install go2rtc on bob

installs_on_host/go2rtc/pkg/doorbird/backchannel.go

@@ -0,0 +1,95 @@
+package doorbird
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"time"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/pion/rtp"
+)
+
+type Client struct {
+	core.Connection
+	conn net.Conn
+}
+
+func Dial(rawURL string) (*Client, error) {
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		return nil, err
+	}
+
+	user := u.User.Username()
+	pass, _ := u.User.Password()
+
+	if u.Port() == "" {
+		u.Host += ":80"
+	}
+
+	conn, err := net.DialTimeout("tcp", u.Host, core.ConnDialTimeout)
+	if err != nil {
+		return nil, err
+	}
+
+	s := fmt.Sprintf("POST /bha-api/audio-transmit.cgi?http-user=%s&http-password=%s HTTP/1.0\r\n", user, pass) +
+		"Content-Type: audio/basic\r\n" +
+		"Content-Length: 9999999\r\n" +
+		"Connection: Keep-Alive\r\n" +
+		"Cache-Control: no-cache\r\n" +
+		"\r\n"
+
+	_ = conn.SetWriteDeadline(time.Now().Add(core.ConnDeadline))
+	if _, err = conn.Write([]byte(s)); err != nil {
+		return nil, err
+	}
+
+	medias := []*core.Media{
+		{
+			Kind:      core.KindAudio,
+			Direction: core.DirectionSendonly,
+			Codecs: []*core.Codec{
+				{Name: core.CodecPCMU, ClockRate: 8000},
+			},
+		},
+	}
+
+	return &Client{
+		core.Connection{
+			ID:         core.NewID(),
+			FormatName: "doorbird",
+			Protocol:   "http",
+			URL:        rawURL,
+			Medias:     medias,
+			Transport:  conn,
+		},
+		conn,
+	}, nil
+}
+
+func (c *Client) GetTrack(media *core.Media, codec *core.Codec) (*core.Receiver, error) {
+	return nil, core.ErrCantGetTrack
+}
+
+func (c *Client) AddTrack(media *core.Media, codec *core.Codec, track *core.Receiver) error {
+	sender := core.NewSender(media, track.Codec)
+
+	sender.Handler = func(pkt *rtp.Packet) {
+		_ = c.conn.SetWriteDeadline(time.Now().Add(core.ConnDeadline))
+		if n, err := c.conn.Write(pkt.Payload); err == nil {
+			c.Send += n
+		}
+	}
+
+	sender.HandleRTP(track)
+	c.Senders = append(c.Senders, sender)
+	return nil
+}
+
+func (c *Client) Start() (err error) {
+	// just block until c.conn closed
+	b := make([]byte, 1)
+	_, err = c.conn.Read(b)
+	return
+}