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//go:build !js
// +build !js
package main
import (
"errors"
"fmt"
"io"
"net"
"github.com/pion/webrtc/v3"
"github.com/pion/webrtc/v3/examples/internal/signal"
)
func main() {
peerConnection, err := webrtc.NewPeerConnection(webrtc.Configuration{
ICEServers: []webrtc.ICEServer{
{
URLs: []string{"stun:stun.l.google.com:19302"},
},
},
})
if err != nil {
panic(err)
}
// Open a UDP Listener for RTP Packets on port 5004
listener, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.ParseIP("127.0.0.1"), Port: 5004})
if err != nil {
panic(err)
}
defer func() {
if err = listener.Close(); err != nil {
panic(err)
}
}()
// Create a video track
videoTrack, err := webrtc.NewTrackLocalStaticRTP(webrtc.RTPCodecCapability{MimeType: webrtc.MimeTypeVP8}, "video", "pion")
if err != nil {
panic(err)
}
rtpSender, err := peerConnection.AddTrack(videoTrack)
if err != nil {
panic(err)
}
// Read incoming RTCP packets
// Before these packets are returned they are processed by interceptors. For things
// like NACK this needs to be called.
go func() {
rtcpBuf := make([]byte, 1500)
for {
if _, _, rtcpErr := rtpSender.Read(rtcpBuf); rtcpErr != nil {
return
}
}
}()
// Set the handler for ICE connection state
// This will notify you when the peer has connected/disconnected
peerConnection.OnICEConnectionStateChange(func(connectionState webrtc.ICEConnectionState) {
fmt.Printf("Connection State has changed %s \n", connectionState.String())
if connectionState == webrtc.ICEConnectionStateFailed {
if closeErr := peerConnection.Close(); closeErr != nil {
panic(closeErr)
}
}
})
// Wait for the offer to be pasted
offer := webrtc.SessionDescription{}
signal.Decode(signal.MustReadStdin(), &offer)
// Set the remote SessionDescription
if err = peerConnection.SetRemoteDescription(offer); err != nil {
panic(err)
}
// Create answer
answer, err := peerConnection.CreateAnswer(nil)
if err != nil {
panic(err)
}
// Create channel that is blocked until ICE Gathering is complete
gatherComplete := webrtc.GatheringCompletePromise(peerConnection)
// Sets the LocalDescription, and starts our UDP listeners
if err = peerConnection.SetLocalDescription(answer); err != nil {
panic(err)
}
// Block until ICE Gathering is complete, disabling trickle ICE
// we do this because we only can exchange one signaling message
// in a production application you should exchange ICE Candidates via OnICECandidate
<-gatherComplete
// Output the answer in base64 so we can paste it in browser
fmt.Println(signal.Encode(*peerConnection.LocalDescription()))
// Read RTP packets forever and send them to the WebRTC Client
inboundRTPPacket := make([]byte, 1600) // UDP MTU
for {
n, _, err := listener.ReadFrom(inboundRTPPacket)
if err != nil {
panic(fmt.Sprintf("error during read: %s", err))
}
if _, err = videoTrack.Write(inboundRTPPacket[:n]); err != nil {
if errors.Is(err, io.ErrClosedPipe) {
// The peerConnection has been closed.
return
}
panic(err)
}
}
}
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