Merge branch 'master' of https://github.com/pcprince/wav-spectrogram

README.md

@@ -16,7 +16,11 @@ reader.onload = function() {
 
     var arrayBuffer = reader.result;
 
-    wavSpectro.drawSpectrogram(arrayBuffer, canvasElem, 'jet');
+    wavSpectro.drawSpectrogram({arrayBuffer: arrayBuffer, canvasElem: canvasElem, cmap: 'jet'}, function () {
+    
+        console.log("Done.");
+    
+    });
 
 };
 
@@ -25,7 +29,7 @@ reader.readAsArrayBuffer(fileInput.files[0]);
 
 ### Functions ###
 
-The draw function can be run with the following parameters.
+The draw function must be handed parameters in an object, named as such. Parameters with default values can be left out.
 
 Option         | Default     | Description
 ---------------|-------------|------------
@@ -35,3 +39,5 @@ Option         | Default     | Description
 `nfft`         | 512         | Buffer size of Fast Fourier Transform
 `frameLengthMs`| 0.1         | Length of frames signal is divided into before FFT is applied (given in milliseconds)
 `frameStepMs`  | 0.005       | Size of steps forward each frame takes (if less than `frameLengthMs` then frames overlap)
+
+As well as the params object, the draw function accepts a callback function.

wav-spectrogram.js

@@ -63,9 +63,16 @@ function medianFilter(array) {
 
 }
 
-function drawSpectrogram(arrayBuffer, canvasElem, cmap, nfft = 512, frameLengthMs = 0.1, frameStepMs = 0.005) {
+function drawSpectrogram(params, callback) {
 
-    var err, sampleRate, samples, sampleArray, frameLength, frameStep, numFrames, paddedArrayLength, frames, i, maxValue, minValue, spectrumFrames, spectrum, m, n, a, o, p, ctx, specWidth, specHeight, colours;
+    var arrayBuffer, canvasElem, cmap, nfft, frameLengthMs, frameStepMs, err, sampleRate, samples, sampleArray, frameLength, frameStep, numFrames, paddedArrayLength, frames, i, maxValue, minValue, spectrumFrames, spectrum, m, n, a, o, p, ctx, specWidth, specHeight, colours;
+
+    arrayBuffer = params.arrayBuffer;
+    canvasElem = params.canvasElem;
+    cmap = params.cmap;
+    nfft = params.nfft || 512;
+    frameLengthMs = params.frameLengthMs || 0.1;
+    frameStepMs = params.frameStepMs || 0.005;
 
     decode(arrayBuffer, (err, audioBuffer) => {
 
@@ -174,6 +181,8 @@ function drawSpectrogram(arrayBuffer, canvasElem, cmap, nfft = 512, frameLengthM
 
         }
 
+        typeof callback === 'function' && callback();
+
     });
 
 }