mirror of
https://github.com/pion/webrtc.git
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336 lines
9.1 KiB
Go
336 lines
9.1 KiB
Go
// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
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// SPDX-License-Identifier: MIT
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//go:build !js
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// +build !js
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// play-from-disk-fec demonstrates how to use forward error correction (FlexFEC-03)
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// while sending video to your Chrome-based browser from files saved to disk.
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package main
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import (
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"bufio"
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"context"
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"encoding/base64"
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"encoding/json"
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"errors"
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"fmt"
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"io"
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"os"
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"strings"
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"sync"
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"time"
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"github.com/pion/interceptor"
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"github.com/pion/rtp"
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"github.com/pion/webrtc/v4"
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"github.com/pion/webrtc/v4/pkg/media"
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"github.com/pion/webrtc/v4/pkg/media/ivfreader"
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)
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const (
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videoFileName = "output.ivf"
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answerFileName = "answer.txt"
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)
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func main() { //nolint:gocognit,cyclop,gocyclo,maintidx
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// Assert that we have a video file
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_, err := os.Stat(videoFileName)
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if os.IsNotExist(err) {
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panic("Could not find `" + videoFileName + "`")
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}
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// Create mediaEngine with default codecs
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mediaEngine := &webrtc.MediaEngine{}
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if err = mediaEngine.RegisterDefaultCodecs(); err != nil {
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panic(err)
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}
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// Create interceptorRegistry with default interceptots
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interceptorRegistry := &interceptor.Registry{}
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interceptorRegistry.Add(packetDropInterceptorFactory{})
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// Configure flexfec-03
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if err = webrtc.ConfigureFlexFEC03(49, mediaEngine, interceptorRegistry); err != nil {
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panic(err)
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}
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if err = webrtc.RegisterDefaultInterceptors(mediaEngine, interceptorRegistry); err != nil {
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panic(err)
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}
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api := webrtc.NewAPI(
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webrtc.WithMediaEngine(mediaEngine),
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webrtc.WithInterceptorRegistry(interceptorRegistry),
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)
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// Create a new RTCPeerConnection
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peerConnection, err := api.NewPeerConnection(webrtc.Configuration{
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ICEServers: []webrtc.ICEServer{
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{
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URLs: []string{"stun:stun.l.google.com:19302"},
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},
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},
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})
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if err != nil {
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panic(err)
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}
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defer func() {
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if cErr := peerConnection.Close(); cErr != nil {
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fmt.Printf("cannot close peerConnection: %v\n", cErr)
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}
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}()
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iceConnectedCtx, iceConnectedCtxCancel := context.WithCancel(context.Background())
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file, openErr := os.Open(videoFileName)
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if openErr != nil {
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panic(openErr)
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}
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_, header, openErr := ivfreader.NewWith(file)
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if openErr != nil {
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panic(openErr)
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}
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// Determine video codec
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var trackCodec string
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switch header.FourCC {
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case "AV01":
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trackCodec = webrtc.MimeTypeAV1
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case "VP90":
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trackCodec = webrtc.MimeTypeVP9
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case "VP80":
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trackCodec = webrtc.MimeTypeVP8
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default:
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panic(fmt.Sprintf("Unable to handle FourCC %s", header.FourCC))
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}
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// Create a video track
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videoTrack, videoTrackErr := webrtc.NewTrackLocalStaticSample(
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webrtc.RTPCodecCapability{MimeType: trackCodec}, "video", "pion",
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)
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if videoTrackErr != nil {
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panic(videoTrackErr)
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}
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rtpSender, videoTrackErr := peerConnection.AddTrack(videoTrack)
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if videoTrackErr != nil {
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panic(videoTrackErr)
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}
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// Read incoming RTCP packets
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// Before these packets are returned they are processed by interceptors. For things
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// like NACK this needs to be called.
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go func() {
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rtcpBuf := make([]byte, 1500)
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for {
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if _, _, rtcpErr := rtpSender.Read(rtcpBuf); rtcpErr != nil {
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return
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}
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}
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}()
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go func() {
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// Open a IVF file and start reading using our IVFReader
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file, ivfErr := os.Open(videoFileName)
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if ivfErr != nil {
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panic(ivfErr)
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}
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ivf, header, ivfErr := ivfreader.NewWith(file)
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if ivfErr != nil {
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panic(ivfErr)
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}
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// Wait for connection established
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<-iceConnectedCtx.Done()
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// 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.
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// This isn't required since the video is timestamped, but we will such much higher loss if we send all at once.
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//
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// It is important to use a time.Ticker instead of time.Sleep because
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// * avoids accumulating skew, just calling time.Sleep didn't compensate for the time spent parsing the data
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// * works around latency issues with Sleep (see https://github.com/golang/go/issues/44343)
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ticker := time.NewTicker(
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time.Millisecond * time.Duration((float32(header.TimebaseNumerator)/float32(header.TimebaseDenominator))*1000),
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)
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defer ticker.Stop()
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for ; true; <-ticker.C {
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frame, _, ivfErr := ivf.ParseNextFrame()
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if errors.Is(ivfErr, io.EOF) {
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fmt.Printf("All video frames parsed and sent")
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os.Exit(0)
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}
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if ivfErr != nil {
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panic(ivfErr)
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}
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if ivfErr = videoTrack.WriteSample(media.Sample{Data: frame, Duration: time.Second}); ivfErr != nil {
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panic(ivfErr)
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}
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}
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}()
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// Set the handler for ICE connection state
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// This will notify you when the peer has connected/disconnected
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peerConnection.OnICEConnectionStateChange(func(connectionState webrtc.ICEConnectionState) {
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fmt.Printf("Connection State has changed %s \n", connectionState.String())
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if connectionState == webrtc.ICEConnectionStateConnected {
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iceConnectedCtxCancel()
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}
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})
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// Set the handler for Peer connection state
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// This will notify you when the peer has connected/disconnected
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peerConnection.OnConnectionStateChange(func(state webrtc.PeerConnectionState) {
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fmt.Printf("Peer Connection State has changed: %s\n", state.String())
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if state == webrtc.PeerConnectionStateFailed {
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// Wait until PeerConnection has had no network activity for 30 seconds or another failure.
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// It may be reconnected using an ICE Restart.
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// Use webrtc.PeerConnectionStateDisconnected if you are interested in detecting faster timeout.
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// Note that the PeerConnection may come back from PeerConnectionStateDisconnected.
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fmt.Println("Peer Connection has gone to failed exiting")
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os.Exit(0)
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}
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if state == webrtc.PeerConnectionStateClosed {
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// PeerConnection was explicitly closed. This usually happens from a DTLS CloseNotify
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fmt.Println("Peer Connection has gone to closed exiting")
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os.Exit(0)
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}
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})
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// Create offer
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offer, err := peerConnection.CreateOffer(nil)
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if err != nil {
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panic(err)
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}
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// Create channel that is blocked until ICE Gathering is complete
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gatherComplete := webrtc.GatheringCompletePromise(peerConnection)
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// Sets the LocalDescription, and starts our UDP listeners
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if err = peerConnection.SetLocalDescription(offer); err != nil {
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panic(err)
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}
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// Block until ICE Gathering is complete, disabling trickle ICE
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// we do this because we only can exchange one signaling message
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// in a production application you should exchange ICE Candidates via OnICECandidate
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<-gatherComplete
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// Output the offer in base64 so we can paste it in browser
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fmt.Println(encode(peerConnection.LocalDescription()))
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// Wait for user to save the answer and press enter
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fmt.Printf("Save the browser's answer to '%s' and press Enter to continue...\n", answerFileName)
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_, err = bufio.NewReader(os.Stdin).ReadBytes('\n')
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if err != nil {
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panic(err)
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}
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// Read the answer from file
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answerData, readErr := os.ReadFile(answerFileName)
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if readErr != nil {
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panic(readErr)
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}
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answerStr := strings.TrimSpace(string(answerData))
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if len(answerStr) == 0 {
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panic("Answer file is empty")
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}
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answer := webrtc.SessionDescription{}
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decode(answerStr, &answer)
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// Set the remote SessionDescription
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if err = peerConnection.SetRemoteDescription(answer); err != nil {
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panic(err)
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}
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fmt.Println("Answer received and set successfully!")
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// Block forever
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select {}
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}
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// JSON encode + base64 a SessionDescription.
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func encode(obj *webrtc.SessionDescription) string {
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b, err := json.Marshal(obj)
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if err != nil {
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panic(err)
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}
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return base64.StdEncoding.EncodeToString(b)
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}
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// Decode a base64 and unmarshal JSON into a SessionDescription.
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func decode(in string, obj *webrtc.SessionDescription) {
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b, err := base64.StdEncoding.DecodeString(in)
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if err != nil {
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panic(err)
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}
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if err = json.Unmarshal(b, obj); err != nil {
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panic(err)
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}
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}
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// Factory for creating the interceptor.
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type packetDropInterceptorFactory struct{}
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func (f packetDropInterceptorFactory) NewInterceptor(_ string) (interceptor.Interceptor, error) {
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return &dropFilter{}, nil
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}
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// dropFilter drops outgoing video packets based on sequence number.
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type dropFilter struct {
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interceptor.NoOp
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mu sync.Mutex
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mediaPacketsTotal int
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fecPacketsTotal int
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droppedPacketsTotal int
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}
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func (i *dropFilter) BindLocalStream(info *interceptor.StreamInfo, writer interceptor.RTPWriter) interceptor.RTPWriter {
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if !strings.HasPrefix(strings.ToLower(info.MimeType), "video/") {
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return writer
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}
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return interceptor.RTPWriterFunc(func(header *rtp.Header, payload []byte, attrs interceptor.Attributes) (int, error) {
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i.mu.Lock()
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defer i.mu.Unlock()
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// Check if this is a FEC packet
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if header.SSRC == info.SSRCForwardErrorCorrection {
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i.fecPacketsTotal++
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return writer.Write(header, payload, attrs)
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}
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// Log stats periodically
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if i.mediaPacketsTotal%100 == 0 {
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dropRatio := float64(i.droppedPacketsTotal) / float64(i.mediaPacketsTotal)
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fmt.Printf("Stats: Media: %d, FEC: %d, Dropped: %d, Drop ratio: %.4f%%\n",
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i.mediaPacketsTotal, i.fecPacketsTotal, i.droppedPacketsTotal, dropRatio*100)
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}
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// Count all media packets
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i.mediaPacketsTotal++
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// 40% loss
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if i.mediaPacketsTotal%5 <= 1 {
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i.droppedPacketsTotal++
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return len(payload), nil // Pretend we wrote the packet but actually drop it
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}
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return writer.Write(header, payload, attrs)
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})
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}
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