feat(lyrics,replaygain): add LyricsPlus provider and ReplayGain batch scanning

LyricsPlus (KPOE): word-by-word synced lyrics with multi-server failover, converted to enhanced LRC. ReplayGain: standalone EBU R128 (re)scan writing REPLAYGAIN_TRACK_* tags via native writers or FFmpeg, with batch action in queue/album screens and SAF support.
2026-06-29 17:50:00 +02:00 · 2026-06-12 01:59:26 +07:00
parent adea3de737
commit 2a2e2924eb
27 changed files with 1816 additions and 165 deletions
@@ -31,6 +31,7 @@ const (
 	LyricsProviderYouTube    = "youtube"
 	LyricsProviderKugou      = "kugou"
 	LyricsProviderGenius     = "genius"
+	LyricsProviderLyricsPlus = "lyricsplus"
 )

 var DefaultLyricsProviders = []string{
@@ -112,6 +113,7 @@ func SetLyricsProviderOrder(providers []string) {
 		LyricsProviderYouTube:    true,
 		LyricsProviderKugou:      true,
 		LyricsProviderGenius:     true,
+		LyricsProviderLyricsPlus: true,
 	}

 	var valid []string
@@ -151,6 +153,7 @@ func GetAvailableLyricsProviders() []map[string]interface{} {
 		{"id": LyricsProviderYouTube, "name": "YouTube", "has_proxy_dependency": true, "description": "YouTube lyrics"},
 		{"id": LyricsProviderKugou, "name": "Kugou", "has_proxy_dependency": true, "description": "Kugou lyrics"},
 		{"id": LyricsProviderGenius, "name": "Genius", "has_proxy_dependency": true, "description": "Genius lyrics"},
+		{"id": LyricsProviderLyricsPlus, "name": "LyricsPlus", "has_proxy_dependency": true, "description": "Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ)"},
 	}
 }

@@ -612,6 +615,37 @@ func (c *LyricsClient) FetchLyricsAllSources(spotifyID, trackName, artistName st
 				lyrics, err = geniusClient.FetchLyrics(simplifiedTrack, primaryArtist, durationSec)
 			}

+		case LyricsProviderLyricsPlus:
+			lyricsPlusClient := NewLyricsPlusClient()
+			lyrics, err = lyricsPlusClient.FetchLyrics(
+				trackName,
+				primaryArtist,
+				"",
+				durationSec,
+				fetchOptions.MultiPersonWordByWord,
+				fetchOptions.AppleElrcWordSync,
+			)
+			if err != nil && primaryArtist != artistName {
+				lyrics, err = lyricsPlusClient.FetchLyrics(
+					trackName,
+					artistName,
+					"",
+					durationSec,
+					fetchOptions.MultiPersonWordByWord,
+					fetchOptions.AppleElrcWordSync,
+				)
+			}
+			if err != nil && simplifiedTrack != trackName {
+				lyrics, err = lyricsPlusClient.FetchLyrics(
+					simplifiedTrack,
+					primaryArtist,
+					"",
+					durationSec,
+					fetchOptions.MultiPersonWordByWord,
+					fetchOptions.AppleElrcWordSync,
+				)
+			}
+
 		default:
 			GoLog("[Lyrics] Unknown provider: %s, skipping\n", providerName)
 			continue
@@ -0,0 +1,243 @@
+package gobackend
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// LyricsPlus (KPOE) provider.
+//
+// LyricsPlus aggregates word-by-word ("karaoke") synced lyrics from Apple
+// Music, Musixmatch, Spotify and QQ Music via a community-run backend. It
+// frequently has word-level timing for tracks that other providers only offer
+// line-synced or not at all.
+//
+// API: GET {server}/v2/lyrics/get?title=&artist=&album=&duration=&isrc=
+// The response is the KPOE JSON format which we convert into the same enhanced
+// LRC text the Apple/QQ providers emit, so embedding/export behaves identically.
+
+// Public LyricsPlus / KPOE servers (mirrors). Tried in order with failover.
+// Sourced from the upstream YouLy+ client server list.
+var lyricsPlusServers = []string{
+	"https://lyricsplus.prjktla.my.id",
+	"https://lyricsplus.atomix.one",
+	"https://lyricsplus.binimum.org",
+	"https://lyricsplus.prjktla.workers.dev",
+	"https://lyricsplus-seven.vercel.app",
+	"https://lyrics-plus-backend.vercel.app",
+}
+
+type LyricsPlusClient struct {
+	httpClient *http.Client
+}
+
+func NewLyricsPlusClient() *LyricsPlusClient {
+	return &LyricsPlusClient{httpClient: NewMetadataHTTPClient(15 * time.Second)}
+}
+
+type lyricsPlusSyllable struct {
+	Text         string  `json:"text"`
+	Time         float64 `json:"time"`     // absolute ms
+	Duration     float64 `json:"duration"` // ms
+	IsBackground bool    `json:"isBackground"`
+}
+
+type lyricsPlusLine struct {
+	Time     float64              `json:"time"`     // absolute ms
+	Duration float64              `json:"duration"` // ms
+	Text     string               `json:"text"`
+	Syllabus []lyricsPlusSyllable `json:"syllabus"`
+}
+
+type lyricsPlusResponse struct {
+	Type   string           `json:"type"` // "Word" | "Line" | "Syllable" | "None"
+	Lyrics []lyricsPlusLine `json:"lyrics"`
+}
+
+// FetchLyrics tries each LyricsPlus server in order until one returns usable
+// lyrics. multiPersonWordByWord and preserveWordTiming mirror the Apple/QQ
+// options so word/background timing is only emitted when the user enabled it.
+func (c *LyricsPlusClient) FetchLyrics(
+	trackName,
+	artistName,
+	isrc string,
+	durationSec float64,
+	multiPersonWordByWord bool,
+	preserveWordTiming bool,
+) (*LyricsResponse, error) {
+	if strings.TrimSpace(trackName) == "" || strings.TrimSpace(artistName) == "" {
+		return nil, fmt.Errorf("lyricsplus: missing track or artist")
+	}
+
+	var lastErr error
+	for _, server := range lyricsPlusServers {
+		lyrics, err := c.fetchFromServer(server, trackName, artistName, isrc, durationSec, multiPersonWordByWord, preserveWordTiming)
+		if err == nil && lyricsHasUsableText(lyrics) {
+			return lyrics, nil
+		}
+		if err != nil {
+			lastErr = err
+			GoLog("[Lyrics] LyricsPlus server %s failed: %v\n", server, err)
+		}
+	}
+
+	if lastErr != nil {
+		return nil, lastErr
+	}
+	return nil, fmt.Errorf("lyricsplus: no lyrics found")
+}
+
+func (c *LyricsPlusClient) fetchFromServer(
+	server,
+	trackName,
+	artistName,
+	isrc string,
+	durationSec float64,
+	multiPersonWordByWord bool,
+	preserveWordTiming bool,
+) (*LyricsResponse, error) {
+	base := strings.TrimRight(strings.TrimSpace(server), "/")
+	if base == "" {
+		return nil, fmt.Errorf("empty server")
+	}
+
+	params := url.Values{}
+	params.Set("title", trackName)
+	params.Set("artist", artistName)
+	if durationSec > 0 {
+		params.Set("duration", strconv.FormatFloat(durationSec, 'f', 3, 64))
+	}
+	if strings.TrimSpace(isrc) != "" {
+		params.Set("isrc", strings.TrimSpace(isrc))
+	}
+
+	fullURL := base + "/v2/lyrics/get?" + params.Encode()
+
+	req, err := http.NewRequest("GET", fullURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("User-Agent", appUserAgent())
+
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode == http.StatusNotFound {
+		// Retry without the ISRC filter, which can be too strict.
+		if strings.TrimSpace(isrc) != "" {
+			return c.fetchFromServer(server, trackName, artistName, "", durationSec, multiPersonWordByWord, preserveWordTiming)
+		}
+		return nil, fmt.Errorf("lyrics not found")
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("HTTP %d", resp.StatusCode)
+	}
+
+	var payload lyricsPlusResponse
+	if err := json.NewDecoder(resp.Body).Decode(&payload); err != nil {
+		return nil, fmt.Errorf("failed to decode lyricsplus response: %w", err)
+	}
+	if len(payload.Lyrics) == 0 {
+		return nil, fmt.Errorf("lyricsplus returned no lines")
+	}
+
+	lrcText := buildLyricsPlusLRC(&payload, multiPersonWordByWord, preserveWordTiming)
+	if strings.TrimSpace(lrcText) == "" {
+		return nil, fmt.Errorf("lyricsplus produced empty lyrics")
+	}
+
+	lyrics := lyricsResponseFromText(lrcText, "LyricsPlus")
+	return lyrics, nil
+}
+
+// buildLyricsPlusLRC converts the KPOE JSON into enhanced LRC text. When word
+// timing is available and enabled, each syllable is emitted as an inline
+// <mm:ss.xx> tag (matching the Apple/QQ output); otherwise a line-synced LRC
+// is produced from the full line text.
+func buildLyricsPlusLRC(resp *lyricsPlusResponse, multiPersonWordByWord bool, preserveWordTiming bool) string {
+	isWordType := strings.EqualFold(resp.Type, "Word") || strings.EqualFold(resp.Type, "Syllable")
+
+	var sb strings.Builder
+	first := true
+	for _, line := range resp.Lyrics {
+		lineText := line.Text
+		hasSyllables := len(line.Syllabus) > 0
+
+		timestamp := msToLRCTimestamp(int64(line.Time))
+
+		if isWordType && preserveWordTiming && hasSyllables {
+			mainSyllables := make([]lyricsPlusSyllable, 0, len(line.Syllabus))
+			bgSyllables := make([]lyricsPlusSyllable, 0)
+			for _, syl := range line.Syllabus {
+				if syl.IsBackground {
+					bgSyllables = append(bgSyllables, syl)
+				} else {
+					mainSyllables = append(mainSyllables, syl)
+				}
+			}
+			if len(mainSyllables) == 0 {
+				mainSyllables = line.Syllabus
+				bgSyllables = nil
+			}
+
+			if !first {
+				sb.WriteString("\n")
+			}
+			first = false
+
+			sb.WriteString(timestamp)
+			appendLyricsPlusSyllables(&sb, mainSyllables)
+
+			if multiPersonWordByWord && len(bgSyllables) > 0 {
+				sb.WriteString("\n[bg:")
+				appendLyricsPlusSyllables(&sb, bgSyllables)
+				sb.WriteString("]")
+			}
+			continue
+		}
+
+		// Line-synced fallback. Reconstruct text from syllables if needed.
+		if strings.TrimSpace(lineText) == "" && hasSyllables {
+			var lineBuilder strings.Builder
+			for _, syl := range line.Syllabus {
+				lineBuilder.WriteString(syl.Text)
+			}
+			lineText = lineBuilder.String()
+		}
+
+		lineText = strings.TrimSpace(lineText)
+		if lineText == "" {
+			continue
+		}
+
+		if !first {
+			sb.WriteString("\n")
+		}
+		first = false
+
+		sb.WriteString(timestamp)
+		sb.WriteString(lineText)
+	}
+
+	return strings.TrimSpace(sb.String())
+}
+
+// appendLyricsPlusSyllables writes each syllable as "<mm:ss.xx>text". KPOE
+// already embeds spacing inside the syllable text, so no extra spaces are added.
+func appendLyricsPlusSyllables(sb *strings.Builder, syllables []lyricsPlusSyllable) {
+	for _, syl := range syllables {
+		sb.WriteString("<")
+		sb.WriteString(msToLRCTimestampInline(int64(syl.Time)))
+		sb.WriteString(">")
+		sb.WriteString(syl.Text)
+	}
+}
@@ -458,6 +458,66 @@ abstract class AppLocalizations {
  /// **'Disabled: no loudness normalization tags'**
  String get optionsReplayGainSubtitleOff;

+  /// Three-dot menu option to scan loudness and write ReplayGain tags
+  ///
+  /// In en, this message translates to:
+  /// **'Rescan ReplayGain'**
+  String get trackReplayGain;
+
+  /// Subtitle for the rescan ReplayGain menu option
+  ///
+  /// In en, this message translates to:
+  /// **'Analyze loudness and write ReplayGain tags'**
+  String get trackReplayGainSubtitle;
+
+  /// Snackbar/progress message while scanning ReplayGain for a single track
+  ///
+  /// In en, this message translates to:
+  /// **'Analyzing loudness...'**
+  String get trackReplayGainScanning;
+
+  /// Snackbar message after ReplayGain tags written for a single track
+  ///
+  /// In en, this message translates to:
+  /// **'ReplayGain tags added'**
+  String get trackReplayGainSuccess;
+
+  /// Snackbar message when ReplayGain scan/write fails
+  ///
+  /// In en, this message translates to:
+  /// **'Failed to add ReplayGain tags'**
+  String get trackReplayGainFailed;
+
+  /// Batch selection action button label for ReplayGain
+  ///
+  /// In en, this message translates to:
+  /// **'ReplayGain ({count})'**
+  String selectionReplayGainCount(int count);
+
+  /// Title of the batch ReplayGain confirmation dialog
+  ///
+  /// In en, this message translates to:
+  /// **'Add ReplayGain'**
+  String get replayGainBatchConfirmTitle;
+
+  /// Message of the batch ReplayGain confirmation dialog
+  ///
+  /// In en, this message translates to:
+  /// **'Analyze loudness and write ReplayGain tags to {count} track(s)?'**
+  String replayGainBatchConfirmMessage(int count);
+
+  /// Progress dialog title while batch scanning ReplayGain
+  ///
+  /// In en, this message translates to:
+  /// **'Analyzing ReplayGain...'**
+  String get replayGainBatchAnalyzing;
+
+  /// Snackbar after batch ReplayGain completes
+  ///
+  /// In en, this message translates to:
+  /// **'ReplayGain added to {success} of {total} tracks'**
+  String replayGainBatchSuccess(int success, int total);
+
  /// Setting title for how artist metadata is written into files
  ///
  /// In en, this message translates to:
@@ -4885,6 +4945,12 @@ abstract class AppLocalizations {
  /// **'QQ Music (good for Chinese songs, via proxy)'**
  String get lyricsProviderQqMusicDesc;

+  /// Description for LyricsPlus provider
+  ///
+  /// In en, this message translates to:
+  /// **'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)'**
+  String get lyricsProviderLyricsPlusDesc;
+
  /// Generic description for extension-based lyrics providers
  ///
  /// In en, this message translates to:
@@ -187,6 +187,43 @@ class AppLocalizationsAr extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsAr extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -190,6 +190,43 @@ class AppLocalizationsDe extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Deaktiviert: keine Lautstärke-Normalisierungs-Tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Künstler Tag-Modus';

@@ -2857,6 +2894,10 @@ class AppLocalizationsDe extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (gut für chinesische Lieder, via Proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Erweiterungsanbieter';

@@ -187,6 +187,43 @@ class AppLocalizationsEn extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsEn extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -187,6 +187,43 @@ class AppLocalizationsEs extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsEs extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -191,6 +191,43 @@ class AppLocalizationsFr extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Désactivé : aucune balise de normalisation du volume';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Mode « Artiste »';

@@ -2897,6 +2934,10 @@ class AppLocalizationsFr extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (idéal pour écouter des titres chinois, via un proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Fournisseur d\'extensions';

@@ -187,6 +187,43 @@ class AppLocalizationsHi extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsHi extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -188,6 +188,43 @@ class AppLocalizationsId extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Dinonaktifkan: tidak ada tag normalisasi kenyaringan';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Mode Tag Artis';

@@ -2828,6 +2865,10 @@ class AppLocalizationsId extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -186,6 +186,43 @@ class AppLocalizationsJa extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2809,6 +2846,10 @@ class AppLocalizationsJa extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -184,6 +184,43 @@ class AppLocalizationsKo extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2806,6 +2843,10 @@ class AppLocalizationsKo extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -187,6 +187,43 @@ class AppLocalizationsNl extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsNl extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -187,6 +187,43 @@ class AppLocalizationsPt extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsPt extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -190,6 +190,43 @@ class AppLocalizationsRu extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2876,6 +2913,10 @@ class AppLocalizationsRu extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Музыка (хорошо подходит для китайских песен, через прокси)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Поставщик расширений';

@@ -190,6 +190,43 @@ class AppLocalizationsTr extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Devre dışı: Ses normalleştirme etiketi yok';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Sanatçı Etiketi Modu';

@@ -2850,6 +2887,10 @@ class AppLocalizationsTr extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -191,6 +191,43 @@ class AppLocalizationsUk extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Вимкнено: немає тегів нормалізації гучності';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Режим тегу виконавця';

@@ -2865,6 +2902,10 @@ class AppLocalizationsUk extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (добре для китайських пісень, через проксі)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Постачальник розширень';

@@ -187,6 +187,43 @@ class AppLocalizationsZh extends AppLocalizations {
  String get optionsReplayGainSubtitleOff =>
      'Disabled: no loudness normalization tags';

+  @override
+  String get trackReplayGain => 'Rescan ReplayGain';
+
+  @override
+  String get trackReplayGainSubtitle =>
+      'Analyze loudness and write ReplayGain tags';
+
+  @override
+  String get trackReplayGainScanning => 'Analyzing loudness...';
+
+  @override
+  String get trackReplayGainSuccess => 'ReplayGain tags added';
+
+  @override
+  String get trackReplayGainFailed => 'Failed to add ReplayGain tags';
+
+  @override
+  String selectionReplayGainCount(int count) {
+    return 'ReplayGain ($count)';
+  }
+
+  @override
+  String get replayGainBatchConfirmTitle => 'Add ReplayGain';
+
+  @override
+  String replayGainBatchConfirmMessage(int count) {
+    return 'Analyze loudness and write ReplayGain tags to $count track(s)?';
+  }
+
+  @override
+  String get replayGainBatchAnalyzing => 'Analyzing ReplayGain...';
+
+  @override
+  String replayGainBatchSuccess(int success, int total) {
+    return 'ReplayGain added to $success of $total tracks';
+  }
+
  @override
  String get optionsArtistTagMode => 'Artist Tag Mode';

@@ -2821,6 +2858,10 @@ class AppLocalizationsZh extends AppLocalizations {
  String get lyricsProviderQqMusicDesc =>
      'QQ Music (good for Chinese songs, via proxy)';

+  @override
+  String get lyricsProviderLyricsPlusDesc =>
+      'Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)';
+
  @override
  String get lyricsProviderExtensionDesc => 'Extension provider';

@@ -226,6 +226,64 @@
  "@optionsReplayGainSubtitleOff": {
    "description": "Subtitle when ReplayGain is disabled"
  },
+  "trackReplayGain": "Rescan ReplayGain",
+  "@trackReplayGain": {
+    "description": "Three-dot menu option to scan loudness and write ReplayGain tags"
+  },
+  "trackReplayGainSubtitle": "Analyze loudness and write ReplayGain tags",
+  "@trackReplayGainSubtitle": {
+    "description": "Subtitle for the rescan ReplayGain menu option"
+  },
+  "trackReplayGainScanning": "Analyzing loudness...",
+  "@trackReplayGainScanning": {
+    "description": "Snackbar/progress message while scanning ReplayGain for a single track"
+  },
+  "trackReplayGainSuccess": "ReplayGain tags added",
+  "@trackReplayGainSuccess": {
+    "description": "Snackbar message after ReplayGain tags written for a single track"
+  },
+  "trackReplayGainFailed": "Failed to add ReplayGain tags",
+  "@trackReplayGainFailed": {
+    "description": "Snackbar message when ReplayGain scan/write fails"
+  },
+  "selectionReplayGainCount": "ReplayGain ({count})",
+  "@selectionReplayGainCount": {
+    "description": "Batch selection action button label for ReplayGain",
+    "placeholders": {
+      "count": {
+        "type": "int"
+      }
+    }
+  },
+  "replayGainBatchConfirmTitle": "Add ReplayGain",
+  "@replayGainBatchConfirmTitle": {
+    "description": "Title of the batch ReplayGain confirmation dialog"
+  },
+  "replayGainBatchConfirmMessage": "Analyze loudness and write ReplayGain tags to {count} track(s)?",
+  "@replayGainBatchConfirmMessage": {
+    "description": "Message of the batch ReplayGain confirmation dialog",
+    "placeholders": {
+      "count": {
+        "type": "int"
+      }
+    }
+  },
+  "replayGainBatchAnalyzing": "Analyzing ReplayGain...",
+  "@replayGainBatchAnalyzing": {
+    "description": "Progress dialog title while batch scanning ReplayGain"
+  },
+  "replayGainBatchSuccess": "ReplayGain added to {success} of {total} tracks",
+  "@replayGainBatchSuccess": {
+    "description": "Snackbar after batch ReplayGain completes",
+    "placeholders": {
+      "success": {
+        "type": "int"
+      },
+      "total": {
+        "type": "int"
+      }
+    }
+  },
  "optionsArtistTagMode": "Artist Tag Mode",
  "@optionsArtistTagMode": {
    "description": "Setting title for how artist metadata is written into files"
@@ -3737,6 +3795,10 @@
  "@lyricsProviderQqMusicDesc": {
    "description": "Description for QQ Music provider"
  },
+  "lyricsProviderLyricsPlusDesc": "Word-by-word karaoke lyrics (Apple/Musixmatch/Spotify/QQ, via proxy)",
+  "@lyricsProviderLyricsPlusDesc": {
+    "description": "Description for LyricsPlus provider"
+  },
  "lyricsProviderExtensionDesc": "Extension provider",
  "@lyricsProviderExtensionDesc": {
    "description": "Generic description for extension-based lyrics providers"
@@ -7,6 +7,7 @@ import 'package:share_plus/share_plus.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:spotiflac_android/services/cover_cache_manager.dart';
 import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/replaygain_service.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/services/history_database.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
@@ -1412,6 +1413,80 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
    }
  }

+  Future<void> _runBatchReplayGain(List<DownloadHistoryItem> tracks) async {
+    final tracksById = {for (final t in tracks) t.id: t};
+    final selected = <DownloadHistoryItem>[];
+    for (final id in _selectedIds) {
+      final item = tracksById[id];
+      if (item == null) continue;
+      selected.add(item);
+    }
+
+    if (selected.isEmpty) return;
+
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: Text(ctx.l10n.replayGainBatchConfirmTitle),
+        content: Text(
+          ctx.l10n.replayGainBatchConfirmMessage(selected.length),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx, false),
+            child: Text(ctx.l10n.dialogCancel),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.pop(ctx, true),
+            child: Text(ctx.l10n.replayGainBatchConfirmTitle),
+          ),
+        ],
+      ),
+    );
+
+    if (confirmed != true || !mounted) return;
+
+    var cancelled = false;
+    int successCount = 0;
+    final total = selected.length;
+
+    BatchProgressDialog.show(
+      context: context,
+      title: context.l10n.replayGainBatchAnalyzing,
+      total: total,
+      icon: Icons.graphic_eq,
+      onCancel: () {
+        cancelled = true;
+        BatchProgressDialog.dismiss(context);
+      },
+    );
+
+    for (int i = 0; i < total; i++) {
+      if (!mounted || cancelled) break;
+      final item = selected[i];
+      BatchProgressDialog.update(current: i + 1, detail: item.trackName);
+      try {
+        final ok = await ReplayGainService.applyToFile(item.filePath);
+        if (ok) successCount++;
+      } catch (_) {}
+    }
+
+    _exitSelectionMode();
+
+    if (!mounted) return;
+    if (!cancelled) {
+      BatchProgressDialog.dismiss(context);
+    }
+    ScaffoldMessenger.of(context).clearSnackBars();
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(
+          context.l10n.replayGainBatchSuccess(successCount, total),
+        ),
+      ),
+    );
+  }
+
  Widget _buildSelectionBottomBar(
    BuildContext context,
    ColorScheme colorScheme,
@@ -1508,10 +1583,12 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
              ),
              const SizedBox(height: 12),

-              Row(
-                children: [
-                  Expanded(
-                    child: _DownloadedAlbumSelectionActionButton(
+              LayoutBuilder(
+                builder: (context, constraints) {
+                  const spacing = 8.0;
+                  final itemWidth = (constraints.maxWidth - spacing) / 2;
+                  final actions = <Widget>[
+                    _DownloadedAlbumSelectionActionButton(
                      icon: Icons.share_outlined,
                      label: context.l10n.selectionShareCount(selectedCount),
                      onPressed: selectedCount > 0
@@ -1519,10 +1596,7 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                  const SizedBox(width: 8),
-                  Expanded(
-                    child: _DownloadedAlbumSelectionActionButton(
+                    _DownloadedAlbumSelectionActionButton(
                      icon: Icons.swap_horiz,
                      label: context.l10n.selectionConvertCount(selectedCount),
                      onPressed: selectedCount > 0
@@ -1530,8 +1604,27 @@ class _DownloadedAlbumScreenState extends ConsumerState<DownloadedAlbumScreen> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                ],
+                    _DownloadedAlbumSelectionActionButton(
+                      icon: Icons.graphic_eq,
+                      label: context.l10n.selectionReplayGainCount(
+                        selectedCount,
+                      ),
+                      onPressed: selectedCount > 0
+                          ? () => _runBatchReplayGain(tracks)
+                          : null,
+                      colorScheme: colorScheme,
+                    ),
+                  ];
+
+                  return Wrap(
+                    spacing: spacing,
+                    runSpacing: spacing,
+                    children: [
+                      for (final action in actions)
+                        SizedBox(width: itemWidth, child: action),
+                    ],
+                  );
+                },
              ),

              const SizedBox(height: 8),
@@ -14,6 +14,7 @@ import 'package:spotiflac_android/utils/image_cache_utils.dart';
 import 'package:spotiflac_android/utils/lyrics_metadata_helper.dart';
 import 'package:spotiflac_android/services/library_database.dart';
 import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/replaygain_service.dart';
 import 'package:spotiflac_android/services/local_track_redownload_service.dart';
 import 'package:spotiflac_android/widgets/batch_progress_dialog.dart';
 import 'package:spotiflac_android/widgets/re_enrich_field_dialog.dart';
@@ -1681,6 +1682,80 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
    }
  }

+  Future<void> _runBatchReplayGain(List<LocalLibraryItem> tracks) async {
+    final tracksById = {for (final t in tracks) t.id: t};
+    final selected = <LocalLibraryItem>[];
+    for (final id in _selectedIds) {
+      final item = tracksById[id];
+      if (item == null) continue;
+      selected.add(item);
+    }
+
+    if (selected.isEmpty) return;
+
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: Text(ctx.l10n.replayGainBatchConfirmTitle),
+        content: Text(
+          ctx.l10n.replayGainBatchConfirmMessage(selected.length),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx, false),
+            child: Text(ctx.l10n.dialogCancel),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.pop(ctx, true),
+            child: Text(ctx.l10n.replayGainBatchConfirmTitle),
+          ),
+        ],
+      ),
+    );
+
+    if (confirmed != true || !mounted) return;
+
+    var cancelled = false;
+    int successCount = 0;
+    final total = selected.length;
+
+    BatchProgressDialog.show(
+      context: context,
+      title: context.l10n.replayGainBatchAnalyzing,
+      total: total,
+      icon: Icons.graphic_eq,
+      onCancel: () {
+        cancelled = true;
+        BatchProgressDialog.dismiss(context);
+      },
+    );
+
+    for (int i = 0; i < total; i++) {
+      if (!mounted || cancelled) break;
+      final item = selected[i];
+      BatchProgressDialog.update(current: i + 1, detail: item.trackName);
+      try {
+        final ok = await ReplayGainService.applyToFile(item.filePath);
+        if (ok) successCount++;
+      } catch (_) {}
+    }
+
+    _exitSelectionMode();
+
+    if (!mounted) return;
+    if (!cancelled) {
+      BatchProgressDialog.dismiss(context);
+    }
+    ScaffoldMessenger.of(context).clearSnackBars();
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(
+          context.l10n.replayGainBatchSuccess(successCount, total),
+        ),
+      ),
+    );
+  }
+
  Widget _buildSelectionBottomBar(
    BuildContext context,
    ColorScheme colorScheme,
@@ -1778,22 +1853,26 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
              ),
              const SizedBox(height: 12),

-              Row(
-                children: [
-                  if (flacEligibleCount > 0) ...[
-                    Expanded(
-                      child: _LocalAlbumSelectionActionButton(
+              LayoutBuilder(
+                builder: (context, constraints) {
+                  const spacing = 8.0;
+                  final itemWidth = (constraints.maxWidth - spacing) / 2;
+                  final actions = <Widget>[];
+
+                  if (flacEligibleCount > 0) {
+                    actions.add(
+                      _LocalAlbumSelectionActionButton(
                        icon: Icons.download_for_offline_outlined,
                        label:
                            '${context.l10n.queueFlacAction} ($flacEligibleCount)',
                        onPressed: () => _queueSelectedAsFlac(tracks),
                        colorScheme: colorScheme,
                      ),
-                    ),
-                    const SizedBox(width: 8),
-                  ],
-                  Expanded(
-                    child: _LocalAlbumSelectionActionButton(
+                    );
+                  }
+
+                  actions.add(
+                    _LocalAlbumSelectionActionButton(
                      icon: Icons.auto_fix_high_outlined,
                      label: '${context.l10n.trackReEnrich} ($selectedCount)',
                      onPressed: selectedCount > 0
@@ -1801,10 +1880,10 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                  const SizedBox(width: 8),
-                  Expanded(
-                    child: _LocalAlbumSelectionActionButton(
+                  );
+
+                  actions.add(
+                    _LocalAlbumSelectionActionButton(
                      icon: Icons.swap_horiz,
                      label: context.l10n.selectionConvertCount(selectedCount),
                      onPressed: selectedCount > 0
@@ -1812,8 +1891,30 @@ class _LocalAlbumScreenState extends ConsumerState<LocalAlbumScreen> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                ],
+                  );
+
+                  actions.add(
+                    _LocalAlbumSelectionActionButton(
+                      icon: Icons.graphic_eq,
+                      label: context.l10n.selectionReplayGainCount(
+                        selectedCount,
+                      ),
+                      onPressed: selectedCount > 0
+                          ? () => _runBatchReplayGain(tracks)
+                          : null,
+                      colorScheme: colorScheme,
+                    ),
+                  );
+
+                  return Wrap(
+                    spacing: spacing,
+                    runSpacing: spacing,
+                    children: [
+                      for (final action in actions)
+                        SizedBox(width: itemWidth, child: action),
+                    ],
+                  );
+                },
              ),

              const SizedBox(height: 8),
@@ -7,6 +7,7 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:share_plus/share_plus.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/replaygain_service.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/utils/app_bar_layout.dart';
@@ -5421,6 +5422,95 @@ class _QueueTabState extends ConsumerState<QueueTab> {
    }
  }

+  /// Batch-scan loudness and write ReplayGain tags to the selected tracks.
+  Future<void> _runBatchReplayGain(
+    List<UnifiedLibraryItem> allItems,
+  ) async {
+    final itemsById = {for (final item in allItems) item.id: item};
+    final selectedItems = <UnifiedLibraryItem>[];
+    for (final id in _selectedIds) {
+      final item = itemsById[id];
+      if (item == null) continue;
+      selectedItems.add(item);
+    }
+
+    if (selectedItems.isEmpty) return;
+
+    _hideSelectionOverlay();
+    _hidePlaylistSelectionOverlay();
+
+    final confirmed = await showDialog<bool>(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: Text(ctx.l10n.replayGainBatchConfirmTitle),
+        content: Text(
+          ctx.l10n.replayGainBatchConfirmMessage(selectedItems.length),
+        ),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx, false),
+            child: Text(ctx.l10n.dialogCancel),
+          ),
+          FilledButton(
+            onPressed: () => Navigator.pop(ctx, true),
+            child: Text(ctx.l10n.replayGainBatchConfirmTitle),
+          ),
+        ],
+      ),
+    );
+
+    if (!mounted) return;
+    if (confirmed != true) {
+      if (_isSelectionMode) {
+        _syncSelectionOverlay(
+          items: allItems,
+          bottomPadding: MediaQuery.of(context).padding.bottom,
+        );
+      }
+      return;
+    }
+
+    var cancelled = false;
+    int successCount = 0;
+    final total = selectedItems.length;
+
+    BatchProgressDialog.show(
+      context: context,
+      title: context.l10n.replayGainBatchAnalyzing,
+      total: total,
+      icon: Icons.graphic_eq,
+      onCancel: () {
+        cancelled = true;
+        BatchProgressDialog.dismiss(context);
+      },
+    );
+
+    for (int i = 0; i < total; i++) {
+      if (!mounted || cancelled) break;
+      final item = selectedItems[i];
+      BatchProgressDialog.update(current: i + 1, detail: item.trackName);
+      try {
+        final ok = await ReplayGainService.applyToFile(item.filePath);
+        if (ok) successCount++;
+      } catch (_) {}
+    }
+
+    _exitSelectionMode();
+
+    if (!mounted) return;
+    if (!cancelled) {
+      BatchProgressDialog.dismiss(context);
+    }
+    ScaffoldMessenger.of(context).clearSnackBars();
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(
+          context.l10n.replayGainBatchSuccess(successCount, total),
+        ),
+      ),
+    );
+  }
+
  Widget _buildSelectionBottomBar(
    BuildContext context,
    ColorScheme colorScheme,
@@ -5524,11 +5614,15 @@ class _QueueTabState extends ConsumerState<QueueTab> {

              const SizedBox(height: 12),

-              Row(
-                children: [
-                  if (localOnlySelection && flacEligibleCount > 0) ...[
-                    Expanded(
-                      child: _SelectionActionButton(
+              LayoutBuilder(
+                builder: (context, constraints) {
+                  const spacing = 8.0;
+                  final itemWidth = (constraints.maxWidth - spacing) / 2;
+                  final actions = <Widget>[];
+
+                  if (localOnlySelection && flacEligibleCount > 0) {
+                    actions.add(
+                      _SelectionActionButton(
                        icon: Icons.download_for_offline_outlined,
                        label:
                            '${context.l10n.queueFlacAction} ($flacEligibleCount)',
@@ -5536,11 +5630,11 @@ class _QueueTabState extends ConsumerState<QueueTab> {
                            _queueSelectedLocalAsFlac(unifiedItems),
                        colorScheme: colorScheme,
                      ),
-                    ),
-                    const SizedBox(width: 8),
-                  ],
-                  Expanded(
-                    child: _SelectionActionButton(
+                    );
+                  }
+
+                  actions.add(
+                    _SelectionActionButton(
                      icon: localOnlySelection
                          ? Icons.auto_fix_high_outlined
                          : Icons.share_outlined,
@@ -5554,10 +5648,10 @@ class _QueueTabState extends ConsumerState<QueueTab> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                  const SizedBox(width: 8),
-                  Expanded(
-                    child: _SelectionActionButton(
+                  );
+
+                  actions.add(
+                    _SelectionActionButton(
                      icon: Icons.swap_horiz,
                      label: context.l10n.selectionConvertCount(selectedCount),
                      onPressed: selectedCount > 0
@@ -5565,8 +5659,30 @@ class _QueueTabState extends ConsumerState<QueueTab> {
                          : null,
                      colorScheme: colorScheme,
                    ),
-                  ),
-                ],
+                  );
+
+                  actions.add(
+                    _SelectionActionButton(
+                      icon: Icons.graphic_eq,
+                      label: context.l10n.selectionReplayGainCount(
+                        selectedCount,
+                      ),
+                      onPressed: selectedCount > 0
+                          ? () => _runBatchReplayGain(unifiedItems)
+                          : null,
+                      colorScheme: colorScheme,
+                    ),
+                  );
+
+                  return Wrap(
+                    spacing: spacing,
+                    runSpacing: spacing,
+                    children: [
+                      for (final action in actions)
+                        SizedBox(width: itemWidth, child: action),
+                    ],
+                  );
+                },
              ),

              const SizedBox(height: 8),
@@ -26,6 +26,7 @@ class _LyricsProviderPriorityPageState
    'youtube',
    'kugou',
    'genius',
+    'lyricsplus',
  ];

  late List<String> _enabledProviders;
@@ -245,6 +246,12 @@ class _LyricsProviderPriorityPageState
          description: context.l10n.lyricsProviderExtensionDesc,
          icon: Icons.auto_awesome_outlined,
        );
+      case 'lyricsplus':
+        return _LyricsProviderInfo(
+          name: 'LyricsPlus',
+          description: context.l10n.lyricsProviderLyricsPlusDesc,
+          icon: Icons.lyrics_outlined,
+        );
      default:
        return _LyricsProviderInfo(
          name: id,
@@ -221,6 +221,7 @@ class LyricsSettingsPage extends ConsumerWidget {
    'youtube': 'YouTube',
    'kugou': 'Kugou',
    'genius': 'Genius',
+    'lyricsplus': 'LyricsPlus',
  };

  String _getLyricsProvidersSubtitle(
@@ -16,6 +16,7 @@ import 'package:spotiflac_android/providers/playback_provider.dart';
 import 'package:spotiflac_android/providers/settings_provider.dart';
 import 'package:spotiflac_android/services/platform_bridge.dart';
 import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/replaygain_service.dart';
 import 'package:spotiflac_android/l10n/l10n.dart';
 import 'package:spotiflac_android/utils/audio_conversion_utils.dart';
 import 'package:spotiflac_android/utils/logger.dart';
@@ -3259,136 +3260,196 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
    showModalBottomSheet<void>(
      context: screenContext,
      useRootNavigator: true,
+      backgroundColor: colorScheme.surfaceContainerHigh,
      shape: const RoundedRectangleBorder(
-        borderRadius: BorderRadius.vertical(top: Radius.circular(20)),
+        borderRadius: BorderRadius.vertical(top: Radius.circular(28)),
      ),
      isScrollControlled: true,
-      constraints: BoxConstraints(
-        maxHeight: MediaQuery.of(screenContext).size.height * 0.7,
-      ),
-      builder: (sheetContext) => SafeArea(
-        child: SingleChildScrollView(
-          child: Column(
-            mainAxisSize: MainAxisSize.min,
-            children: [
-              const SizedBox(height: 8),
-              Container(
-                width: 40,
-                height: 4,
-                decoration: BoxDecoration(
-                  color: colorScheme.onSurfaceVariant.withValues(alpha: 0.4),
-                  borderRadius: BorderRadius.circular(2),
-                ),
-              ),
-              const SizedBox(height: 16),
-              ListTile(
-                leading: const Icon(Icons.copy),
-                title: Text(sheetContext.l10n.trackCopyFilePath),
-                onTap: () {
-                  _closeOptionsMenuAndRun(
-                    sheetContext,
-                    () => _copyToClipboard(screenContext, cleanFilePath),
-                  );
-                },
-              ),
-              if (_fileExists)
-                ListTile(
-                  leading: const Icon(Icons.edit_outlined),
-                  title: Text(sheetContext.l10n.trackEditMetadata),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(
-                      sheetContext,
-                      () => _showEditMetadataSheet(
-                        screenContext,
-                        ref,
-                        colorScheme,
-                      ),
-                    );
-                  },
-                ),
-              if (!_isLocalItem && (_coverUrl != null || _fileExists))
-                ListTile(
-                  leading: const Icon(Icons.image_outlined),
-                  title: Text(sheetContext.l10n.trackSaveCoverArt),
-                  subtitle: Text(sheetContext.l10n.trackSaveCoverArtSubtitle),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(sheetContext, _saveCoverArt);
-                  },
-                ),
-              if (!_isLocalItem)
-                ListTile(
-                  leading: const Icon(Icons.lyrics_outlined),
-                  title: Text(sheetContext.l10n.trackSaveLyrics),
-                  subtitle: Text(sheetContext.l10n.trackSaveLyricsSubtitle),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(sheetContext, _saveLyrics);
-                  },
-                ),
-              if (_fileExists)
-                ListTile(
-                  leading: const Icon(Icons.travel_explore),
-                  title: Text(sheetContext.l10n.trackReEnrich),
-                  subtitle: Text(sheetContext.l10n.trackReEnrichOnlineSubtitle),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(sheetContext, _reEnrichMetadata);
-                  },
-                ),
-              if (_fileExists && _isConvertibleFormat)
-                ListTile(
-                  leading: const Icon(Icons.swap_horiz),
-                  title: Text(sheetContext.l10n.trackConvertFormat),
-                  subtitle: Text(sheetContext.l10n.trackConvertFormatSubtitle),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(
-                      sheetContext,
-                      () => _showConvertSheet(screenContext),
-                    );
-                  },
-                ),
-              if (_fileExists && _isCueFile)
-                ListTile(
-                  leading: const Icon(Icons.call_split),
-                  title: Text(sheetContext.l10n.cueSplitTitle),
-                  subtitle: Text(sheetContext.l10n.cueSplitSubtitle),
-                  onTap: () {
-                    _closeOptionsMenuAndRun(
-                      sheetContext,
-                      () => _showCueSplitSheet(screenContext),
-                    );
-                  },
-                ),
-              const Divider(height: 1),
-              ListTile(
-                leading: const Icon(Icons.share),
-                title: Text(sheetContext.l10n.trackMetadataShare),
-                onTap: () {
-                  _closeOptionsMenuAndRun(
-                    sheetContext,
-                    () => _shareFile(screenContext),
-                  );
-                },
-              ),
-              ListTile(
-                leading: Icon(Icons.delete, color: colorScheme.error),
-                title: Text(
-                  sheetContext.l10n.trackRemoveFromDevice,
-                  style: TextStyle(color: colorScheme.error),
-                ),
-                onTap: () {
-                  _closeOptionsMenuAndRun(
-                    sheetContext,
-                    () => _confirmDelete(screenContext, ref, colorScheme),
-                  );
-                },
-              ),
-              const SizedBox(height: 16),
-            ],
+      builder: (sheetContext) {
+        final l10n = sheetContext.l10n;
+
+        final options = <_MetadataOption>[
+          _MetadataOption(
+            icon: Icons.copy_outlined,
+            label: l10n.trackCopyFilePath,
+            onTap: () => _copyToClipboard(screenContext, cleanFilePath),
          ),
-        ),
-      ),
+          if (_fileExists)
+            _MetadataOption(
+              icon: Icons.edit_outlined,
+              label: l10n.trackEditMetadata,
+              onTap: () =>
+                  _showEditMetadataSheet(screenContext, ref, colorScheme),
+            ),
+          if (!_isLocalItem && (_coverUrl != null || _fileExists))
+            _MetadataOption(
+              icon: Icons.image_outlined,
+              label: l10n.trackSaveCoverArt,
+              onTap: _saveCoverArt,
+            ),
+          if (!_isLocalItem)
+            _MetadataOption(
+              icon: Icons.lyrics_outlined,
+              label: l10n.trackSaveLyrics,
+              onTap: _saveLyrics,
+            ),
+          if (_fileExists)
+            _MetadataOption(
+              icon: Icons.travel_explore,
+              label: l10n.trackReEnrich,
+              onTap: _reEnrichMetadata,
+            ),
+          if (_fileExists && _isConvertibleFormat)
+            _MetadataOption(
+              icon: Icons.swap_horiz,
+              label: l10n.trackConvertFormat,
+              onTap: () => _showConvertSheet(screenContext),
+            ),
+          if (_fileExists && !_isCueFile)
+            _MetadataOption(
+              icon: Icons.graphic_eq,
+              label: l10n.trackReplayGain,
+              onTap: () => _rescanReplayGain(),
+            ),
+          if (_fileExists && _isCueFile)
+            _MetadataOption(
+              icon: Icons.call_split,
+              label: l10n.cueSplitTitle,
+              onTap: () => _showCueSplitSheet(screenContext),
+            ),
+          _MetadataOption(
+            icon: Icons.share_outlined,
+            label: l10n.trackMetadataShare,
+            onTap: () => _shareFile(screenContext),
+          ),
+          _MetadataOption(
+            icon: Icons.delete_outline,
+            label: l10n.trackRemoveFromDevice,
+            destructive: true,
+            onTap: () => _confirmDelete(screenContext, ref, colorScheme),
+          ),
+        ];
+
+        return SafeArea(
+          child: ConstrainedBox(
+            constraints: BoxConstraints(
+              maxHeight: MediaQuery.of(sheetContext).size.height * 0.85,
+            ),
+            child: SingleChildScrollView(
+              child: Column(
+                mainAxisSize: MainAxisSize.min,
+                children: [
+                  const SizedBox(height: 8),
+                  Center(
+                    child: Container(
+                      width: 40,
+                      height: 4,
+                      decoration: BoxDecoration(
+                        color: colorScheme.onSurfaceVariant.withValues(
+                          alpha: 0.4,
+                        ),
+                        borderRadius: BorderRadius.circular(2),
+                      ),
+                    ),
+                  ),
+                  Padding(
+                    padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
+                    child: Row(
+                      children: [
+                        ClipRRect(
+                          borderRadius: BorderRadius.circular(8),
+                          child: _buildOptionsHeaderCover(colorScheme),
+                        ),
+                        const SizedBox(width: 12),
+                        Expanded(
+                          child: Column(
+                            crossAxisAlignment: CrossAxisAlignment.start,
+                            children: [
+                              Text(
+                                trackName,
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                                style: Theme.of(sheetContext)
+                                    .textTheme
+                                    .titleMedium
+                                    ?.copyWith(fontWeight: FontWeight.w600),
+                              ),
+                              const SizedBox(height: 2),
+                              Text(
+                                artistName,
+                                maxLines: 1,
+                                overflow: TextOverflow.ellipsis,
+                                style: Theme.of(sheetContext)
+                                    .textTheme
+                                    .bodyMedium
+                                    ?.copyWith(
+                                      color: colorScheme.onSurfaceVariant,
+                                    ),
+                              ),
+                            ],
+                          ),
+                        ),
+                      ],
+                    ),
+                  ),
+                  Divider(
+                    height: 1,
+                    color: colorScheme.outlineVariant.withValues(alpha: 0.5),
+                  ),
+                  const SizedBox(height: 4),
+                  for (final option in options)
+                    _MetadataOptionTile(
+                      option: option,
+                      colorScheme: colorScheme,
+                      onTap: () =>
+                          _closeOptionsMenuAndRun(sheetContext, option.onTap),
+                    ),
+                  const SizedBox(height: 16),
+                ],
+              ),
+            ),
+          ),
+        );
+      },
    );
  }

+  Widget _buildOptionsHeaderCover(ColorScheme colorScheme) {
+    const size = 56.0;
+    const cacheWidth = 112;
+
+    Widget placeholder() => Container(
+      width: size,
+      height: size,
+      color: colorScheme.surfaceContainerHighest,
+      child: Icon(Icons.music_note, color: colorScheme.onSurfaceVariant),
+    );
+
+    if (_coverUrl != null) {
+      return CachedCoverImage(
+        imageUrl: _coverUrl!,
+        width: size,
+        height: size,
+        fit: BoxFit.cover,
+        memCacheWidth: cacheWidth,
+        errorWidget: (_, _, _) => placeholder(),
+      );
+    }
+
+    if (_localCoverPath != null && _localCoverPath!.isNotEmpty) {
+      return Image.file(
+        File(_localCoverPath!),
+        width: size,
+        height: size,
+        fit: BoxFit.cover,
+        cacheWidth: cacheWidth,
+        errorBuilder: (_, _, _) => placeholder(),
+      );
+    }
+
+    return placeholder();
+  }
+
  /// Whether the current file format supports conversion
  bool get _isConvertibleFormat {
    final lower = cleanFilePath.toLowerCase();
@@ -3572,6 +3633,35 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
    return normalized;
  }

+  Future<void> _rescanReplayGain() async {
+    if (!_fileExists) return;
+    final messenger = ScaffoldMessenger.of(context);
+    messenger.clearSnackBars();
+    messenger.showSnackBar(
+      SnackBar(
+        content: Text(context.l10n.trackReplayGainScanning),
+        duration: const Duration(seconds: 30),
+      ),
+    );
+    bool ok = false;
+    try {
+      ok = await ReplayGainService.applyToFile(cleanFilePath);
+    } catch (e) {
+      _log.w('ReplayGain rescan failed: $e');
+    }
+    if (!mounted) return;
+    messenger.hideCurrentSnackBar();
+    messenger.showSnackBar(
+      SnackBar(
+        content: Text(
+          ok
+              ? context.l10n.trackReplayGainSuccess
+              : context.l10n.trackReplayGainFailed,
+        ),
+      ),
+    );
+  }
+
  void _showConvertSheet(BuildContext context) {
    final currentFormat = _currentFileFormat;
    final isLosslessSource = currentFormat == 'FLAC' || currentFormat == 'M4A';
@@ -4859,3 +4949,57 @@ class _TrackMetadataScreenState extends ConsumerState<TrackMetadataScreen> {
    }
  }
 }
+
+class _MetadataOption {
+  final IconData icon;
+  final String label;
+  final VoidCallback onTap;
+  final bool destructive;
+
+  const _MetadataOption({
+    required this.icon,
+    required this.label,
+    required this.onTap,
+    this.destructive = false,
+  });
+}
+
+class _MetadataOptionTile extends StatelessWidget {
+  final _MetadataOption option;
+  final ColorScheme colorScheme;
+  final VoidCallback onTap;
+
+  const _MetadataOptionTile({
+    required this.option,
+    required this.colorScheme,
+    required this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final boxColor = option.destructive
+        ? colorScheme.errorContainer
+        : colorScheme.primaryContainer;
+    final iconColor = option.destructive
+        ? colorScheme.onErrorContainer
+        : colorScheme.onPrimaryContainer;
+    final titleColor = option.destructive ? colorScheme.error : null;
+
+    return ListTile(
+      contentPadding: const EdgeInsets.symmetric(horizontal: 24, vertical: 4),
+      leading: Container(
+        padding: const EdgeInsets.all(10),
+        decoration: BoxDecoration(
+          color: boxColor,
+          borderRadius: BorderRadius.circular(12),
+        ),
+        child: Icon(option.icon, color: iconColor, size: 20),
+      ),
+      title: Text(
+        option.label,
+        style: TextStyle(fontWeight: FontWeight.w500, color: titleColor),
+      ),
+      onTap: onTap,
+    );
+  }
+}
@@ -1292,6 +1292,71 @@ class FFmpegService {
    return false;
  }

+  /// Write track ReplayGain tags to a file via FFmpeg, replacing it in place.
+  ///
+  /// Used for formats that are not handled by the native tag writers
+  /// (MP3/Opus). All existing streams and metadata are preserved via
+  /// `-map 0 -c copy -map_metadata 0`; only the REPLAYGAIN_TRACK_* fields are
+  /// added/overwritten. Returns `true` when the file was rewritten in place.
+  static Future<bool> writeTrackReplayGainTags(
+    String filePath,
+    String trackGain,
+    String trackPeak,
+  ) async {
+    final ext = filePath.contains('.')
+        ? '.${filePath.split('.').last}'
+        : '.tmp';
+    final tempDir = await getTemporaryDirectory();
+    final tempOutput = _nextTempEmbedPath(tempDir.path, ext);
+    final arguments = <String>[
+      '-v',
+      'error',
+      '-hide_banner',
+      '-i',
+      filePath,
+      '-map',
+      '0',
+      '-c',
+      'copy',
+      '-map_metadata',
+      '0',
+      '-metadata',
+      'REPLAYGAIN_TRACK_GAIN=$trackGain',
+      '-metadata',
+      'REPLAYGAIN_TRACK_PEAK=$trackPeak',
+      tempOutput,
+      '-y',
+    ];
+
+    _log.d('Writing track ReplayGain tags via FFmpeg');
+    final result = await _executeWithArguments(arguments);
+
+    if (result.success) {
+      try {
+        final tempFile = File(tempOutput);
+        if (await tempFile.exists()) {
+          final originalFile = File(filePath);
+          if (await originalFile.exists()) {
+            await originalFile.delete();
+          }
+          await tempFile.copy(filePath);
+          await tempFile.delete();
+          _log.d('Track ReplayGain tags written successfully');
+          return true;
+        }
+      } catch (e) {
+        _log.w('Failed to replace file with track ReplayGain: $e');
+      }
+    }
+
+    try {
+      final tempFile = File(tempOutput);
+      if (await tempFile.exists()) await tempFile.delete();
+    } catch (_) {}
+
+    return false;
+  }
+
  static Future<String?> embedMetadata({
    required String flacPath,
    String? coverPath,
@@ -0,0 +1,104 @@
+import 'dart:io';
+
+import 'package:spotiflac_android/services/ffmpeg_service.dart';
+import 'package:spotiflac_android/services/platform_bridge.dart';
+import 'package:spotiflac_android/utils/file_access.dart';
+import 'package:spotiflac_android/utils/logger.dart';
+
+/// Standalone ReplayGain (re)scanning for existing audio files.
+///
+/// Computes EBU R128 loudness via FFmpeg and writes REPLAYGAIN_TRACK_* tags
+/// back into the file in place:
+///   - FLAC / M4A / MP4 / APE / WV / MPC -> native tag writer (PlatformBridge)
+///   - MP3 / Opus / OGG / others         -> FFmpeg copy-with-metadata
+///
+/// Handles SAF content:// URIs transparently by working on a temporary copy
+/// and writing it back to the original document.
+class ReplayGainService {
+  ReplayGainService._();
+
+  static final _log = AppLogger('ReplayGain');
+
+  static const _nativeExtensions = <String>{
+    '.flac',
+    '.m4a',
+    '.mp4',
+    '.m4b',
+    '.ape',
+    '.wv',
+    '.mpc',
+  };
+
+  static bool _isNativeWritableFormat(String path) {
+    final lower = path.toLowerCase();
+    return _nativeExtensions.any(lower.endsWith);
+  }
+
+  /// Scans [filePath] for loudness and writes track ReplayGain tags in place.
+  ///
+  /// Returns `true` when tags were successfully written, `false` otherwise
+  /// (scan failed, write failed, or SAF write-back failed).
+  static Future<bool> applyToFile(String filePath) async {
+    if (filePath.isEmpty) return false;
+
+    final isSaf = isContentUri(filePath);
+    var workingPath = filePath;
+    String? safTempPath;
+
+    try {
+      if (isSaf) {
+        safTempPath = await PlatformBridge.copyContentUriToTemp(filePath);
+        if (safTempPath == null || safTempPath.isEmpty) {
+          _log.w('Failed to copy SAF file to temp for ReplayGain scan');
+          return false;
+        }
+        workingPath = safTempPath;
+      }
+
+      final rg = await FFmpegService.scanReplayGain(workingPath);
+      if (rg == null) {
+        _log.w('ReplayGain scan returned no result for $workingPath');
+        return false;
+      }
+
+      bool written;
+      if (_isNativeWritableFormat(workingPath)) {
+        final result = await PlatformBridge.editFileMetadata(workingPath, {
+          'replaygain_track_gain': rg.trackGain,
+          'replaygain_track_peak': rg.trackPeak,
+        });
+        written = result['error'] == null;
+        if (!written) {
+          _log.w('Native ReplayGain write failed: ${result['error']}');
+        }
+      } else {
+        written = await FFmpegService.writeTrackReplayGainTags(
+          workingPath,
+          rg.trackGain,
+          rg.trackPeak,
+        );
+      }
+
+      if (!written) return false;
+
+      if (isSaf) {
+        final ok = await PlatformBridge.writeTempToSaf(workingPath, filePath);
+        if (!ok) {
+          _log.w('Failed to write ReplayGain temp file back to SAF document');
+        }
+        return ok;
+      }
+
+      return true;
+    } catch (e) {
+      _log.e('Failed to apply ReplayGain', e);
+      return false;
+    } finally {
+      if (safTempPath != null) {
+        try {
+          await File(safTempPath).delete();
+        } catch (_) {}
+      }
+    }
+  }
+}