Basic decoding with edge effects

index.html

@@ -12,24 +12,24 @@
   <script src="wrapper.js"></script>
     <input type="file" id="file" name="file" />
   <script>
+    var minPortion = 20480;
+    var maxPortion = 40960;
     var time = 0;
     var ctx = new AudioContext();
     ctx.suspend();
     var decoder;
+    var fragments = [];
+    var noize = [];
+    var decoding = false;
     function onChange(e) {
         var file = e.target.files[0];
         
         var reader = new FileReader();
         reader.onload = function(e) {
             decoder = new Module.Decoder();
-            var buffer = reader.result;
-            var src = new Uint8Array(buffer);
-            var ptr = Module._malloc(buffer.byteLength);
-            var arr = new Uint8Array(Module.HEAPU8.buffer, ptr, buffer.byteLength);
-            arr.set(src, 0);
+            createFileFragments(reader.result);
             
-            decoder.addFragment(ptr, buffer.byteLength);
-            schedule();
+            scheduleData();
             ctx.resume();
         }
         reader.readAsArrayBuffer(file);
@@ -37,8 +37,9 @@
     }
     
     function schedule() {
+        decoding = false;
         if (decoder.hasMore()) {
-            var audio = decoder.decode(50);
+            var audio = decoder.decode(20);
             if (audio) {
                 var source = ctx.createBufferSource();
                 source.buffer = audio;
@@ -47,14 +48,55 @@
                 time += audio.duration;
                 
                 setTimeout(schedule, Math.floor(audio.duration * 200));
+                decoding = true;
             } else {
-                decoder.delete();
+                //decoder.delete();
             }
         } else {
-            decoder.delete();
+            //decoder.delete();
         }
     }
     
+    function scheduleData() {
+        if (fragments.length) {
+            var frag = fragments.shift();
+            
+            decoder.addFragment(frag.ptr, frag.length);
+            
+            if (fragments.length) {
+                setTimeout(scheduleData, 50);
+            }
+            
+            if (!decoding) {
+                schedule();
+            }
+        }
+    }
+    
+    function createFileFragments(buffer) {
+        var src = new Uint8Array(buffer);
+        var shoved = 0;
+        
+        while (shoved !== src.length) {
+            var ps = Math.min(Math.floor(Math.random() * (maxPortion - minPortion) + minPortion), src.length - shoved);
+            var ptr = Module._malloc(ps);
+            
+            var arr = new Uint8Array(Module.HEAPU8.buffer, ptr, ps);
+            var portion = new Uint8Array(buffer, shoved, ps)
+            arr.set(portion, 0);
+            
+            shoved += ps;
+            
+            fragments.push({
+                ptr: ptr,
+                length: ps
+            });
+            
+            noize.push(Module._malloc(256));
+        }
+    }
+    
+    
     document.getElementById("file").addEventListener("change", onChange, false);
   </script>
   </body>