install go2rtc on bob

installs_on_host/go2rtc/pkg/webrtc/track.go

@@ -0,0 +1,83 @@
+package webrtc
+
+import (
+	"sync"
+
+	"github.com/pion/rtp"
+	"github.com/pion/webrtc/v4"
+)
+
+type Track struct {
+	kind     string
+	id       string
+	streamID string
+	sequence uint16
+	ssrc     uint32
+	writer   webrtc.TrackLocalWriter
+	mu       sync.Mutex
+}
+
+func NewTrack(kind string) *Track {
+	return &Track{
+		kind:     kind,
+		id:       "go2rtc-" + kind,
+		streamID: "go2rtc",
+	}
+}
+
+func (t *Track) Bind(context webrtc.TrackLocalContext) (webrtc.RTPCodecParameters, error) {
+	t.mu.Lock()
+	t.ssrc = uint32(context.SSRC())
+	t.writer = context.WriteStream()
+	t.mu.Unlock()
+
+	for _, parameters := range context.CodecParameters() {
+		// return first parameters
+		return parameters, nil
+	}
+
+	return webrtc.RTPCodecParameters{}, nil
+}
+
+func (t *Track) Unbind(context webrtc.TrackLocalContext) error {
+	t.mu.Lock()
+	t.writer = nil
+	t.mu.Unlock()
+	return nil
+}
+
+func (t *Track) ID() string {
+	return t.id
+}
+
+func (t *Track) RID() string {
+	return "" // don't know what it is
+}
+
+func (t *Track) StreamID() string {
+	return t.streamID
+}
+
+func (t *Track) Kind() webrtc.RTPCodecType {
+	return webrtc.NewRTPCodecType(t.kind)
+}
+
+func (t *Track) WriteRTP(payloadType uint8, packet *rtp.Packet) (err error) {
+	// using mutex because Unbind https://github.com/AlexxIT/go2rtc/issues/994
+	t.mu.Lock()
+
+	// in case when we start WriteRTP before Track.Bind
+	if t.writer != nil {
+		// important to have internal counter if input packets from different sources
+		t.sequence++
+
+		header := packet.Header
+		header.SSRC = t.ssrc
+		header.PayloadType = payloadType
+		header.SequenceNumber = t.sequence
+		_, err = t.writer.WriteRTP(&header, packet.Payload)
+	}
+
+	t.mu.Unlock()
+	return
+}