Add support creality format for webrtc client #1600

Author: AlexxIT

internal/webrtc/client.go

@@ -54,6 +54,8 @@ func streamsHandler(rawURL string) (core.Producer, error) {
 			} else if format == "wyze" {
 				// https://github.com/mrlt8/docker-wyze-bridge
 				return wyzeClient(rawURL)
+			} else if format == "creality" {
+				return crealityClient(rawURL)
 			} else {
 				return whepClient(rawURL)
 			}

internal/webrtc/client_creality.go

@@ -0,0 +1,110 @@
+package webrtc
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/AlexxIT/go2rtc/pkg/webrtc"
+)
+
+// https://github.com/AlexxIT/go2rtc/issues/1600
+func crealityClient(url string) (core.Producer, error) {
+	pc, err := PeerConnection(true)
+	if err != nil {
+		return nil, err
+	}
+
+	prod := webrtc.NewConn(pc)
+	prod.FormatName = "webrtc/creality"
+	prod.Mode = core.ModeActiveProducer
+	prod.Protocol = "http"
+	prod.URL = url
+
+	medias := []*core.Media{
+		{Kind: core.KindVideo, Direction: core.DirectionRecvonly},
+		{Kind: core.KindAudio, Direction: core.DirectionRecvonly},
+	}
+
+	// TODO: return webrtc.SessionDescription
+	offer, err := prod.CreateCompleteOffer(medias)
+	if err != nil {
+		return nil, err
+	}
+
+	body, err := offerToB64(offer)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "plain/text")
+
+	// TODO: change http.DefaultClient settings
+	client := http.Client{Timeout: time.Second * 5000}
+	defer client.CloseIdleConnections()
+
+	res, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	answer, err := answerFromB64(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	if err = prod.SetAnswer(answer); err != nil {
+		return nil, err
+	}
+
+	return prod, nil
+}
+
+func offerToB64(sdp string) (io.Reader, error) {
+	// JS object
+	v := map[string]string{
+		"type": "offer",
+		"sdp":  sdp,
+	}
+
+	// bytes
+	b, err := json.Marshal(v)
+	if err != nil {
+		return nil, err
+	}
+
+	// base64, why? who knows...
+	s := base64.StdEncoding.EncodeToString(b)
+
+	return strings.NewReader(s), nil
+}
+
+func answerFromB64(r io.Reader) (string, error) {
+	// base64
+	b, err := io.ReadAll(r)
+	if err != nil {
+		return "", err
+	}
+
+	// bytes
+	if b, err = base64.StdEncoding.DecodeString(string(b)); err != nil {
+		return "", err
+	}
+
+	// JS object
+	var v map[string]string
+	if err = json.Unmarshal(b, &v); err != nil {
+		return "", err
+	}
+
+	// string "v=0..."
+	return v["sdp"], nil
+}