2 lines
4.4 KiB
JavaScript
2 lines
4.4 KiB
JavaScript
!function(){"use strict";function t(t){return function(t){if(Array.isArray(t))return e(t)}(t)||function(t){if("undefined"!=typeof Symbol&&null!=t[Symbol.iterator]||null!=t["@@iterator"])return Array.from(t)}(t)||function(t,r){if(!t)return;if("string"==typeof t)return e(t,r);var i=Object.prototype.toString.call(t).slice(8,-1);"Object"===i&&t.constructor&&(i=t.constructor.name);if("Map"===i||"Set"===i)return Array.from(t);if("Arguments"===i||/^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(i))return e(t,r)}(t)||function(){throw new TypeError("Invalid attempt to spread non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.")}()}function e(t,e){(null==e||e>t.length)&&(e=t.length);for(var r=0,i=new Array(e);r<e;r++)i[r]=t[r];return i}function r(t,e,r,i){this.fromSampleRate=t,this.toSampleRate=e,this.channels=0|r,this.noReturn=!!i,this.initialize()}r.prototype.initialize=function(){if(!(this.fromSampleRate>0&&this.toSampleRate>0&&this.channels>0))throw new Error("Invalid settings specified for the resampler.");this.fromSampleRate==this.toSampleRate?(this.resampler=this.bypassResampler,this.ratioWeight=1):(this.fromSampleRate<this.toSampleRate?(this.lastWeight=1,this.resampler=this.compileLinearInterpolation):(this.tailExists=!1,this.lastWeight=0,this.resampler=this.compileMultiTap),this.ratioWeight=this.fromSampleRate/this.toSampleRate)},r.prototype.compileLinearInterpolation=function(t){var e=t.length;this.initializeBuffers(e);var r,i,s=this.outputBufferSize,a=this.ratioWeight,f=this.lastWeight,n=0,o=0,h=0,l=this.outputBuffer;if(e%this.channels==0){if(e>0){for(;f<1;f+=a)for(n=1-(o=f%1),r=0;r<this.channels;++r)l[h++]=this.lastOutput[r]*n+t[r]*o;for(f--,e-=this.channels,i=Math.floor(f)*this.channels;h<s&&i<e;){for(n=1-(o=f%1),r=0;r<this.channels;++r)l[h++]=t[i+r]*n+t[i+this.channels+r]*o;f+=a,i=Math.floor(f)*this.channels}for(r=0;r<this.channels;++r)this.lastOutput[r]=t[i++];return this.lastWeight=f%1,this.bufferSlice(h)}return this.noReturn?0:[]}throw new Error("Buffer was of incorrect sample length.")},r.prototype.compileMultiTap=function(t){var e=[],r=t.length;this.initializeBuffers(r);var i=this.outputBufferSize;if(r%this.channels==0){if(r>0){for(var s=this.ratioWeight,a=0,f=0;f<this.channels;++f)e[f]=0;var n=0,o=0,h=!this.tailExists;this.tailExists=!1;var l=this.outputBuffer,u=0,p=0;do{if(h)for(a=s,f=0;f<this.channels;++f)e[f]=0;else{for(a=this.lastWeight,f=0;f<this.channels;++f)e[f]+=this.lastOutput[f];h=!0}for(;a>0&&n<r;){if(!(a>=(o=1+n-p))){for(f=0;f<this.channels;++f)e[f]+=t[n+f]*a;p+=a,a=0;break}for(f=0;f<this.channels;++f)e[f]+=t[n++]*o;p=n,a-=o}if(0!=a){for(this.lastWeight=a,f=0;f<this.channels;++f)this.lastOutput[f]=e[f];this.tailExists=!0;break}for(f=0;f<this.channels;++f)l[u++]=e[f]/s}while(n<r&&u<i);return this.bufferSlice(u)}return this.noReturn?0:[]}throw new Error("Buffer was of incorrect sample length.")},r.prototype.bypassResampler=function(t){return this.noReturn?(this.outputBuffer=t,t.length):t},r.prototype.bufferSlice=function(t){if(this.noReturn)return t;try{return this.outputBuffer.subarray(0,t)}catch(e){try{return this.outputBuffer.length=t,this.outputBuffer}catch(e){return this.outputBuffer.slice(0,t)}}},r.prototype.initializeBuffers=function(t){this.outputBufferSize=Math.ceil(t*this.toSampleRate/this.fromSampleRate);try{this.outputBuffer=new Float32Array(this.outputBufferSize),this.lastOutput=new Float32Array(this.channels)}catch(t){this.outputBuffer=[],this.lastOutput=[]}},self.transData=function(t){return"short16"===self.arrayBufferType&&(t=function(t){for(var e=new ArrayBuffer(2*t.length),r=new DataView(e),i=0,s=0;s<t.length;s+=1,i+=2){var a=Math.max(-1,Math.min(1,t[s]));r.setInt16(i,a<0?32768*a:32767*a,!0)}return r.buffer}(t=self.resampler.resampler(t))),t},self.onmessage=function(e){var i=e.data,s=i.type,a=i.data;if("init"===s){var f=a.frameSize,n=a.toSampleRate,o=a.fromSampleRate,h=a.arrayBufferType;return self.frameSize=f*Math.floor(o/n),self.resampler=new r(o,n,1),self.frameBuffer=[],void(self.arrayBufferType=h)}if("stop"===s&&(self.postMessage({frameBuffer:self.transData(self.frameBuffer),isLastFrame:!0}),self.frameBuffer=[]),"message"===s){var l,u=a;if(self.frameSize)return(l=self.frameBuffer).push.apply(l,t(u)),self.frameBuffer.length>=self.frameSize&&(self.postMessage({frameBuffer:self.transData(this.frameBuffer),isLastFrame:!1}),self.frameBuffer=[]),!0;u&&self.postMessage({frameBuffer:self.transData(u),isLastFrame:!1})}}}();
|