Add client for SwitchBot Camera WebRTC (supports special SessionDescription).

internal/webrtc/client.go

@@ -41,9 +41,11 @@ func streamsHandler(rawURL string) (core.Producer, error) {
 				// https://aws.amazon.com/kinesis/video-streams/
 				// https://docs.aws.amazon.com/kinesisvideostreams-webrtc-dg/latest/devguide/what-is-kvswebrtc.html
 				// https://github.com/orgs/awslabs/repositories?q=kinesis+webrtc
-				return kinesisClient(rawURL, query, "webrtc/kinesis")
+				return kinesisClient(rawURL, query, "webrtc/kinesis", &kinesisClientOpts{})
 			} else if format == "openipc" {
 				return openIPCClient(rawURL, query)
+			} else if format == "switchbot" {
+				return switchbotClient(rawURL, query)
 			} else {
 				return go2rtcClient(rawURL)
 			}

internal/webrtc/kinesis.go

@@ -34,7 +34,12 @@ func (k kinesisResponse) String() string {
 	return fmt.Sprintf("type=%s, payload=%s", k.Type, k.Payload)
 }
 
-func kinesisClient(rawURL string, query url.Values, format string) (core.Producer, error) {
+type kinesisClientOpts struct {
+	SessionDescriptionModifier func(*pion.SessionDescription) ([]byte, error)
+	MediaModifier              func() ([]*core.Media, error)
+}
+
+func kinesisClient(rawURL string, query url.Values, format string, opts *kinesisClientOpts) (core.Producer, error) {
 	// 1. Connect to signalign server
 	conn, _, err := websocket.DefaultDialer.Dial(rawURL, nil)
 	if err != nil {
@@ -112,6 +117,12 @@ func kinesisClient(rawURL string, query url.Values, format string) (core.Produce
 		{Kind: core.KindVideo, Direction: core.DirectionRecvonly},
 		{Kind: core.KindAudio, Direction: core.DirectionRecvonly},
 	}
+	if opts.MediaModifier != nil {
+		medias, err = opts.MediaModifier()
+		if err != nil {
+			return nil, err
+		}
+	}
 
 	// 4. Create offer
 	offer, err := prod.CreateOffer(medias)
@@ -121,10 +132,15 @@ func kinesisClient(rawURL string, query url.Values, format string) (core.Produce
 
 	// 5. Send offer
 	req.Action = "SDP_OFFER"
-	req.Payload, _ = json.Marshal(pion.SessionDescription{
+	sessionDescription := pion.SessionDescription{
 		Type: pion.SDPTypeOffer,
 		SDP:  offer,
-	})
+	}
+	if opts.SessionDescriptionModifier != nil {
+		req.Payload, _ = opts.SessionDescriptionModifier(&sessionDescription)
+	} else {
+		req.Payload, _ = json.Marshal(sessionDescription)
+	}
 	if err = conn.WriteJSON(req); err != nil {
 		return nil, err
 	}
@@ -218,5 +234,5 @@ func wyzeClient(rawURL string) (core.Producer, error) {
 		"ice_servers": []string{string(kvs.Servers)},
 	}
 
-	return kinesisClient(kvs.URL, query, "webrtc/wyze")
+	return kinesisClient(kvs.URL, query, "webrtc/wyze", &kinesisClientOpts{})
 }

internal/webrtc/switchbot.go

@@ -0,0 +1,62 @@
+package webrtc
+
+import (
+	"encoding/json"
+	"net/url"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	pion "github.com/pion/webrtc/v3"
+)
+
+// SessionDescription is used to expose local and remote session descriptions.
+type SwitchBotSessionDescription struct {
+	Type       string              `json:"type"`
+	SDP        string              `json:"sdp"`
+	Resolution SwitchBotResolution `json:"resolution"`
+	PlayType   int                 `json:"play_type"`
+}
+
+func switchbotClient(rawURL string, query url.Values) (core.Producer, error) {
+	return kinesisClient(rawURL, query, "webrtc/switchbot", &kinesisClientOpts{
+		SessionDescriptionModifier: func(sd *pion.SessionDescription) ([]byte, error) {
+			resolution, ok := parseSwitchBotResolution(query.Get("resolution"))
+			if !ok {
+				resolution = SwitchBotResolutionSD
+			}
+			json, err := json.Marshal(SwitchBotSessionDescription{
+				Type:       sd.Type.String(),
+				SDP:        sd.SDP,
+				Resolution: resolution,
+				PlayType:   0,
+			})
+			return json, err
+		},
+		MediaModifier: func() ([]*core.Media, error) {
+			return []*core.Media{
+				{Kind: core.KindVideo, Direction: core.DirectionRecvonly},
+				//{Kind: core.KindAudio, Direction: core.DirectionRecvonly},
+				//{Kind: core.KindAudio, Direction: core.DirectionSendRecv},
+				//{Kind: "Data", Direction: core.DirectionSendRecv},
+			}, nil
+		},
+	})
+}
+
+type SwitchBotResolution int
+
+const (
+	SwitchBotResolutionHD SwitchBotResolution = 0
+	SwitchBotResolutionSD                     = 1
+)
+
+func parseSwitchBotResolution(str string) (SwitchBotResolution, bool) {
+	var (
+		resolutionMap = map[string]SwitchBotResolution{
+			"hd": SwitchBotResolutionHD,
+			"sd": SwitchBotResolutionSD,
+		}
+	)
+	c, ok := resolutionMap[strings.ToLower(str)]
+	return c, ok
+}