diff --git a/go.mod b/go.mod
index 8d94754c..92d1084a 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.18
 require (
 	code.cloudfoundry.org/bytefmt v0.0.0
 	github.com/abema/go-mp4 v0.0.0
-	github.com/aler9/gortsplib/v2 v2.0.0-20230103153002-0ce435414414
+	github.com/aler9/gortsplib/v2 v2.0.0-20230106140016-a759ba9d014b
 	github.com/asticode/go-astits v1.10.1-0.20220319093903-4abe66a9b757
 	github.com/fsnotify/fsnotify v1.4.9
 	github.com/gin-gonic/gin v1.8.1
diff --git a/go.sum b/go.sum
index 97e4a9c1..72d7426f 100644
--- a/go.sum
+++ b/go.sum
@@ -4,8 +4,8 @@ github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d h1:UQZhZ2O0vMHr2c
 github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d/go.mod h1:rBZYJk541a8SKzHPHnH3zbiI+7dagKZ0cgpgrD7Fyho=
 github.com/aler9/go-mp4 v0.0.0-20221229200349-f3d01e787968 h1:wU8pLx4dc8bLB+JuVPWuGp+BoMkOabj98a0RmO3gqvw=
 github.com/aler9/go-mp4 v0.0.0-20221229200349-f3d01e787968/go.mod h1:vPl9t5ZK7K0x68jh12/+ECWBCXoWuIDtNgPtU2f04ws=
-github.com/aler9/gortsplib/v2 v2.0.0-20230103153002-0ce435414414 h1:pVyJ7Uuk5kdU/RhCepxJQJEC9hsrFgxIIw1mIHn02Zs=
-github.com/aler9/gortsplib/v2 v2.0.0-20230103153002-0ce435414414/go.mod h1:lMdAxc6daduSzVwh75yQkvH9UHCYHpng/vJ8uXKFzdA=
+github.com/aler9/gortsplib/v2 v2.0.0-20230106140016-a759ba9d014b h1:6Yg4zJ6XowH8dJpSYfyBnp1VR4wOFvCiNdkSdhK+OWQ=
+github.com/aler9/gortsplib/v2 v2.0.0-20230106140016-a759ba9d014b/go.mod h1:lMdAxc6daduSzVwh75yQkvH9UHCYHpng/vJ8uXKFzdA=
 github.com/aler9/writerseeker v0.0.0-20220601075008-6f0e685b9c82 h1:9WgSzBLo3a9ToSVV7sRTBYZ1GGOZUpq4+5H3SN0UZq4=
 github.com/aler9/writerseeker v0.0.0-20220601075008-6f0e685b9c82/go.mod h1:qsMrZCbeBf/mCLOeF16KDkPu4gktn/pOWyaq1aYQE7U=
 github.com/asticode/go-astikit v0.20.0 h1:+7N+J4E4lWx2QOkRdOf6DafWJMv6O4RRfgClwQokrH8=
diff --git a/internal/core/hls_source.go b/internal/core/hls_source.go
index 96319b16..95fab82d 100644
--- a/internal/core/hls_source.go
+++ b/internal/core/hls_source.go
@@ -43,8 +43,6 @@ func (s *hlsSource) Log(level logger.Level, format string, args ...interface{})
 // run implements sourceStaticImpl.
 func (s *hlsSource) run(ctx context.Context) error {
 	var stream *stream
-	var videoMedia *media.Media
-	var audioMedia *media.Media
 
 	defer func() {
 		if stream != nil {
@@ -52,23 +50,51 @@ func (s *hlsSource) run(ctx context.Context) error {
 		}
 	}()
 
-	onTracks := func(videoFormat *format.H264, audioFormat *format.MPEG4Audio) error {
+	c, err := hls.NewClient(
+		s.ur,
+		s.fingerprint,
+		s,
+	)
+	if err != nil {
+		return err
+	}
+
+	c.OnTracks(func(tracks []format.Format) error {
 		var medias media.Medias
 
-		if videoFormat != nil {
-			videoMedia = &media.Media{
+		for _, track := range tracks {
+			medi := &media.Media{
 				Type:    media.TypeVideo,
-				Formats: []format.Format{videoFormat},
+				Formats: []format.Format{track},
 			}
-			medias = append(medias, videoMedia)
-		}
+			medias = append(medias, medi)
+			ctrack := track
 
-		if audioFormat != nil {
-			audioMedia = &media.Media{
-				Type:    media.TypeAudio,
-				Formats: []format.Format{audioFormat},
+			switch track.(type) {
+			case *format.H264:
+				c.OnData(track, func(pts time.Duration, dat interface{}) {
+					err := stream.writeData(medi, ctrack, &formatprocessor.DataH264{
+						PTS: pts,
+						AU:  dat.([][]byte),
+						NTP: time.Now(),
+					})
+					if err != nil {
+						s.Log(logger.Warn, "%v", err)
+					}
+				})
+
+			case *format.MPEG4Audio:
+				c.OnData(track, func(pts time.Duration, dat interface{}) {
+					err := stream.writeData(medi, ctrack, &formatprocessor.DataMPEG4Audio{
+						PTS: pts,
+						AUs: [][]byte{dat.([]byte)},
+						NTP: time.Now(),
+					})
+					if err != nil {
+						s.Log(logger.Warn, "%v", err)
+					}
+				})
 			}
-			medias = append(medias, audioMedia)
 		}
 
 		res := s.parent.sourceStaticImplSetReady(pathSourceStaticSetReadyReq{
@@ -83,41 +109,9 @@ func (s *hlsSource) run(ctx context.Context) error {
 		stream = res.stream
 
 		return nil
-	}
+	})
 
-	onVideoData := func(pts time.Duration, au [][]byte) {
-		err := stream.writeData(videoMedia, videoMedia.Formats[0], &formatprocessor.DataH264{
-			PTS: pts,
-			AU:  au,
-			NTP: time.Now(),
-		})
-		if err != nil {
-			s.Log(logger.Warn, "%v", err)
-		}
-	}
-
-	onAudioData := func(pts time.Duration, au []byte) {
-		err := stream.writeData(audioMedia, audioMedia.Formats[0], &formatprocessor.DataMPEG4Audio{
-			PTS: pts,
-			AUs: [][]byte{au},
-			NTP: time.Now(),
-		})
-		if err != nil {
-			s.Log(logger.Warn, "%v", err)
-		}
-	}
-
-	c, err := hls.NewClient(
-		s.ur,
-		s.fingerprint,
-		onTracks,
-		onVideoData,
-		onAudioData,
-		s,
-	)
-	if err != nil {
-		return err
-	}
+	c.Start()
 
 	select {
 	case err := <-c.Wait():
diff --git a/internal/hls/client.go b/internal/hls/client.go
index 11a015a8..b30baccd 100644
--- a/internal/hls/client.go
+++ b/internal/hls/client.go
@@ -35,13 +35,12 @@ type ClientLogger interface {
 // Client is a HLS client.
 type Client struct {
 	fingerprint string
-	onTracks    func(*format.H264, *format.MPEG4Audio) error
-	onVideoData func(time.Duration, [][]byte)
-	onAudioData func(time.Duration, []byte)
 	logger      ClientLogger
 
 	ctx         context.Context
 	ctxCancel   func()
+	onTracks    func([]format.Format) error
+	onData      map[format.Format]func(time.Duration, interface{})
 	playlistURL *url.URL
 
 	// out
@@ -52,9 +51,6 @@ type Client struct {
 func NewClient(
 	playlistURLStr string,
 	fingerprint string,
-	onTracks func(*format.H264, *format.MPEG4Audio) error,
-	onVideoData func(time.Duration, [][]byte),
-	onAudioData func(time.Duration, []byte),
 	logger ClientLogger,
 ) (*Client, error) {
 	playlistURL, err := url.Parse(playlistURLStr)
@@ -66,21 +62,22 @@ func NewClient(
 
 	c := &Client{
 		fingerprint: fingerprint,
-		onTracks:    onTracks,
-		onVideoData: onVideoData,
-		onAudioData: onAudioData,
 		logger:      logger,
 		ctx:         ctx,
 		ctxCancel:   ctxCancel,
 		playlistURL: playlistURL,
+		onData:      make(map[format.Format]func(time.Duration, interface{})),
 		outErr:      make(chan error, 1),
 	}
 
-	go c.run()
-
 	return c, nil
 }
 
+// Start starts the client.
+func (c *Client) Start() {
+	go c.run()
+}
+
 // Close closes all the Client resources.
 func (c *Client) Close() {
 	c.ctxCancel()
@@ -91,6 +88,16 @@ func (c *Client) Wait() chan error {
 	return c.outErr
 }
 
+// OnTracks sets a callback that is called when tracks are read.
+func (c *Client) OnTracks(cb func([]format.Format) error) {
+	c.onTracks = cb
+}
+
+// OnData sets a callback that is called when data arrives.
+func (c *Client) OnData(forma format.Format, cb func(time.Duration, interface{})) {
+	c.onData[forma] = cb
+}
+
 func (c *Client) run() {
 	c.outErr <- c.runInner()
 }
@@ -104,8 +111,7 @@ func (c *Client) runInner() error {
 		c.logger,
 		rp,
 		c.onTracks,
-		c.onVideoData,
-		c.onAudioData,
+		c.onData,
 	)
 	rp.add(dl)
 
diff --git a/internal/hls/client_downloader_primary.go b/internal/hls/client_downloader_primary.go
index e930ac72..0851e90e 100644
--- a/internal/hls/client_downloader_primary.go
+++ b/internal/hls/client_downloader_primary.go
@@ -96,16 +96,15 @@ type clientTimeSync interface{}
 type clientDownloaderPrimary struct {
 	primaryPlaylistURL *url.URL
 	logger             ClientLogger
-	onTracks           func(*format.H264, *format.MPEG4Audio) error
-	onVideoData        func(time.Duration, [][]byte)
-	onAudioData        func(time.Duration, []byte)
+	onTracks           func([]format.Format) error
+	onData             map[format.Format]func(time.Duration, interface{})
 	rp                 *clientRoutinePool
 
 	httpClient      *http.Client
 	leadingTimeSync clientTimeSync
 
 	// in
-	streamFormats chan []format.Format
+	streamTracks chan []format.Format
 
 	// out
 	startStreaming       chan struct{}
@@ -117,9 +116,8 @@ func newClientDownloaderPrimary(
 	fingerprint string,
 	logger ClientLogger,
 	rp *clientRoutinePool,
-	onTracks func(*format.H264, *format.MPEG4Audio) error,
-	onVideoData func(time.Duration, [][]byte),
-	onAudioData func(time.Duration, []byte),
+	onTracks func([]format.Format) error,
+	onData map[format.Format]func(time.Duration, interface{}),
 ) *clientDownloaderPrimary {
 	var tlsConfig *tls.Config
 	if fingerprint != "" {
@@ -145,15 +143,14 @@ func newClientDownloaderPrimary(
 		primaryPlaylistURL: primaryPlaylistURL,
 		logger:             logger,
 		onTracks:           onTracks,
-		onVideoData:        onVideoData,
-		onAudioData:        onAudioData,
+		onData:             onData,
 		rp:                 rp,
 		httpClient: &http.Client{
 			Transport: &http.Transport{
 				TLSClientConfig: tlsConfig,
 			},
 		},
-		streamFormats:        make(chan []format.Format),
+		streamTracks:         make(chan []format.Format),
 		startStreaming:       make(chan struct{}),
 		leadingTimeSyncReady: make(chan struct{}),
 	}
@@ -179,11 +176,11 @@ func (d *clientDownloaderPrimary) run(ctx context.Context) error {
 			plt,
 			d.logger,
 			d.rp,
-			d.onStreamFormats,
+			d.onStreamTracks,
 			d.onSetLeadingTimeSync,
 			d.onGetLeadingTimeSync,
-			d.onVideoData,
-			d.onAudioData)
+			d.onData,
+		)
 		d.rp.add(ds)
 		streamCount++
 
@@ -205,11 +202,11 @@ func (d *clientDownloaderPrimary) run(ctx context.Context) error {
 			nil,
 			d.logger,
 			d.rp,
-			d.onStreamFormats,
+			d.onStreamTracks,
 			d.onSetLeadingTimeSync,
 			d.onGetLeadingTimeSync,
-			d.onVideoData,
-			d.onAudioData)
+			d.onData,
+		)
 		d.rp.add(ds)
 		streamCount++
 
@@ -231,11 +228,11 @@ func (d *clientDownloaderPrimary) run(ctx context.Context) error {
 				nil,
 				d.logger,
 				d.rp,
-				d.onStreamFormats,
+				d.onStreamTracks,
 				d.onSetLeadingTimeSync,
 				d.onGetLeadingTimeSync,
-				d.onVideoData,
-				d.onAudioData)
+				d.onData,
+			)
 			d.rp.add(ds)
 			streamCount++
 		}
@@ -248,31 +245,18 @@ func (d *clientDownloaderPrimary) run(ctx context.Context) error {
 
 	for i := 0; i < streamCount; i++ {
 		select {
-		case streamFormats := <-d.streamFormats:
-			tracks = append(tracks, streamFormats...)
+		case streamTracks := <-d.streamTracks:
+			tracks = append(tracks, streamTracks...)
 		case <-ctx.Done():
 			return fmt.Errorf("terminated")
 		}
 	}
 
-	var videoTrack *format.H264
-	var audioTrack *format.MPEG4Audio
-
-	for _, track := range tracks {
-		switch ttrack := track.(type) {
-		case *format.H264:
-			videoTrack = ttrack
-
-		case *format.MPEG4Audio:
-			audioTrack = ttrack
-		}
-	}
-
-	if videoTrack == nil && audioTrack == nil {
+	if len(tracks) == 0 {
 		return fmt.Errorf("no supported tracks found")
 	}
 
-	err = d.onTracks(videoTrack, audioTrack)
+	err = d.onTracks(tracks)
 	if err != nil {
 		return err
 	}
@@ -282,9 +266,9 @@ func (d *clientDownloaderPrimary) run(ctx context.Context) error {
 	return nil
 }
 
-func (d *clientDownloaderPrimary) onStreamFormats(ctx context.Context, tracks []format.Format) bool {
+func (d *clientDownloaderPrimary) onStreamTracks(ctx context.Context, tracks []format.Format) bool {
 	select {
-	case d.streamFormats <- tracks:
+	case d.streamTracks <- tracks:
 	case <-ctx.Done():
 		return false
 	}
diff --git a/internal/hls/client_downloader_stream.go b/internal/hls/client_downloader_stream.go
index bc3e398a..9b91797c 100644
--- a/internal/hls/client_downloader_stream.go
+++ b/internal/hls/client_downloader_stream.go
@@ -50,11 +50,10 @@ type clientDownloaderStream struct {
 	initialPlaylist      *m3u8.MediaPlaylist
 	logger               ClientLogger
 	rp                   *clientRoutinePool
-	onStreamFormats      func(context.Context, []format.Format) bool
+	onStreamTracks       func(context.Context, []format.Format) bool
 	onSetLeadingTimeSync func(clientTimeSync)
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool)
-	onVideoData          func(time.Duration, [][]byte)
-	onAudioData          func(time.Duration, []byte)
+	onData               map[format.Format]func(time.Duration, interface{})
 
 	curSegmentID *uint64
 }
@@ -66,11 +65,10 @@ func newClientDownloaderStream(
 	initialPlaylist *m3u8.MediaPlaylist,
 	logger ClientLogger,
 	rp *clientRoutinePool,
-	onStreamFormats func(context.Context, []format.Format) bool,
+	onStreamTracks func(context.Context, []format.Format) bool,
 	onSetLeadingTimeSync func(clientTimeSync),
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool),
-	onVideoData func(time.Duration, [][]byte),
-	onAudioData func(time.Duration, []byte),
+	onData map[format.Format]func(time.Duration, interface{}),
 ) *clientDownloaderStream {
 	return &clientDownloaderStream{
 		isLeading:            isLeading,
@@ -79,11 +77,10 @@ func newClientDownloaderStream(
 		initialPlaylist:      initialPlaylist,
 		logger:               logger,
 		rp:                   rp,
-		onStreamFormats:      onStreamFormats,
+		onStreamTracks:       onStreamTracks,
 		onSetLeadingTimeSync: onSetLeadingTimeSync,
 		onGetLeadingTimeSync: onGetLeadingTimeSync,
-		onVideoData:          onVideoData,
-		onAudioData:          onAudioData,
+		onData:               onData,
 	}
 }
 
@@ -113,11 +110,10 @@ func (d *clientDownloaderStream) run(ctx context.Context) error {
 			segmentQueue,
 			d.logger,
 			d.rp,
-			d.onStreamFormats,
+			d.onStreamTracks,
 			d.onSetLeadingTimeSync,
 			d.onGetLeadingTimeSync,
-			d.onVideoData,
-			d.onAudioData,
+			d.onData,
 		)
 		if err != nil {
 			return err
@@ -130,11 +126,10 @@ func (d *clientDownloaderStream) run(ctx context.Context) error {
 			segmentQueue,
 			d.logger,
 			d.rp,
-			d.onStreamFormats,
+			d.onStreamTracks,
 			d.onSetLeadingTimeSync,
 			d.onGetLeadingTimeSync,
-			d.onVideoData,
-			d.onAudioData,
+			d.onData,
 		)
 		d.rp.add(proc)
 	}
diff --git a/internal/hls/client_processor_fmp4.go b/internal/hls/client_processor_fmp4.go
index 37dda07c..7060a413 100644
--- a/internal/hls/client_processor_fmp4.go
+++ b/internal/hls/client_processor_fmp4.go
@@ -14,7 +14,8 @@ import (
 func fmp4PickLeadingTrack(init *fmp4.Init) int {
 	// pick first video track
 	for _, track := range init.Tracks {
-		if _, ok := track.Format.(*format.H264); ok {
+		switch track.Format.(type) {
+		case *format.H264, *format.H265:
 			return track.ID
 		}
 	}
@@ -30,8 +31,7 @@ type clientProcessorFMP4 struct {
 	rp                   *clientRoutinePool
 	onSetLeadingTimeSync func(clientTimeSync)
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool)
-	onVideoData          func(time.Duration, [][]byte)
-	onAudioData          func(time.Duration, []byte)
+	onData               map[format.Format]func(time.Duration, interface{})
 
 	init           fmp4.Init
 	leadingTrackID int
@@ -51,8 +51,7 @@ func newClientProcessorFMP4(
 	onStreamFormats func(context.Context, []format.Format) bool,
 	onSetLeadingTimeSync func(clientTimeSync),
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool),
-	onVideoData func(time.Duration, [][]byte),
-	onAudioData func(time.Duration, []byte),
+	onData map[format.Format]func(time.Duration, interface{}),
 ) (*clientProcessorFMP4, error) {
 	p := &clientProcessorFMP4{
 		isLeading:            isLeading,
@@ -61,8 +60,7 @@ func newClientProcessorFMP4(
 		rp:                   rp,
 		onSetLeadingTimeSync: onSetLeadingTimeSync,
 		onGetLeadingTimeSync: onGetLeadingTimeSync,
-		onVideoData:          onVideoData,
-		onAudioData:          onAudioData,
+		onData:               onData,
 		subpartProcessed:     make(chan struct{}, clientFMP4MaxPartTracksPerSegment),
 	}
 
@@ -186,21 +184,27 @@ func (p *clientProcessorFMP4) initializeTrackProcs(ts *clientTimeSyncFMP4) {
 	for _, track := range p.init.Tracks {
 		var cb func(time.Duration, []byte) error
 
+		cb2, ok := p.onData[track.Format]
+		if !ok {
+			cb2 = func(time.Duration, interface{}) {
+			}
+		}
+
 		switch track.Format.(type) {
-		case *format.H264:
+		case *format.H264, *format.H265:
 			cb = func(pts time.Duration, payload []byte) error {
 				nalus, err := h264.AVCCUnmarshal(payload)
 				if err != nil {
 					return err
 				}
 
-				p.onVideoData(pts, nalus)
+				cb2(pts, nalus)
 				return nil
 			}
 
-		case *format.MPEG4Audio:
+		case *format.MPEG4Audio, *format.Opus:
 			cb = func(pts time.Duration, payload []byte) error {
-				p.onAudioData(pts, payload)
+				cb2(pts, payload)
 				return nil
 			}
 		}
diff --git a/internal/hls/client_processor_mpegts.go b/internal/hls/client_processor_mpegts.go
index 26f41e62..62451221 100644
--- a/internal/hls/client_processor_mpegts.go
+++ b/internal/hls/client_processor_mpegts.go
@@ -36,8 +36,7 @@ type clientProcessorMPEGTS struct {
 	onStreamFormats      func(context.Context, []format.Format) bool
 	onSetLeadingTimeSync func(clientTimeSync)
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool)
-	onVideoData          func(time.Duration, [][]byte)
-	onAudioData          func(time.Duration, []byte)
+	onData               map[format.Format]func(time.Duration, interface{})
 
 	mpegtsTracks    []*mpegts.Track
 	leadingTrackPID uint16
@@ -52,8 +51,7 @@ func newClientProcessorMPEGTS(
 	onStreamFormats func(context.Context, []format.Format) bool,
 	onSetLeadingTimeSync func(clientTimeSync),
 	onGetLeadingTimeSync func(context.Context) (clientTimeSync, bool),
-	onVideoData func(time.Duration, [][]byte),
-	onAudioData func(time.Duration, []byte),
+	onData map[format.Format]func(time.Duration, interface{}),
 ) *clientProcessorMPEGTS {
 	return &clientProcessorMPEGTS{
 		isLeading:            isLeading,
@@ -63,8 +61,7 @@ func newClientProcessorMPEGTS(
 		onStreamFormats:      onStreamFormats,
 		onSetLeadingTimeSync: onSetLeadingTimeSync,
 		onGetLeadingTimeSync: onGetLeadingTimeSync,
-		onVideoData:          onVideoData,
-		onAudioData:          onAudioData,
+		onData:               onData,
 	}
 }
 
@@ -174,10 +171,16 @@ func (p *clientProcessorMPEGTS) processSegment(ctx context.Context, byts []byte)
 func (p *clientProcessorMPEGTS) initializeTrackProcs(ts *clientTimeSyncMPEGTS) {
 	p.trackProcs = make(map[uint16]*clientProcessorMPEGTSTrack)
 
-	for _, mt := range p.mpegtsTracks {
+	for _, track := range p.mpegtsTracks {
 		var cb func(time.Duration, []byte) error
 
-		switch mt.Format.(type) {
+		cb2, ok := p.onData[track.Format]
+		if !ok {
+			cb2 = func(time.Duration, interface{}) {
+			}
+		}
+
+		switch track.Format.(type) {
 		case *format.H264:
 			cb = func(pts time.Duration, payload []byte) error {
 				nalus, err := h264.AnnexBUnmarshal(payload)
@@ -186,7 +189,7 @@ func (p *clientProcessorMPEGTS) initializeTrackProcs(ts *clientTimeSyncMPEGTS) {
 					return nil
 				}
 
-				p.onVideoData(pts, nalus)
+				cb2(pts, nalus)
 				return nil
 			}
 
@@ -199,7 +202,7 @@ func (p *clientProcessorMPEGTS) initializeTrackProcs(ts *clientTimeSyncMPEGTS) {
 				}
 
 				for i, pkt := range adtsPkts {
-					p.onAudioData(
+					cb2(
 						pts+time.Duration(i)*mpeg4audio.SamplesPerAccessUnit*time.Second/time.Duration(pkt.SampleRate),
 						pkt.AU)
 				}
@@ -213,6 +216,6 @@ func (p *clientProcessorMPEGTS) initializeTrackProcs(ts *clientTimeSyncMPEGTS) {
 			cb,
 		)
 		p.rp.add(proc)
-		p.trackProcs[mt.ES.ElementaryPID] = proc
+		p.trackProcs[track.ES.ElementaryPID] = proc
 	}
 }
diff --git a/internal/hls/client_test.go b/internal/hls/client_test.go
index b630fcc5..c2a2f06a 100644
--- a/internal/hls/client_test.go
+++ b/internal/hls/client_test.go
@@ -277,29 +277,32 @@ func TestClientMPEGTS(t *testing.T) {
 			c, err := NewClient(
 				prefix+"://localhost:5780/stream.m3u8",
 				"33949E05FFFB5FF3E8AA16F8213A6251B4D9363804BA53233C4DA9A46D6F2739",
-				func(videoTrack *format.H264, audioTrack *format.MPEG4Audio) error {
-					require.Equal(t, &format.H264{
-						PayloadTyp:        96,
-						PacketizationMode: 1,
-					}, videoTrack)
-					require.Equal(t, (*format.MPEG4Audio)(nil), audioTrack)
-					return nil
-				},
-				func(pts time.Duration, nalus [][]byte) {
-					require.Equal(t, 2*time.Second, pts)
-					require.Equal(t, [][]byte{
-						{7, 1, 2, 3},
-						{8},
-						{5},
-					}, nalus)
-					close(packetRecv)
-				},
-				func(pts time.Duration, au []byte) {
-				},
 				testLogger{},
 			)
 			require.NoError(t, err)
 
+			onH264 := func(pts time.Duration, dat interface{}) {
+				require.Equal(t, 2*time.Second, pts)
+				require.Equal(t, [][]byte{
+					{7, 1, 2, 3},
+					{8},
+					{5},
+				}, dat)
+				close(packetRecv)
+			}
+
+			c.OnTracks(func(tracks []format.Format) error {
+				require.Equal(t, 1, len(tracks))
+				require.Equal(t, &format.H264{
+					PayloadTyp:        96,
+					PacketizationMode: 1,
+				}, tracks[0])
+				c.OnData(tracks[0], onH264)
+				return nil
+			})
+
+			c.Start()
+
 			<-packetRecv
 
 			c.Close()
@@ -341,34 +344,33 @@ func TestClientFMP4(t *testing.T) {
 
 	packetRecv := make(chan struct{})
 
+	onH264 := func(pts time.Duration, dat interface{}) {
+		require.Equal(t, 2*time.Second, pts)
+		require.Equal(t, [][]byte{
+			{7, 1, 2, 3},
+			{8},
+			{5},
+		}, dat)
+		close(packetRecv)
+	}
+
 	c, err := NewClient(
 		"http://localhost:5780/stream.m3u8",
 		"",
-		func(videoTrack *format.H264, audioTrack *format.MPEG4Audio) error {
-			require.Equal(t, &format.H264{
-				PayloadTyp:        96,
-				PacketizationMode: 1,
-				SPS:               videoTrack.SPS,
-				PPS:               videoTrack.PPS,
-			}, videoTrack)
-			require.Equal(t, (*format.MPEG4Audio)(nil), audioTrack)
-			return nil
-		},
-		func(pts time.Duration, nalus [][]byte) {
-			require.Equal(t, 2*time.Second, pts)
-			require.Equal(t, [][]byte{
-				{7, 1, 2, 3},
-				{8},
-				{5},
-			}, nalus)
-			close(packetRecv)
-		},
-		func(pts time.Duration, au []byte) {
-		},
 		testLogger{},
 	)
 	require.NoError(t, err)
 
+	c.OnTracks(func(tracks []format.Format) error {
+		require.Equal(t, 1, len(tracks))
+		_, ok := tracks[0].(*format.H264)
+		require.Equal(t, true, ok)
+		c.OnData(tracks[0], onH264)
+		return nil
+	})
+
+	c.Start()
+
 	<-packetRecv
 
 	c.Close()
@@ -425,23 +427,26 @@ func TestClientInvalidSequenceID(t *testing.T) {
 
 	packetRecv := make(chan struct{})
 
+	onH264 := func(pts time.Duration, dat interface{}) {
+		close(packetRecv)
+	}
+
 	c, err := NewClient(
 		"http://localhost:5780/stream.m3u8",
 		"",
-		func(*format.H264, *format.MPEG4Audio) error {
-			return nil
-		},
-		func(pts time.Duration, nalus [][]byte) {
-			close(packetRecv)
-		},
-		nil,
 		testLogger{},
 	)
 	require.NoError(t, err)
 
+	c.OnTracks(func(tracks []format.Format) error {
+		c.OnData(tracks[0], onH264)
+		return nil
+	})
+
+	c.Start()
+
 	<-packetRecv
 
-	// c.Close()
 	err = <-c.Wait()
 	require.EqualError(t, err, "following segment not found or not ready yet")