x-recorder.html

<!--
  Copyright (c) 2016 Ryoya Kawai.  All rights reserved.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<dom-module id="x-recorder">
  <template>
    <style>
     .ctrlbutton {
       display: flex;
       justify-content: center;
       align-items: center;
       margin: 0px; padding: 4px;
       width: 30px; height: 30px;
       background-color:#ffffff;
       outline: 0px #ffffff solid;
       font-weight:bold;
       width:100px;
       box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px rgba(0,0,0,0.24);
       transition: all 0.3s cubic-bezier(.25,.8,.25,1);
     }
     .ctrlbutton:hover {
       box-shadow: 0 3px 6px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
     }
     .ctrlbutton:active {
       box-shadow: 0 0px 0px rgba(0,0,0,0.16), 0 3px 6px rgba(0,0,0,0.23);
     }
     .ctrlframe {
       display:table;
       margin:10px auto;
     }
     .record {
       border-radius:50px;
       background-color:#ffffff;
       border: 0px solid #cfcfcf;
       color: #ed1720/*D32F2F*/;
       font-size:1.2em
     }
     .recording {
       border-radius:10px;
       background-color: #ed1720/*D32F2F*/;
       border: 0px solid #cfcfcf;
       color: #ffffff;
       font-size:1.3em
     }
     .container {
       padding:20px;
       width:400px; height:320px;
       background: #fff;
       border:1px solid #eeeeee;
       border-radius: 4px;
       clear:both;
       margin:0 auto;
     }
     .wavearea {
       width:390px; height:280px;
       margin:0px auto;
     }
     .clearboth { clear:both }
    </style>
    <div class="container">
      <div id="wave" class="wavearea"><canvas id="wcanvas"></canvas></div>
      <div class="ctrlframe"><button id="ctrl" class="ctrlbutton record">●</button></div>
    </div> 
   <div class="clearboth"></div>
  </template>
  <script>
  Polymer({
       is: "x-recorder",
       properties: {
           bufSize: {
               type: Number,
               value: 4096
           }
       },
       ready: function() {
           this.audioCtx=new AudioContext();
           this.audioBuf=[];
           this.stream=null;
           this.analyser=null;
           this.sp=null;
           this.isRecording=false;
           this.canvas=document.querySelector("#wcanvas");
           this.canvas.width="390"; this.canvas.height="270";
           this.cCtx=this.canvas.getContext("2d");
           this.drawScale();

           this.$["ctrl"].addEventListener("mousedown", toggleRec.bind(this));
           function toggleRec(event) {
               if(this.isRecording===false) {
                   this.startRec.bind(this)();
                   this.isRecording=true;
                   event.target.innerHTML="■";
                   event.target.className=
                       event.target.className.replace(/ record/, "").trim()+ " recording";
               } else {
                   this.stopRec.bind(this)();
                   this.isRecording=false;
                   event.target.innerHTML="●";
                   event.target.className=
                       event.target.className.replace(/ recording/, "").trim() + " record";
               }
           }
       },
       drawScale: function() {
           const w=this.canvas.width; const h=this.canvas.height;
           this.cCtx.fillStyle="rgba(220, 220, 220, 0.4)";
           this.cCtx.clearRect(0, 0, w, h);
           this.cCtx.fillRect(0, 0, w, h);

           this.cCtx.beginPath();
           this.cCtx.strokeStyle="rgba(255, 255, 255, 1)";
           this.cCtx.moveTo(0, h/2);
           this.cCtx.lineTo(w, h/2);

           const vLine=3;
           this.cCtx.lineTo(i*w/vLine, h);
           for(var i=1; i<vLine; i++) {
               this.cCtx.moveTo(i*w/vLine, 0);
               this.cCtx.lineTo(i*w/vLine, h);
           }
           this.cCtx.stroke();
           this.cCtx.closePath();
       },
       drawRecordedWave: function(wave) {
           const w=this.canvas.width, h=this.canvas.height;
           const center={x:w/2, y:h/2};

           this.drawScale();
           this.cCtx.lineWidth=0.5;
           //this.cCtx.strokeStyle="rgba(155, 155, 155, 1)";
           //this.cCtx.strokeStyle="rgba(0,230,118,1)";// #00E676
           this.cCtx.strokeStyle="rgba(62,179,112,1)";// #3EB370
           this.cCtx.beginPath();
           this.cCtx.moveTo(0, center.y);
           const tick={x:w/(wave.data.length), y:h/(2.2*Math.ceil(wave.stat.max))};
           for(var i=0; i<wave.data.length; i++) {
               this.cCtx.lineTo(i*tick.x, wave.data[i]*tick.y+h/2);
           }
           this.cCtx.closePath();
           this.cCtx.stroke();
       },
       drawRecordingLevel: function() {
           const graphType="spectrum"; // "spectrum" "waveform"
           const data = new Uint8Array(512);
           const w=this.canvas.width, h=this.canvas.height;
           const center={x:w/2, y:h/2};
           const tick={x:w/256, y:h/(2.2*1.2)};
           this.drawScale();

           switch(graphType) {
               case "spectrum":
                   // Spectrum Data
                   this.analyser.getByteFrequencyData(data);
                   //this.cCtx.fillStyle = "rgba(204, 204, 204, 0.8)";
                   //this.cCtx.fillStyle = "rgba(255,138,128, 1)"; // #FF8A80
                   this.cCtx.fillStyle = "rgba(253,106,108, 1)"; // #FD6A6C
                   for(var i = 0; i < 256; ++i) {
                       this.cCtx.fillRect(i*tick.x, h - data[i], 1, data[i]);
                   }
                   this.cCtx.stroke();
                   break;
               case "waveform":
                   // WaveForm Data
                   this.analyser.getByteTimeDomainData(data);
                   //this.cCtx.strokeStyle="rgba(155, 155, 155, 1)";
                   this.cCtx.strokeStyle = "rgba(255,138,128, 1)"; // #FF8A80
                   this.cCtx.moveTo(0, center.y);
                   this.cCtx.beginPath();
                   for(var i = 0; i < 256; ++i) {
                       this.cCtx.lineTo(i*tick.x, data[i]+7);
                   }
                   this.cCtx.closePath();
                   this.cCtx.stroke();
                   break;
           }

           this.animationId=requestAnimationFrame(this.drawRecordingLevel.bind(this));
       },
       record: function(stream) {
           this.analyser=this.audioCtx.createAnalyser();
           this.stream=stream;
           this.audioBuf=[];
           const mediaStream=this.audioCtx.createMediaStreamSource(this.stream);
           this.sp=this.audioCtx.createScriptProcessor(this.bufSize, 1, 1);
           mediaStream.connect(this.analyser).connect(this.sp);
           this.sp.onaudioprocess = process.bind(this);
           function process(event) {
               const data=event.inputBuffer.getChannelData(0);
               const buf=new Float32Array(this.bufSize);
               for(var i=0; i<this.bufSize; i++) {
                   buf[i]=data[i];
               }
               this.audioBuf.push(buf);
           };
           this.sp.connect(this.audioCtx.destination);
           this.drawRecordingLevel.bind(this)();
       },
       startRec: function() {  
           if(this.isRecording===false) {
               this.isRecording=true;
               if(this.stream===null) {
                   options={video:false, audio:true};
                   navigator.getUserMedia(
                       options,
                       (stream) => { 
                           this.record(stream); 
                       },
                       (msg) => { console.log("[err] ", msg); }
                   );
               } else {
                   this.record(stream);
               }
           }
       },
       stopRec: function() {
           if(this.isRecording===true) {
               this.isRecording=false;
               this.sp.disconnect();
               if(this.stream!=null) {
                   var tracks=this.stream.getTracks();
                   for(var i=0; i<tracks.length; i++) tracks[i].stop();
                   this.stream=null;
               }
               const buf=this.audioCtx.createBuffer(
                   1, 
                   this.audioBuf.length * this.bufSize, this.audioCtx.sampleRate);
               const chData=buf.getChannelData(0);
               var stat={min:999999, max:-999999};
               for (var i = 0; i < this.audioBuf.length; i++) {
                   for (var j = 0; j < this.bufSize; j++) {
                       if(stat.min>this.audioBuf[i][j]) stat.min=this.audioBuf[i][j];
                       if(stat.max<this.audioBuf[i][j]) stat.max=this.audioBuf[i][j];
                       chData[i * this.bufSize + j] = this.audioBuf[i][j];
                   }
               }
               this.data={raw: this.audioBuf, audioBuffer: buf, Float32Array: {stat: stat, data:chData} };
               cancelAnimationFrame(this.animationId);
               this.drawRecordedWave(this.data.Float32Array);
               this.fire("record-stop");
           }
       },
       getAudioBuffer: function() {
           if(this.isRecording===false) {
               /*
               // test code whether recording is succeed
               var src=this.audioCtx.createBufferSource();
               src.buffer=this.data.buf;
               src.connect(this.audioCtx.destination);
               src.start();
               */
               return this.data;
           } else {
               console.log("[Still Recording]");
           }
       }
   });
  </script>
</dom-module>