feat(subsonic): expose replaygain tags

server/ctrlsubsonic/spec/construct_by_folder.go

@@ -102,6 +102,14 @@ func NewTCTrackByFolder(t *db.Track, parent *db.Album) *TrackChild {
 	for _, a := range t.Artists {
 		trCh.Artists = append(trCh.Artists, &ArtistRef{ID: a.SID(), Name: a.Name})
 	}
+	if t.ReplayGainTrackGain != 0 || t.ReplayGainAlbumGain != 0 {
+		trCh.ReplayGain = &ReplayGain{
+			TrackGain: t.ReplayGainTrackGain,
+			TrackPeak: t.ReplayGainTrackPeak,
+			AlbumGain: t.ReplayGainAlbumGain,
+			AlbumPeak: t.ReplayGainAlbumPeak,
+		}
+	}
 	return trCh
 }
 

server/ctrlsubsonic/spec/construct_by_tags.go

@@ -112,6 +112,14 @@ func NewTrackByTags(t *db.Track, album *db.Album) *TrackChild {
 	for _, a := range album.Artists {
 		ret.AlbumArtists = append(ret.AlbumArtists, &ArtistRef{ID: a.SID(), Name: a.Name})
 	}
+	if t.ReplayGainTrackGain != 0 || t.ReplayGainAlbumGain != 0 {
+		ret.ReplayGain = &ReplayGain{
+			TrackGain: t.ReplayGainTrackGain,
+			TrackPeak: t.ReplayGainTrackPeak,
+			AlbumGain: t.ReplayGainAlbumGain,
+			AlbumPeak: t.ReplayGainAlbumPeak,
+		}
+	}
 	return ret
 }
 

server/ctrlsubsonic/spec/spec.go

@@ -169,6 +169,13 @@ type TranscodeMeta struct {
 	TranscodedSuffix      string `xml:"transcodedSuffix,attr,omitempty"      json:"transcodedSuffix,omitempty"`
 }
 
+type ReplayGain struct {
+	TrackGain float32 `xml:"trackGain,attr" json:"trackGain"`
+	TrackPeak float32 `xml:"trackPeak,attr" json:"trackPeak"`
+	AlbumGain float32 `xml:"albumGain,attr" json:"albumGain"`
+	AlbumPeak float32 `xml:"albumPeak,attr" json:"albumPeak"`
+}
+
 // https://opensubsonic.netlify.app/docs/responses/child/
 type TrackChild struct {
 	ID      *specid.ID `xml:"id,attr,omitempty"          json:"id,omitempty"`
@@ -211,6 +218,8 @@ type TrackChild struct {
 	UserRating    int        `xml:"userRating,attr,omitempty"      json:"userRating,omitempty"`
 	AverageRating string     `xml:"averageRating,attr,omitempty"   json:"averageRating,omitempty"`
 
+	ReplayGain *ReplayGain `xml:"replayGain" json:"replayGain"`
+
 	TranscodeMeta
 }