install go2rtc on bob

installs_on_host/go2rtc/pkg/xiaomi/miss/backchannel.go

@@ -0,0 +1,74 @@
+package miss
+
+import (
+	"time"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/AlexxIT/go2rtc/pkg/opus"
+	"github.com/AlexxIT/go2rtc/pkg/pcm"
+	"github.com/pion/rtp"
+)
+
+func (p *Producer) AddTrack(media *core.Media, _ *core.Codec, track *core.Receiver) error {
+	if err := p.client.StartSpeaker(); err != nil {
+		return err
+	}
+	// TODO: check this!!!
+	time.Sleep(time.Second)
+
+	sender := core.NewSender(media, track.Codec)
+
+	switch track.Codec.Name {
+	case core.CodecPCMA:
+		var buf []byte
+
+		if p.client.SpeakerCodec() == codecPCM {
+			dst := &core.Codec{Name: core.CodecPCML, ClockRate: 8000}
+			transcode := pcm.Transcode(dst, track.Codec)
+
+			sender.Handler = func(pkt *rtp.Packet) {
+				buf = append(buf, transcode(pkt.Payload)...)
+				const size = 2 * 8000 * 0.040 // 16bit 40ms
+				for len(buf) >= size {
+					p.Send += size
+					_ = p.client.WriteAudio(codecPCM, buf[:size])
+					buf = buf[size:]
+				}
+			}
+		} else {
+			sender.Handler = func(pkt *rtp.Packet) {
+				buf = append(buf, pkt.Payload...)
+				const size = 8000 * 0.040 // 8bit 40 ms
+				for len(buf) >= size {
+					p.Send += size
+					_ = p.client.WriteAudio(codecPCMA, buf[:size])
+					buf = buf[size:]
+				}
+			}
+		}
+	case core.CodecOpus:
+		if p.client.SpeakerCodec() == codecOPUS {
+			var buf []byte
+			sender.Handler = func(pkt *rtp.Packet) {
+				if buf == nil {
+					buf = pkt.Payload
+				} else {
+					// convert two 20ms to one 40ms
+					buf = opus.JoinFrames(buf, pkt.Payload)
+					p.Send += len(buf)
+					_ = p.client.WriteAudio(codecOPUS, buf)
+					buf = nil
+				}
+			}
+		} else {
+			sender.Handler = func(pkt *rtp.Packet) {
+				p.Send += len(pkt.Payload)
+				_ = p.client.WriteAudio(codecOPUS, pkt.Payload)
+			}
+		}
+	}
+
+	sender.HandleRTP(track)
+	p.Senders = append(p.Senders, sender)
+	return nil
+}