Add examples/play-from-disk

Using IVFReader demonstrate how users can stream a video
from hard disk to browser.

Relates to #636

examples/README.md

@@ -8,7 +8,8 @@ For more full featured examples that use 3rd party libraries see our **[example-
 
 ### Overview
 #### Media API
-* [Echo](echo): The echo example demonstrates how to have Pion send back to the user exactly what it receives using the same PeerConnection .
+* [Echo](echo): The echo example demonstrates how to have Pion send back to the user exactly what it receives using the same PeerConnection.
+* [Play from disk](play-from-disk): The play-from-disk example demonstrates how to send video to your browser from a file saved to disk.
 * [Save to Disk](save-to-disk): The save-to-disk example shows how to record your webcam and save the footage to disk on the server side.
 * [SFU Minimal](sfu-minimal): The SFU example demonstrates how to broadcast a video to multiple peers. A broadcaster uploads the video once and the server forwards it to all other peers.
 

examples/echo/main.go

@@ -30,9 +30,9 @@ func main() {
 		panic(err)
 	}
 
-	preferredCodec, err := mediaEngine.FirstCodecOfKind(webrtc.RTPCodecTypeVideo)
-	if err != nil {
-		panic("no video codec in offer sdp")
+	videoCodecs := mediaEngine.GetCodecsByKind(webrtc.RTPCodecTypeVideo)
+	if len(videoCodecs) == 0 {
+		panic("Offer contained no video codecs")
 	}
 
 	api := webrtc.NewAPI(webrtc.WithMediaEngine(mediaEngine))
@@ -57,7 +57,7 @@ func main() {
 	}
 
 	// Create Track that we send video back to browser on
-	outputTrack, err := peerConnection.NewTrack(preferredCodec.PayloadType, rand.Uint32(), "video", "pion")
+	outputTrack, err := peerConnection.NewTrack(videoCodecs[0].PayloadType, rand.Uint32(), "video", "pion")
 	if err != nil {
 		panic(err)
 	}

examples/examples.json

@@ -35,6 +35,12 @@
 		"description": "Example pion-to-pion is an example of two pion instances communicating directly! It therefore has no corresponding web page.",
 		"type": "browser"
 	},
+	{
+		"title": "Play from Disk",
+		"link": "play-from-disk",
+		"description": "The play-from-disk example demonstrates how to send video to your browser from a file saved to disk.",
+		"type": "browser"
+	},
 	{
 		"title": "Save to Disk",
 		"link": "save-to-disk",

examples/play-from-disk/README.md

@@ -0,0 +1,33 @@
+# play-from-disk
+play-from-disk demonstrates how to send video to your browser from a file saved to disk.
+
+## Instructions
+### Create IVF named `output.ivf` that contains a VP8 track
+```
+ffmpeg -i $INPUT_FILE -g 30 output.ivf
+```
+
+### Download play-from-disk
+```
+go get github.com/pion/webrtc/examples/play-from-disk
+```
+
+### Open play-from-disk example page
+[jsfiddle.net](https://jsfiddle.net/z7ms3u5r/) you should see two text-areas and a 'Start Session' button
+
+### Run play-from-disk with your browsers SessionDescription as stdin
+The `output.ivf` you created should be in the same directory as `play-from-disk`. In the jsfiddle the top textarea is your browser, copy that and:
+
+#### Linux/macOS
+Run `echo $BROWSER_SDP | play-from-disk`
+#### Windows
+1. Paste the SessionDescription into a file.
+1. Run `play-from-disk < my_file`
+
+### Input play-from-disk's SessionDescription into your browser
+Copy the text that `play-from-disk` just emitted and copy into second text area
+
+### Hit 'Start Session' in jsfiddle, enjoy your video!
+A video should start playing in your browser above the input boxes. `play-from-disk` will exit when the file reaches the end
+
+Congrats, you have used Pion WebRTC! Now start building something cool

examples/play-from-disk/jsfiddle/demo.css

@@ -0,0 +1,4 @@
+textarea {
+    width: 500px;
+    min-height: 75px;
+}

examples/play-from-disk/jsfiddle/demo.details

@@ -0,0 +1,5 @@
+---
+ name: play-from-disk
+ description: play-from-disk demonstrates how to send video to your browser from a file saved to disk.
+ authors:
+   - Sean DuBois

examples/play-from-disk/jsfiddle/demo.html

@@ -0,0 +1,14 @@
+Browser base64 Session Description<br />
+<textarea id="localSessionDescription" readonly="true"></textarea> <br />
+
+Golang base64 Session Description<br />
+<textarea id="remoteSessionDescription"> </textarea> <br/>
+<button onclick="window.startSession()"> Start Session </button><br />
+
+<br />
+
+Video<br />
+<div id="remoteVideos"></div> <br />
+
+Logs<br />
+<div id="div"></div>

examples/play-from-disk/jsfiddle/demo.js

@@ -0,0 +1,39 @@
+/* eslint-env browser */
+
+let pc = new RTCPeerConnection()
+let log = msg => {
+  document.getElementById('div').innerHTML += msg + '<br>'
+}
+
+pc.ontrack = function (event) {
+  var el = document.createElement(event.track.kind)
+  el.srcObject = event.streams[0]
+  el.autoplay = true
+  el.controls = true
+
+  document.getElementById('remoteVideos').appendChild(el)
+}
+
+pc.oniceconnectionstatechange = e => log(pc.iceConnectionState)
+pc.onicecandidate = event => {
+  if (event.candidate === null) {
+    document.getElementById('localSessionDescription').value = btoa(JSON.stringify(pc.localDescription))
+  }
+}
+
+// Offer to receive 1 audio, and 2 video tracks
+pc.addTransceiver('video', {'direction': 'sendrecv'})
+pc.createOffer().then(d => pc.setLocalDescription(d)).catch(log)
+
+window.startSession = () => {
+  let sd = document.getElementById('remoteSessionDescription').value
+  if (sd === '') {
+    return alert('Session Description must not be empty')
+  }
+
+  try {
+    pc.setRemoteDescription(new RTCSessionDescription(JSON.parse(atob(sd))))
+  } catch (e) {
+    alert(e)
+  }
+}

examples/play-from-disk/main.go

@@ -0,0 +1,119 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/pion/webrtc/v2"
+	"github.com/pion/webrtc/v2/pkg/media"
+	"github.com/pion/webrtc/v2/pkg/media/ivfreader"
+
+	"github.com/pion/webrtc/v2/examples/internal/signal"
+)
+
+func main() {
+	// Wait for the offer to be pasted
+	offer := webrtc.SessionDescription{}
+	signal.Decode(signal.MustReadStdin(), &offer)
+
+	// We make our own mediaEngine so we can place the sender's codecs in it.  This because we must use the
+	// dynamic media type from the sender in our answer. This is not required if we are the offerer
+	mediaEngine := webrtc.MediaEngine{}
+	err := mediaEngine.PopulateFromSDP(offer)
+	if err != nil {
+		panic(err)
+	}
+
+	// Search for VP8 Payload type. If the offer doesn't support VP8 exit since
+	// since they won't be able to decode anything we send them
+	var payloadType uint8
+	for _, videoCodec := range mediaEngine.GetCodecsByKind(webrtc.RTPCodecTypeVideo) {
+		if videoCodec.Name == "VP8" {
+			payloadType = videoCodec.PayloadType
+			break
+		}
+	}
+	if payloadType == 0 {
+		panic("Remote peer does not support VP8")
+	}
+
+	// Create a new RTCPeerConnection
+	api := webrtc.NewAPI(webrtc.WithMediaEngine(mediaEngine))
+	peerConnection, err := api.NewPeerConnection(webrtc.Configuration{
+		ICEServers: []webrtc.ICEServer{
+			{
+				URLs: []string{"stun:stun.l.google.com:19302"},
+			},
+		},
+	})
+	if err != nil {
+		panic(err)
+	}
+
+	// Create a video track
+	videoTrack, err := peerConnection.NewTrack(payloadType, rand.Uint32(), "video", "pion")
+	if err != nil {
+		panic(err)
+	}
+	if _, err = peerConnection.AddTrack(videoTrack); err != nil {
+		panic(err)
+	}
+
+	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)
+		}
+
+		// 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.
+		sleepTime := time.Millisecond * time.Duration((float32(header.TimebaseNumerator)/float32(header.TimebaseDenominator))*1000)
+		for {
+			frame, _, ivfErr := ivf.ParseNextFrame()
+			if ivfErr != nil {
+				panic(ivfErr)
+			}
+
+			time.Sleep(sleepTime)
+			if ivfErr = videoTrack.WriteSample(media.Sample{Data: frame, Samples: 90000}); 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())
+	})
+
+	// 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)
+	}
+
+	// Sets the LocalDescription, and starts our UDP listeners
+	if err = peerConnection.SetLocalDescription(answer); err != nil {
+		panic(err)
+	}
+
+	// Output the answer in base64 so we can paste it in browser
+	fmt.Println(signal.Encode(answer))
+
+	// Block forever
+	select {}
+}

mediaengine.go

@@ -88,15 +88,6 @@ func (m *MediaEngine) PopulateFromSDP(sd SessionDescription) error {
 	return nil
 }
 
-// FirstCodecOfKind returns the first codec of a chosen kind in the codecs list
-func (m *MediaEngine) FirstCodecOfKind(kind RTPCodecType) (*RTPCodec, error) {
-	foundCodecs := m.getCodecsByKind(kind)
-	if len(foundCodecs) == 0 {
-		return nil, fmt.Errorf("none found")
-	}
-	return foundCodecs[0], nil
-}
-
 func (m *MediaEngine) getCodec(payloadType uint8) (*RTPCodec, error) {
 	for _, codec := range m.codecs {
 		if codec.PayloadType == payloadType {
@@ -119,7 +110,8 @@ func (m *MediaEngine) getCodecSDP(sdpCodec sdp.Codec) (*RTPCodec, error) {
 	return nil, ErrCodecNotFound
 }
 
-func (m *MediaEngine) getCodecsByKind(kind RTPCodecType) []*RTPCodec {
+// GetCodecsByKind returns all codecs of a chosen kind in the codecs list
+func (m *MediaEngine) GetCodecsByKind(kind RTPCodecType) []*RTPCodec {
 	var codecs []*RTPCodec
 	for _, codec := range m.codecs {
 		if codec.Type == kind {

peerconnection.go

@@ -1364,7 +1364,7 @@ func (pc *PeerConnection) AddTransceiverFromKind(kind RTPCodecType, init ...RtpT
 			return nil, err
 		}
 
-		codecs := pc.api.mediaEngine.getCodecsByKind(kind)
+		codecs := pc.api.mediaEngine.GetCodecsByKind(kind)
 		if len(codecs) == 0 {
 			return nil, fmt.Errorf("no %s codecs found", kind.String())
 		}
@@ -1662,7 +1662,7 @@ func (pc *PeerConnection) addTransceiverSDP(d *sdp.SessionDescription, midValue
 		WithPropertyAttribute(sdp.AttrKeyRTCPMux).
 		WithPropertyAttribute(sdp.AttrKeyRTCPRsize)
 
-	codecs := pc.api.mediaEngine.getCodecsByKind(t.kind)
+	codecs := pc.api.mediaEngine.GetCodecsByKind(t.kind)
 	for _, codec := range codecs {
 		media.WithCodec(codec.PayloadType, codec.Name, codec.ClockRate, codec.Channels, codec.SDPFmtpLine)
 

pkg/media/ivfreader/ivfreader.go

@@ -15,23 +15,23 @@ const (
 // IVFFileHeader 32-byte header for IVF files
 // https://wiki.multimedia.cx/index.php/IVF
 type IVFFileHeader struct {
-	signature     string // 0-3
-	version       uint16 // 4-5
-	headerSize    uint16 // 6-7
-	fourcc        string // 8-11
-	width         uint16 // 12-13
-	height        uint16 // 14-15
-	timebaseDenum uint32 // 16-19
-	timebaseNum   uint32 // 20-23
-	numFrames     uint32 // 24-27
-	unused        uint32 // 28-31
+	signature           string // 0-3
+	version             uint16 // 4-5
+	headerSize          uint16 // 6-7
+	FourCC              string // 8-11
+	Width               uint16 // 12-13
+	Height              uint16 // 14-15
+	TimebaseDenominator uint32 // 16-19
+	TimebaseNumerator   uint32 // 20-23
+	NumFrames           uint32 // 24-27
+	unused              uint32 // 28-31
 }
 
 // IVFFrameHeader 12-byte header for IVF frames
 // https://wiki.multimedia.cx/index.php/IVF
 type IVFFrameHeader struct {
-	frameSize uint32 // 0-3
-	timestamp uint64 // 4-11
+	FrameSize uint32 // 0-3
+	Timestamp uint64 // 4-11
 }
 
 // IVFReader is used to read IVF files and return frame payloads
@@ -75,15 +75,15 @@ func (i *IVFReader) ParseNextFrame() ([]byte, *IVFFrameHeader, error) {
 	}
 
 	header = &IVFFrameHeader{
-		frameSize: binary.LittleEndian.Uint32(buffer[:4]),
-		timestamp: binary.LittleEndian.Uint64(buffer[4:12]),
+		FrameSize: binary.LittleEndian.Uint32(buffer[:4]),
+		Timestamp: binary.LittleEndian.Uint64(buffer[4:12]),
 	}
 
-	payload := make([]byte, header.frameSize)
+	payload := make([]byte, header.FrameSize)
 	bytesRead, err = i.stream.Read(payload)
 	if err != nil {
 		return nil, nil, err
-	} else if bytesRead != int(header.frameSize) {
+	} else if bytesRead != int(header.FrameSize) {
 		return nil, nil, fmt.Errorf("incomplete frame data")
 	}
 	return payload, header, nil
@@ -102,16 +102,16 @@ func (i *IVFReader) parseFileHeader() (*IVFFileHeader, error) {
 	}
 
 	header := &IVFFileHeader{
-		signature:     string(buffer[:4]),
-		version:       binary.LittleEndian.Uint16(buffer[4:6]),
-		headerSize:    binary.LittleEndian.Uint16(buffer[6:8]),
-		fourcc:        string(buffer[8:12]),
-		width:         binary.LittleEndian.Uint16(buffer[12:14]),
-		height:        binary.LittleEndian.Uint16(buffer[14:16]),
-		timebaseDenum: binary.LittleEndian.Uint32(buffer[16:20]),
-		timebaseNum:   binary.LittleEndian.Uint32(buffer[20:24]),
-		numFrames:     binary.LittleEndian.Uint32(buffer[24:28]),
-		unused:        binary.LittleEndian.Uint32(buffer[28:32]),
+		signature:           string(buffer[:4]),
+		version:             binary.LittleEndian.Uint16(buffer[4:6]),
+		headerSize:          binary.LittleEndian.Uint16(buffer[6:8]),
+		FourCC:              string(buffer[8:12]),
+		Width:               binary.LittleEndian.Uint16(buffer[12:14]),
+		Height:              binary.LittleEndian.Uint16(buffer[14:16]),
+		TimebaseDenominator: binary.LittleEndian.Uint32(buffer[16:20]),
+		TimebaseNumerator:   binary.LittleEndian.Uint32(buffer[20:24]),
+		NumFrames:           binary.LittleEndian.Uint32(buffer[24:28]),
+		unused:              binary.LittleEndian.Uint32(buffer[28:32]),
 	}
 
 	if header.signature != ivfFileHeaderSignature {

pkg/media/ivfreader/ivfreader_test.go

@@ -43,12 +43,12 @@ func TestIVFReader_ParseValidFileHeader(t *testing.T) {
 
 	assert.Equal("DKIF", header.signature, "signature is 'DKIF'")
 	assert.Equal(uint16(0), header.version, "version should be 0")
-	assert.Equal("VP80", header.fourcc, "FourCC should be 'VP80'")
-	assert.Equal(uint16(176), header.width, "width should be 176")
-	assert.Equal(uint16(144), header.height, "height should be 144")
-	assert.Equal(uint32(30000), header.timebaseDenum, "timebase denominator should be 30000")
-	assert.Equal(uint32(1000), header.timebaseNum, "timebase numerator should be 1000")
-	assert.Equal(uint32(29), header.numFrames, "number of frames should be 29")
+	assert.Equal("VP80", header.FourCC, "FourCC should be 'VP80'")
+	assert.Equal(uint16(176), header.Width, "width should be 176")
+	assert.Equal(uint16(144), header.Height, "height should be 144")
+	assert.Equal(uint32(30000), header.TimebaseDenominator, "timebase denominator should be 30000")
+	assert.Equal(uint32(1000), header.TimebaseNumerator, "timebase numerator should be 1000")
+	assert.Equal(uint32(29), header.NumFrames, "number of frames should be 29")
 	assert.Equal(uint32(0), header.unused, "bytes should be unused")
 }
 
@@ -81,7 +81,7 @@ func TestIVFReader_ParseValidFrames(t *testing.T) {
 	payload, header, err := reader.ParseNextFrame()
 
 	assert.Nil(err, "Should have parsed frame #1 without error")
-	assert.Equal(uint32(4), header.frameSize, "Frame header frameSize should be 4")
+	assert.Equal(uint32(4), header.FrameSize, "Frame header frameSize should be 4")
 	assert.Equal(4, len(payload), "Payload should be length 4")
 	assert.Equal(
 		payload,
@@ -94,7 +94,7 @@ func TestIVFReader_ParseValidFrames(t *testing.T) {
 	payload, header, err = reader.ParseNextFrame()
 
 	assert.Nil(err, "Should have parsed frame #2 without error")
-	assert.Equal(uint32(12), header.frameSize, "Frame header frameSize should be 4")
+	assert.Equal(uint32(12), header.FrameSize, "Frame header frameSize should be 4")
 	assert.Equal(12, len(payload), "Payload should be length 12")
 	assert.Equal(
 		payload,