snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

examples/insertable-streams/main.go

@@ -0,0 +1,224 @@
+// SPDX-FileCopyrightText: 2026 The Pion community <https://pion.ly>
+// SPDX-License-Identifier: MIT
+
+//go:build !js
+
+// insertable-streams demonstrates how to use insertable streams with Pion
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/pion/webrtc/v4"
+	"github.com/pion/webrtc/v4/pkg/media"
+	"github.com/pion/webrtc/v4/pkg/media/ivfreader"
+)
+
+const cipherKey = 0xAA
+
+// nolint:gocognit, cyclop
+func main() {
+	peerConnection, err := webrtc.NewPeerConnection(webrtc.Configuration{
+		ICEServers: []webrtc.ICEServer{
+			{
+				URLs: []string{"stun:stun.l.google.com:19302"},
+			},
+		},
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer func() {
+		if cErr := peerConnection.Close(); cErr != nil {
+			fmt.Printf("cannot close peerConnection: %v\n", cErr)
+		}
+	}()
+
+	// Create a video track
+	videoTrack, err := webrtc.NewTrackLocalStaticSample(
+		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
+			}
+		}
+	}()
+
+	iceConnectedCtx, iceConnectedCtxCancel := context.WithCancel(context.Background())
+	go func() {
+		// Open a IVF file and start reading using our IVFReader
+		file, ivfErr := os.Open("output.ivf")
+		if ivfErr != nil {
+			panic(ivfErr)
+		}
+
+		ivf, header, ivfErr := ivfreader.NewWith(file)
+		if ivfErr != nil {
+			panic(ivfErr)
+		}
+
+		// Wait for connection established
+		<-iceConnectedCtx.Done()
+
+		// Send our video file frame at a time. Pace our sending so we send it at the same speed it should be played back as.
+		// This isn't required since the video is timestamped, but we will such much higher loss if we send all at once.
+		//
+		// It is important to use a time.Ticker instead of time.Sleep because
+		// * avoids accumulating skew, just calling time.Sleep didn't compensate for the time spent parsing the data
+		// * works around latency issues with Sleep (see https://github.com/golang/go/issues/44343)
+		ticker := time.NewTicker(
+			time.Millisecond * time.Duration((float32(header.TimebaseNumerator)/float32(header.TimebaseDenominator))*1000),
+		)
+		defer ticker.Stop()
+		for range ticker.C {
+			frame, _, ivfErr := ivf.ParseNextFrame()
+			if errors.Is(ivfErr, io.EOF) {
+				fmt.Printf("All frames parsed and sent")
+				os.Exit(0)
+			}
+
+			if ivfErr != nil {
+				panic(ivfErr)
+			}
+
+			// Encrypt video using XOR Cipher
+			for i := range frame {
+				frame[i] ^= cipherKey
+			}
+
+			if ivfErr = videoTrack.WriteSample(media.Sample{Data: frame, Duration: time.Second}); ivfErr != nil {
+				panic(ivfErr)
+			}
+		}
+	}()
+
+	// 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.ICEConnectionStateConnected {
+			iceConnectedCtxCancel()
+		}
+	})
+
+	// Set the handler for Peer connection state
+	// This will notify you when the peer has connected/disconnected
+	peerConnection.OnConnectionStateChange(func(state webrtc.PeerConnectionState) {
+		fmt.Printf("Peer Connection State has changed: %s\n", state.String())
+
+		if state == webrtc.PeerConnectionStateFailed {
+			// Wait until PeerConnection has had no network activity for 30 seconds or another failure.
+			// It may be reconnected using an ICE Restart.
+			// Use webrtc.PeerConnectionStateDisconnected if you are interested in detecting faster timeout.
+			// Note that the PeerConnection may come back from PeerConnectionStateDisconnected.
+			fmt.Println("Peer Connection has gone to failed exiting")
+			os.Exit(0)
+		}
+
+		if state == webrtc.PeerConnectionStateClosed {
+			// PeerConnection was explicitly closed. This usually happens from a DTLS CloseNotify
+			fmt.Println("Peer Connection has gone to closed exiting")
+			os.Exit(0)
+		}
+	})
+
+	// Wait for the offer to be pasted
+	offer := webrtc.SessionDescription{}
+	decode(readUntilNewline(), &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(encode(peerConnection.LocalDescription()))
+
+	// Block forever
+	select {}
+}
+
+// Read from stdin until we get a newline.
+func readUntilNewline() (in string) {
+	var err error
+
+	r := bufio.NewReader(os.Stdin)
+	for {
+		in, err = r.ReadString('\n')
+		if err != nil && !errors.Is(err, io.EOF) {
+			panic(err)
+		}
+
+		if in = strings.TrimSpace(in); len(in) > 0 {
+			break
+		}
+	}
+
+	fmt.Println("")
+
+	return
+}
+
+// JSON encode + base64 a SessionDescription.
+func encode(obj *webrtc.SessionDescription) string {
+	b, err := json.Marshal(obj)
+	if err != nil {
+		panic(err)
+	}
+
+	return base64.StdEncoding.EncodeToString(b)
+}
+
+// Decode a base64 and unmarshal JSON into a SessionDescription.
+func decode(in string, obj *webrtc.SessionDescription) {
+	b, err := base64.StdEncoding.DecodeString(in)
+	if err != nil {
+		panic(err)
+	}
+
+	if err = json.Unmarshal(b, obj); err != nil {
+		panic(err)
+	}
+}