized)) {
+      return normalized;
+    }
+    return 'in_app_first';
+  }
+
   String? _sanitizeRetiredBuiltInProviderId(String? providerId) {
     final normalized = providerId?.trim().toLowerCase();
     if (normalized == null || normalized.isEmpty) return providerId;
@@ -557,6 +573,14 @@ class SettingsNotifier extends Notifier<AppSettings> {
     _saveSettings();
   }
 
+  void setExtensionVerificationBrowserMode(String mode) {
+    state = state.copyWith(
+      extensionVerificationBrowserMode:
+          _normalizeExtensionVerificationBrowserMode(mode),
+    );
+    _saveSettings();
+  }
+
   void setLocale(String locale) {
     state = state.copyWith(locale: locale);
     _saveSettings();

lib/providers/track_provider.dart

@@ -683,12 +683,26 @@ class TrackNotifier extends Notifier<TrackState> {
           }
         });
 
+    final browserMode = ref
+        .read(settingsProvider)
+        .extensionVerificationBrowserMode;
+    Uri? authUri;
+    Timer? helpDialogTimer;
+
     try {
       final opened = await openPendingExtensionVerification(
         normalizedExtensionId,
+        browserMode: browserMode,
+        onAuthUri: (uri) => authUri = uri,
       );
       if (!opened) return false;
 
+      helpDialogTimer = scheduleExtensionVerificationHelpDialog(
+        normalizedExtensionId,
+        authUri,
+        browserMode: browserMode,
+      );
+
       final event = await grantCompleter.future.timeout(
         const Duration(minutes: 5),
       );
@@ -699,6 +713,7 @@ class TrackNotifier extends Notifier<TrackState> {
       );
       return false;
     } finally {
+      helpDialogTimer?.cancel();
       await grantSub.cancel();
     }
   }

lib/screens/downloaded_album_screen.dart

@@ -1140,6 +1140,7 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
     showModalBottomSheet<void>(
       context: context,
       useRootNavigator: true,
+      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
       ),
@@ -1149,13 +1150,14 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
         confirmLabel: sheetConfirmLabel,
         sourceBitDepth: lowestKnownPositiveInt(sourceBitDepths),
         sourceSampleRate: lowestKnownPositiveInt(sourceSampleRates),
-        onConvert: (format, bitrate, losslessQuality) {
+        onConvert: (format, bitrate, losslessQuality, losslessProcessing) {
           Navigator.pop(sheetContext);
           _performBatchConversion(
             allTracks: allTracks,
             targetFormat: format,
             bitrate: bitrate,
             losslessQuality: losslessQuality,
+            losslessProcessing: losslessProcessing,
           );
         },
       ),
@@ -1168,6 +1170,8 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
     required String bitrate,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) async {
     final tracksById = {for (final t in allTracks) t.id: t};
     final selected = <DownloadHistoryItem>[];
@@ -1322,6 +1326,7 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
           deleteOriginal: !isSaf,
           sourceBitDepth: item.bitDepth,
           losslessQuality: losslessQuality,
+          losslessProcessing: losslessProcessing,
         );
 
         if (coverPath != null) {

lib/screens/local_album_screen.dart

@@ -1319,6 +1319,7 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
     showModalBottomSheet<void>(
       context: context,
       useRootNavigator: true,
+      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
       ),
@@ -1328,13 +1329,14 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
         confirmLabel: sheetConfirmLabel,
         sourceBitDepth: lowestKnownPositiveInt(sourceBitDepths),
         sourceSampleRate: lowestKnownPositiveInt(sourceSampleRates),
-        onConvert: (format, bitrate, losslessQuality) {
+        onConvert: (format, bitrate, losslessQuality, losslessProcessing) {
           Navigator.pop(sheetContext);
           _performBatchConversion(
             allTracks: allTracks,
             targetFormat: format,
             bitrate: bitrate,
             losslessQuality: losslessQuality,
+            losslessProcessing: losslessProcessing,
           );
         },
       ),
@@ -1347,6 +1349,8 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
     required String bitrate,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) async {
     final tracksById = {for (final t in allTracks) t.id: t};
     final selected = <LocalLibraryItem>[];
@@ -1500,6 +1504,7 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
           deleteOriginal: !isSaf,
           sourceBitDepth: item.bitDepth,
           losslessQuality: losslessQuality,
+          losslessProcessing: losslessProcessing,
         );
 
         if (coverPath != null) {

lib/screens/queue_tab.dart

@@ -5560,6 +5560,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     await showModalBottomSheet<void>(
       context: context,
       useRootNavigator: true,
+      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
       ),
@@ -5569,7 +5570,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
         confirmLabel: sheetConfirmLabel,
         sourceBitDepth: lowestKnownPositiveInt(sourceBitDepths),
         sourceSampleRate: lowestKnownPositiveInt(sourceSampleRates),
-        onConvert: (format, bitrate, losslessQuality) {
+        onConvert: (format, bitrate, losslessQuality, losslessProcessing) {
           didStartConversion = true;
           Navigator.pop(sheetContext);
           _performBatchConversion(
@@ -5577,6 +5578,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
             targetFormat: format,
             bitrate: bitrate,
             losslessQuality: losslessQuality,
+            losslessProcessing: losslessProcessing,
           );
         },
       ),
@@ -5611,6 +5613,8 @@ class _QueueTabState extends ConsumerState<QueueTab> {
     required String bitrate,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) async {
     final itemsById = {for (final item in allItems) item.id: item};
     final selectedItems = <UnifiedLibraryItem>[];
@@ -5770,6 +5774,7 @@ class _QueueTabState extends ConsumerState<QueueTab> {
           sourceBitDepth:
               item.historyItem?.bitDepth ?? item.localItem?.bitDepth,
           losslessQuality: losslessQuality,
+          losslessProcessing: losslessProcessing,
         );
 
         if (coverPath != null) {

lib/screens/settings/app_settings_page.dart

@@ -75,6 +75,12 @@ class AppSettingsPage extends ConsumerWidget {
                         .read(settingsProvider.notifier)
                         .setShowExtensionStore(v),
                   ),
+                  _VerificationBrowserModeSelector(
+                    currentMode: settings.extensionVerificationBrowserMode,
+                    onChanged: (mode) => ref
+                        .read(settingsProvider.notifier)
+                        .setExtensionVerificationBrowserMode(mode),
+                  ),
                   SettingsSwitchItem(
                     icon: Icons.system_update,
                     title: context.l10n.optionsCheckUpdates,
@@ -374,6 +380,96 @@ class _UpdateChannelSelector extends StatelessWidget {
   }
 }
 
+class _VerificationBrowserModeSelector extends StatelessWidget {
+  final String currentMode;
+  final ValueChanged<String> onChanged;
+
+  const _VerificationBrowserModeSelector({
+    required this.currentMode,
+    required this.onChanged,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final colorScheme = Theme.of(context).colorScheme;
+    final normalizedMode = currentMode == 'in_app_first'
+        ? 'in_app_first'
+        : currentMode == 'external_first'
+        ? 'external_first'
+        : 'in_app_first';
+
+    return Column(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Padding(
+          padding: const EdgeInsets.all(20),
+          child: Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              Row(
+                children: [
+                  Icon(
+                    Icons.open_in_browser,
+                    color: colorScheme.onSurfaceVariant,
+                    size: 24,
+                  ),
+                  const SizedBox(width: 16),
+                  Expanded(
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Text(
+                          context.l10n.extensionVerificationBrowserTitle,
+                          style: Theme.of(context).textTheme.bodyLarge,
+                        ),
+                        const SizedBox(height: 2),
+                        Text(
+                          normalizedMode == 'external_first'
+                              ? context
+                                    .l10n
+                                    .extensionVerificationBrowserSubtitleExternal
+                              : context
+                                    .l10n
+                                    .extensionVerificationBrowserSubtitleInApp,
+                          style: Theme.of(context).textTheme.bodyMedium
+                              ?.copyWith(color: colorScheme.onSurfaceVariant),
+                        ),
+                      ],
+                    ),
+                  ),
+                ],
+              ),
+              const SizedBox(height: 16),
+              Row(
+                children: [
+                  _ChannelChip(
+                    label: context.l10n.extensionVerificationBrowserExternal,
+                    isSelected: normalizedMode == 'external_first',
+                    onTap: () => onChanged('external_first'),
+                  ),
+                  const SizedBox(width: 8),
+                  _ChannelChip(
+                    label: context.l10n.extensionVerificationBrowserInApp,
+                    isSelected: normalizedMode == 'in_app_first',
+                    onTap: () => onChanged('in_app_first'),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+        Divider(
+          height: 1,
+          thickness: 1,
+          indent: 56,
+          endIndent: 20,
+          color: colorScheme.outlineVariant.withValues(alpha: 0.3),
+        ),
+      ],
+    );
+  }
+}
+
 class _ChannelChip extends StatelessWidget {
   final String label;
   final bool isSelected;

lib/screens/track_metadata_screen.dart

@@ -3822,12 +3822,15 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
     bool isLosslessTarget = isLosslessConversionTarget(selectedFormat);
     int? selectedMaxBitDepth;
     int? selectedMaxSampleRate;
+    String selectedDither = 'none';
+    String selectedResampler = 'swr';
     final bitDepthOptions = availableLosslessBitDepthOptions(bitDepth);
     final sampleRateOptions = availableLosslessSampleRateOptions(sampleRate);
 
     showModalBottomSheet<void>(
       context: context,
       useRootNavigator: true,
+      isScrollControlled: true,
       shape: const RoundedRectangleBorder(
         borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
       ),
@@ -3911,270 +3914,352 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
               );
             }
 
-            return SafeArea(
+            return Padding(
-              child: SingleChildScrollView(
+              padding: EdgeInsets.only(
-                padding: const EdgeInsets.fromLTRB(20, 12, 20, 20),
+                bottom: MediaQuery.of(context).viewInsets.bottom,
-                child: Column(
+              ),
-                  mainAxisSize: MainAxisSize.min,
+              child: DraggableScrollableSheet(
-                  crossAxisAlignment: CrossAxisAlignment.start,
+                initialChildSize: 0.85,
-                  children: [
+                minChildSize: 0.5,
-                    Center(
+                maxChildSize: 0.95,
-                      child: Container(
+                expand: false,
-                        width: 40,
+                builder: (context, scrollController) => SafeArea(
-                        height: 4,
+                  child: SingleChildScrollView(
-                        decoration: BoxDecoration(
+                    controller: scrollController,
-                          color: colorScheme.onSurfaceVariant.withValues(
+                    padding: const EdgeInsets.fromLTRB(20, 12, 20, 20),
-                            alpha: 0.4,
+                    child: Column(
+                      mainAxisSize: MainAxisSize.min,
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        Center(
+                          child: Container(
+                            width: 40,
+                            height: 4,
+                            decoration: BoxDecoration(
+                              color: colorScheme.onSurfaceVariant.withValues(
+                                alpha: 0.4,
+                              ),
+                              borderRadius: BorderRadius.circular(2),
+                            ),
                           ),
-                          borderRadius: BorderRadius.circular(2),
                         ),
-                      ),
+                        const SizedBox(height: 18),
-                    ),
+                        Text(
-                    const SizedBox(height: 18),
+                          context.l10n.trackConvertTitle,
-                    Text(
+                          style: Theme.of(context).textTheme.titleLarge
-                      context.l10n.trackConvertTitle,
+                              ?.copyWith(fontWeight: FontWeight.bold),
-                      style: Theme.of(context).textTheme.titleLarge?.copyWith(
+                        ),
-                        fontWeight: FontWeight.bold,
+                        const SizedBox(height: 4),
-                      ),
+                        Text(
-                    ),
+                          currentFormat,
-                    const SizedBox(height: 4),
+                          style: Theme.of(context).textTheme.bodyMedium
-                    Text(
+                              ?.copyWith(color: colorScheme.onSurfaceVariant),
-                      currentFormat,
+                        ),
-                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                        const SizedBox(height: 20),
-                        color: colorScheme.onSurfaceVariant,
-                      ),
-                    ),
-                    const SizedBox(height: 20),
 
-                    card(
+                        card(
-                      child: Column(
+                          child: Column(
-                        crossAxisAlignment: CrossAxisAlignment.start,
+                            crossAxisAlignment: CrossAxisAlignment.start,
-                        children: [
+                            children: [
-                          sectionLabel(context.l10n.trackConvertTargetFormat),
+                              sectionLabel(
-                          Wrap(
+                                context.l10n.trackConvertTargetFormat,
-                            spacing: 8,
+                              ),
-                            runSpacing: 8,
+                              Wrap(
-                            children: formats.map((format) {
+                                spacing: 8,
-                              return choice(
+                                runSpacing: 8,
-                                label: format,
+                                children: formats.map((format) {
-                                selected: format == selectedFormat,
+                                  return choice(
-                                onTap: () {
+                                    label: format,
-                                  setSheetState(() {
+                                    selected: format == selectedFormat,
-                                    selectedFormat = format;
+                                    onTap: () {
-                                    isLosslessTarget =
+                                      setSheetState(() {
-                                        isLosslessConversionTarget(format);
+                                        selectedFormat = format;
-                                    if (!isLosslessTarget) {
+                                        isLosslessTarget =
-                                      selectedBitrate = defaultBitrateForFormat(
+                                            isLosslessConversionTarget(format);
-                                        format,
+                                        if (!isLosslessTarget) {
+                                          selectedBitrate =
+                                              defaultBitrateForFormat(format);
+                                        } else {
+                                          selectedMaxBitDepth = null;
+                                          selectedMaxSampleRate = null;
+                                          selectedDither = 'none';
+                                          selectedResampler = 'swr';
+                                        }
+                                      });
+                                    },
+                                  );
+                                }).toList(),
+                              ),
+                            ],
+                          ),
+                        ),
+
+                        if (!isLosslessTarget)
+                          card(
+                            child: Column(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: [
+                                sectionLabel(context.l10n.trackConvertBitrate),
+                                Wrap(
+                                  spacing: 8,
+                                  runSpacing: 8,
+                                  children: bitrates.map((br) {
+                                    return choice(
+                                      label: br,
+                                      selected: br == selectedBitrate,
+                                      onTap: () => setSheetState(
+                                        () => selectedBitrate = br,
+                                      ),
+                                    );
+                                  }).toList(),
+                                ),
+                              ],
+                            ),
+                          ),
+
+                        if (isLosslessTarget && bitDepthOptions.isNotEmpty)
+                          card(
+                            child: Column(
+                              crossAxisAlignment: CrossAxisAlignment.start,
+                              children: [
+                                sectionLabel(
+                                  context.l10n.audioAnalysisBitDepth,
+                                ),
+                                Wrap(
+                                  spacing: 8,
+                                  runSpacing: 8,
+                                  children: [
+                                    choice(
+                                      label: losslessBitDepthLabel(
+                                        null,
+                                        originalLabel: labels.original,
+                                      ),
+                                      selected: selectedMaxBitDepth == null,
+                                      onTap: () => setSheetState(() {
+                                        selectedMaxBitDepth = null;
+                                        selectedDither = 'none';
+                                      }),
+                                    ),
+                                    ...bitDepthOptions.map((depth) {
+                                      return choice(
+                                        label: losslessBitDepthLabel(
+                                          depth,
+                                          originalLabel: labels.original,
+                                        ),
+                                        selected: depth == selectedMaxBitDepth,
+                                        onTap: () => setSheetState(
+                                          () => selectedMaxBitDepth = depth,
+                                        ),
                                       );
-                                    } else {
+                                    }),
-                                      selectedMaxBitDepth = null;
+                                  ],
-                                      selectedMaxSampleRate = null;
-                                    }
-                                  });
-                                },
-                              );
-                            }).toList(),
-                          ),
-                        ],
-                      ),
-                    ),
-
-                    if (!isLosslessTarget)
-                      card(
-                        child: Column(
-                          crossAxisAlignment: CrossAxisAlignment.start,
-                          children: [
-                            sectionLabel(context.l10n.trackConvertBitrate),
-                            Wrap(
-                              spacing: 8,
-                              runSpacing: 8,
-                              children: bitrates.map((br) {
-                                return choice(
-                                  label: br,
-                                  selected: br == selectedBitrate,
-                                  onTap: () =>
-                                      setSheetState(() => selectedBitrate = br),
-                                );
-                              }).toList(),
-                            ),
-                          ],
-                        ),
-                      ),
-
-                    if (isLosslessTarget && bitDepthOptions.isNotEmpty)
-                      card(
-                        child: Column(
-                          crossAxisAlignment: CrossAxisAlignment.start,
-                          children: [
-                            sectionLabel(context.l10n.audioAnalysisBitDepth),
-                            Wrap(
-                              spacing: 8,
-                              runSpacing: 8,
-                              children: [
-                                choice(
-                                  label: losslessBitDepthLabel(
-                                    null,
-                                    originalLabel: labels.original,
-                                  ),
-                                  selected: selectedMaxBitDepth == null,
-                                  onTap: () => setSheetState(
-                                    () => selectedMaxBitDepth = null,
-                                  ),
                                 ),
-                                ...bitDepthOptions.map((depth) {
-                                  return choice(
-                                    label: losslessBitDepthLabel(
-                                      depth,
-                                      originalLabel: labels.original,
-                                    ),
-                                    selected: depth == selectedMaxBitDepth,
-                                    onTap: () => setSheetState(
-                                      () => selectedMaxBitDepth = depth,
-                                    ),
-                                  );
-                                }),
                               ],
                             ),
-                          ],
+                          ),
-                        ),
-                      ),
 
-                    if (isLosslessTarget && sampleRateOptions.isNotEmpty)
+                        if (isLosslessTarget && sampleRateOptions.isNotEmpty)
-                      card(
+                          card(
-                        child: Column(
+                            child: Column(
-                          crossAxisAlignment: CrossAxisAlignment.start,
+                              crossAxisAlignment: CrossAxisAlignment.start,
-                          children: [
-                            sectionLabel(context.l10n.audioAnalysisSampleRate),
-                            Wrap(
-                              spacing: 8,
-                              runSpacing: 8,
                               children: [
-                                choice(
+                                sectionLabel(
-                                  label: losslessSampleRateLabel(
+                                  context.l10n.audioAnalysisSampleRate,
-                                    null,
-                                    originalLabel: labels.original,
-                                  ),
-                                  selected: selectedMaxSampleRate == null,
-                                  onTap: () => setSheetState(
-                                    () => selectedMaxSampleRate = null,
-                                  ),
                                 ),
-                                ...sampleRateOptions.map((rate) {
+                                Wrap(
-                                  return choice(
+                                  spacing: 8,
-                                    label: losslessSampleRateLabel(
+                                  runSpacing: 8,
-                                      rate,
+                                  children: [
-                                      originalLabel: labels.original,
+                                    choice(
+                                      label: losslessSampleRateLabel(
+                                        null,
+                                        originalLabel: labels.original,
+                                      ),
+                                      selected: selectedMaxSampleRate == null,
+                                      onTap: () => setSheetState(() {
+                                        selectedMaxSampleRate = null;
+                                        selectedResampler = 'swr';
+                                      }),
                                     ),
-                                    selected: rate == selectedMaxSampleRate,
+                                    ...sampleRateOptions.map((rate) {
-                                    onTap: () => setSheetState(
+                                      return choice(
-                                      () => selectedMaxSampleRate = rate,
+                                        label: losslessSampleRateLabel(
-                                    ),
+                                          rate,
-                                  );
+                                          originalLabel: labels.original,
-                                }),
+                                        ),
+                                        selected: rate == selectedMaxSampleRate,
+                                        onTap: () => setSheetState(
+                                          () => selectedMaxSampleRate = rate,
+                                        ),
+                                      );
+                                    }),
+                                  ],
+                                ),
                               ],
                             ),
-                          ],
-                        ),
-                      ),
-
-                    if (isLosslessTarget && isLosslessSource)
-                      Container(
-                        width: double.infinity,
-                        margin: const EdgeInsets.only(bottom: 12),
-                        padding: const EdgeInsets.symmetric(
-                          horizontal: 14,
-                          vertical: 12,
-                        ),
-                        decoration: BoxDecoration(
-                          color: colorScheme.primaryContainer.withValues(
-                            alpha: 0.4,
                           ),
-                          borderRadius: BorderRadius.circular(14),
+
-                        ),
+                        if (isLosslessTarget && selectedMaxBitDepth != null)
-                        child: Row(
+                          card(
-                          children: [
+                            child: Column(
-                            Icon(
+                              crossAxisAlignment: CrossAxisAlignment.start,
-                              Icons.verified,
+                              children: [
-                              size: 18,
+                                sectionLabel(
-                              color: colorScheme.primary,
+                                  context.l10n.trackConvertDithering,
+                                ),
+                                Wrap(
+                                  spacing: 8,
+                                  runSpacing: 8,
+                                  children: losslessDitherOptions.map((mode) {
+                                    return choice(
+                                      label: context.l10n
+                                          .losslessDitherOptionLabel(mode),
+                                      selected: mode == selectedDither,
+                                      onTap: () => setSheetState(
+                                        () => selectedDither = mode,
+                                      ),
+                                    );
+                                  }).toList(),
+                                ),
+                              ],
                             ),
-                            const SizedBox(width: 8),
+                          ),
-                            Expanded(
+
-                              child: Text(
+                        if (isLosslessTarget && selectedMaxSampleRate != null)
-                                selectedMaxBitDepth == null &&
+                          card(
-                                        selectedMaxSampleRate == null
+                            child: Column(
-                                    ? context.l10n.trackConvertLosslessHint
+                              crossAxisAlignment: CrossAxisAlignment.start,
-                                    : context.l10n
+                              children: [
-                                          .trackConvertLosslessOutputWithCap(
+                                sectionLabel(
-                                            losslessQualityLabel(
+                                  context.l10n.trackConvertResampler,
-                                              LosslessConversionQuality(
+                                ),
-                                                maxBitDepth:
+                                Wrap(
-                                                    selectedMaxBitDepth,
+                                  spacing: 8,
-                                                maxSampleRate:
+                                  runSpacing: 8,
-                                                    selectedMaxSampleRate,
+                                  children: losslessResamplerOptions.map((
+                                    mode,
+                                  ) {
+                                    return choice(
+                                      label: context.l10n
+                                          .losslessResamplerOptionLabel(mode),
+                                      selected: mode == selectedResampler,
+                                      onTap: () => setSheetState(
+                                        () => selectedResampler = mode,
+                                      ),
+                                    );
+                                  }).toList(),
+                                ),
+                              ],
+                            ),
+                          ),
+
+                        if (isLosslessTarget && isLosslessSource)
+                          Container(
+                            width: double.infinity,
+                            margin: const EdgeInsets.only(bottom: 12),
+                            padding: const EdgeInsets.symmetric(
+                              horizontal: 14,
+                              vertical: 12,
+                            ),
+                            decoration: BoxDecoration(
+                              color: colorScheme.primaryContainer.withValues(
+                                alpha: 0.4,
+                              ),
+                              borderRadius: BorderRadius.circular(14),
+                            ),
+                            child: Row(
+                              children: [
+                                Icon(
+                                  Icons.verified,
+                                  size: 18,
+                                  color: colorScheme.primary,
+                                ),
+                                const SizedBox(width: 8),
+                                Expanded(
+                                  child: Text(
+                                    selectedMaxBitDepth == null &&
+                                            selectedMaxSampleRate == null
+                                        ? context.l10n.trackConvertLosslessHint
+                                        : context.l10n
+                                              .trackConvertLosslessOutputWithCap(
+                                                losslessQualityLabel(
+                                                  LosslessConversionQuality(
+                                                    maxBitDepth:
+                                                        selectedMaxBitDepth,
+                                                    maxSampleRate:
+                                                        selectedMaxSampleRate,
+                                                  ),
+                                                  originalLabel:
+                                                      labels.original,
+                                                  originalQualityLabel:
+                                                      labels.originalQuality,
+                                                ),
                                               ),
-                                              originalLabel: labels.original,
+                                    style: Theme.of(context).textTheme.bodySmall
-                                              originalQualityLabel:
+                                        ?.copyWith(color: colorScheme.primary),
-                                                  labels.originalQuality,
+                                  ),
-                                            ),
+                                ),
-                                          ),
+                              ],
-                                style: Theme.of(context).textTheme.bodySmall
+                            ),
-                                    ?.copyWith(color: colorScheme.primary),
+                          ),
+
+                        const SizedBox(height: 8),
+                        SizedBox(
+                          width: double.infinity,
+                          child: FilledButton.icon(
+                            onPressed: () {
+                              Navigator.pop(context);
+                              _confirmAndConvert(
+                                context: this.context,
+                                sourceFormat: currentFormat,
+                                targetFormat: selectedFormat,
+                                bitrate: selectedBitrate,
+                                losslessQuality: LosslessConversionQuality(
+                                  maxBitDepth: selectedMaxBitDepth,
+                                  maxSampleRate: selectedMaxSampleRate,
+                                ),
+                                losslessProcessing:
+                                    LosslessConversionProcessing(
+                                      dither: selectedDither,
+                                      resampler: selectedResampler,
+                                    ),
+                              );
+                            },
+                            icon: const Icon(Icons.swap_horiz),
+                            style: FilledButton.styleFrom(
+                              padding: const EdgeInsets.symmetric(vertical: 16),
+                              shape: RoundedRectangleBorder(
+                                borderRadius: BorderRadius.circular(14),
                               ),
                             ),
-                          ],
+                            label: Text(
-                        ),
+                              isLosslessTarget
-                      ),
+                                  ? context.l10n
-
+                                        .trackConvertActionLabelLossless(
-                    const SizedBox(height: 8),
+                                          currentFormat,
-                    SizedBox(
+                                          selectedFormat,
-                      width: double.infinity,
+                                          losslessQualityLabel(
-                      child: FilledButton.icon(
+                                            LosslessConversionQuality(
-                        onPressed: () {
+                                              maxBitDepth: selectedMaxBitDepth,
-                          Navigator.pop(context);
+                                              maxSampleRate:
-                          _confirmAndConvert(
+                                                  selectedMaxSampleRate,
-                            context: this.context,
+                                            ),
-                            sourceFormat: currentFormat,
+                                            originalLabel: labels.original,
-                            targetFormat: selectedFormat,
+                                            originalQualityLabel:
-                            bitrate: selectedBitrate,
+                                                labels.originalQuality,
-                            losslessQuality: LosslessConversionQuality(
+                                          ),
-                              maxBitDepth: selectedMaxBitDepth,
+                                        )
-                              maxSampleRate: selectedMaxSampleRate,
+                                  : context.l10n.trackConvertActionLabelLossy(
+                                      currentFormat,
+                                      selectedFormat,
+                                      selectedBitrate,
+                                    ),
                             ),
-                          );
-                        },
-                        icon: const Icon(Icons.swap_horiz),
-                        style: FilledButton.styleFrom(
-                          padding: const EdgeInsets.symmetric(vertical: 16),
-                          shape: RoundedRectangleBorder(
-                            borderRadius: BorderRadius.circular(14),
                           ),
                         ),
-                        label: Text(
+                      ],
-                          isLosslessTarget
-                              ? context.l10n.trackConvertActionLabelLossless(
-                                  currentFormat,
-                                  selectedFormat,
-                                  losslessQualityLabel(
-                                    LosslessConversionQuality(
-                                      maxBitDepth: selectedMaxBitDepth,
-                                      maxSampleRate: selectedMaxSampleRate,
-                                    ),
-                                    originalLabel: labels.original,
-                                    originalQualityLabel:
-                                        labels.originalQuality,
-                                  ),
-                                )
-                              : context.l10n.trackConvertActionLabelLossy(
-                                  currentFormat,
-                                  selectedFormat,
-                                  selectedBitrate,
-                                ),
-                        ),
-                      ),
                     ),
-                  ],
+                  ),
                 ),
               ),
             );
@@ -4642,6 +4727,8 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
     required String bitrate,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) {
     final isLossless = isLosslessConversionTarget(targetFormat);
     showDialog<void>(
@@ -4687,6 +4774,7 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
                   targetFormat: targetFormat,
                   bitrate: bitrate,
                   losslessQuality: losslessQuality,
+                  losslessProcessing: losslessProcessing,
                 );
               },
               child: Text(dialogContext.l10n.trackConvertFormat),
@@ -4702,6 +4790,8 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
     required String bitrate,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) async {
     if (_isConverting) return;
     setState(() => _isConverting = true);
@@ -4778,6 +4868,7 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
         deleteOriginal: !isSaf,
         sourceBitDepth: bitDepth,
         losslessQuality: losslessQuality,
+        losslessProcessing: losslessProcessing,
       );
 
       if (coverPath != null) {

lib/services/app_navigation_service.dart

@@ -0,0 +1,8 @@
+import 'package:flutter/material.dart';
+
+class AppNavigationService {
+  static final GlobalKey<NavigatorState> rootNavigatorKey =
+      GlobalKey<NavigatorState>();
+
+  const AppNavigationService._();
+}

lib/services/ffmpeg_service.dart

@@ -393,12 +393,19 @@ class FFmpegService {
     required String codec,
     int? targetBitDepth,
     int? targetSampleRate,
+    LosslessConversionProcessing processing =
+        const LosslessConversionProcessing(),
   }) {
-    if (targetSampleRate != null && targetSampleRate > 0) {
+    final sampleFmt = _losslessOutputSampleFormat(
-      arguments
+      codec: codec,
-        ..add('-ar')
+      targetBitDepth: targetBitDepth,
-        ..add(targetSampleRate.toString());
+    );
-    }
+    _appendLosslessAresampleFilter(
+      arguments,
+      targetSampleRate: targetSampleRate,
+      outputSampleFormat: sampleFmt,
+      processing: processing,
+    );
     if (targetBitDepth == null || targetBitDepth <= 0) return;
 
     if (codec == 'flac') {
@@ -431,6 +438,48 @@ class FFmpegService {
     }
   }
 
+  static String? _losslessOutputSampleFormat({
+    required String codec,
+    int? targetBitDepth,
+  }) {
+    if (targetBitDepth == null || targetBitDepth <= 0) return null;
+
+    if (codec == 'flac') {
+      return targetBitDepth <= 16 ? 's16' : 's32';
+    }
+    if (codec == 'alac') {
+      return targetBitDepth <= 16 ? 's16p' : 's32p';
+    }
+    if (codec == 'pcm') {
+      return targetBitDepth <= 16 ? 's16' : 's32';
+    }
+    return null;
+  }
+
+  static void _appendLosslessAresampleFilter(
+    List<String> arguments, {
+    int? targetSampleRate,
+    String? outputSampleFormat,
+    LosslessConversionProcessing processing =
+        const LosslessConversionProcessing(),
+  }) {
+    final hasSampleRate = targetSampleRate != null && targetSampleRate > 0;
+    final hasSampleFormat =
+        outputSampleFormat != null && outputSampleFormat.trim().isNotEmpty;
+    if (!hasSampleRate && !hasSampleFormat && !processing.hasDither) return;
+
+    final options = <String>[
+      'resampler=${processing.normalizedResampler}',
+      if (hasSampleRate) 'osr=$targetSampleRate',
+      if (hasSampleFormat) 'osf=${outputSampleFormat.trim()}',
+      if (processing.hasDither) 'dither_method=${processing.normalizedDither}',
+    ];
+
+    arguments
+      ..add('-af')
+      ..add('aresample=${options.join(':')}');
+  }
+
   static Future<String?> convertM4aToFlac(String inputPath) async {
     final outputPath = _buildOutputPath(inputPath, '.flac');
 
@@ -2349,6 +2398,8 @@ class FFmpegService {
     int? sourceBitDepth,
     LosslessConversionQuality losslessQuality =
         const LosslessConversionQuality(),
+    LosslessConversionProcessing losslessProcessing =
+        const LosslessConversionProcessing(),
   }) async {
     final format = targetFormat.toLowerCase();
     if (!const {
@@ -2380,6 +2431,7 @@ class FFmpegService {
         coverPath: coverPath,
         targetBitDepth: resolvedLosslessQuality.targetBitDepth,
         targetSampleRate: resolvedLosslessQuality.targetSampleRate,
+        processing: losslessProcessing,
         deleteOriginal: deleteOriginal,
       );
     }
@@ -2391,6 +2443,7 @@ class FFmpegService {
         artistTagMode: artistTagMode,
         targetBitDepth: resolvedLosslessQuality.targetBitDepth,
         targetSampleRate: resolvedLosslessQuality.targetSampleRate,
+        processing: losslessProcessing,
         deleteOriginal: deleteOriginal,
       );
     }
@@ -2403,6 +2456,7 @@ class FFmpegService {
         sourceBitDepth: sourceBitDepth,
         targetBitDepth: resolvedLosslessQuality.targetBitDepth,
         targetSampleRate: resolvedLosslessQuality.targetSampleRate,
+        processing: losslessProcessing,
         deleteOriginal: deleteOriginal,
       );
     }
@@ -2500,6 +2554,8 @@ class FFmpegService {
     String? coverPath,
     int? targetBitDepth,
     int? targetSampleRate,
+    LosslessConversionProcessing processing =
+        const LosslessConversionProcessing(),
     bool deleteOriginal = true,
   }) async {
     final outputPath = _buildOutputPath(inputPath, '.m4a');
@@ -2539,6 +2595,7 @@ class FFmpegService {
       codec: 'alac',
       targetBitDepth: targetBitDepth,
       targetSampleRate: targetSampleRate,
+      processing: processing,
     );
     arguments
       ..add('-map_metadata')
@@ -2553,7 +2610,9 @@ class FFmpegService {
     _log.i(
       'Converting ${inputPath.split(Platform.pathSeparator).last} to ALAC'
       '${targetBitDepth != null ? ' $targetBitDepth-bit' : ''}'
-      '${targetSampleRate != null ? ' @ ${targetSampleRate}Hz' : ''}',
+      '${targetSampleRate != null ? ' @ ${targetSampleRate}Hz' : ''}'
+      '${processing.hasDither ? ' dither=${processing.normalizedDither}' : ''}'
+      '${processing.normalizedResampler != 'swr' ? ' resampler=${processing.normalizedResampler}' : ''}',
     );
     final result = await _executeWithArguments(arguments);
 
@@ -2583,6 +2642,8 @@ class FFmpegService {
     String artistTagMode = artistTagModeJoined,
     int? targetBitDepth,
     int? targetSampleRate,
+    LosslessConversionProcessing processing =
+        const LosslessConversionProcessing(),
     bool deleteOriginal = true,
   }) async {
     final outputPath = _buildOutputPath(inputPath, '.flac');
@@ -2624,6 +2685,7 @@ class FFmpegService {
       codec: 'flac',
       targetBitDepth: targetBitDepth,
       targetSampleRate: targetSampleRate,
+      processing: processing,
     );
     arguments
       ..add('-map_metadata')
@@ -2642,7 +2704,9 @@ class FFmpegService {
     _log.i(
       'Converting ${inputPath.split(Platform.pathSeparator).last} to FLAC'
       '${targetBitDepth != null ? ' $targetBitDepth-bit' : ''}'
-      '${targetSampleRate != null ? ' @ ${targetSampleRate}Hz' : ''}',
+      '${targetSampleRate != null ? ' @ ${targetSampleRate}Hz' : ''}'
+      '${processing.hasDither ? ' dither=${processing.normalizedDither}' : ''}'
+      '${processing.normalizedResampler != 'swr' ? ' resampler=${processing.normalizedResampler}' : ''}',
     );
     final result = await _executeWithArguments(arguments);
 
@@ -2676,6 +2740,8 @@ class FFmpegService {
     int? sourceBitDepth,
     int? targetBitDepth,
     int? targetSampleRate,
+    LosslessConversionProcessing processing =
+        const LosslessConversionProcessing(),
     bool deleteOriginal = true,
   }) async {
     final isAiff = container == 'aiff';
@@ -2697,22 +2763,24 @@ class FFmpegService {
       inputPath,
       '-map',
       '0:a',
-      '-c:a',
-      codec,
-      if (targetSampleRate != null && targetSampleRate > 0) ...[
-        '-ar',
-        targetSampleRate.toString(),
-      ],
-      '-map_metadata',
-      '-1',
-      outputPath,
-      '-y',
     ];
+    _appendLosslessAresampleFilter(
+      arguments,
+      targetSampleRate: targetSampleRate,
+      outputSampleFormat: _losslessOutputSampleFormat(
+        codec: 'pcm',
+        targetBitDepth: targetBitDepth,
+      ),
+      processing: processing,
+    );
+    arguments.addAll(['-c:a', codec, '-map_metadata', '-1', outputPath, '-y']);
 
     _log.i(
       'Converting ${inputPath.split(Platform.pathSeparator).last} to '
       '${container.toUpperCase()} (${use24 ? 24 : 16}-bit'
-      '${targetSampleRate != null ? ', ${targetSampleRate}Hz' : ''})',
+      '${targetSampleRate != null ? ', ${targetSampleRate}Hz' : ''}'
+      '${processing.hasDither ? ', dither=${processing.normalizedDither}' : ''}'
+      '${processing.normalizedResampler != 'swr' ? ', resampler=${processing.normalizedResampler}' : ''})',
     );
     final result = await _executeWithArguments(arguments);
     if (!result.success) {

lib/utils/audio_conversion_utils.dart

@@ -19,6 +19,36 @@ const List<int> losslessConversionSampleRateOptions = [
 
 const List<int> losslessConversionBitDepthOptions = [16, 24];
 
+const List<String> losslessDitherOptions = [
+  'none',
+  'triangular',
+  'triangular_hp',
+];
+
+const List<String> losslessResamplerOptions = ['swr', 'soxr'];
+
+class LosslessConversionProcessing {
+  final String dither;
+  final String resampler;
+
+  const LosslessConversionProcessing({
+    this.dither = 'none',
+    this.resampler = 'swr',
+  });
+
+  String get normalizedDither {
+    final normalized = dither.trim().toLowerCase();
+    return losslessDitherOptions.contains(normalized) ? normalized : 'none';
+  }
+
+  String get normalizedResampler {
+    final normalized = resampler.trim().toLowerCase();
+    return losslessResamplerOptions.contains(normalized) ? normalized : 'swr';
+  }
+
+  bool get hasDither => normalizedDither != 'none';
+}
+
 List<int> availableLosslessBitDepthOptions(int? sourceBitDepth) {
   if (sourceBitDepth == null || sourceBitDepth <= 0) {
     return losslessConversionBitDepthOptions;
@@ -189,12 +219,29 @@ extension LosslessConversionLabelsL10n on AppLocalizations {
         originalQuality: trackConvertOriginalQuality,
         lossless: trackConvertLosslessSuffix,
       );
+
+  String losslessDitherOptionLabel(String dither) {
+    switch (dither.trim().toLowerCase()) {
+      case 'triangular':
+        return trackConvertDitherTriangular;
+      case 'triangular_hp':
+        return trackConvertDitherTriangularHp;
+      default:
+        return trackConvertDitherNone;
+    }
+  }
+
+  String losslessResamplerOptionLabel(String resampler) {
+    switch (resampler.trim().toLowerCase()) {
+      case 'soxr':
+        return trackConvertResamplerSoxr;
+      default:
+        return trackConvertResamplerSwr;
+    }
+  }
 }
 
-String losslessBitDepthLabel(
+String losslessBitDepthLabel(int? bitDepth, {required String originalLabel}) {
-  int? bitDepth, {
-  required String originalLabel,
-}) {
   return bitDepth == null ? originalLabel : '$bitDepth-bit';
 }
 
@@ -216,10 +263,7 @@ String losslessQualityLabel(
   final parts = <String>[];
   if (quality.maxBitDepth != null) {
     parts.add(
-      losslessBitDepthLabel(
+      losslessBitDepthLabel(quality.maxBitDepth, originalLabel: originalLabel),
-        quality.maxBitDepth,
-        originalLabel: originalLabel,
-      ),
     );
   }
   if (quality.maxSampleRate != null) {
@@ -250,11 +294,7 @@ String convertedAudioQualityLabel({
       return '$upper ${losslessBitDepthLabel(actualBitDepth, originalLabel: labels.original)}/${losslessSampleRateLabel(actualSampleRate, originalLabel: labels.original)}';
     }
     if (losslessQuality.hasCaps) {
-      return '$upper ${losslessQualityLabel(
+      return '$upper ${losslessQualityLabel(losslessQuality, originalLabel: labels.original, originalQualityLabel: labels.originalQuality)}';
-        losslessQuality,
-        originalLabel: labels.original,
-        originalQualityLabel: labels.originalQuality,
-      )}';
     }
     return '$upper ${labels.lossless}';
   }

lib/utils/extension_auth_launcher.dart

@@ -1,3 +1,9 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:spotiflac_android/l10n/l10n.dart';
+import 'package:spotiflac_android/services/app_navigation_service.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/utils/logger.dart';
 import 'package:url_launcher/url_launcher.dart';
@@ -27,7 +33,11 @@ bool _containsHttpStatusCode(String message, String code) {
       message.contains('$code;');
 }
 
-Future<bool> openPendingExtensionVerification(String extensionId) async {
+Future<bool> openPendingExtensionVerification(
+  String extensionId, {
+  String browserMode = 'in_app_first',
+  void Function(Uri authUri)? onAuthUri,
+}) async {
   final normalizedExtensionId = extensionId.trim();
   if (normalizedExtensionId.isEmpty) return false;
 
@@ -40,11 +50,9 @@ Future<bool> openPendingExtensionVerification(String extensionId) async {
 
     final uri = Uri.tryParse(authUrl);
     if (uri == null) return false;
+    onAuthUri?.call(uri);
 
-    var launched = await launchUrl(uri, mode: LaunchMode.inAppBrowserView);
+    final launched = await _launchVerificationUrl(uri, browserMode);
-    if (!launched) {
-      launched = await launchUrl(uri, mode: LaunchMode.externalApplication);
-    }
 
     if (launched) {
       _log.i('Opened verification challenge for $normalizedExtensionId');
@@ -52,6 +60,12 @@ Future<bool> openPendingExtensionVerification(String extensionId) async {
       _log.w(
         'Could not open verification challenge for $normalizedExtensionId',
       );
+      return showExtensionVerificationHelpDialog(
+        normalizedExtensionId,
+        uri,
+        browserMode: browserMode,
+        immediateFailure: true,
+      );
     }
     return launched;
   } catch (e) {
@@ -61,3 +75,120 @@ Future<bool> openPendingExtensionVerification(String extensionId) async {
     return false;
   }
 }
+
+Timer? scheduleExtensionVerificationHelpDialog(
+  String extensionId,
+  Uri? authUri, {
+  String browserMode = 'in_app_first',
+  Duration delay = const Duration(seconds: 20),
+}) {
+  final normalizedExtensionId = extensionId.trim();
+  if (normalizedExtensionId.isEmpty || authUri == null) return null;
+
+  return Timer(delay, () {
+    unawaited(
+      showExtensionVerificationHelpDialog(
+        normalizedExtensionId,
+        authUri,
+        browserMode: browserMode,
+      ),
+    );
+  });
+}
+
+Future<bool> showExtensionVerificationHelpDialog(
+  String extensionId,
+  Uri authUri, {
+  String browserMode = 'in_app_first',
+  bool immediateFailure = false,
+}) async {
+  final context = AppNavigationService.rootNavigatorKey.currentContext;
+  if (context == null) {
+    _log.w('Cannot show verification help dialog without root context');
+    return false;
+  }
+
+  final l10n = context.l10n;
+  final title = immediateFailure
+      ? l10n.extensionVerificationHelpTitleManual
+      : l10n.extensionVerificationHelpTitleWaiting;
+  final message = immediateFailure
+      ? l10n.extensionVerificationHelpMessageManual
+      : l10n.extensionVerificationHelpMessageWaiting;
+
+  await showDialog<void>(
+    context: context,
+    useRootNavigator: true,
+    barrierDismissible: false,
+    builder: (dialogContext) {
+      final dialogL10n = dialogContext.l10n;
+      return AlertDialog(
+        title: Text(title),
+        content: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            Text(message),
+            const SizedBox(height: 16),
+            DecoratedBox(
+              decoration: BoxDecoration(
+                color: Theme.of(dialogContext).colorScheme.surfaceContainerHigh,
+                borderRadius: BorderRadius.circular(8),
+              ),
+              child: Padding(
+                padding: const EdgeInsets.all(12),
+                child: SelectableText(
+                  authUri.toString(),
+                  maxLines: 4,
+                  minLines: 1,
+                ),
+              ),
+            ),
+          ],
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(dialogContext).pop(),
+            child: Text(dialogL10n.extensionVerificationClose),
+          ),
+          TextButton.icon(
+            icon: const Icon(Icons.copy),
+            label: Text(dialogL10n.extensionVerificationCopyLink),
+            onPressed: () {
+              Clipboard.setData(ClipboardData(text: authUri.toString()));
+              ScaffoldMessenger.maybeOf(dialogContext)?.showSnackBar(
+                SnackBar(
+                  content: Text(dialogL10n.extensionVerificationLinkCopied),
+                ),
+              );
+            },
+          ),
+          FilledButton.icon(
+            icon: const Icon(Icons.open_in_browser),
+            label: Text(dialogL10n.extensionVerificationOpenBrowser),
+            onPressed: () {
+              unawaited(_launchVerificationUrl(authUri, browserMode));
+            },
+          ),
+        ],
+      );
+    },
+  );
+  return true;
+}
+
+Future<bool> _launchVerificationUrl(Uri uri, String browserMode) async {
+  final preferInApp = browserMode.trim().toLowerCase() == 'in_app_first';
+  final firstMode = preferInApp
+      ? LaunchMode.inAppBrowserView
+      : LaunchMode.externalApplication;
+  final fallbackMode = preferInApp
+      ? LaunchMode.externalApplication
+      : LaunchMode.inAppBrowserView;
+
+  var launched = await launchUrl(uri, mode: firstMode);
+  if (!launched) {
+    launched = await launchUrl(uri, mode: fallbackMode);
+  }
+  return launched;
+}

lib/widgets/batch_convert_sheet.dart

@@ -16,6 +16,7 @@ class BatchConvertSheet extends StatefulWidget {
     String format,
     String bitrate,
     LosslessConversionQuality losslessQuality,
+    LosslessConversionProcessing losslessProcessing,
   )
   onConvert;
 
@@ -42,6 +43,8 @@ class _BatchConvertSheetState extends State<BatchConvertSheet> {
   late String _selectedBitrate;
   int? _selectedMaxBitDepth;
   int? _selectedMaxSampleRate;
+  String _selectedDither = 'none';
+  String _selectedResampler = 'swr';
 
   String _defaultBitrateForFormat(String format) {
     if (format == 'Opus') return '128k';
@@ -70,242 +73,322 @@ class _BatchConvertSheetState extends State<BatchConvertSheet> {
       widget.sourceSampleRate,
     );
 
-    return SafeArea(
+    return Padding(
-      child: SingleChildScrollView(
+      padding: EdgeInsets.only(
-        padding: const EdgeInsets.fromLTRB(20, 12, 20, 20),
+        bottom: MediaQuery.of(context).viewInsets.bottom,
-        child: Column(
+      ),
-          mainAxisSize: MainAxisSize.min,
+      child: DraggableScrollableSheet(
-          crossAxisAlignment: CrossAxisAlignment.start,
+        initialChildSize: 0.85,
-          children: [
+        minChildSize: 0.5,
-            Center(
+        maxChildSize: 0.95,
-              child: Container(
+        expand: false,
-                width: 40,
+        builder: (context, scrollController) => SafeArea(
-                height: 4,
+          child: SingleChildScrollView(
-                decoration: BoxDecoration(
+            controller: scrollController,
-                  color: cs.onSurfaceVariant.withValues(alpha: 0.4),
+            padding: const EdgeInsets.fromLTRB(20, 12, 20, 20),
-                  borderRadius: BorderRadius.circular(2),
+            child: Column(
+              mainAxisSize: MainAxisSize.min,
+              crossAxisAlignment: CrossAxisAlignment.start,
+              children: [
+                Center(
+                  child: Container(
+                    width: 40,
+                    height: 4,
+                    decoration: BoxDecoration(
+                      color: cs.onSurfaceVariant.withValues(alpha: 0.4),
+                      borderRadius: BorderRadius.circular(2),
+                    ),
+                  ),
                 ),
-              ),
+                const SizedBox(height: 18),
-            ),
+                Text(
-            const SizedBox(height: 18),
+                  widget.title,
-            Text(
+                  style: Theme.of(
-              widget.title,
+                    context,
-              style: Theme.of(
+                  ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
-                context,
+                ),
-              ).textTheme.titleLarge?.copyWith(fontWeight: FontWeight.bold),
+                if (widget.subtitle != null) ...[
-            ),
+                  const SizedBox(height: 4),
-            if (widget.subtitle != null) ...[
+                  Text(
-              const SizedBox(height: 4),
+                    widget.subtitle!,
-              Text(
+                    style: Theme.of(context).textTheme.bodyMedium?.copyWith(
-                widget.subtitle!,
+                      color: cs.onSurfaceVariant,
-                style: Theme.of(
+                    ),
-                  context,
-                ).textTheme.bodyMedium?.copyWith(color: cs.onSurfaceVariant),
-              ),
-            ],
-            const SizedBox(height: 20),
-
-            _card(
-              cs,
-              child: Column(
-                crossAxisAlignment: CrossAxisAlignment.start,
-                children: [
-                  _sectionLabel(cs, context.l10n.trackConvertTargetFormat),
-                  Wrap(
-                    spacing: 8,
-                    runSpacing: 8,
-                    children: widget.formats.map((format) {
-                      return _choice(
-                        cs,
-                        label: format,
-                        selected: format == _selectedFormat,
-                        onTap: () {
-                          setState(() {
-                            _selectedFormat = format;
-                            _isLosslessTarget = isLosslessConversionTarget(
-                              format,
-                            );
-                            if (!_isLosslessTarget) {
-                              _selectedBitrate = _defaultBitrateForFormat(
-                                format,
-                              );
-                            } else {
-                              _selectedMaxBitDepth = null;
-                              _selectedMaxSampleRate = null;
-                            }
-                          });
-                        },
-                      );
-                    }).toList(),
                   ),
                 ],
-              ),
+                const SizedBox(height: 20),
-            ),
 
-            if (!_isLosslessTarget)
+                _card(
-              _card(
+                  cs,
-                cs,
+                  child: Column(
-                child: Column(
+                    crossAxisAlignment: CrossAxisAlignment.start,
-                  crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
-                  children: [
+                      _sectionLabel(cs, context.l10n.trackConvertTargetFormat),
-                    _sectionLabel(cs, context.l10n.trackConvertBitrate),
+                      Wrap(
-                    Wrap(
+                        spacing: 8,
-                      spacing: 8,
+                        runSpacing: 8,
-                      runSpacing: 8,
+                        children: widget.formats.map((format) {
-                      children: _bitrates.map((br) {
-                        return _choice(
-                          cs,
-                          label: br,
-                          selected: br == _selectedBitrate,
-                          onTap: () => setState(() => _selectedBitrate = br),
-                        );
-                      }).toList(),
-                    ),
-                  ],
-                ),
-              ),
-
-            if (_isLosslessTarget && bitDepthOptions.isNotEmpty)
-              _card(
-                cs,
-                child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
-                  children: [
-                    _sectionLabel(cs, context.l10n.audioAnalysisBitDepth),
-                    Wrap(
-                      spacing: 8,
-                      runSpacing: 8,
-                      children: [
-                        _choice(
-                          cs,
-                          label: losslessBitDepthLabel(
-                            null,
-                            originalLabel: labels.original,
-                          ),
-                          selected: _selectedMaxBitDepth == null,
-                          onTap: () =>
-                              setState(() => _selectedMaxBitDepth = null),
-                        ),
-                        ...bitDepthOptions.map((depth) {
                           return _choice(
                             cs,
-                            label: losslessBitDepthLabel(
+                            label: format,
-                              depth,
+                            selected: format == _selectedFormat,
-                              originalLabel: labels.original,
+                            onTap: () {
-                            ),
+                              setState(() {
-                            selected: depth == _selectedMaxBitDepth,
+                                _selectedFormat = format;
-                            onTap: () =>
+                                _isLosslessTarget = isLosslessConversionTarget(
-                                setState(() => _selectedMaxBitDepth = depth),
+                                  format,
+                                );
+                                if (!_isLosslessTarget) {
+                                  _selectedBitrate = _defaultBitrateForFormat(
+                                    format,
+                                  );
+                                } else {
+                                  _selectedMaxBitDepth = null;
+                                  _selectedMaxSampleRate = null;
+                                  _selectedDither = 'none';
+                                  _selectedResampler = 'swr';
+                                }
+                              });
+                            },
                           );
-                        }),
+                        }).toList(),
-                      ],
+                      ),
-                    ),
+                    ],
-                  ],
+                  ),
                 ),
-              ),
 
-            if (_isLosslessTarget && sampleRateOptions.isNotEmpty)
+                if (!_isLosslessTarget)
-              _card(
+                  _card(
-                cs,
+                    cs,
-                child: Column(
+                    child: Column(
-                  crossAxisAlignment: CrossAxisAlignment.start,
+                      crossAxisAlignment: CrossAxisAlignment.start,
-                  children: [
-                    _sectionLabel(cs, context.l10n.audioAnalysisSampleRate),
-                    Wrap(
-                      spacing: 8,
-                      runSpacing: 8,
                       children: [
-                        _choice(
+                        _sectionLabel(cs, context.l10n.trackConvertBitrate),
-                          cs,
+                        Wrap(
-                          label: losslessSampleRateLabel(
+                          spacing: 8,
-                            null,
+                          runSpacing: 8,
-                            originalLabel: labels.original,
+                          children: _bitrates.map((br) {
-                          ),
+                            return _choice(
-                          selected: _selectedMaxSampleRate == null,
+                              cs,
-                          onTap: () =>
+                              label: br,
-                              setState(() => _selectedMaxSampleRate = null),
+                              selected: br == _selectedBitrate,
+                              onTap: () =>
+                                  setState(() => _selectedBitrate = br),
+                            );
+                          }).toList(),
                         ),
-                        ...sampleRateOptions.map((rate) {
-                          return _choice(
-                            cs,
-                            label: losslessSampleRateLabel(
-                              rate,
-                              originalLabel: labels.original,
-                            ),
-                            selected: rate == _selectedMaxSampleRate,
-                            onTap: () =>
-                                setState(() => _selectedMaxSampleRate = rate),
-                          );
-                        }),
                       ],
                     ),
-                  ],
+                  ),
-                ),
-              ),
 
-            if (_isLosslessTarget)
+                if (_isLosslessTarget && bitDepthOptions.isNotEmpty)
-              Container(
+                  _card(
-                width: double.infinity,
+                    cs,
-                margin: const EdgeInsets.only(bottom: 12),
+                    child: Column(
-                padding: const EdgeInsets.symmetric(
+                      crossAxisAlignment: CrossAxisAlignment.start,
-                  horizontal: 14,
+                      children: [
-                  vertical: 12,
+                        _sectionLabel(cs, context.l10n.audioAnalysisBitDepth),
-                ),
+                        Wrap(
-                decoration: BoxDecoration(
+                          spacing: 8,
-                  color: cs.primaryContainer.withValues(alpha: 0.4),
+                          runSpacing: 8,
-                  borderRadius: BorderRadius.circular(14),
+                          children: [
-                ),
+                            _choice(
-                child: Row(
+                              cs,
-                  children: [
+                              label: losslessBitDepthLabel(
-                    Icon(Icons.verified, size: 18, color: cs.primary),
+                                null,
-                    const SizedBox(width: 8),
+                                originalLabel: labels.original,
-                    Expanded(
-                      child: Text(
-                        _selectedMaxBitDepth == null &&
-                                _selectedMaxSampleRate == null
-                            ? context.l10n.trackConvertLosslessHint
-                            : context.l10n.trackConvertLosslessOutputWithCap(
-                                losslessQualityLabel(
-                                  LosslessConversionQuality(
-                                    maxBitDepth: _selectedMaxBitDepth,
-                                    maxSampleRate: _selectedMaxSampleRate,
-                                  ),
-                                  originalLabel: labels.original,
-                                  originalQualityLabel: labels.originalQuality,
-                                ),
                               ),
-                        style: Theme.of(
+                              selected: _selectedMaxBitDepth == null,
-                          context,
+                              onTap: () => setState(() {
-                        ).textTheme.bodySmall?.copyWith(color: cs.primary),
+                                _selectedMaxBitDepth = null;
+                                _selectedDither = 'none';
+                              }),
+                            ),
+                            ...bitDepthOptions.map((depth) {
+                              return _choice(
+                                cs,
+                                label: losslessBitDepthLabel(
+                                  depth,
+                                  originalLabel: labels.original,
+                                ),
+                                selected: depth == _selectedMaxBitDepth,
+                                onTap: () => setState(
+                                  () => _selectedMaxBitDepth = depth,
+                                ),
+                              );
+                            }),
+                          ],
+                        ),
+                      ],
+                    ),
+                  ),
+
+                if (_isLosslessTarget && sampleRateOptions.isNotEmpty)
+                  _card(
+                    cs,
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        _sectionLabel(cs, context.l10n.audioAnalysisSampleRate),
+                        Wrap(
+                          spacing: 8,
+                          runSpacing: 8,
+                          children: [
+                            _choice(
+                              cs,
+                              label: losslessSampleRateLabel(
+                                null,
+                                originalLabel: labels.original,
+                              ),
+                              selected: _selectedMaxSampleRate == null,
+                              onTap: () => setState(() {
+                                _selectedMaxSampleRate = null;
+                                _selectedResampler = 'swr';
+                              }),
+                            ),
+                            ...sampleRateOptions.map((rate) {
+                              return _choice(
+                                cs,
+                                label: losslessSampleRateLabel(
+                                  rate,
+                                  originalLabel: labels.original,
+                                ),
+                                selected: rate == _selectedMaxSampleRate,
+                                onTap: () => setState(
+                                  () => _selectedMaxSampleRate = rate,
+                                ),
+                              );
+                            }),
+                          ],
+                        ),
+                      ],
+                    ),
+                  ),
+
+                if (_isLosslessTarget && _selectedMaxBitDepth != null)
+                  _card(
+                    cs,
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        _sectionLabel(cs, context.l10n.trackConvertDithering),
+                        Wrap(
+                          spacing: 8,
+                          runSpacing: 8,
+                          children: losslessDitherOptions.map((mode) {
+                            return _choice(
+                              cs,
+                              label: context.l10n.losslessDitherOptionLabel(
+                                mode,
+                              ),
+                              selected: mode == _selectedDither,
+                              onTap: () =>
+                                  setState(() => _selectedDither = mode),
+                            );
+                          }).toList(),
+                        ),
+                      ],
+                    ),
+                  ),
+
+                if (_isLosslessTarget && _selectedMaxSampleRate != null)
+                  _card(
+                    cs,
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        _sectionLabel(cs, context.l10n.trackConvertResampler),
+                        Wrap(
+                          spacing: 8,
+                          runSpacing: 8,
+                          children: losslessResamplerOptions.map((mode) {
+                            return _choice(
+                              cs,
+                              label: context.l10n.losslessResamplerOptionLabel(
+                                mode,
+                              ),
+                              selected: mode == _selectedResampler,
+                              onTap: () =>
+                                  setState(() => _selectedResampler = mode),
+                            );
+                          }).toList(),
+                        ),
+                      ],
+                    ),
+                  ),
+
+                if (_isLosslessTarget)
+                  Container(
+                    width: double.infinity,
+                    margin: const EdgeInsets.only(bottom: 12),
+                    padding: const EdgeInsets.symmetric(
+                      horizontal: 14,
+                      vertical: 12,
+                    ),
+                    decoration: BoxDecoration(
+                      color: cs.primaryContainer.withValues(alpha: 0.4),
+                      borderRadius: BorderRadius.circular(14),
+                    ),
+                    child: Row(
+                      children: [
+                        Icon(Icons.verified, size: 18, color: cs.primary),
+                        const SizedBox(width: 8),
+                        Expanded(
+                          child: Text(
+                            _selectedMaxBitDepth == null &&
+                                    _selectedMaxSampleRate == null
+                                ? context.l10n.trackConvertLosslessHint
+                                : context.l10n
+                                      .trackConvertLosslessOutputWithCap(
+                                        losslessQualityLabel(
+                                          LosslessConversionQuality(
+                                            maxBitDepth: _selectedMaxBitDepth,
+                                            maxSampleRate:
+                                                _selectedMaxSampleRate,
+                                          ),
+                                          originalLabel: labels.original,
+                                          originalQualityLabel:
+                                              labels.originalQuality,
+                                        ),
+                                      ),
+                            style: Theme.of(
+                              context,
+                            ).textTheme.bodySmall?.copyWith(color: cs.primary),
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+
+                const SizedBox(height: 8),
+                SizedBox(
+                  width: double.infinity,
+                  child: FilledButton.icon(
+                    onPressed: () => widget.onConvert(
+                      _selectedFormat,
+                      _selectedBitrate,
+                      LosslessConversionQuality(
+                        maxBitDepth: _selectedMaxBitDepth,
+                        maxSampleRate: _selectedMaxSampleRate,
+                      ),
+                      LosslessConversionProcessing(
+                        dither: _selectedDither,
+                        resampler: _selectedResampler,
                       ),
                     ),
-                  ],
+                    icon: const Icon(Icons.swap_horiz),
-                ),
+                    style: FilledButton.styleFrom(
-              ),
+                      padding: const EdgeInsets.symmetric(vertical: 16),
-
+                      shape: RoundedRectangleBorder(
-            const SizedBox(height: 8),
+                        borderRadius: BorderRadius.circular(14),
-            SizedBox(
+                      ),
-              width: double.infinity,
+                    ),
-              child: FilledButton.icon(
+                    label: Text(widget.confirmLabel),
-                onPressed: () => widget.onConvert(
-                  _selectedFormat,
-                  _selectedBitrate,
-                  LosslessConversionQuality(
-                    maxBitDepth: _selectedMaxBitDepth,
-                    maxSampleRate: _selectedMaxSampleRate,
                   ),
                 ),
-                icon: const Icon(Icons.swap_horiz),
+              ],
-                style: FilledButton.styleFrom(
-                  padding: const EdgeInsets.symmetric(vertical: 16),
-                  shape: RoundedRectangleBorder(
-                    borderRadius: BorderRadius.circular(14),
-                  ),
-                ),
-                label: Text(widget.confirmLabel),
-              ),
             ),
-          ],
+          ),
         ),
       ),
     );

pubspec.yaml

@@ -1,7 +1,7 @@
 name: spotiflac_android
 description: Download Spotify tracks in FLAC using extension providers
 publish_to: "none"
-version: 4.7.0+136
+version: 4.7.1+137
 
 environment:
   sdk: ^3.10.0