Add examples/stats

Example demonstrates how to use the new webrtc-stats interceptor

examples/stats/README.md

@@ -0,0 +1,48 @@
+# stats
+stats demonstrates how to use the [webrtc-stats](https://www.w3.org/TR/webrtc-stats/) implementation provided by Pion WebRTC.
+
+This API gives you access to the statistical information about a PeerConnection. This can help you understand what is happening
+during a session and why.
+
+## Instructions
+### Download stats
+```
+export GO111MODULE=on
+go get github.com/pion/webrtc/v3/examples/stats
+```
+
+### Open stats example page
+[jsfiddle.net](https://jsfiddle.net/s179hacu/) you should see your Webcam, two text-areas and two buttons: `Copy browser SDP to clipboard`, `Start Session`.
+
+### Run stats, with your browsers SessionDescription as stdin
+In the jsfiddle the top textarea is your browser's Session Description. Press `Copy browser SDP to clipboard` or copy the base64 string manually.
+We will use this value in the next step.
+
+#### Linux/macOS
+Run `echo $BROWSER_SDP | stats`
+#### Windows
+1. Paste the SessionDescription into a file.
+1. Run `stats < my_file`
+
+### Input stats' SessionDescription into your browser
+Copy the text that `stats` just emitted and copy into second text area
+
+### Hit 'Start Session' in jsfiddle
+The `stats` program will now print the InboundRTPStreamStats for each incoming stream. You will see the following in
+your console. The exact fields will change as we add more values.
+
+```
+Stats for: video/VP8
+InboundRTPStreamStats:
+        PacketsReceived: 1255
+        PacketsLost: 0
+        Jitter: 588.9559641717999
+        LastPacketReceivedTimestamp: 2023-04-26 13:16:16.63591134 -0400 EDT m=+18.317378921
+        HeaderBytesReceived: 25100
+        BytesReceived: 1361125
+        FIRCount: 0
+        PLICount: 0
+        NACKCount: 0
+```
+
+Congrats, you have used Pion WebRTC! Now start building something cool

examples/stats/main.go

@@ -0,0 +1,141 @@
+//go:build !js
+// +build !js
+
+// stats demonstrates how to use the webrtc-stats implementation provided by Pion WebRTC.
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/pion/interceptor"
+	"github.com/pion/interceptor/pkg/stats"
+	"github.com/pion/webrtc/v3"
+	"github.com/pion/webrtc/v3/examples/internal/signal"
+)
+
+// nolint:gocognit
+func main() {
+	// Everything below is the Pion WebRTC API! Thanks for using it ❤️.
+
+	// Create a MediaEngine object to configure the supported codec
+	m := &webrtc.MediaEngine{}
+
+	if err := m.RegisterDefaultCodecs(); err != nil {
+		panic(err)
+	}
+
+	// Create a InterceptorRegistry. This is the user configurable RTP/RTCP Pipeline.
+	// This provides NACKs, RTCP Reports and other features. If you use `webrtc.NewPeerConnection`
+	// this is enabled by default. If you are manually managing You MUST create a InterceptorRegistry
+	// for each PeerConnection.
+	i := &interceptor.Registry{}
+
+	statsInterceptorFactory, err := stats.NewInterceptor()
+	if err != nil {
+		panic(err)
+	}
+
+	var statsGetter stats.Getter
+	statsInterceptorFactory.OnNewPeerConnection(func(_ string, g stats.Getter) {
+		statsGetter = g
+	})
+	i.Add(statsInterceptorFactory)
+
+	// Use the default set of Interceptors
+	if err = webrtc.RegisterDefaultInterceptors(m, i); err != nil {
+		panic(err)
+	}
+
+	// Create the API object with the MediaEngine
+	api := webrtc.NewAPI(webrtc.WithMediaEngine(m), webrtc.WithInterceptorRegistry(i))
+
+	// Prepare the configuration
+	config := webrtc.Configuration{
+		ICEServers: []webrtc.ICEServer{
+			{
+				URLs: []string{"stun:stun.l.google.com:19302"},
+			},
+		},
+	}
+
+	// Create a new RTCPeerConnection
+	peerConnection, err := api.NewPeerConnection(config)
+	if err != nil {
+		panic(err)
+	}
+
+	// Allow us to receive 1 audio track, and 1 video track
+	if _, err = peerConnection.AddTransceiverFromKind(webrtc.RTPCodecTypeAudio); err != nil {
+		panic(err)
+	} else if _, err = peerConnection.AddTransceiverFromKind(webrtc.RTPCodecTypeVideo); err != nil {
+		panic(err)
+	}
+
+	// Set a handler for when a new remote track starts. We read the incoming packets, but then
+	// immediately discard them
+	peerConnection.OnTrack(func(track *webrtc.TrackRemote, receiver *webrtc.RTPReceiver) {
+		fmt.Printf("New incoming track with codec: %s\n", track.Codec().MimeType)
+
+		go func() {
+			for {
+				stats := statsGetter.Get(uint32(track.SSRC()))
+
+				fmt.Printf("Stats for: %s\n", track.Codec().MimeType)
+				fmt.Println(stats.InboundRTPStreamStats)
+
+				time.Sleep(time.Second * 5)
+			}
+		}()
+
+		rtpBuff := make([]byte, 1500)
+		for {
+			_, _, readErr := track.Read(rtpBuff)
+			if readErr != nil {
+				panic(readErr)
+			}
+		}
+	})
+
+	// 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())
+	})
+
+	// Wait for the offer to be pasted
+	offer := webrtc.SessionDescription{}
+	signal.Decode(signal.MustReadStdin(), &offer)
+
+	// Set the remote SessionDescription
+	err = peerConnection.SetRemoteDescription(offer)
+	if 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
+	err = peerConnection.SetLocalDescription(answer)
+	if 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()))
+
+	// Block forever
+	select {}
+}

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/pion/datachannel v1.5.5
 	github.com/pion/dtls/v2 v2.2.6
 	github.com/pion/ice/v2 v2.3.2
-	github.com/pion/interceptor v0.1.15
+	github.com/pion/interceptor v0.1.16
 	github.com/pion/logging v0.2.2
 	github.com/pion/randutil v0.1.0
 	github.com/pion/rtcp v1.2.10

go.sum

@@ -46,8 +46,8 @@ github.com/pion/dtls/v2 v2.2.6 h1:yXMxKr0Skd+Ub6A8UqXTRLSywskx93ooMRHsQUtd+Z4=
 github.com/pion/dtls/v2 v2.2.6/go.mod h1:t8fWJCIquY5rlQZwA2yWxUS1+OCrAdXrhVKXB5oD/wY=
 github.com/pion/ice/v2 v2.3.2 h1:vh+fi4RkZ8H5fB4brZ/jm3j4BqFgMmNs+aB3X52Hu7M=
 github.com/pion/ice/v2 v2.3.2/go.mod h1:AMIpuJqcpe+UwloocNebmTSWhCZM1TUCo9v7nW50jX0=
-github.com/pion/interceptor v0.1.15 h1:vBjnKoSqcNYg2Xq3kz/2m7qp57c0yVH0n/2HJ2rP0hQ=
-github.com/pion/interceptor v0.1.15/go.mod h1:SY8kpmfVBvrbUzvj2bsXz7OJt5JvmVNZ+4Kjq7FcwrI=
+github.com/pion/interceptor v0.1.16 h1:0GDZrfNO+BmVNWymS31fMlVtPO2IJVBzy2Qq5XCYMIg=
+github.com/pion/interceptor v0.1.16/go.mod h1:SY8kpmfVBvrbUzvj2bsXz7OJt5JvmVNZ+4Kjq7FcwrI=
 github.com/pion/logging v0.2.2 h1:M9+AIj/+pxNsDfAT64+MAVgJO0rsyLnoJKCqf//DoeY=
 github.com/pion/logging v0.2.2/go.mod h1:k0/tDVsRCX2Mb2ZEmTqNa7CWsQPc+YYCB7Q+5pahoms=
 github.com/pion/mdns v0.0.7 h1:P0UB4Sr6xDWEox0kTVxF0LmQihtCbSAdW0H2nEgkA3U=