meyda/dist/web/meyda.min.js

Real-time feature extraction for the web audio api

!function(r,t){"object"==typeof exports&&"undefined"!=typeof module?module.exports=t():"function"==typeof define&&define.amd?define(t):(r="undefined"!=typeof globalThis?globalThis:r||self).Meyda=t()}(this,(function(){"use strict";function r(r,t,e){if(e||2===arguments.length)for(var a,n=0,o=t.length;n<o;n++)!a&&n in t||(a||(a=Array.prototype.slice.call(t,0,n)),a[n]=t[n]);return r.concat(a||Array.prototype.slice.call(t))}var t=Object.freeze({__proto__:null,blackman:function(r){for(var t=new Float32Array(r),e=2*Math.PI/(r-1),a=2*e,n=0;n<r/2;n++)t[n]=.42-.5*Math.cos(n*e)+.08*Math.cos(n*a);for(n=Math.ceil(r/2);n>0;n--)t[r-n]=t[n-1];return t},hamming:function(r){for(var t=new Float32Array(r),e=0;e<r;e++)t[e]=.54-.46*Math.cos(2*Math.PI*(e/r-1));return t},hanning:function(r){for(var t=new Float32Array(r),e=0;e<r;e++)t[e]=.5-.5*Math.cos(2*Math.PI*e/(r-1));return t},sine:function(r){for(var t=Math.PI/(r-1),e=new Float32Array(r),a=0;a<r;a++)e[a]=Math.sin(t*a);return e}}),e={};function a(r){for(;r%2==0&&r>1;)r/=2;return 1===r}function n(r,a){if("rect"!==a){if(""!==a&&a||(a="hanning"),e[a]||(e[a]={}),!e[a][r.length])try{e[a][r.length]=t[a](r.length)}catch(r){throw new Error("Invalid windowing function")}r=function(r,t){for(var e=[],a=0;a<Math.min(r.length,t.length);a++)e[a]=r[a]*t[a];return e}(r,e[a][r.length])}return r}function o(r,t,e){for(var a=new Float32Array(r),n=0;n<a.length;n++)a[n]=n*t/e,a[n]=13*Math.atan(a[n]/1315.8)+3.5*Math.atan(Math.pow(a[n]/7518,2));return a}function i(r){return Float32Array.from(r)}function u(r){return 1125*Math.log(1+r/700)}function f(r,t,e){for(var a,n=new Float32Array(r+2),o=new Float32Array(r+2),i=t/2,f=u(0),c=(u(i)-f)/(r+1),l=new Array(r+2),s=0;s<n.length;s++)n[s]=s*c,o[s]=(a=n[s],700*(Math.exp(a/1125)-1)),l[s]=Math.floor((e+1)*o[s]/t);for(var m=new Array(r),p=0;p<m.length;p++){m[p]=new Array(e/2+1).fill(0);for(s=l[p];s<l[p+1];s++)m[p][s]=(s-l[p])/(l[p+1]-l[p]);for(s=l[p+1];s<l[p+2];s++)m[p][s]=(l[p+2]-s)/(l[p+2]-l[p+1])}return m}function c(t,e,a,n,o,i,u){void 0===n&&(n=5),void 0===o&&(o=2),void 0===i&&(i=!0),void 0===u&&(u=440);var f=Math.floor(a/2)+1,c=new Array(a).fill(0).map((function(r,n){return t*function(r,t){return Math.log2(16*r/t)}(e*n/a,u)}));c[0]=c[1]-1.5*t;var l,s,m,p=c.slice(1).map((function(r,t){return Math.max(r-c[t])}),1).concat([1]),h=Math.round(t/2),g=new Array(t).fill(0).map((function(r,e){return c.map((function(r){return(10*t+h+r-e)%t-h}))})),w=g.map((function(r,t){return r.map((function(r,e){return Math.exp(-.5*Math.pow(2*g[t][e]/p[e],2))}))}));if(s=(l=w)[0].map((function(){return 0})),m=l.reduce((function(r,t){return t.forEach((function(t,e){r[e]+=Math.pow(t,2)})),r}),s).map(Math.sqrt),w=l.map((function(r,t){return r.map((function(r,t){return r/(m[t]||1)}))})),o){var v=c.map((function(r){return Math.exp(-.5*Math.pow((r/t-n)/o,2))}));w=w.map((function(r){return r.map((function(r,t){return r*v[t]}))}))}return i&&(w=r(r([],w.slice(3),!0),w.slice(0,3),!0)),w.map((function(r){return r.slice(0,f)}))}function l(r,t){for(var e=0,a=0,n=0;n<t.length;n++)e+=Math.pow(n,r)*Math.abs(t[n]),a+=t[n];return e/a}function s(r){var t=r.ampSpectrum,e=r.barkScale,a=r.numberOfBarkBands,n=void 0===a?24:a;if("object"!=typeof t||"object"!=typeof e)throw new TypeError;var o=n,i=new Float32Array(o),u=0,f=t,c=new Int32Array(o+1);c[0]=0;for(var l=e[f.length-1]/o,s=1,m=0;m<f.length;m++)for(;e[m]>l;)c[s++]=m,l=s*e[f.length-1]/o;c[o]=f.length-1;for(m=0;m<o;m++){for(var p=0,h=c[m];h<c[m+1];h++)p+=f[h];i[m]=Math.pow(p,.23)}for(m=0;m<i.length;m++)u+=i[m];return{specific:i,total:u}}function m(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;for(var e=new Float32Array(t.length),a=0;a<e.length;a++)e[a]=Math.pow(t[a],2);return e}function p(r){var t=r.ampSpectrum,e=r.melFilterBank,a=r.bufferSize;if("object"!=typeof t)throw new TypeError("Valid ampSpectrum is required to generate melBands");if("object"!=typeof e)throw new TypeError("Valid melFilterBank is required to generate melBands");for(var n=m({ampSpectrum:t}),o=e.length,i=Array(o),u=new Float32Array(o),f=0;f<u.length;f++){i[f]=new Float32Array(a/2),u[f]=0;for(var c=0;c<a/2;c++)i[f][c]=e[f][c]*n[c],u[f]+=i[f][c];u[f]=Math.log(u[f]+1)}return Array.prototype.slice.call(u)}function h(r){return r&&r.__esModule&&Object.prototype.hasOwnProperty.call(r,"default")?r.default:r}var g=null;var w=h((function(r,t){var e=r.length;return t=t||2,g&&g[e]||function(r){(g=g||{})[r]=new Array(r*r);for(var t=Math.PI/r,e=0;e<r;e++)for(var a=0;a<r;a++)g[r][a+e*r]=Math.cos(t*(a+.5)*e)}(e),r.map((function(){return 0})).map((function(a,n){return t*r.reduce((function(r,t,a,o){return r+t*g[e][a+n*e]}),0)}))}));var v=Object.freeze({__proto__:null,amplitudeSpectrum:function(r){return r.ampSpectrum},buffer:function(r){return r.signal},chroma:function(r){var t=r.ampSpectrum,e=r.chromaFilterBank;if("object"!=typeof t)throw new TypeError("Valid ampSpectrum is required to generate chroma");if("object"!=typeof e)throw new TypeError("Valid chromaFilterBank is required to generate chroma");var a=e.map((function(r,e){return t.reduce((function(t,e,a){return t+e*r[a]}),0)})),n=Math.max.apply(Math,a);return n?a.map((function(r){return r/n})):a},complexSpectrum:function(r){return r.complexSpectrum},energy:function(r){var t=r.signal;if("object"!=typeof t)throw new TypeError;for(var e=0,a=0;a<t.length;a++)e+=Math.pow(Math.abs(t[a]),2);return e},loudness:s,melBands:p,mfcc:function(r){var t=r.ampSpectrum,e=r.melFilterBank,a=r.numberOfMFCCCoefficients,n=r.bufferSize,o=Math.min(40,Math.max(1,a||13));if(e.length<o)throw new Error("Insufficient filter bank for requested number of coefficients");var i=p({ampSpectrum:t,melFilterBank:e,bufferSize:n});return w(i).slice(0,o)},perceptualSharpness:function(r){for(var t=s({ampSpectrum:r.ampSpectrum,barkScale:r.barkScale}),e=t.specific,a=0,n=0;n<e.length;n++)a+=n<15?(n+1)*e[n+1]:.066*Math.exp(.171*(n+1));return a*=.11/t.total},perceptualSpread:function(r){for(var t=s({ampSpectrum:r.ampSpectrum,barkScale:r.barkScale}),e=0,a=0;a<t.specific.length;a++)t.specific[a]>e&&(e=t.specific[a]);return Math.pow((t.total-e)/t.total,2)},powerSpectrum:m,rms:function(r){var t=r.signal;if("object"!=typeof t)throw new TypeError;for(var e=0,a=0;a<t.length;a++)e+=Math.pow(t[a],2);return e/=t.length,e=Math.sqrt(e)},spectralCentroid:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;return l(1,t)},spectralCrest:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;var e=0,a=-1/0;return t.forEach((function(r){e+=Math.pow(r,2),a=r>a?r:a})),e/=t.length,e=Math.sqrt(e),a/e},spectralFlatness:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;for(var e=0,a=0,n=0;n<t.length;n++)e+=Math.log(t[n]),a+=t[n];return Math.exp(e/t.length)*t.length/a},spectralFlux:function(r){var t=r.signal,e=r.previousSignal,a=r.bufferSize;if("object"!=typeof t||"object"!=typeof e)throw new TypeError;for(var n=0,o=-a/2;o<t.length/2-1;o++)x=Math.abs(t[o])-Math.abs(e[o]),n+=(x+Math.abs(x))/2;return n},spectralKurtosis:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;var e=t,a=l(1,e),n=l(2,e),o=l(3,e),i=l(4,e);return(-3*Math.pow(a,4)+6*a*n-4*a*o+i)/Math.pow(Math.sqrt(n-Math.pow(a,2)),4)},spectralRolloff:function(r){var t=r.ampSpectrum,e=r.sampleRate;if("object"!=typeof t)throw new TypeError;for(var a=t,n=e/(2*(a.length-1)),o=0,i=0;i<a.length;i++)o+=a[i];for(var u=.99*o,f=a.length-1;o>u&&f>=0;)o-=a[f],--f;return(f+1)*n},spectralSkewness:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;var e=l(1,t),a=l(2,t),n=l(3,t);return(2*Math.pow(e,3)-3*e*a+n)/Math.pow(Math.sqrt(a-Math.pow(e,2)),3)},spectralSlope:function(r){var t=r.ampSpectrum,e=r.sampleRate,a=r.bufferSize;if("object"!=typeof t)throw new TypeError;for(var n=0,o=0,i=new Float32Array(t.length),u=0,f=0,c=0;c<t.length;c++){n+=t[c];var l=c*e/a;i[c]=l,u+=l*l,o+=l,f+=l*t[c]}return(t.length*f-o*n)/(n*(u-Math.pow(o,2)))},spectralSpread:function(r){var t=r.ampSpectrum;if("object"!=typeof t)throw new TypeError;return Math.sqrt(l(2,t)-Math.pow(l(1,t),2))},zcr:function(r){var t=r.signal;if("object"!=typeof t)throw new TypeError;for(var e=0,a=1;a<t.length;a++)(t[a-1]>=0&&t[a]<0||t[a-1]<0&&t[a]>=0)&&e++;return e}});function d(r){if(Array.isArray(r)){for(var t=0,e=Array(r.length);t<r.length;t++)e[t]=r[t];return e}return Array.from(r)}var y={},S={},_={bitReverseArray:function(r){if(void 0===y[r]){for(var t=(r-1).toString(2).length,e="0".repeat(t),a={},n=0;n<r;n++){var o=n.toString(2);o=e.substr(o.length)+o,o=[].concat(d(o)).reverse().join(""),a[n]=parseInt(o,2)}y[r]=a}return y[r]},multiply:function(r,t){return{real:r.real*t.real-r.imag*t.imag,imag:r.real*t.imag+r.imag*t.real}},add:function(r,t){return{real:r.real+t.real,imag:r.imag+t.imag}},subtract:function(r,t){return{real:r.real-t.real,imag:r.imag-t.imag}},euler:function(r,t){var e=-2*Math.PI*r/t;return{real:Math.cos(e),imag:Math.sin(e)}},conj:function(r){return r.imag*=-1,r},constructComplexArray:function(r){var t={};t.real=void 0===r.real?r.slice():r.real.slice();var e=t.real.length;return void 0===S[e]&&(S[e]=Array.apply(null,Array(e)).map(Number.prototype.valueOf,0)),t.imag=S[e].slice(),t}},b=function(r){var t={};void 0===r.real||void 0===r.imag?t=_.constructComplexArray(r):(t.real=r.real.slice(),t.imag=r.imag.slice());var e=t.real.length,a=Math.log2(e);if(Math.round(a)!=a)throw new Error("Input size must be a power of 2.");if(t.real.length!=t.imag.length)throw new Error("Real and imaginary components must have the same length.");for(var n=_.bitReverseArray(e),o={real:[],imag:[]},i=0;i<e;i++)o.real[n[i]]=t.real[i],o.imag[n[i]]=t.imag[i];for(var u=0;u<e;u++)t.real[u]=o.real[u],t.imag[u]=o.imag[u];for(var f=1;f<=a;f++)for(var c=Math.pow(2,f),l=0;l<c/2;l++)for(var s=_.euler(l,c),m=0;m<e/c;m++){var p=c*m+l,h=c*m+l+c/2,g={real:t.real[p],imag:t.imag[p]},w={real:t.real[h],imag:t.imag[h]},v=_.multiply(s,w),d=_.subtract(g,v);t.real[h]=d.real,t.imag[h]=d.imag;var y=_.add(v,g);t.real[p]=y.real,t.imag[p]=y.imag}return t},M=b,F=function(){function r(r,t){var e=this;if(this._m=t,!r.audioContext)throw this._m.errors.noAC;if(r.bufferSize&&!a(r.bufferSize))throw this._m._errors.notPow2;if(!r.source)throw this._m._errors.noSource;this._m.audioContext=r.audioContext,this._m.bufferSize=r.bufferSize||this._m.bufferSize||256,this._m.hopSize=r.hopSize||this._m.hopSize||this._m.bufferSize,this._m.sampleRate=r.sampleRate||this._m.audioContext.sampleRate||44100,this._m.callback=r.callback,this._m.windowingFunction=r.windowingFunction||"hanning",this._m.featureExtractors=v,this._m.EXTRACTION_STARTED=r.startImmediately||!1,this._m.channel="number"==typeof r.channel?r.channel:0,this._m.inputs=r.inputs||1,this._m.outputs=r.outputs||1,this._m.numberOfMFCCCoefficients=r.numberOfMFCCCoefficients||this._m.numberOfMFCCCoefficients||13,this._m.numberOfBarkBands=r.numberOfBarkBands||this._m.numberOfBarkBands||24,this._m.spn=this._m.audioContext.createScriptProcessor(this._m.bufferSize,this._m.inputs,this._m.outputs),this._m.spn.connect(this._m.audioContext.destination),this._m._featuresToExtract=r.featureExtractors||[],this._m.barkScale=o(this._m.bufferSize,this._m.sampleRate,this._m.bufferSize),this._m.melFilterBank=f(Math.max(this._m.melBands,this._m.numberOfMFCCCoefficients),this._m.sampleRate,this._m.bufferSize),this._m.inputData=null,this._m.previousInputData=null,this._m.frame=null,this._m.previousFrame=null,this.setSource(r.source),this._m.spn.onaudioprocess=function(r){var t;null!==e._m.inputData&&(e._m.previousInputData=e._m.inputData),e._m.inputData=r.inputBuffer.getChannelData(e._m.channel),e._m.previousInputData?((t=new Float32Array(e._m.previousInputData.length+e._m.inputData.length-e._m.hopSize)).set(e._m.previousInputData.slice(e._m.hopSize)),t.set(e._m.inputData,e._m.previousInputData.length-e._m.hopSize)):t=e._m.inputData;var a=function(r,t,e){if(r.length<t)throw new Error("Buffer is too short for frame length");if(e<1)throw new Error("Hop length cannot be less that 1");if(t<1)throw new Error("Frame length cannot be less that 1");var a=1+Math.floor((r.length-t)/e);return new Array(a).fill(0).map((function(a,n){return r.slice(n*e,n*e+t)}))}(t,e._m.bufferSize,e._m.hopSize);a.forEach((function(r){e._m.frame=r;var t=e._m.extract(e._m._featuresToExtract,e._m.frame,e._m.previousFrame);"function"==typeof e._m.callback&&e._m.EXTRACTION_STARTED&&e._m.callback(t),e._m.previousFrame=e._m.frame}))}}return r.prototype.start=function(r){this._m._featuresToExtract=r||this._m._featuresToExtract,this._m.EXTRACTION_STARTED=!0},r.prototype.stop=function(){this._m.EXTRACTION_STARTED=!1},r.prototype.setSource=function(r){this._m.source&&this._m.source.disconnect(this._m.spn),this._m.source=r,this._m.source.connect(this._m.spn)},r.prototype.setChannel=function(r){r<=this._m.inputs?this._m.channel=r:console.error("Channel ".concat(r," does not exist. Make sure you've provided a value for 'inputs' that is greater than ").concat(r," when instantiating the MeydaAnalyzer"))},r.prototype.get=function(r){return this._m.inputData?this._m.extract(r||this._m._featuresToExtract,this._m.inputData,this._m.previousInputData):null},r}(),A={audioContext:null,spn:null,bufferSize:512,sampleRate:44100,melBands:26,chromaBands:12,callback:null,windowingFunction:"hanning",featureExtractors:v,EXTRACTION_STARTED:!1,numberOfMFCCCoefficients:13,numberOfBarkBands:24,_featuresToExtract:[],windowing:n,_errors:{notPow2:new Error("Meyda: Buffer size must be a power of 2, e.g. 64 or 512"),featureUndef:new Error("Meyda: No features defined."),invalidFeatureFmt:new Error("Meyda: Invalid feature format"),invalidInput:new Error("Meyda: Invalid input."),noAC:new Error("Meyda: No AudioContext specified."),noSource:new Error("Meyda: No source node specified.")},createMeydaAnalyzer:function(r){return new F(r,Object.assign({},A))},listAvailableFeatureExtractors:function(){return Object.keys(this.featureExtractors)},extract:function(r,t,e){var n=this;if(!t)throw this._errors.invalidInput;if("object"!=typeof t)throw this._errors.invalidInput;if(!r)throw this._errors.featureUndef;if(!a(t.length))throw this._errors.notPow2;void 0!==this.barkScale&&this.barkScale.length==this.bufferSize||(this.barkScale=o(this.bufferSize,this.sampleRate,this.bufferSize)),void 0!==this.melFilterBank&&this.barkScale.length==this.bufferSize&&this.melFilterBank.length==this.melBands||(this.melFilterBank=f(Math.max(this.melBands,this.numberOfMFCCCoefficients),this.sampleRate,this.bufferSize)),void 0!==this.chromaFilterBank&&this.chromaFilterBank.length==this.chromaBands||(this.chromaFilterBank=c(this.chromaBands,this.sampleRate,this.bufferSize)),"buffer"in t&&void 0===t.buffer?this.signal=i(t):this.signal=t;var u=E(t,this.windowingFunction,this.bufferSize);if(this.signal=u.windowedSignal,this.complexSpectrum=u.complexSpectrum,this.ampSpectrum=u.ampSpectrum,e){var l=E(e,this.windowingFunction,this.bufferSize);this.previousSignal=l.windowedSignal,this.previousComplexSpectrum=l.complexSpectrum,this.previousAmpSpectrum=l.ampSpectrum}var s=function(r){return n.featureExtractors[r]({ampSpectrum:n.ampSpectrum,chromaFilterBank:n.chromaFilterBank,complexSpectrum:n.complexSpectrum,signal:n.signal,bufferSize:n.bufferSize,sampleRate:n.sampleRate,barkScale:n.barkScale,melFilterBank:n.melFilterBank,previousSignal:n.previousSignal,previousAmpSpectrum:n.previousAmpSpectrum,previousComplexSpectrum:n.previousComplexSpectrum,numberOfMFCCCoefficients:n.numberOfMFCCCoefficients,numberOfBarkBands:n.numberOfBarkBands})};if("object"==typeof r)return r.reduce((function(r,t){var e;return Object.assign({},r,((e={})[t]=s(t),e))}),{});if("string"==typeof r)return s(r);throw this._errors.invalidFeatureFmt}},E=function(r,t,e){var a={};void 0===r.buffer?a.signal=i(r):a.signal=r,a.windowedSignal=n(a.signal,t),a.complexSpectrum=M(a.windowedSignal),a.ampSpectrum=new Float32Array(e/2);for(var o=0;o<e/2;o++)a.ampSpectrum[o]=Math.sqrt(Math.pow(a.complexSpectrum.real[o],2)+Math.pow(a.complexSpectrum.imag[o],2));return a};return"undefined"!=typeof window&&(window.Meyda=A),A}));
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