Decode audio files with AudioContext

js/ngfile.js

@@ -128,8 +128,8 @@ app.controller('mainController', function ($scope, $http, wave) {
         }
 
 
-        reader.onload = function (e) {
+      function parseTextData(inputText) {
-            var x = reader.result.split(/[\s,;\t\r\n]+/);
+        var x = inputText.split(/[\s,;\t\r\n]+/);
 
         var j = 0;
 
@@ -158,15 +158,44 @@ app.controller('mainController', function ($scope, $http, wave) {
         wave.sigData.splice(j, rm);
         }
         */
+      }
+
+      async function parseAudioData(inputBuffer) {
+        console.log("Converting a", inputBuffer.byteLength,
+          "bytes audio buffer to linear PCM");
+
+        var audioCtx = new AudioContext({ sampleRate: 44100 });
+        var pcmData = await audioCtx.decodeAudioData(inputBuffer);
+        var pcmSamples = pcmData.getChannelData(0); // Float32Array
+
+        wave.sigData = new Float64Array(pcmSamples);
+        wave.sigLength = pcmSamples.length;
+      }
+
+      reader.onload = async function (e) {
+        var input = reader.result;
+
+        if (input instanceof ArrayBuffer)
+          await parseAudioData(input);
+        else
+          parseTextData(input);
+
+        console.log("Input wave:", wave.sigLength, "samples");
+
         if (wave.transform == 1) {
           location.href = '#/display';
         } else if (wave.transform == 2) {
           location.href = '#/cdisplay';
         } else if (wave.transform == 4) {
           location.href = '#/denoise';
+        } else {
+          location.href = '#/cdisplay';
         }
       }
 
+      if (finp1.type == "audio/mpeg")
+        reader.readAsArrayBuffer(finp1);
+      else
         reader.readAsText(finp1);
     }