feat(homekit): add Speaker service and enhance Consumer with backtrack audio handling

pkg/hap/camera/accessory.go

@@ -13,6 +13,7 @@ func NewAccessory(manuf, model, name, serial, firmware string) *hap.Accessory {
 			ServiceCameraRTPStreamManagement(),
 			//hap.ServiceHAPProtocolInformation(),
 			ServiceMicrophone(),
+			ServiceSpeaker(),
 		},
 	}
 	acc.InitIID()
@@ -32,6 +33,7 @@ func NewHKSVAccessory(manuf, model, name, serial, firmware string) *hap.Accessor
 			hap.ServiceAccessoryInformation(manuf, model, name, serial, firmware),
 			rtpStream,
 			ServiceMicrophone(),
+			ServiceSpeaker(),
 			motionSensor,
 			operatingMode,
 			recordingMgmt,
@@ -60,6 +62,7 @@ func NewHKSVDoorbellAccessory(manuf, model, name, serial, firmware string) *hap.
 			hap.ServiceAccessoryInformation(manuf, model, name, serial, firmware),
 			rtpStream,
 			ServiceMicrophone(),
+			ServiceSpeaker(),
 			motionSensor,
 			operatingMode,
 			recordingMgmt,
@@ -75,6 +78,20 @@ func NewHKSVDoorbellAccessory(manuf, model, name, serial, firmware string) *hap.
 	return acc
 }
 
+func ServiceSpeaker() *hap.Service {
+	return &hap.Service{
+		Type: "113", // 'Speaker'
+		Characters: []*hap.Character{
+			{
+				Type:   "11A",
+				Format: hap.FormatBool,
+				Value:  0,
+				Perms:  hap.EVPRPW,
+			},
+		},
+	}
+}
+
 func ServiceMicrophone() *hap.Service {
 	return &hap.Service{
 		Type: "112", // 'Microphone'

pkg/homekit/consumer.go

@@ -26,6 +26,8 @@ type Consumer struct {
 	videoSession *srtp.Session
 	audioSession *srtp.Session
 	audioRTPTime byte
+
+	backTrack *core.Receiver // backchannel audio (HomeKit viewer → camera)
 }
 
 func NewConsumer(conn net.Conn, server *srtp.Server) *Consumer {
@@ -44,6 +46,13 @@ func NewConsumer(conn net.Conn, server *srtp.Server) *Consumer {
 				{Name: core.CodecOpus},
 			},
 		},
+		{
+			Kind:      core.KindAudio,
+			Direction: core.DirectionRecvonly,
+			Codecs: []*core.Codec{
+				{Name: core.CodecOpus},
+			},
+		},
 	}
 	return &Consumer{
 		Connection: core.Connection{
@@ -130,6 +139,26 @@ func (c *Consumer) SetConfig(conf *camera.SelectedStreamConfiguration) bool {
 	return true
 }
 
+func (c *Consumer) GetTrack(media *core.Media, codec *core.Codec) (*core.Receiver, error) {
+	if codec.Kind() != core.KindAudio {
+		return nil, core.ErrCantGetTrack
+	}
+
+	c.backTrack = core.NewReceiver(media, codec)
+
+	c.audioSession.OnReadRTP = func(packet *rtp.Packet) {
+		c.backTrack.WriteRTP(packet)
+		c.Recv += len(packet.Payload)
+	}
+
+	c.Receivers = append(c.Receivers, c.backTrack)
+	return c.backTrack, nil
+}
+
+func (c *Consumer) Start() error {
+	return nil
+}
+
 func (c *Consumer) AddTrack(media *core.Media, codec *core.Codec, track *core.Receiver) error {
 	var session *srtp.Session
 	if codec.Kind() == core.KindVideo {