Initial support for serverless mode via copy and pasting offer.

.gitmodules

@@ -0,0 +1,6 @@
+[submodule "external/LZMA-JS"]
+	path = external/LZMA-JS
+	url = https://github.com/LZMA-JS/LZMA-JS.git
+[submodule "external/base64.js"]
+	path = external/base64.js
+	url = https://gist.github.com/72c423f727d395eeaa09697058238727.git

camera/static/js/base64.js

@@ -0,0 +1 @@
+../../../external/base64.js/base64.js

camera/static/js/lzma_worker.js

@@ -0,0 +1 @@
+../../../external/LZMA-JS/src/lzma_worker.js

camera/static/js/prefix

@@ -0,0 +1,175 @@
+{"description":{"type":"answer","sdp":"v=0
+o=- 0 2 IN IP4 127.0.0.1
+s=-
+t=0 0
+a=group:BUNDLE 0
+a=msid-semantic: WMS
+m=audio 9 UDP/TLS/RTP/SAVPF 109 9 0 8 101
+c=IN IP4 0.0.0.0
+a=rtcp:9 IN IP4 0.0.0.0
+a=candidate:0 1 udp 0 a.local 0 typ host generation 0 network-cost 999
+a=ice-ufrag:
+a=ice-pwd:
+a=ice-options:trickle
+a=fingerprint:sha-256 000:01:12:23:34:45:56:67:78:89:9A:AB:BC:CD:DE:EF:F0:02:03:04:05:06:07:08:09:0A:0B:0C:0D:0E:0F
+a=setup:active
+a=mid:0
+a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
+a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid
+a=recvonly
+a=rtcp-mux
+a=rtpmap:109 opus/48000/2
+a=fmtp:109 minptime=10;useinbandfec=1
+a=rtpmap:9 G722/8000
+a=rtpmap:0 PCMU/8000
+a=rtpmap:8 PCMA/8000
+a=rtpmap:101 telephone-event/8000
+"}}
+{"description":{"type":"offer","sdp":"v=0
+o=mozilla...THIS_IS_SDPARTA-68.8.1 0 0 IN IP4 0.0.0.0
+s=-
+t=0 0
+a=sendrecv
+a=fingerprint:sha-256 0:10:11:12:13:14:15:16:17:18:19:1A:1B:1C:1D:1E:1F:20:21:22:23:24:25:26:27:28:29:2A:2B:2C:2D
+a=group:BUNDLE 0
+a=ice-options:trickle
+a=msid-semantic:WMS *
+m=audio 40000 UDP/TLS/RTP/SAVPF 109 9 0 8 101
+c=IN IP4 192.168.0.0
+a=candidate:0 1 UDP 2100000000 192.168.0.0 40000 typ host
+a=candidate:1 1 UDP 2100000000 ::1 40000 typ host
+a=candidate:2 1 TCP 2100000000 192.168.0.0 40000 typ host tcptype passive
+a=candidate:2 1 TCP 2100000000 192.168.0.0 9 typ host tcptype active
+a=candidate:3 1 TCP 2100000000 ::1 40000 typ host tcptype passive
+a=candidate:3 1 TCP 2100000000 ::1 9 typ host tcptype active
+a=candidate:0 2 UDP 2100000000 192.168.0.0 40000 typ host
+a=candidate:1 2 UDP 2100000000 ::1 40000 typ host
+a=candidate:2 2 TCP 2100000000 192.168.0.0 40000 typ host tcptype passive
+a=candidate:2 2 TCP 2100000000 192.168.0.0 9 typ host tcptype active
+a=candidate:3 2 TCP 2100000000 ::1 40000 typ host tcptype passive
+a=candidate:3 2 TCP 2100000000 ::1 9 typ host tcptype active
+a=sendrecv
+a=end-of-candidates
+a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
+a=extmap:2/recvonly urn:ietf:params:rtp-hdrext:csrc-audio-level
+a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid
+a=fmtp:109 maxplaybackrate=48000;stereo=1;useinbandfec=1
+a=fmtp:101 0-15
+a=ice-pwd:
+a=ice-ufrag:
+a=mid:0
+a=msid:{}
+a=rtcp:40000 IN IP4 192.168.0.0
+a=rtcp-mux
+a=rtpmap:109 opus/48000/2
+a=rtpmap:9 G722/8000/1
+a=rtpmap:0 PCMU/8000
+a=rtpmap:8 PCMA/8000
+a=rtpmap:101 telephone-event/8000
+a=setup:actpass
+a=ssrc:0 cname:{}
+"}}
+{"description":{"type":"answer","sdp":"v=0
+o=- 0 2 IN IP4 127.0.0.1
+s=-
+t=0 0
+a=group:BUNDLE 0
+a=msid-semantic: WMS
+m=video 9 UDP/TLS/RTP/SAVPF 120 121
+c=IN IP4 0.0.0.0
+a=rtcp:9 IN IP4 0.0.0.0
+a=candidate:0 1 udp 2100000000 abc.local 40000 typ host generation 0 network-cost 999
+a=ice-ufrag:
+a=ice-pwd:
+a=ice-options:trickle
+a=fingerprint:sha-256 0:2E:2F:30:31:32:33:34:35:36:37:38:39:3A:3B:3C:3D:3E:3F:40:41:42:43:44:45:46:47:48:49:4A:4B
+a=setup:active
+a=mid:0
+a=extmap:5 urn:ietf:params:rtp-hdrext:toffset
+a=extmap:4 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
+a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid
+a=recvonly
+a=rtcp-mux
+a=rtpmap:120 VP8/90000
+a=rtcp-fb:120 goog-remb
+a=rtcp-fb:120 ccm fir
+a=rtcp-fb:120 nack
+a=rtcp-fb:120 nack pli
+a=rtpmap:121 VP9/90000
+a=rtcp-fb:121 goog-remb
+a=rtcp-fb:121 ccm fir
+a=rtcp-fb:121 nack
+a=rtcp-fb:121 nack pli
+a=fmtp:121 profile-id=0
+"}}
+{"description":{"type":"offer","sdp":"v=0
+o=mozilla...THIS_IS_SDPARTA-68.8.1 0 0 IN IP4 0.0.0.0
+s=-
+t=0 0
+a=sendrecv
+a=fingerprint:sha-256 0:4C:4D:4E:4F:50:51:52:53:54:55:56:57:58:59:5A:5B:5C:5D:5E:5F:60:61:62:63:64:65:66:67:68:69
+a=group:BUNDLE 0
+a=ice-options:trickle
+a=msid-semantic:WMS *
+m=video 40000 UDP/TLS/RTP/SAVPF 120 121
+c=IN IP4 192.168.0.0
+a=candidate:0 1 UDP 2100000000 192.168.0.0 40000 typ host
+a=candidate:1 1 UDP 2100000000 ::1 40000 typ host
+a=candidate:2 1 TCP 2100000000 192.168.0.0 40000 typ host tcptype passive
+a=candidate:2 1 TCP 2100000000 192.168.0.0 9 typ host tcptype active
+a=candidate:3 1 TCP 2100000000 ::1 40000 typ host tcptype passive
+a=candidate:3 1 TCP 2100000000 ::1 9 typ host tcptype active
+a=candidate:0 2 UDP 2100000000 192.168.0.0 40000 typ host
+a=candidate:1 2 UDP 2100000000 ::1 40000 typ host
+a=candidate:2 2 TCP 2100000000 192.168.0.0 40000 typ host tcptype passive
+a=candidate:2 2 TCP 2100000000 192.168.0.0 9 typ host tcptype active
+a=candidate:3 2 TCP 2100000000 ::1 40000 typ host tcptype passive
+a=candidate:3 2 TCP 2100000000 ::1 9 typ host tcptype active
+a=sendrecv
+a=end-of-candidates
+a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid
+a=extmap:4 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
+a=extmap:5 urn:ietf:params:rtp-hdrext:toffset
+a=fmtp:120 max-fs=12288;max-fr=60
+a=fmtp:121 max-fs=12288;max-fr=60
+a=ice-pwd:
+a=ice-ufrag:
+a=mid:0
+a=msid:{}
+a=rtcp:40000 IN IP4 192.168.0.0
+a=rtcp-fb:120 nack
+a=rtcp-fb:120 nack pli
+a=rtcp-fb:120 ccm fir
+a=rtcp-fb:120 goog-remb
+a=rtcp-fb:121 nack
+a=rtcp-fb:121 nack pli
+a=rtcp-fb:121 ccm fir
+a=rtcp-fb:121 goog-remb
+a=rtcp-mux
+a=rtpmap:120 VP8/90000
+a=rtpmap:121 VP9/90000
+a=setup:actpass
+a=ssrc:0 cname:{}
+"}}
+{"description":{"type":"offer","sdp":"v=0
+o=mozilla...THIS_IS_SDPARTA-75.0 0 0 IN IP4 0.0.0.0
+s=-
+t=0 0
+a=sendrecv
+a=fingerprint:sha-256 6A:6B:6C:6D:6E:6F:70:71:72:73:74:75:76:77:78:79:7A:7B:7C:7D:7E:7F:80:81:82:83:84:85:86:87:88:89
+a=group:BUNDLE 0
+a=ice-options:trickle
+a=msid-semantic:WMS *
+m=application 9 UDP/DTLS/SCTP webrtc-datachannel
+c=IN IP4 0.0.0.0
+a=candidate:0 1 UDP 2100000000 0.local 40000 typ host
+a=candidate:1 1 TCP 2100000000 0.local 9 typ host tcptype active
+a=sendrecv
+a=end-of-candidates
+a=ice-pwd:
+a=ice-ufrag:
+a=mid:0
+a=setup:actpass
+a=sctp-port:5000
+a=max-message-size:
+"}}

camera/static/js/prefixCompressor.js

@@ -0,0 +1,47 @@
+async function loadLZMAPrefixCompressor(prefixFilename) {
+  class PrefixCompressor {
+    constructor(prefix, compress, decompress, bytesToIgnore) {
+      this.prefix = prefix;
+      this.prefixCompressed = compress(prefix);
+      this.bytesToIgnore = bytesToIgnore;
+      this.baseCompress = compress;
+      this.baseDecompress = decompress;
+    }
+
+    compress(str) {
+      const c = this.baseCompress(this.prefix + str);
+      for (var i = this.bytesToIgnore;
+           i < this.prefixCompressed.length
+             && this.prefixCompressed[i] == c[i];
+           i++) { }
+      const omittedBytes = this.prefixCompressed.length - i;
+      const res = c.subarray(i - 1);
+      res[0] = omittedBytes;
+      return res;
+    }
+
+    decompress(arr) {
+      const omittedBytes = arr[0];
+      const prefixBytes = this.prefixCompressed.length-omittedBytes;
+      const c = new Uint8Array(prefixBytes + arr.length-1);
+      c.set(this.prefixCompressed.subarray(0, prefixBytes));
+      c.set(arr.subarray(1), prefixBytes);
+      const d = this.baseDecompress(c);
+      return d.substring(this.prefix.length);
+    }
+  }
+  async function loadDictionary() {
+    const response = await fetch(prefixFilename);
+    return await response.text();
+  }
+  const prefix = await loadDictionary();
+
+  return new PrefixCompressor(prefix, str => {
+    const res = new Uint8Array(LZMA.compress(str, 9));
+    // Clear uncompressed size as it will be invalid.
+    for (var i = 5; i < 13; i++) res[i] = 255;
+    return res;
+  }, arr => {
+    return LZMA.decompress(arr).toString();
+  }, 12);
+}

camera/templates/index.html

@@ -12,13 +12,13 @@ body.justVideo {
 body.justVideo #status, body.justVideo form {
   display: none;
 }
-#qrcodelink {
+.qrcontainer {
   position: sticky;
   top: 0;
   right: 0;
   float: right;
 }
-#qrcodelink svg path {
+.qrcontainer svg path {
   min-width: 30vw;
   max-width: 100vw;
   max-height: 50vh;
@@ -57,15 +57,29 @@ form label {
 }
     </style>
     <script type="text/javascript" src="static/js/qrcodegen.js"></script>
+    <script type="text/javascript" src="static/js/lzma_worker.js"></script>
+    <script type="text/javascript" src="static/js/prefixCompressor.js"></script>
   </head>
   <body>
-    <a id="qrcodelink" style="display:none;">
+    <a class="qrcontainer" id="qrcodelink" style="display:none;">
       <svg xmlns="http://www.w3.org/2000/svg" id="qrcode" style="width:20em; height:20em;" stroke="none">
         <rect width="100%" height="100%" fill="#FFFFFF"/>
         <path d="" fill="#000000"/>
       </svg>
     </a>
+    <div class="qrcontainer" id="qrcodeObjContainer" style="display:none;">
+      <svg xmlns="http://www.w3.org/2000/svg" id="qrcodeObj" style="width:20em; height:20em;" stroke="none">
+        <rect width="100%" height="100%" fill="#FFFFFF"/>
+        <path d="" fill="#000000"/>
+      </svg> <br/>
+      <textarea id="localOffer" readonly></textarea>
+      <button id="copyLocalOffer">Copy</button>
+    </div>
     <form name="settings">
+      <label>
+        Serverless mode:
+        <input name="serverless" type="checkbox" value="true" />
+      </label>
       <label>
         Recieve remote video:
         <select name="client-video">
@@ -99,6 +113,12 @@ form label {
         <input name="debug" type="checkbox" value="true" />
       </label>
     </form>
+    <form id="serverlessOffer" style="display: none;">
+      <label>
+        Paste offer here:
+        <textarea name="remoteOffer"></textarea>
+      </label>
+    </form>
     <div id="status"></div>
     <div id="videos">
       <button id="unmute" style="display:none;">Unmute</button>
@@ -106,19 +126,36 @@ form label {
       <video id="remoteView" width="100%" autoplay muted style="display:none;"></video>
       <video id="selfView" width="200" height="150" autoplay muted style="display:none;"></video>
     </div>
-    <script >
+    <script type="module" >
+      import * as b64 from "./static/js/base64.js";
+
+    async function initialize() {
       const create = (container, type) => container.appendChild(document.createElement(type));
       const QRGen = qrcodegen.QrCode;
 
+      var compressor = null;
+      async function getCompressor() {
+        if (compressor == null) {
+          compressor = await loadLZMAPrefixCompressor('static/js/prefix');
+        }
+        return compressor;
+      }
+
       const body = document.querySelector("body");
       const out = document.getElementById("status");
       const qrcode = document.getElementById("qrcode");
       const qrcodelink = document.getElementById("qrcodelink");
+      const qrcodeObjContainer = document.getElementById("qrcodeObjContainer");
+      const qrcodeObj = document.getElementById("qrcodeObj");
       const remoteView = document.getElementById("remoteView");
       const selfView = document.getElementById("selfView");
       const start = document.getElementById("start");
       const unmute = document.getElementById("unmute");
       const form = document.forms["settings"];
+      const remoteOfferForm = document.forms["serverlessOffer"];
+      const remoteOffer = remoteOfferForm.elements["remoteOffer"];
+      const localOfferArea = document.getElementById("localOffer");
+      const localOfferCopyButton = document.getElementById("copyLocalOffer");
 
       function _log(str, tag) {
         const logEntry = document.createElement(tag);
@@ -157,19 +194,52 @@ form label {
         });
       }
 
+      function isServerless() {
+        return settings && 'serverless' in settings && settings.serverless;
+      }
+
       function withHash(hash) {
         return window.location.href.split('#')[0] + '#' + hash;
       }
-      function displayQRUrl(url) {
+      function displayQR(qrcode, val) {
-        qrcodelink.href = url;
+        const encodeFunc = val instanceof Uint8Array
-        const qr = QRGen.encodeText(url, QRGen.Ecc.MEDIUM);
+          ? QRGen.encodeBinary
+          : QRGen.encodeText;
+        const qr = encodeFunc(val, QRGen.Ecc.MEDIUM);
         const code = qr.toSvgString(1);
         const viewBox = (/ viewBox="([^"]*)"/.exec(code))[1];
         const pathD = (/ d="([^"]*)"/.exec(code))[1];
         qrcode.setAttribute("viewBox", viewBox);
         qrcode.querySelector("path").setAttribute("d", pathD);
+      }
+      function displayQRUrl(url) {
+        qrcodelink.href = url;
+        displayQR(qrcode, url);
         qrcodelink.style.display = '';
       }
+      function displayQRUrlForObj(obj) {
+        const json = JSON.stringify(obj);
+        log("Encoding message in QR code/link:");
+        logPre(json);
+        const compressed = compressor.compress(json);
+        const encoded = b64.bytesToBase64(compressed);
+        displayQRUrl(withHash('^' + encoded));
+      }
+      function displayQRCodeForObj(obj) {
+        const json = JSON.stringify(obj);
+        log("Encoding message in QR code for copy/paste:");
+        logPre(json);
+        const compressed = compressor.compress(json);
+        const encoded = b64.bytesToBase64(compressed);
+        displayQR(qrcodeObj, compressed);
+        localOfferArea.value = encoded;
+        localOfferCopyButton.onclick = _ => {
+          localOfferArea.focus();
+          localOfferArea.select();
+          document.execCommand('copy');
+        };
+        qrcodeObjContainer.style.display = '';
+      }
 
       let roomName = window.location.hash;
       let isHost = roomName === undefined || !roomName;
@@ -195,6 +265,25 @@ form label {
           log("Failed to read settings from hash: " + error);
         }
       }
+      var firstMessage = undefined;
+      if (roomName && roomName.startsWith("#^")) {
+        roomName = undefined;
+        isHost = false;
+
+        try {
+          const hash = decodeURI(window.location.hash);
+          log("Reading first message from hash:");
+          logPre(hash);
+          log("Decoded base64:");
+          const decoded = (await getCompressor()).decompress(b64.base64ToBytes(hash.substring(2)));
+          logPre(decoded);
+          firstMessage = decoded;
+          settings = {serverless: true};
+        } catch (error) {
+          log("Failed to read message from hash: " + error);
+        }
+      }
+
       if (isHost) {
         // From https://stackoverflow.com/a/1349426
         function makeid(length) {
@@ -207,15 +296,23 @@ form label {
           return result;
         }
 
-        roomName = makeid(8);
+        if (!isServerless()) {
-        displayQRUrl(withHash(roomName));
+          roomName = makeid(8);
+          displayQRUrl(withHash(roomName));
+        }
       } else {
-        roomName = roomName.substring(1);
+        if (!isServerless()) {
+          roomName = roomName.substring(1);
+        }
         qrcodelink.style.display = 'none';
         form.style.display = 'none';
       }
 
-      log("Room: " + roomName);
+      if (isServerless()) {
+        log("In serverless mode.");
+      } else {
+        log("Room: " + roomName);
+      }
 
       var webSocket = undefined;
 
@@ -225,6 +322,10 @@ form label {
         const method = dcReady ? "dataConnection" : "webSocket";
         log("Sending message via " + method + "...");
         logPre(toSend);
+        if (isServerless() && !dcReady) {
+          log("ERROR: Attempted to use webSocket in serverless mode.");
+          return;
+        }
         (dcReady ? dc : webSocket).send(toSend);
       }
 
@@ -233,7 +334,12 @@ form label {
 
       function sendOffer() {
         if (pc.iceGatheringState == "complete") {
-          sendJson({
+          const sendFunc = !isServerless() || dc && dc.readyState == "open"
+            ? sendJson
+            : isHost
+              ? displayQRUrlForObj
+              : displayQRCodeForObj;
+          sendFunc({
             description: pc.localDescription
           });
         }
@@ -284,6 +390,7 @@ form label {
             receiveMessage({source: "dataChannel", data: e.data});
           }
           log('Data channel initialized.');
+          qrcodeObjContainer.style.display = 'none';
         }
 
         if (isHost) {
@@ -292,6 +399,7 @@ form label {
             receiveMessage({source: "dataChannel", data: e.data});
           }
           dc.onopen = e => {
+            remoteOffer.disabled = true;
             log("Data channel open, sending settings...")
             settings = readSettingsForm(true);
             sendJson({settings});
@@ -414,16 +522,32 @@ form label {
         return webSocket;
       }
 
-      webSocket = createWebSocket();
+      if (!isServerless()) {
+        webSocket = createWebSocket();
 
-      if (!isHost) {
+        if (!isHost) {
-        // To make serverless and server mode more similar,
+          // To make serverless and server mode more similar,
-        //  always make the first RTCPeerConnection offer from the host,
+          //  always make the first RTCPeerConnection offer from the host,
-        //  so here just notify the host to start the process.
+          //  so here just notify the host to start the process.
-        webSocket.onopen = _ => sendJson({ready: true});
+          webSocket.onopen = _ => sendJson({ready: true});
+        }
+      } else if (isHost) {
+        await getCompressor();
+        pc = createRTCPeerConnection();
+        remoteOffer.value = '';
+        remoteOffer.onchange = _ => {
+          const decoded = b64.base64ToBytes(remoteOffer.value);
+          const decompressed = compressor.decompress(decoded);
+          receiveMessage({source: 'textarea', data: decompressed});
+        }
+        remoteOfferForm.style.display = '';
+      } else {
+        receiveMessage({source: 'URL', data: firstMessage});
       }
 
       log("Finished <script> block.");
+    }
+    initialize();
     </script>
   </body>
 </html>

external/LZMA-JS

@@ -0,0 +1 @@
+Subproject commit 8f98fe85a1ef78ab6e9d26ab85ce338f50095a23

external/base64.js

@@ -0,0 +1 @@
+Subproject commit 74d3cbf82481545bc26c104de2419f4ee30c7dd7