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![var onAudioProcess = function (ev) {
inputBuffer = ev.inputBuffer;
outputBuffer = ev.outputBuffer;
inputData = inputBuffer.getChannelData(0);
outputData0 = outputBuffer.getChannelData(0);
outputData1 = outputBuffer.getChannelData(1);
for (var sample = 0, len = inputData.length; sample < len; sample++) {
outputData0[sample] = (1 - panelX) * inputData[sample];
outputData1[sample] = panelX * inputData[sample];
}
}](https://image.slidesharecdn.com/jsconfuy20152-150425140203-conversion-gate02/85/Digital-Signal-Processing-w-Javascript-13-320.jpg)
![// Original (37)
[1.1, 1.8, 2.3, 2.4, 1.9, 2.7, 3.2, 3.4, 3.1]
// Quantized (19)
[1, 2, 2, 2, 2, 3, 3, 3, 3]
// Compressed (15)
[1, ‘2 4’, ‘3 4’]](https://image.slidesharecdn.com/jsconfuy20152-150425140203-conversion-gate02/85/Digital-Signal-Processing-w-Javascript-20-320.jpg)
![var red = [];
var green = [];
var blue = [];
var alpha = [];
for (var i = 4; i < imgData.data.length; i+=4) {
red.push(imgData.data[i])
green.push(imgData.data[i+1])
blue.push(imgData.data[i+2])
alpha.push(imgData.data[i+3])
}](https://image.slidesharecdn.com/jsconfuy20152-150425140203-conversion-gate02/85/Digital-Signal-Processing-w-Javascript-27-320.jpg)
Uploaded byRafael Specht da Silva
Digital Signal Processing w/ Javascript
The document outlines digital signal processing techniques using JavaScript, focusing on mathematical manipulation of audio signals. It includes code snippets for audio buffer playback, processing, and image data manipulation, along with examples of quantization and compression. Additionally, references to various images and projects are provided to support the concepts discussed.
Digital Signal Processing w/ Javascript
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- 5. “... mathematical manipulation ofan information signal to modify or improve it”
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- 12. var playBuffer =function (buffer) { source = context.createBufferSource(); source.buffer = buffer; var processor = context.createScriptProcessor(512, 2, 2); processor.onaudioprocess = onAudioProcess; source.connect(processor); processor.connect(context.destination); source.start(0, startOffset % buffer.duration); }
- 13. var onAudioProcess =function (ev) { inputBuffer = ev.inputBuffer; outputBuffer = ev.outputBuffer; inputData = inputBuffer.getChannelData(0); outputData0 = outputBuffer.getChannelData(0); outputData1 = outputBuffer.getChannelData(1); for (var sample = 0, len = inputData.length; sample < len; sample++) { outputData0[sample] = (1 - panelX) * inputData[sample]; outputData1[sample] = panelX * inputData[sample]; } }
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- 20. // Original (37) [1.1,1.8, 2.3, 2.4, 1.9, 2.7, 3.2, 3.4, 3.1] // Quantized (19) [1, 2, 2, 2, 2, 3, 3, 3, 3] // Compressed (15) [1, ‘2 4’, ‘3 4’]
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- 22. var canvas =document.getElementById('canvas'); var ctx = canvas.getContext('2d'); function make_base(src) { base_image = new Image(); base_image.src = src; base_image.onload = function(){ ctx.drawImage(base_image, 0, 0); imageLoaded(base_image); } }
- 23. var img =ctx.getImageData( 0, 0, canvas.width, canvas.height );
- 24. img.height // number img.width// number img.data // Uint8ClampedArray r g b a r g b a [65, 113, 130, 255, 65, 113, 130, 255, ...
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- 27. var red =[]; var green = []; var blue = []; var alpha = []; for (var i = 4; i < imgData.data.length; i+=4) { red.push(imgData.data[i]) green.push(imgData.data[i+1]) blue.push(imgData.data[i+2]) alpha.push(imgData.data[i+3]) }
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