diff --git a/internal/service/subtitle.go b/internal/service/subtitle.go
index 5974f3d..008862f 100644
--- a/internal/service/subtitle.go
+++ b/internal/service/subtitle.go
@@ -19,7 +19,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net/url"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -27,9 +26,7 @@ import (
 
 	"go.uber.org/zap"
 
-	"github.com/ShukeBta/MediaStationGo/internal/model"
 	"github.com/ShukeBta/MediaStationGo/internal/repository"
-	"github.com/ShukeBta/MediaStationGo/internal/service/cloud"
 )
 
 // SubtitleService is the discovery + conversion entry point.
@@ -83,7 +80,7 @@ func (s *SubtitleService) Discover(ctx context.Context, mediaID string) ([]Subti
 		return nil, errors.New("media not found")
 	}
 	if strings.HasPrefix(strings.ToLower(strings.TrimSpace(m.Path)), "cloud://") {
-		return s.discoverCloud(ctx, *m), nil
+		return discoverCloudSubtitles(ctx, s, *m), nil
 	}
 	dir := filepath.Dir(m.Path)
 	base := strings.TrimSuffix(filepath.Base(m.Path), filepath.Ext(m.Path))
@@ -128,126 +125,6 @@ func (s *SubtitleService) Discover(ctx context.Context, mediaID string) ([]Subti
 	return tracks, nil
 }
 
-func (s *SubtitleService) discoverCloud(ctx context.Context, m model.Media) []SubtitleTrack {
-	if s == nil || s.storage == nil {
-		return []SubtitleTrack{}
-	}
-	typ, mediaRef, ok := cloudSubtitleMediaRef(m)
-	if !ok {
-		return []SubtitleTrack{}
-	}
-	dirRef, mediaName := splitCloudRef(mediaRef)
-	if mediaName == "" {
-		return []SubtitleTrack{}
-	}
-	base := strings.TrimSuffix(mediaName, filepath.Ext(mediaName))
-	entries, err := s.storage.CloudList(ctx, typ, dirRef)
-	if err != nil {
-		if s.log != nil {
-			s.log.Debug("list cloud subtitles failed", zap.String("provider", typ), zap.String("dir", dirRef), zap.Error(err))
-		}
-		return []SubtitleTrack{}
-	}
-	tracks := cloudSubtitleTracks(typ, entries, base, false)
-	for _, entry := range entries {
-		if !entry.IsDir || !isSubtitleDirectory(entry.Name) || strings.TrimSpace(entry.ID) == "" {
-			continue
-		}
-		subEntries, err := s.storage.CloudList(ctx, typ, entry.ID)
-		if err != nil {
-			continue
-		}
-		tracks = append(tracks, cloudSubtitleTracks(typ, subEntries, base, true)...)
-	}
-	return tracks
-}
-
-func cloudSubtitleTracks(typ string, entries []cloud.FileEntry, base string, subdir bool) []SubtitleTrack {
-	tracks := make([]SubtitleTrack, 0)
-	baseLower := strings.ToLower(base)
-	for _, entry := range entries {
-		if entry.IsDir {
-			continue
-		}
-		ext := strings.ToLower(filepath.Ext(entry.Name))
-		codec, ok := extToCodec[ext]
-		if !ok {
-			continue
-		}
-		fullName := strings.TrimSuffix(entry.Name, ext)
-		if !subdir && !strings.HasPrefix(strings.ToLower(fullName), baseLower) {
-			continue
-		}
-		ref := cloudEntryRef(typ, entry.ID, entry.PickCode)
-		if ref == "" {
-			continue
-		}
-		lang := detectLang(fullName, base)
-		tracks = append(tracks, SubtitleTrack{
-			Lang:  lang,
-			Label: lang,
-			Path:  buildCloudSubtitlePath(typ, ref, entry.Name),
-			Codec: codec,
-		})
-	}
-	return tracks
-}
-
-func cloudSubtitleMediaRef(m model.Media) (typ, ref string, ok bool) {
-	if info, parsed := ParseCloudLibraryMount(m.Path); parsed && strings.TrimSpace(info.DisplayDir) != "" {
-		return info.Provider, info.DisplayDir, true
-	}
-	if typ, ref, parsed := parseCloudMediaPlaybackURL(m.STRMURL); parsed {
-		return typ, ref, true
-	}
-	return "", "", false
-}
-
-func splitCloudRef(ref string) (dir, name string) {
-	ref = strings.Trim(strings.ReplaceAll(strings.TrimSpace(ref), "\\", "/"), "/")
-	if ref == "" {
-		return "", ""
-	}
-	idx := strings.LastIndex(ref, "/")
-	if idx < 0 {
-		return "", ref
-	}
-	return ref[:idx], ref[idx+1:]
-}
-
-func isSubtitleDirectory(name string) bool {
-	switch strings.ToLower(strings.TrimSpace(name)) {
-	case "subs", "sub", ".sub", "subtitles", "subtitle":
-		return true
-	default:
-		return false
-	}
-}
-
-func buildCloudSubtitlePath(typ, ref, name string) string {
-	u := url.URL{
-		Scheme: "cloud",
-		Host:   strings.TrimSpace(typ),
-		Path:   "/" + strings.TrimLeft(strings.TrimSpace(ref), "/"),
-	}
-	q := u.Query()
-	q.Set("name", strings.TrimSpace(name))
-	u.RawQuery = q.Encode()
-	return u.String()
-}
-
-func parseCloudSubtitlePath(raw string) (typ, ref, name string, ok bool) {
-	u, err := url.Parse(strings.TrimSpace(raw))
-	if err != nil || strings.ToLower(u.Scheme) != "cloud" || strings.TrimSpace(u.Host) == "" {
-		return "", "", "", false
-	}
-	ref = strings.TrimLeft(u.EscapedPath(), "/")
-	if decoded, err := url.PathUnescape(ref); err == nil {
-		ref = decoded
-	}
-	return strings.TrimSpace(u.Host), strings.TrimSpace(ref), strings.TrimSpace(u.Query().Get("name")), ref != ""
-}
-
 // langTag matches the .zh / .zh-cn / .chs language sub-extensions.
 var langTag = regexp.MustCompile(`(?i)\.([a-z]{2,3}(?:[-_][a-z]{2,4})?)$`)
 
@@ -272,7 +149,7 @@ func (s *SubtitleService) Serve(ctx context.Context, mediaID, sub string, w io.W
 		return errors.New("media not found")
 	}
 	if typ, ref, name, ok := parseCloudSubtitlePath(sub); ok {
-		return s.serveCloud(ctx, *m, typ, ref, name, w)
+		return serveCloudSubtitle(ctx, s, *m, typ, ref, name, w)
 	}
 	abs, err := filepath.Abs(sub)
 	if err != nil {
@@ -305,99 +182,3 @@ func (s *SubtitleService) Serve(ctx context.Context, mediaID, sub string, w io.W
 	}
 	return err
 }
-
-func (s *SubtitleService) serveCloud(ctx context.Context, m model.Media, typ, ref, name string, w io.Writer) error {
-	if s == nil || s.storage == nil {
-		return errors.New("cloud storage service unavailable")
-	}
-	mediaTyp, _, ok := cloudSubtitleMediaRef(m)
-	if !ok || mediaTyp != typ {
-		return ErrCloudPlaybackUnavailable
-	}
-	allowed := false
-	for _, track := range s.discoverCloud(ctx, m) {
-		if track.Path == buildCloudSubtitlePath(typ, ref, name) {
-			allowed = true
-			break
-		}
-	}
-	if !allowed {
-		return fmt.Errorf("path escape")
-	}
-	body, err := s.storage.CloudReadText(ctx, typ, ref, 8<<20)
-	if err != nil {
-		return err
-	}
-	ext := strings.ToLower(filepath.Ext(firstNonEmpty(name, ref)))
-	switch ext {
-	case ".vtt":
-		_, err = io.WriteString(w, body)
-	case ".srt":
-		_, err = io.WriteString(w, srtToVTT(body))
-	case ".ass", ".ssa":
-		_, err = io.WriteString(w, assToVTT(body))
-	default:
-		return errors.New("unsupported subtitle format")
-	}
-	return err
-}
-
-// srtToVTT performs the minimal SRT → WebVTT transformation: prepend
-// "WEBVTT\n\n" and replace ',' with '.' in the timecode separators.
-func srtToVTT(body string) string {
-	body = strings.ReplaceAll(body, "\r\n", "\n")
-	out := strings.Builder{}
-	out.WriteString("WEBVTT\n\n")
-	for _, line := range strings.Split(body, "\n") {
-		if strings.Contains(line, "-->") {
-			line = strings.ReplaceAll(line, ",", ".")
-		}
-		out.WriteString(line)
-		out.WriteByte('\n')
-	}
-	return out.String()
-}
-
-// assToVTT extracts the dialogue lines from an ASS/SSA subtitle. Styling
-// is dropped — the goal is to produce something usable in <track> rather
-// than a pixel-perfect render.
-func assToVTT(body string) string {
-	out := strings.Builder{}
-	out.WriteString("WEBVTT\n\n")
-	for i, line := range strings.Split(body, "\n") {
-		line = strings.TrimSpace(line)
-		if !strings.HasPrefix(line, "Dialogue:") {
-			continue
-		}
-		parts := strings.SplitN(line, ",", 10)
-		if len(parts) < 10 {
-			continue
-		}
-		fmt.Fprintf(&out, "%d\n%s --> %s\n%s\n\n",
-			i,
-			normaliseTimecode(parts[1]),
-			normaliseTimecode(parts[2]),
-			stripASSTags(parts[9]),
-		)
-	}
-	return out.String()
-}
-
-func normaliseTimecode(t string) string {
-	t = strings.TrimSpace(t)
-	parts := strings.Split(t, ":")
-	if len(parts) != 3 {
-		return t
-	}
-	hh := parts[0]
-	if len(hh) == 1 {
-		hh = "0" + hh
-	}
-	return hh + ":" + parts[1] + ":" + strings.ReplaceAll(parts[2], ".", ".")
-}
-
-var assTag = regexp.MustCompile(`\{[^}]*\}`)
-
-func stripASSTags(s string) string {
-	return assTag.ReplaceAllString(s, "")
-}
diff --git a/internal/service/subtitle_cloud.go b/internal/service/subtitle_cloud.go
new file mode 100644
index 0000000..70b79d9
--- /dev/null
+++ b/internal/service/subtitle_cloud.go
@@ -0,0 +1,172 @@
+package service
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"path/filepath"
+	"strings"
+
+	"go.uber.org/zap"
+
+	"github.com/ShukeBta/MediaStationGo/internal/model"
+	"github.com/ShukeBta/MediaStationGo/internal/service/cloud"
+)
+
+func discoverCloudSubtitles(ctx context.Context, s *SubtitleService, m model.Media) []SubtitleTrack {
+	if s == nil || s.storage == nil {
+		return []SubtitleTrack{}
+	}
+	typ, mediaRef, ok := cloudSubtitleMediaRef(m)
+	if !ok {
+		return []SubtitleTrack{}
+	}
+	dirRef, mediaName := splitCloudRef(mediaRef)
+	if mediaName == "" {
+		return []SubtitleTrack{}
+	}
+	base := strings.TrimSuffix(mediaName, filepath.Ext(mediaName))
+	entries, err := s.storage.CloudList(ctx, typ, dirRef)
+	if err != nil {
+		if s.log != nil {
+			s.log.Debug("list cloud subtitles failed", zap.String("provider", typ), zap.String("dir", dirRef), zap.Error(err))
+		}
+		return []SubtitleTrack{}
+	}
+	tracks := cloudSubtitleTracks(typ, entries, base, false)
+	for _, entry := range entries {
+		if !entry.IsDir || !isSubtitleDirectory(entry.Name) || strings.TrimSpace(entry.ID) == "" {
+			continue
+		}
+		subEntries, err := s.storage.CloudList(ctx, typ, entry.ID)
+		if err != nil {
+			continue
+		}
+		tracks = append(tracks, cloudSubtitleTracks(typ, subEntries, base, true)...)
+	}
+	return tracks
+}
+
+func cloudSubtitleTracks(typ string, entries []cloud.FileEntry, base string, subdir bool) []SubtitleTrack {
+	tracks := make([]SubtitleTrack, 0)
+	baseLower := strings.ToLower(base)
+	for _, entry := range entries {
+		if entry.IsDir {
+			continue
+		}
+		ext := strings.ToLower(filepath.Ext(entry.Name))
+		codec, ok := extToCodec[ext]
+		if !ok {
+			continue
+		}
+		fullName := strings.TrimSuffix(entry.Name, ext)
+		if !subdir && !strings.HasPrefix(strings.ToLower(fullName), baseLower) {
+			continue
+		}
+		ref := cloudEntryRef(typ, entry.ID, entry.PickCode)
+		if ref == "" {
+			continue
+		}
+		lang := detectLang(fullName, base)
+		tracks = append(tracks, SubtitleTrack{
+			Lang:  lang,
+			Label: lang,
+			Path:  buildCloudSubtitlePath(typ, ref, entry.Name),
+			Codec: codec,
+		})
+	}
+	return tracks
+}
+
+func cloudSubtitleMediaRef(m model.Media) (typ, ref string, ok bool) {
+	if info, parsed := ParseCloudLibraryMount(m.Path); parsed && strings.TrimSpace(info.DisplayDir) != "" {
+		return info.Provider, info.DisplayDir, true
+	}
+	if typ, ref, parsed := parseCloudMediaPlaybackURL(m.STRMURL); parsed {
+		return typ, ref, true
+	}
+	return "", "", false
+}
+
+func splitCloudRef(ref string) (dir, name string) {
+	ref = strings.Trim(strings.ReplaceAll(strings.TrimSpace(ref), "\\", "/"), "/")
+	if ref == "" {
+		return "", ""
+	}
+	idx := strings.LastIndex(ref, "/")
+	if idx < 0 {
+		return "", ref
+	}
+	return ref[:idx], ref[idx+1:]
+}
+
+func isSubtitleDirectory(name string) bool {
+	switch strings.ToLower(strings.TrimSpace(name)) {
+	case "subs", "sub", ".sub", "subtitles", "subtitle":
+		return true
+	default:
+		return false
+	}
+}
+
+func buildCloudSubtitlePath(typ, ref, name string) string {
+	u := url.URL{
+		Scheme: "cloud",
+		Host:   strings.TrimSpace(typ),
+		Path:   "/" + strings.TrimLeft(strings.TrimSpace(ref), "/"),
+	}
+	q := u.Query()
+	q.Set("name", strings.TrimSpace(name))
+	u.RawQuery = q.Encode()
+	return u.String()
+}
+
+func parseCloudSubtitlePath(raw string) (typ, ref, name string, ok bool) {
+	u, err := url.Parse(strings.TrimSpace(raw))
+	if err != nil || strings.ToLower(u.Scheme) != "cloud" || strings.TrimSpace(u.Host) == "" {
+		return "", "", "", false
+	}
+	ref = strings.TrimLeft(u.EscapedPath(), "/")
+	if decoded, err := url.PathUnescape(ref); err == nil {
+		ref = decoded
+	}
+	return strings.TrimSpace(u.Host), strings.TrimSpace(ref), strings.TrimSpace(u.Query().Get("name")), ref != ""
+}
+
+func serveCloudSubtitle(ctx context.Context, s *SubtitleService, m model.Media, typ, ref, name string, w io.Writer) error {
+	if s == nil || s.storage == nil {
+		return errors.New("cloud storage service unavailable")
+	}
+	mediaTyp, _, ok := cloudSubtitleMediaRef(m)
+	if !ok || mediaTyp != typ {
+		return ErrCloudPlaybackUnavailable
+	}
+	allowed := false
+	for _, track := range discoverCloudSubtitles(ctx, s, m) {
+		if track.Path == buildCloudSubtitlePath(typ, ref, name) {
+			allowed = true
+			break
+		}
+	}
+	if !allowed {
+		return fmt.Errorf("path escape")
+	}
+	body, err := s.storage.CloudReadText(ctx, typ, ref, 8<<20)
+	if err != nil {
+		return err
+	}
+	ext := strings.ToLower(filepath.Ext(firstNonEmpty(name, ref)))
+	switch ext {
+	case ".vtt":
+		_, err = io.WriteString(w, body)
+	case ".srt":
+		_, err = io.WriteString(w, srtToVTT(body))
+	case ".ass", ".ssa":
+		_, err = io.WriteString(w, assToVTT(body))
+	default:
+		return errors.New("unsupported subtitle format")
+	}
+	return err
+}
diff --git a/internal/service/subtitle_convert.go b/internal/service/subtitle_convert.go
new file mode 100644
index 0000000..7c1a299
--- /dev/null
+++ b/internal/service/subtitle_convert.go
@@ -0,0 +1,66 @@
+package service
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+// srtToVTT performs the minimal SRT -> WebVTT transformation: prepend
+// "WEBVTT\n\n" and replace ',' with '.' in the timecode separators.
+func srtToVTT(body string) string {
+	body = strings.ReplaceAll(body, "\r\n", "\n")
+	out := strings.Builder{}
+	out.WriteString("WEBVTT\n\n")
+	for _, line := range strings.Split(body, "\n") {
+		if strings.Contains(line, "-->") {
+			line = strings.ReplaceAll(line, ",", ".")
+		}
+		out.WriteString(line)
+		out.WriteByte('\n')
+	}
+	return out.String()
+}
+
+// assToVTT extracts the dialogue lines from an ASS/SSA subtitle. Styling
+// is dropped so the browser <track> element can still display text.
+func assToVTT(body string) string {
+	out := strings.Builder{}
+	out.WriteString("WEBVTT\n\n")
+	for i, line := range strings.Split(body, "\n") {
+		line = strings.TrimSpace(line)
+		if !strings.HasPrefix(line, "Dialogue:") {
+			continue
+		}
+		parts := strings.SplitN(line, ",", 10)
+		if len(parts) < 10 {
+			continue
+		}
+		fmt.Fprintf(&out, "%d\n%s --> %s\n%s\n\n",
+			i,
+			normaliseTimecode(parts[1]),
+			normaliseTimecode(parts[2]),
+			stripASSTags(parts[9]),
+		)
+	}
+	return out.String()
+}
+
+func normaliseTimecode(t string) string {
+	t = strings.TrimSpace(t)
+	parts := strings.Split(t, ":")
+	if len(parts) != 3 {
+		return t
+	}
+	hh := parts[0]
+	if len(hh) == 1 {
+		hh = "0" + hh
+	}
+	return hh + ":" + parts[1] + ":" + strings.ReplaceAll(parts[2], ".", ".")
+}
+
+var assTag = regexp.MustCompile(`\{[^}]*\}`)
+
+func stripASSTags(s string) string {
+	return assTag.ReplaceAllString(s, "")
+}