FFT.js

"use strict";


/** This and KissFFT.js are extracted from KissFFT-js  
 * https://github.com/j-funk/kissfft-js
 *
 * License is: 
 *
 * See KissFFT licence below for copyright details regarding the transpiled module.
 *
 * All original code in this repo (aside from the KissFFT implementation) is under
 * the following licence:
 *
 * Copyright (c) 2017 Julien Funk
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 *
 * ==================================================================================
 *
 *
 * Copyright (c) 2003-2010 Mark Borgerding
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided
 * with the distribution.
 * * Neither the author nor the names of any contributors may be used to endorse or promote
 * products derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
*/ 


var kissFFTModule = KissFFTModule({});

var kiss_fftr_alloc = kissFFTModule.cwrap(
    'kiss_fftr_alloc', 'number', ['number', 'number', 'number', 'number' ]
);

var kiss_fftr = kissFFTModule.cwrap(
    'kiss_fftr', 'void', ['number', 'number', 'number' ]
);

var kiss_fftri = kissFFTModule.cwrap(
    'kiss_fftri', 'void', ['number', 'number', 'number' ]
);

var kiss_fftr_free = kissFFTModule.cwrap(
    'kiss_fftr_free', 'void', ['number']
);

var kiss_fft_alloc = kissFFTModule.cwrap(
    'kiss_fft_alloc', 'number', ['number', 'number', 'number', 'number' ]
);

var kiss_fft = kissFFTModule.cwrap(
    'kiss_fft', 'void', ['number', 'number', 'number' ]
);

var kiss_fft_free = kissFFTModule.cwrap(
    'kiss_fft_free', 'void', ['number']
);

var FFT = function (size) {

    this.size = size;
    this.fcfg = kiss_fft_alloc(size, false);
    this.icfg = kiss_fft_alloc(size, true);
    
    this.inptr = kissFFTModule._malloc(size*8 + size*8);
    this.outptr = this.inptr + size*8;
    
    this.cin = new Float32Array(kissFFTModule.HEAPU8.buffer, this.inptr, size*2);
    this.cout = new Float32Array(kissFFTModule.HEAPU8.buffer, this.outptr, size*2);
    
    this.forward = function(cin) {
	this.cin.set(cin);
	kiss_fft(this.fcfg, this.inptr, this.outptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.outptr, this.size * 2);
    };
    
    this.inverse = function(cin) {
	this.cin.set(cpx);
	kiss_fft(this.icfg, this.inptr, this.outptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.outptr, this.size * 2);
    };
    
    this.dispose = function() {
	kissFFTModule._free(this.inptr);
	kiss_fft_free(this.fcfg);
	kiss_fft_free(this.icfg);
    }
};

var FFTR = function (size) {

    this.size = size;
    this.fcfg = kiss_fftr_alloc(size, false);
    this.icfg = kiss_fftr_alloc(size, true);
    
    this.rptr = kissFFTModule._malloc(size*4 + (size+2)*4);
    this.cptr = this.rptr + size*4;
    
    this.ri = new Float32Array(kissFFTModule.HEAPU8.buffer, this.rptr, size);
    this.ci = new Float32Array(kissFFTModule.HEAPU8.buffer, this.cptr, size+2);
    
    this.forward = function(real) {
	this.ri.set(real);
	kiss_fftr(this.fcfg, this.rptr, this.cptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.cptr, this.size + 2);
    };
    
    this.inverse = function(cpx) {
	this.ci.set(cpx);
	kiss_fftri(this.icfg, this.cptr, this.rptr);
	return new Float32Array(kissFFTModule.HEAPU8.buffer,
				this.rptr, this.size);
    };
    
    this.dispose = function() {
	kissFFTModule._free(this.rptr);
	kiss_fftr_free(this.fcfg);
	kiss_fftr_free(this.icfg);
    }
};