Extract and display radio ICY metadata (#845)

* extract and display radio ICY metadata

* fix crash when casting radio station

backend/app.go

@@ -449,6 +449,15 @@ func (a *App) SetupWindowsSMTC(hwnd uintptr) {
 			}
 		}()
 	})
+	a.PlaybackManager.OnRadioMetadataChange(func(radioName, title, artist string) {
+		if title != "" {
+			smtc.UpdateMetadata(title, artist)
+			smtc.UpdatePosition(0, 0)
+		} else {
+			smtc.UpdateMetadata(radioName, "")
+			smtc.UpdatePosition(0, 0)
+		}
+	})
 	a.PlaybackManager.OnSeek(func() {
 		playbackStatus := a.PlaybackManager.PlaybackStatus()
 		smtc.UpdatePosition(int(playbackStatus.TimePos*1000), int(playbackStatus.Duration*1000))

backend/mpmedia_mac.go

@@ -69,15 +69,28 @@ func InitMPMediaHandler(playbackManager *PlaybackManager, artURLLookup func(trac
 	mpMediaEventRecipient = mp
 	C.register_os_remote_commands()
 
-	mp.playbackManager.OnSongChange(func(track mediaprovider.MediaItem, _ *mediaprovider.Track) {
+	mp.playbackManager.OnSongChange(func(item mediaprovider.MediaItem, _ *mediaprovider.Track) {
 		// Asynchronously because artwork fetching can take time
 		var meta *mediaprovider.MediaItemMetadata
-		if track != nil {
+		if item != nil {
-			m := track.Metadata()
+			m := item.Metadata()
 			meta = &m
 		}
 		go mp.updateMetadata(meta)
 	})
+	mp.playbackManager.OnRadioMetadataChange(func(radioName, title, artist string) {
+		if title != "" {
+			go mp.updateMetadata(&mediaprovider.MediaItemMetadata{
+				Name:    title,
+				Artists: []string{artist},
+				Album:   radioName,
+			})
+		} else {
+			go mp.updateMetadata(&mediaprovider.MediaItemMetadata{
+				Name: radioName,
+			})
+		}
+	})
 
 	mp.playbackManager.OnStopped(func() {
 		C.set_os_playback_state_stopped()
@@ -103,16 +116,18 @@ func InitMPMediaHandler(playbackManager *PlaybackManager, artURLLookup func(trac
 func (mp *MPMediaHandler) updateMetadata(meta *mediaprovider.MediaItemMetadata) {
 	var title, artist, artURL string
 	var duration int
-	if meta != nil && meta.ID != "" {
+	if meta != nil {
 		title = meta.Name
+		artist = strings.Join(meta.Artists, ", ")
+		duration = int(meta.Duration.Seconds())
+	}
+	if meta != nil && meta.ID != "" {
 		var err error
 		if artURL, err = mp.artURLLookup(meta.CoverArtID); err != nil {
 			if meta.CoverArtID != "" {
 				log.Printf("error fetching art url: %s", err.Error())
 			}
 		}
-		artist = strings.Join(meta.Artists, ", ")
-		duration = int(meta.Duration.Seconds())
 	}
 
 	cTitle := C.CString(title)

backend/mpris.go

@@ -43,6 +43,11 @@ type MPRISHandler struct {
 	pm           *PlaybackManager
 	s            *server.Server
 	evt          *events.EventHandler
+
+	// current radio metadata
+	radioStationName string
+	radioIcyTitle    string
+	radioIcyArtist   string
 }
 
 func NewMPRISHandler(playerName string, pm *PlaybackManager) *MPRISHandler {
@@ -66,6 +71,14 @@ func NewMPRISHandler(playerName string, pm *PlaybackManager) *MPRISHandler {
 			m.evt.Player.OnTitle()
 		}
 	})
+	pm.OnRadioMetadataChange(func(radioName, title, artist string) {
+		m.radioStationName = radioName
+		m.radioIcyTitle = title
+		m.radioIcyArtist = artist
+		if m.connErr == nil {
+			m.evt.Player.OnTitle()
+		}
+	})
 	pm.OnVolumeChange(func(vol int) {
 		if m.connErr == nil {
 			m.evt.Player.OnVolume()
@@ -276,12 +289,23 @@ func (m *MPRISHandler) Metadata() (types.Metadata, error) {
 			artURL = u
 		}
 	}
+
+	title := meta.Name
+	artists := meta.Artists
+	album := meta.Album
+	// if playing a radio station, override title/artist with current Icy metadata if present
+	if m.radioStationName == title && m.radioIcyTitle != "" {
+		title = m.radioIcyTitle
+		artists = []string{m.radioIcyArtist}
+		album = m.radioStationName
+	}
+
 	mprisMeta := types.Metadata{
 		TrackId:     dbus.ObjectPath(trackObjPath),
 		Length:      secondsToMicroseconds(status.Duration),
-		Title:       meta.Name,
+		Title:       title,
-		Album:       meta.Album,
+		Album:       album,
-		Artist:      meta.Artists,
+		Artist:      artists,
 		DiscNumber:  discNumber,
 		TrackNumber: trackNumber,
 		UserRating:  float64(userRating) / 5,

backend/playbackengine.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"math/rand"
+	"strings"
 	"time"
 
 	"github.com/dweymouth/supersonic/backend/mediaprovider"
@@ -103,6 +104,8 @@ type playbackEngine struct {
 	onStopped          []func()
 	onPlaying          []func()
 	onQueueChange      []func()
+
+	onRadioMetadataChange []func(radioName, title, artist string)
 }
 
 func NewPlaybackEngine(
@@ -698,6 +701,22 @@ func (p *playbackEngine) setTrack(idx int, next bool, startTime float64) error {
 					url = filepath
 				}
 			}
+			if mpvP, ok := p.player.(*mpv.Player); ok && !isTrack {
+				mpvP.ObserveIcyRadioTitle(func(icytitle string) {
+					var title, artist string
+					if s := strings.Split(icytitle, " - "); len(s) == 2 {
+						title, artist = s[1], s[0]
+					} else {
+						title = icytitle
+					}
+					log.Println("Radio metadata changed: ", icytitle)
+					for _, cb := range p.onRadioMetadataChange {
+						cb(meta.Name, title, artist)
+					}
+				})
+			} else if ok {
+				mpvP.UnobserveIcyRadioTitle()
+			}
 			if url == "" {
 				return errors.New("no stream URL")
 			}

backend/playbackmanager.go

@@ -318,6 +318,11 @@ func (p *PlaybackManager) OnSongChange(cb func(nowPlaying mediaprovider.MediaIte
 	p.engine.onSongChange = append(p.engine.onSongChange, cb)
 }
 
+// Sets a callback that is notified whenever the Icy radio metadata changes.
+func (p *PlaybackManager) OnRadioMetadataChange(cb func(radioName, title, artist string)) {
+	p.engine.onRadioMetadataChange = append(p.engine.onRadioMetadataChange, cb)
+}
+
 // Registers a callback that is notified whenever the play time should be updated.
 func (p *PlaybackManager) OnPlayTimeUpdate(cb func(curTime float64, totalTime float64, seeked bool)) {
 	p.engine.onPlayTimeUpdate = append(p.engine.onPlayTimeUpdate, cb)

backend/player/mpv/player.go

@@ -72,6 +72,8 @@ type Player struct {
 	peaksEnabled   bool
 	pauseFade      bool
 
+	icyTitleCb func(string)
+
 	fileLoadedLock sync.Mutex
 	fileLoadedSig  *sync.Cond
 
@@ -130,6 +132,8 @@ func (p *Player) Init(maxCacheMB int) error {
 			m.SetOptionString("audio-client-name", p.clientName)
 		}
 
+		m.ObserveProperty(0, "metadata", mpv.FORMAT_NODE)
+
 		if err := m.Initialize(); err != nil {
 			return fmt.Errorf("error initializing mpv: %s", err.Error())
 		}
@@ -442,6 +446,16 @@ func (p *Player) GetMediaInfo() (MediaInfo, error) {
 	return info, nil
 }
 
+func (p *Player) ObserveIcyRadioTitle(cb func(string)) {
+	p.icyTitleCb = cb
+	p.mpv.ObserveProperty(1, "metadata/icy-title", mpv.FORMAT_STRING)
+}
+
+func (p *Player) UnobserveIcyRadioTitle() {
+	p.icyTitleCb = nil
+	p.mpv.UnobserveProperty(1)
+}
+
 func (p *Player) getInt64Property(propName string) (int64, error) {
 	playpos, err := p.mpv.GetProperty(propName, mpv.FORMAT_INT64)
 	if err != nil {
@@ -548,6 +562,11 @@ func (p *Player) eventHandler(ctx context.Context) {
 				p.status.Duration = 0
 				p.status.TimePos = 0
 				p.setState(player.Stopped)
+			case mpv.EVENT_PROPERTY_CHANGE:
+				if e.Reply_Userdata == 1 && p.icyTitleCb != nil {
+					p.icyTitleCb(p.mpv.GetPropertyString("metadata/icy-title"))
+				}
+
 			}
 		}
 	}

ui/bottompanel.go

@@ -35,6 +35,7 @@ func NewBottomPanel(pm *backend.PlaybackManager, im *backend.ImageManager, contr
 	bp.ExtendBaseWidget(bp)
 
 	pm.OnSongChange(bp.onSongChange)
+	pm.OnRadioMetadataChange(bp.onRadioMetadataChange)
 	pm.OnWaveformImgUpdate(bp.updateWaveformImg)
 	pm.OnPlayTimeUpdate(func(cur, total float64, _ bool) {
 		fyne.Do(func() {
@@ -143,6 +144,16 @@ func (bp *BottomPanel) onSongChange(song mediaprovider.MediaItem, _ *mediaprovid
 	})
 }
 
+func (bp *BottomPanel) onRadioMetadataChange(radioName, title, artist string) {
+	fyne.Do(func() {
+		bp.NowPlaying.Update(&mediaprovider.Track{
+			Title:       title,
+			ArtistNames: []string{artist},
+			Album:       radioName,
+		})
+	})
+}
+
 func (bp *BottomPanel) updateWaveformImg(img *backend.WaveformImage) {
 	fyne.Do(func() {
 		bp.Controls.UpdateWaveformImg(img)

ui/mainwindow.go

@@ -109,6 +109,15 @@ func NewMainWindow(fyneApp fyne.App, appName, displayAppName, appVersion string,
 	app.PlaybackManager.OnSongChange(func(item mediaprovider.MediaItem, _ *mediaprovider.Track) {
 		fyne.Do(func() { m.UpdateOnTrackChange(item) })
 	})
+	app.PlaybackManager.OnRadioMetadataChange(func(radioName, title, artist string) {
+		fyne.Do(func() {
+			if title != "" {
+				m.Window.SetTitle(fmt.Sprintf("%s – %s · %s", title, artist, res.DisplayName))
+			} else {
+				m.Window.SetTitle(fmt.Sprintf("%s · %s", radioName, res.DisplayName))
+			}
+		})
+	})
 	app.PlaybackManager.OnQueueChange(func() {
 		fyne.Do(func() { m.Sidebar.SetQueueTracks(app.PlaybackManager.GetPlayQueue()) })
 	})