miselaytes-anton

/**
  Main thread (e.g. index.js)
 **/
const audioCtx = new AudioContext()

// Loads module script via AudioWorklet.
audioCtx.audioWorklet.addModule('reverb-processor.js')
    .then(() => getLiveAudio(audioCtx))
    .then((liveIn) => {
        // After the resolution of module loading, an AudioWorkletNode can be constructed.

miselaytes-anton

const inputSignal = readSignalFromSomewhere()
const outputSignal = new Array(inputSignal.length)
const delayInSamples = 44100
const delayBuffer = new Array(delayInSamples)
const decay = 0.5
let pointer = 0

inputSignal.forEach(sample => {
    const previousSample = delayBuffer[pointer % delayInSamples]
    delayBuffer[pointer] = sample + previousSample * decay

miselaytes-anton

const getImpulseBuffer = (audioCtx, impulseUrl) => {
    return fetch(impulseUrl)
    .then(response => response.arrayBuffer())
    .then(arrayBuffer => audioCtx.decodeAudioData(arrayBuffer))
}

const getLiveAudio = (audioCtx) => {
    return navigator.mediaDevices.getUserMedia({audio: true})
    .then(stream => audioCtx.createMediaStreamSource(stream));
} 

miselaytes-anton

//in this example we assume guitar sound and impulse response are loaded into arrays somehow
const samplingRate = 44100
// 1 second of an input sound (e.g. guitar chord)
const X = new Array(samplingRate * 1)
// 2 seconds of an impulse response (e.g echos of a clap in a room)
const H = new Array(samplingRate * 2)

//output sound (how chord would sound in this room)
const Y = new Array(X.length + H.length)
X.forEach((x, i) => {

miselaytes-anton

// Allows to set a parameter value for multiple nodes (of same kind) at the same time
function mergeParams(params){
    const singleParam = params[0]
    const parameter = {};
    const audioNodeMethods = Object.getOwnPropertyNames(AudioParam.prototype)
    .filter(prop => typeof singleParam[prop] === 'function')
    
    //allows things like parameter.setValueAtTime(x, ctx.currentTime)
    audioNodeMethods.forEach(method => {
        parameter[method] = (...argums) => {

miselaytes-anton

class Freeverb extends CompositeAudioNode {
    get wetGain () {
        return this._wet.gain;
    }
    get dryGain () {
        return this._dry.gain;
    }
    get roomSize() {
        return mergeParams(this._combFilters.map(comb => comb.resonance))
    }

miselaytes-anton

class LowpassCombFilter extends CompositeAudioNode {
    get resonance () {
        return this._gain.gain;
    }
    get dampening () {
        return this._lowPass.frequency;
    }
    get delayTime () {
        return this._delay.delayTime;
    }

miselaytes-anton

// static Low Pass Feedback Comb Filter
const audioCtx = new AudioContext()
const input = getOsc(audioCtx)
const combFilter = getCombFilter(audioCtx)
const output = audioCtx.destination

input
.connect(combFilter)
.connect(output)

miselaytes-anton

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

miselaytes-anton

#!/bin/bash

# Install build dependencies
yum install -y gcc libpng libjpeg libpng-devel libjpeg-devel ghostscript libtiff libtiff-devel freetype freetype-devel

# Get GraphicsMagick source
wget ftp://ftp.graphicsmagick.org/pub/GraphicsMagick/1.3/GraphicsMagick-1.3.9.tar.gz
tar zxvf GraphicsMagick-1.3.9.tar.gz

# Configure and compile