├── .github
    └── assets
    │   ├── out-fft.png
    │   └── out-thr.png
├── lib
    ├── index.d.ts
    └── index.ts
├── package.json
├── .gitignore
├── demo.js
├── README.md
├── tsconfig.json
└── LICENSE


/.github/assets/out-fft.png:
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https://raw.githubusercontent.com/adblockradio/stream-audio-fingerprint/HEAD/.github/assets/out-fft.png


--------------------------------------------------------------------------------
/.github/assets/out-thr.png:
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https://raw.githubusercontent.com/adblockradio/stream-audio-fingerprint/HEAD/.github/assets/out-thr.png


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/lib/index.d.ts:
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 1 | /// <reference types="node" />
 2 | import { Transform } from 'stream';
 3 | interface Options {
 4 |     readableObjectMode: true;
 5 |     highWaterMark: number;
 6 | }
 7 | interface Mark {
 8 |     t: number;
 9 |     i: number[];
10 |     v: number[];
11 | }
12 | export declare class Codegen extends Transform {
13 |     buffer: Buffer;
14 |     bufferDelta: number;
15 |     stepIndex: number;
16 |     marks: Mark[];
17 |     threshold: any[];
18 |     fftData?: any[];
19 |     thrData?: any[];
20 |     peakData?: any[];
21 |     DT: number;
22 |     SAMPLING_RATE: number;
23 |     BPS: number;
24 |     constructor(options?: Partial<Options>);
25 |     _write(chunk: Buffer, _: any, next: Function): void;
26 |     plot(): void;
27 | }
28 | export {};
29 | 


--------------------------------------------------------------------------------
/package.json:
--------------------------------------------------------------------------------
 1 | {
 2 | 	"name": "stream-audio-fingerprint",
 3 | 	"version": "1.0.4",
 4 | 	"description": "Audio landmark fingerprinting as a Node Stream module",
 5 | 	"main": "lib/index.js",
 6 | 	"scripts": {
 7 | 		"prepare": "npm run build",
 8 | 		"prebuild": "del ./lib/*.js",
 9 | 		"build": "tsc -d",
10 | 		"test": "echo \"Error: no test specified\" && exit 1"
11 | 	},
12 | 	"keywords": [
13 | 		"audio",
14 | 		"fingerprint",
15 | 		"stream"
16 | 	],
17 | 	"files": [
18 | 		"lib/*.js",
19 | 		"lib/*.d.ts"
20 | 	],
21 | 	"author": "Alexandre Storelli <a_npm@storelli.fr>",
22 | 	"license": "MPL-2.0",
23 | 	"dependencies": {
24 | 		"@types/node": "13.9.3",
25 | 		"del-cli": "3.0.0",
26 | 		"dsp.js": "git+https://git@github.com/corbanbrook/dsp.js.git",
27 | 		"node-png": "^0.4.3",
28 | 		"typescript": "3.8.3"
29 | 	},
30 | 	"bugs": {
31 | 		"url": "https://github.com/dest4/stream-audio-fingerprint/issues"
32 | 	},
33 | 	"homepage": "https://github.com/dest4/stream-audio-fingerprint"
34 | }
35 | 


--------------------------------------------------------------------------------
/.gitignore:
--------------------------------------------------------------------------------
 1 | # Logs
 2 | logs
 3 | *.log
 4 | npm-debug.log*
 5 | yarn-debug.log*
 6 | yarn-error.log*
 7 | 
 8 | # Runtime data
 9 | pids
10 | *.pid
11 | *.seed
12 | *.pid.lock
13 | 
14 | # Directory for instrumented libs generated by jscoverage/JSCover
15 | lib-cov
16 | 
17 | # Coverage directory used by tools like istanbul
18 | coverage
19 | 
20 | # nyc test coverage
21 | .nyc_output
22 | 
23 | # Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
24 | .grunt
25 | 
26 | # Bower dependency directory (https://bower.io/)
27 | bower_components
28 | 
29 | # node-waf configuration
30 | .lock-wscript
31 | 
32 | # Compiled binary addons (http://nodejs.org/api/addons.html)
33 | build/Release
34 | 
35 | # Dependency directories
36 | node_modules/
37 | jspm_packages/
38 | 
39 | # Typescript v1 declaration files
40 | typings/
41 | 
42 | # Optional npm cache directory
43 | .npm
44 | 
45 | # Optional eslint cache
46 | .eslintcache
47 | 
48 | # Optional REPL history
49 | .node_repl_history
50 | 
51 | # Output of 'npm pack'
52 | *.tgz
53 | 
54 | # Yarn Integrity file
55 | .yarn-integrity
56 | 
57 | # dotenv environment variables file
58 | .env
59 | 
60 | lib/*.js
61 | 
62 | # macOS hidden file
63 | .DS_Store
64 | 


--------------------------------------------------------------------------------
/demo.js:
--------------------------------------------------------------------------------
 1 | // This Source Code Form is subject to the terms of the Mozilla Public
 2 | // License, v. 2.0. If a copy of the MPL was not distributed with this
 3 | // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 4 | 
 5 | // Copyright (c) 2018 Alexandre Storelli
 6 | 
 7 | const childProcess = require('child_process');
 8 | // const { Codegen } = require('stream-audio-fingerprint');
 9 | // Swap the line above if you're running this outside of the repo
10 | const { Codegen } = require('./lib');
11 | 
12 | const decoder = childProcess.spawn('ffmpeg', [
13 | 	'-i', 'pipe:0',
14 | 	'-acodec', 'pcm_s16le',
15 | 	'-ar', '22050',
16 | 	'-ac', '1',
17 | 	'-f', 'wav',
18 | 	'-v', 'fatal',
19 | 	'pipe:1'
20 | ], { stdio: ['pipe', 'pipe', process.stderr] });
21 | 
22 | const fingerprinter = new Codegen();
23 | 
24 | // Pipe ouput of ffmpeg decoder to fingerprinter
25 | decoder.stdout.pipe(fingerprinter);
26 | 
27 | // Pipe input to this file to ffmpeg decoder
28 | process.stdin.pipe(decoder.stdin);
29 | 
30 | // Log all the found fingerprints as they come in
31 | fingerprinter.on('data', data => {
32 | 	for (let i = 0; i < data.tcodes.length; i++) {
33 | 		console.log(`time=${data.tcodes[i]} fingerprint=${data.hcodes[i]}`);
34 | 	}
35 | });
36 | 
37 | fingerprinter.on('end', () => {
38 | 	console.log('Fingerprints stream ended.');
39 | });
40 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Audio landmark fingerprinting as a Node Stream module
 2 | 
 3 | This module is a duplex stream (instance of stream.Transform) that converts a PCM audio signal into a series of audio fingerprints. It works with audio tracks as well as with unlimited audio streams, e.g. broadcast radio.
 4 | 
 5 | It is one of the foundations of the [Adblock Radio project](https://github.com/adblockradio/adblockradio).
 6 | 
 7 | ## Credits
 8 | 
 9 | The [acoustic fingerprinting](https://en.wikipedia.org/wiki/Acoustic_fingerprint) technique used here is the landmark algorithm, as described in the [Shazam 2003 paper](http://www.ee.columbia.edu/~dpwe/papers/Wang03-shazam.pdf).
10 | The implementation in ```codegen_landmark.js``` has been inspired by the MATLAB routine of D. Ellis ["Robust Landmark-Based Audio Fingerprinting" (2009)](http://labrosa.ee.columbia.edu/matlab/fingerprint/). One significant difference with Ellis' implementation is that this module can handle unlimited audio streams, e.g. radio, and not only finished audio tracks.
11 | 
12 | Note the existence of another good landmark fingerprinter in Python, [dejavu](https://github.com/worldveil/dejavu).
13 | 
14 | ## Description
15 | 
16 | In a nutshell,
17 | - a spectrogram is computed from the audio signal
18 | - significant peaks are chosen in this time-frequency map. a latency of 250ms is used to determine if a peak is not followed by a bigger peak.
19 | - fingerprints are computed by linking peaks with ```dt```, ```f1``` and ```f2```, ready to be inserted in a database or to be compared with other fingerprints.
20 | 
21 | ![Spectrogram, peaks and pairs](.github/assets/out-fft.png)
22 | 
23 | In the background, about 12s of musical content is represented as a spectrogram (top frequency is about 10kHz). The blue marks are the chosen spectrogram peaks. Grey lines are peaks pairs that each lead to a fingerprint.
24 | 
25 | ![Threshold and peaks](.github/assets/out-thr.png)
26 | 
27 | Given the same audio, this figure shows the same peaks and the internal *forward* threshold that prevent peaks from being too close in time and frequency. The *backward* threshold selection is not represented here.
28 | 
29 | ## Usage
30 | 
31 | ```shell
32 | npm install stream-audio-fingerprint
33 | ```
34 | 
35 | The algorithm is in `lib/index.ts`.
36 | 
37 | A demo usage is proposed in `demo.js`. It requires the executable [ffmpeg](https://ffmpeg.org/download.html) to run.
38 | 
39 | ```js
40 | const childProcess = require('child_process');
41 | const { Codegen } = require('stream-audio-fingerprint');
42 | 
43 | const decoder = childProcess.spawn('ffmpeg', [
44 | 	'-i', 'pipe:0',
45 | 	'-acodec', 'pcm_s16le',
46 | 	'-ar', '22050',
47 | 	'-ac', '1',
48 | 	'-f', 'wav',
49 | 	'-v', 'fatal',
50 | 	'pipe:1'
51 | ], { stdio: ['pipe', 'pipe', process.stderr] });
52 | 
53 | const fingerprinter = new Codegen();
54 | 
55 | // Pipe ouput of ffmpeg decoder to fingerprinter
56 | decoder.stdout.pipe(fingerprinter);
57 | 
58 | // Pipe input to this file to ffmpeg decoder
59 | process.stdin.pipe(decoder.stdin);
60 | 
61 | // Log all the found fingerprints as they come in
62 | fingerprinter.on('data', data => {
63 | 	for (let i = 0; i < data.tcodes.length; i++) {
64 | 		console.log(`time=${data.tcodes[i]} fingerprint=${data.hcodes[i]}`);
65 | 	}
66 | });
67 | 
68 | fingerprinter.on('end', () => {
69 | 	console.log('Fingerprints stream ended.');
70 | });
71 | ```
72 | 
73 | and then we pipe audio data, either a stream or a file
74 | 
75 | ```shell
76 | curl http://radiofg.impek.com/fg | node demo.js
77 | cat awesome_music.mp3 | node demo.js
78 | ```
79 | on Windows:
80 | ```
81 | type awesome_music.mp3 | node demo.js
82 | ```
83 | 
84 | ## Integration in your project
85 | 
86 | Matching fingerprints in a database is not a trivial topic, I should write a technical note about it some day.
87 | 
88 | For a reference implementation you can have a look at the code of the Adblock Radio algorithm to catch ads https://github.com/adblockradio/adblockradio/blob/master/predictor-db/hotlist.js#L150.
89 | 
90 | ## License
91 | 
92 | See LICENSE file.
93 | 


--------------------------------------------------------------------------------
/tsconfig.json:
--------------------------------------------------------------------------------
 1 | {
 2 |  "compilerOptions": {
 3 |     /* Basic Options */
 4 |     // "incremental": true,                   /* Enable incremental compilation */
 5 |     "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
 6 |     "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
 7 |     // "lib": [],                             /* Specify library files to be included in the compilation. */
 8 |     // "allowJs": true,                       /* Allow javascript files to be compiled. */
 9 |     // "checkJs": true,                       /* Report errors in .js files. */
10 |     // "jsx": "preserve",                     /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
11 |     // "declaration": true,                   /* Generates corresponding '.d.ts' file. */
12 |     // "declarationMap": true,                /* Generates a sourcemap for each corresponding '.d.ts' file. */
13 |     // "sourceMap": true,                     /* Generates corresponding '.map' file. */
14 |     // "outFile": "./",                       /* Concatenate and emit output to single file. */
15 |     // "outDir": "./",                        /* Redirect output structure to the directory. */
16 |     // "rootDir": "./",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
17 |     // "composite": true,                     /* Enable project compilation */
18 |     // "tsBuildInfoFile": "./",               /* Specify file to store incremental compilation information */
19 |     // "removeComments": true,                /* Do not emit comments to output. */
20 |     // "noEmit": true,                        /* Do not emit outputs. */
21 |     // "importHelpers": true,                 /* Import emit helpers from 'tslib'. */
22 |     // "downlevelIteration": true,            /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
23 |     // "isolatedModules": true,               /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
24 | 
25 |     /* Strict Type-Checking Options */
26 |     "strict": true,                           /* Enable all strict type-checking options. */
27 |     "noImplicitAny": false,                 /* Raise error on expressions and declarations with an implied 'any' type. */
28 |     // "strictNullChecks": true,              /* Enable strict null checks. */
29 |     // "strictFunctionTypes": true,           /* Enable strict checking of function types. */
30 |     // "strictBindCallApply": true,           /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
31 |     // "strictPropertyInitialization": true,  /* Enable strict checking of property initialization in classes. */
32 |     // "noImplicitThis": true,                /* Raise error on 'this' expressions with an implied 'any' type. */
33 |     // "alwaysStrict": true,                  /* Parse in strict mode and emit "use strict" for each source file. */
34 | 
35 |     /* Additional Checks */
36 |     // "noUnusedLocals": true,                /* Report errors on unused locals. */
37 |     // "noUnusedParameters": true,            /* Report errors on unused parameters. */
38 |     // "noImplicitReturns": true,             /* Report error when not all code paths in function return a value. */
39 |     // "noFallthroughCasesInSwitch": true,    /* Report errors for fallthrough cases in switch statement. */
40 | 
41 |     /* Module Resolution Options */
42 |     // "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
43 |     // "baseUrl": "./",                       /* Base directory to resolve non-absolute module names. */
44 |     // "paths": {},                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
45 |     // "rootDirs": [],                        /* List of root folders whose combined content represents the structure of the project at runtime. */
46 |     // "typeRoots": [],                       /* List of folders to include type definitions from. */
47 |     // "types": [],                           /* Type declaration files to be included in compilation. */
48 |     // "allowSyntheticDefaultImports": true,  /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
49 |     "esModuleInterop": true,                  /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
50 |     // "preserveSymlinks": true,              /* Do not resolve the real path of symlinks. */
51 |     // "allowUmdGlobalAccess": true,          /* Allow accessing UMD globals from modules. */
52 | 
53 |     /* Source Map Options */
54 |     // "sourceRoot": "",                      /* Specify the location where debugger should locate TypeScript files instead of source locations. */
55 |     // "mapRoot": "",                         /* Specify the location where debugger should locate map files instead of generated locations. */
56 |     // "inlineSourceMap": true,               /* Emit a single file with source maps instead of having a separate file. */
57 |     // "inlineSources": true,                 /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
58 | 
59 |     /* Experimental Options */
60 |     // "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
61 |     // "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
62 | 
63 |     /* Advanced Options */
64 |     "forceConsistentCasingInFileNames": true  /* Disallow inconsistently-cased references to the same file. */
65 |   }
66 | }
67 | 


--------------------------------------------------------------------------------
/lib/index.ts:
--------------------------------------------------------------------------------
  1 | // This Source Code Form is subject to the terms of the Mozilla Public
  2 | // License, v. 2.0. If a copy of the MPL was not distributed with this
  3 | // file, You can obtain one at http://mozilla.org/MPL/2.0/.
  4 | 
  5 | // Copyright (c) 2018 Alexandre Storelli
  6 | 
  7 | // Online implementation of the landmark audio fingerprinting algorithm.
  8 | // inspired by D. Ellis (2009), "Robust Landmark-Based Audio Fingerprinting"
  9 | // http://labrosa.ee.columbia.edu/matlab/fingerprint/
 10 | // itself inspired by Wang 2003 paper
 11 | 
 12 | // This module exports Codegen, an instance of stream.Transform
 13 | // By default, the writable side must be fed with an input signal with the following properties:
 14 | // - single channel
 15 | // - 16bit PCM
 16 | // - 22050 Hz sampling rate
 17 | //
 18 | // The readable side outputs objects of the form
 19 | // { tcodes: [time stamps], hcodes: [fingerprints] }
 20 | 
 21 | import { Transform } from 'stream';
 22 | import dsp from 'dsp.js';
 23 | 
 24 | const log = console.log;
 25 | 
 26 | const SAMPLING_RATE = 22050;
 27 | // sampling rate in Hz. If you change this, you must adapt WINDOW_DT and PRUNING_DT below to match your needs
 28 | // set the Nyquist frequency, SAMPLING_RATE/2, so as to match the max frequencies you want to get landmark fingerprints.
 29 | 
 30 | const BPS = 2;
 31 | // bytes per sample, 2 for 16 bit PCM. If you change this, you must change readInt16LE methods in the code.
 32 | 
 33 | const MNLM = 5;
 34 | // maximum number of local maxima for each spectrum. useful to tune the amount of fingerprints at output
 35 | 
 36 | const MPPP = 3;
 37 | // maximum of hashes each peak can lead to. useful to tune the amount of fingerprints at output
 38 | 
 39 | const NFFT = 512;  // size of the FFT window. As we use real signals, the spectra will have nfft/2 points.
 40 | // Increasing it will give more spectral precision, less temporal precision.
 41 | // It may be good or bad depending on the sounds you want to match and on whether your input is deformed by EQ or noise.
 42 | 
 43 | const STEP = NFFT/2; // 50 % overlap
 44 | // if SAMPLING_RATE is 22050 Hz, this leads to a sampling frequency
 45 | // fs = (SAMPLING_RATE / STEP) /s = 86/s, or dt = 1/fs = 11,61 ms.
 46 | // It's not really useful to change the overlap ratio.
 47 | const DT = 1 / (SAMPLING_RATE / STEP);
 48 | 
 49 | const FFT = new dsp.FFT(NFFT, SAMPLING_RATE);
 50 | 
 51 | const HWIN = new Array(NFFT); // prepare the hann window
 52 | for (var i=0; i<NFFT; i++) {
 53 | 	HWIN[i] = 0.5 * (1 - Math.cos(2*Math.PI*i/(NFFT-1)));
 54 | }
 55 | 
 56 | const MASK_DECAY_LOG = Math.log(0.995); // threshold decay factor between frames.
 57 | 
 58 | // frequency window to generate landmark pairs, in units of DF = SAMPLING_RATE / NFFT. Values between 0 and NFFT/2
 59 | const IF_MIN = 0; // you can increase this to avoid having fingerprints for low frequencies
 60 | const IF_MAX = NFFT/2; // you don't really want to decrease this, better reduce SAMPLING_RATE instead for faster computation.
 61 | 
 62 | const WINDOW_DF = 60; // we set this to avoid getting fingerprints linking very different frequencies.
 63 | // useful to reduce the amount of fingerprints. this can be maxed at NFFT/2 if you wish.
 64 | 
 65 | // time window to generate landmark pairs. time in units of dt (see definition above)
 66 | const WINDOW_DT = 96; // a little more than 1 sec.
 67 | const PRUNING_DT = 24; // about 250 ms, window to remove previous peaks that are superseded by later ones.
 68 | // tune the PRUNING_DT value to match the effects of MASK_DECAY_LOG.
 69 | // also, PRUNING_DT controls the latency of the pipeline. higher PRUNING_DT = higher latency
 70 | 
 71 | // prepare the values of exponential masks.
 72 | const MASK_DF = 3; // mask decay scale in DF units on the frequency axis.
 73 | const EWW = new Array(NFFT/2);
 74 | for (let i=0; i<NFFT/2; i++) {
 75 | 	EWW[i] = new Array(NFFT/2);
 76 | 	for (let j=0; j<NFFT/2; j++) {
 77 | 		EWW[i][j] = -0.5*Math.pow((j-i)/MASK_DF/Math.sqrt(i+3),2); // gaussian mask is a polynom when working on the log-spectrum. log(exp()) = Id()
 78 | 		// MASK_DF is multiplied by Math.sqrt(i+3) to have wider masks at higher frequencies
 79 | 		// see the visualization out-thr.png for better insight of what is happening
 80 | 	}
 81 | }
 82 | 
 83 | const VERBOSE = false;
 84 | let DO_PLOT = false; // limit the amount of audio processing to ~12s, generate plots and stop the routine.
 85 | 
 86 | if (DO_PLOT) {
 87 | 	var fs = require('fs');
 88 | 	var png = require('node-png').PNG;
 89 | }
 90 | 
 91 | const colormap = (x: number, buffer: any[], index: number, color: string) => {
 92 | 	let mask = [1, 1, 1];
 93 | 	if (color == 'r') {
 94 | 		mask = [0, 1, 1];
 95 | 	} else if (color == 'b') {
 96 | 		mask = [1, 1, 0];
 97 | 	} else if (color == 'grey') {
 98 | 		mask = [0.5, 0.5, 0.5];
 99 | 	}
100 | 	const r = 255 * Math.sqrt(Math.min(Math.max(x, 0), 1));
101 | 	buffer[index] = Math.round(255 - r * mask[0]);
102 | 	buffer[index + 1] = Math.round(255 - r * mask[1]);
103 | 	buffer[index + 2] = Math.round(255 - r * mask[2]);
104 | 	buffer[index + 3] = 255; // alpha channel
105 | };
106 | 
107 | const minmax = (a: any[], nDim: number) => {
108 | 	let norm = [0, 0];
109 | 	for (let x = 0; x < a.length; x++) {
110 | 		if (nDim == 1) {
111 | 			norm[0] = Math.min(a[x], norm[0]);
112 | 			norm[1] = Math.max(a[x], norm[1]);
113 | 		} else if (nDim == 2) {
114 | 			for (let y = 0; y < a[0].length; y++) {
115 | 				norm[0] = Math.min(a[x][y], norm[0]);
116 | 				norm[1] = Math.max(a[x][y], norm[1]);
117 | 			}
118 | 		}
119 | 	}
120 | 	return norm;
121 | };
122 | 
123 | interface Image {
124 | 	data: any[]
125 | 	width: number
126 | 	height: number
127 | }
128 | 
129 | const drawMarker = (img: Image, x: number, y: number, radius: number) => {
130 | 	colormap(1, img.data, ((img.width * (img.height - 1 - y) + x) << 2), 'b');
131 | 
132 | 	if (radius > 1) {
133 | 		drawMarker(img, x + 1, y, radius - 1);
134 | 		drawMarker(img, x, y + 1, radius - 1);
135 | 		drawMarker(img, x - 1, y, radius - 1);
136 | 		drawMarker(img, x, y - 1, radius - 1);
137 | 	}
138 | 
139 | 	return;
140 | };
141 | 
142 | const drawLine = (img: Image, x1: number, x2: number, y1: number, y2: number) => {
143 | 	log(`draw line x1=${x1} y1=${y1} x2=${x2} y2=${y2}`);
144 | 	const len = Math.round(Math.sqrt(Math.pow(y2 - y1, 2) + Math.pow(x2 - x1, 2)));
145 | 	for (let i = 0; i <= len; i++) {
146 | 		const x = x1 + Math.round((x2 - x1) * i / len);
147 | 		const y = y1 + Math.round((y2 - y1) * i / len);
148 | 		colormap(1, img.data, ((img.width * (img.height - 1 - y) + x) << 2), 'grey');
149 | 	}
150 | };
151 | 
152 | interface Options { 
153 | 	readableObjectMode: true
154 | 	highWaterMark: number
155 | }
156 | 
157 | interface Mark {
158 | 	t: number
159 | 	i: number[]
160 | 	v: number[]
161 | }
162 | 
163 | export class Codegen extends Transform {
164 | 	buffer: Buffer
165 | 	bufferDelta: number
166 | 	stepIndex: number
167 | 	marks: Mark[]
168 | 	threshold: any[]
169 | 	fftData?: any[]
170 | 	thrData?: any[]
171 | 	peakData?: any[]
172 | 	DT: number
173 | 	SAMPLING_RATE: number
174 | 	BPS: number
175 | 
176 | 	constructor(options: Partial<Options> = {}) {
177 | 		super({
178 | 			readableObjectMode: true,
179 | 			highWaterMark: 10,
180 | 			...options
181 | 		});
182 | 		this.buffer = Buffer.alloc(0);
183 | 		this.bufferDelta = 0;
184 | 
185 | 		this.stepIndex = 0;
186 | 		this.marks = [];
187 | 		this.threshold = new Array(NFFT / 2);
188 | 		for (let i = 0; i < NFFT / 2; i++) {
189 | 			this.threshold[i] = -3;
190 | 		}
191 | 
192 | 		if (DO_PLOT) {
193 | 			this.fftData = [];
194 | 			this.thrData = [];
195 | 			this.peakData = [];
196 | 		}
197 | 
198 | 		// Copy constants to be able to reference them in parent modules
199 | 		this.DT = DT;
200 | 		this.SAMPLING_RATE = SAMPLING_RATE;
201 | 		this.BPS = BPS;
202 | 	}
203 | 
204 | 	_write(chunk: Buffer, _: any, next: Function) {
205 | 		if (VERBOSE) {
206 | 			log(`t=${Math.round(this.stepIndex / STEP)} received ${chunk.length} bytes`);
207 | 		}
208 | 
209 | 		let tcodes: number[] = [];
210 | 		let hcodes: number[] = [];
211 | 
212 | 		this.buffer = Buffer.concat([this.buffer, chunk]);
213 | 
214 | 		while ((this.stepIndex + NFFT) * BPS < this.buffer.length + this.bufferDelta) {
215 | 			let data = new Array(NFFT); // window data
216 | 
217 | 			// Fill the data, windowed (HWIN) and scaled
218 | 			for (let i=0,limit = NFFT; i<limit; i++) {
219 | 				data[i] = HWIN[i] * this.buffer.readInt16LE((this.stepIndex + i) * BPS - this.bufferDelta) / Math.pow(2, 8*BPS-1);
220 | 			}
221 | 			this.stepIndex += STEP;
222 | 
223 | 			FFT.forward(data); 	// compute FFT
224 | 
225 | 			// log-normal surface
226 | 			for (let i=IF_MIN; i<IF_MAX; i++) {
227 | 				// the lower part of the spectrum is damped, the higher part is boosted, leading to a better peaks detection.
228 | 				FFT.spectrum[i] = Math.abs(FFT.spectrum[i])*Math.sqrt(i+16);
229 | 			}
230 | 
231 | 			if (DO_PLOT) {
232 | 				this.fftData?.push(FFT.spectrum.slice());
233 | 			}
234 | 
235 | 			// positive values of the difference between log spectrum and threshold
236 | 			let diff = new Array(NFFT / 2);
237 | 			for (let i = IF_MIN; i < IF_MAX; i++) {
238 | 				diff[i] = Math.max(Math.log(Math.max(1e-6, FFT.spectrum[i])) - this.threshold[i], 0);
239 | 			}
240 | 
241 | 			// find at most MNLM local maxima in the spectrum at this timestamp.
242 | 			let iLocMax = new Array(MNLM);
243 | 			let vLocMax = new Array(MNLM);
244 | 			for (let i = 0; i < MNLM; i++) {
245 | 				iLocMax[i] = NaN;
246 | 				vLocMax[i] = Number.NEGATIVE_INFINITY;
247 | 			}
248 | 			for (let i = IF_MIN + 1; i < IF_MAX - 1; i++) {
249 | 				if (diff[i] > diff[i - 1] && diff[i] > diff[i + 1] && FFT.spectrum[i] > vLocMax[MNLM - 1]) { // if local maximum big enough
250 | 					// insert the newly found local maximum in the ordered list of maxima
251 | 					for (let j = MNLM - 1; j >= 0; j--) {
252 | 						// navigate the table of previously saved maxima
253 | 						if (j >= 1 && FFT.spectrum[i] > vLocMax[j - 1]) continue;
254 | 						for (let k = MNLM - 1; k >= j + 1; k--) {
255 | 							iLocMax[k] = iLocMax[k - 1];	// offset the bottom values
256 | 							vLocMax[k] = vLocMax[k - 1];
257 | 						}
258 | 						iLocMax[j] = i;
259 | 						vLocMax[j] = FFT.spectrum[i];
260 | 						break;
261 | 					}
262 | 				}
263 | 			}
264 | 
265 | 			// now that we have the MNLM highest local maxima of the spectrum,
266 | 			// update the local maximum threshold so that only major peaks are taken into account.
267 | 			for (let i = 0; i < MNLM; i++) {
268 | 				if (vLocMax[i] > Number.NEGATIVE_INFINITY) {
269 | 					for (let j = IF_MIN; j < IF_MAX; j++) {
270 | 						this.threshold[j] = Math.max(this.threshold[j], Math.log(FFT.spectrum[iLocMax[i]]) + EWW[iLocMax[i]][j]);
271 | 					}
272 | 				} else {
273 | 					vLocMax.splice(i, MNLM - i); // remove the last elements.
274 | 					iLocMax.splice(i, MNLM - i);
275 | 					break;
276 | 				}
277 | 			}
278 | 
279 | 			if (DO_PLOT) {
280 | 				let tmp = new Array(NFFT / 2);
281 | 				for (let i = 0; i < IF_MIN; i++) {
282 | 					tmp[i] = 0;
283 | 				}
284 | 				for (let i = IF_MIN; i < IF_MAX; i++) {
285 | 					tmp[i] = Math.exp(this.threshold[i]);
286 | 				}
287 | 				for (let i = IF_MAX; i < NFFT / 2; i++) {
288 | 					tmp[i] = 0;
289 | 				}
290 | 				this.thrData?.push(tmp);
291 | 			}
292 | 
293 | 			// Array that stores local maxima for each time step
294 | 			this.marks.push({
295 | 				t: Math.round(this.stepIndex/STEP),
296 | 				i: iLocMax,
297 | 				v: vLocMax
298 | 			});
299 | 
300 | 			// Remove previous (in time) maxima that would be too close and/or too low.
301 | 			let nm = this.marks.length;
302 | 			let t0 = nm - PRUNING_DT - 1;
303 | 			for (let i = nm - 1; i >= Math.max(t0 + 1, 0); i--) {
304 | 				for (let j = 0; j < this.marks[i].v.length; j++) {
305 | 					if (this.marks[i].i[j] != 0 && Math.log(this.marks[i].v[j]) < this.threshold[this.marks[i].i[j]] + MASK_DECAY_LOG * (nm - 1 - i)) {
306 | 						this.marks[i].v[j] = Number.NEGATIVE_INFINITY;
307 | 						this.marks[i].i[j] = Number.NEGATIVE_INFINITY;
308 | 					}
309 | 				}
310 | 			}
311 | 
312 | 			// Generate hashes for peaks that can no longer be pruned. stepIndex:{f1:f2:deltaindex}
313 | 			let nFingersTotal = 0;
314 | 			if (t0 >= 0) {
315 | 				let m = this.marks[t0];
316 | 
317 | 				loopCurrentPeaks:
318 | 				for (let i = 0; i < m.i.length; i++) {
319 | 					let nFingers = 0;
320 | 
321 | 					loopPastTime:
322 | 					for (let j = t0; j >= Math.max(0, t0 - WINDOW_DT); j--) {
323 | 
324 | 						let m2 = this.marks[j];
325 | 
326 | 						loopPastPeaks:
327 | 						for (let k = 0; k < m2.i.length; k++) {
328 | 							if (m2.i[k] != m.i[i] && Math.abs(m2.i[k] - m.i[i]) < WINDOW_DF) {
329 | 								tcodes.push(m.t); //Math.round(this.stepIndex/STEP));
330 | 								// in the hash: dt=(t0-j) has values between 0 and WINDOW_DT, so for <65 6 bits each
331 | 								//				f1=m2.i[k] , f2=m.i[i] between 0 and NFFT/2-1, so for <255 8 bits each.
332 | 								hcodes.push(m2.i[k] + NFFT / 2 * (m.i[i] + NFFT / 2 * (t0 - j)));
333 | 								nFingers += 1;
334 | 								nFingersTotal += 1;
335 | 								if (DO_PLOT) this.peakData?.push([m.t, j, m.i[i], m2.i[k]]); // t1, t2, f1, f2
336 | 								if (nFingers >= MPPP) continue loopCurrentPeaks;
337 | 							}
338 | 						}
339 | 					}
340 | 				}
341 | 			}
342 | 			if (nFingersTotal > 0 && VERBOSE) {
343 | 				log(`t=${Math.round(this.stepIndex / STEP)} generated ${nFingersTotal} fingerprints`);
344 | 			}
345 | 			if (!DO_PLOT) {
346 | 				this.marks.splice(0, t0 + 1 - WINDOW_DT);
347 | 			}
348 | 
349 | 			// Decrease the threshold for the next iteration
350 | 			for (let j = 0; j < this.threshold.length; j++) {
351 | 				this.threshold[j] += MASK_DECAY_LOG;
352 | 			}
353 | 		}
354 | 
355 | 		if (this.buffer.length > 1000000) {
356 | 			const delta = this.buffer.length - 20000;
357 | 			this.bufferDelta += delta;
358 | 			this.buffer = this.buffer.slice(delta);
359 | 		}
360 | 
361 | 		if (VERBOSE) {
362 | 			// log("fp processed " + (this.practicalDecodedBytes - this.decodedBytesSinceCallback) + " while threshold is " + (0.99*this.thresholdBytes));
363 | 		}
364 | 
365 | 		if (this.stepIndex/STEP > 500 && DO_PLOT) { // approx 12 s of audio data
366 | 			this.plot()
367 | 			DO_PLOT = false;
368 | 			setTimeout(() => {
369 | 				process.exit(0);
370 | 			}, 3000);
371 | 		}
372 | 
373 | 		if (tcodes.length > 0) {
374 | 			this.push({ tcodes, hcodes });
375 | 			// this will eventually trigger data events on the read interface
376 | 		}
377 | 
378 | 		next();
379 | 	}
380 | 
381 | 	plot() {
382 | 		if (!this.fftData || !this.peakData || !this.thrData) {
383 | 			return;
384 | 		}
385 | 
386 | 		// Fft plot
387 | 		{
388 | 			console.log(`fftData len=${this.fftData.length}`);
389 | 			var img = new png({ width: this.fftData.length, height: this.fftData[0].length });
390 | 			img.data = new Buffer(img.width * img.height * 4);
391 | 			var norm = minmax(this.fftData, 2);
392 | 			if (VERBOSE) {
393 | 				log("fft min=" + norm[0] + " max=" + norm[1]);
394 | 			}
395 | 			for (let x = 0; x < img.width; x++) {
396 | 				for (let y = 0; y < img.height; y++) {
397 | 					colormap(Math.abs((this.fftData[x][y] - norm[0]) / (norm[1] - norm[0])), img.data, ((img.width * (img.height - 1 - y) + x) << 2), 'r');
398 | 				}
399 | 			}
400 | 			for (let i = 0; i < this.peakData.length; i++) {
401 | 				drawLine(img, this.peakData[i][0], this.peakData[i][1], this.peakData[i][2], this.peakData[i][3]);
402 | 			}
403 | 
404 | 			for (let x = 0; x < img.width; x++) {
405 | 				for (let i = 0; i < this.marks[x].i.length; i++) {
406 | 					if (this.marks[x].i[i] > Number.NEGATIVE_INFINITY) {
407 | 						drawMarker(img, x, this.marks[x].i[i], 2);
408 | 					}
409 | 				}
410 | 			}
411 | 			img.pack().pipe(fs.createWriteStream('out-fft.png'));
412 | 		}
413 | 
414 | 		// Threshold plot
415 | 		{
416 | 			var img = new png({ width: this.thrData.length, height: this.thrData[0].length });
417 | 			img.data = new Buffer(img.width * img.height * 4);
418 | 			var norm = minmax(this.thrData, 2);
419 | 			if (VERBOSE) {
420 | 				log("thr min=" + norm[0] + " max=" + norm[1]);
421 | 			}
422 | 			for (let x = 0; x < img.width; x++) {
423 | 				for (let y = 0; y < img.height; y++) {
424 | 					colormap(Math.abs((this.thrData[x][y] - norm[0]) / (norm[1] - norm[0])), img.data, ((img.width * (img.height - 1 - y) + x) << 2), 'r');
425 | 				}
426 | 
427 | 				for (let i = 0; i < this.marks[x].i.length; i++) {
428 | 					if (this.marks[x].i[i] > Number.NEGATIVE_INFINITY) {
429 | 						drawMarker(img, x, this.marks[x].i[i], 2);
430 | 					}
431 | 				}
432 | 			}
433 | 			img.pack().pipe(fs.createWriteStream('out-thr.png'));
434 | 		}
435 | 	}
436 | }


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
  1 | Mozilla Public License Version 2.0
  2 | ==================================
  3 | 
  4 | 1. Definitions
  5 | --------------
  6 | 
  7 | 1.1. "Contributor"
  8 |     means each individual or legal entity that creates, contributes to
  9 |     the creation of, or owns Covered Software.
 10 | 
 11 | 1.2. "Contributor Version"
 12 |     means the combination of the Contributions of others (if any) used
 13 |     by a Contributor and that particular Contributor's Contribution.
 14 | 
 15 | 1.3. "Contribution"
 16 |     means Covered Software of a particular Contributor.
 17 | 
 18 | 1.4. "Covered Software"
 19 |     means Source Code Form to which the initial Contributor has attached
 20 |     the notice in Exhibit A, the Executable Form of such Source Code
 21 |     Form, and Modifications of such Source Code Form, in each case
 22 |     including portions thereof.
 23 | 
 24 | 1.5. "Incompatible With Secondary Licenses"
 25 |     means
 26 | 
 27 |     (a) that the initial Contributor has attached the notice described
 28 |         in Exhibit B to the Covered Software; or
 29 | 
 30 |     (b) that the Covered Software was made available under the terms of
 31 |         version 1.1 or earlier of the License, but not also under the
 32 |         terms of a Secondary License.
 33 | 
 34 | 1.6. "Executable Form"
 35 |     means any form of the work other than Source Code Form.
 36 | 
 37 | 1.7. "Larger Work"
 38 |     means a work that combines Covered Software with other material, in
 39 |     a separate file or files, that is not Covered Software.
 40 | 
 41 | 1.8. "License"
 42 |     means this document.
 43 | 
 44 | 1.9. "Licensable"
 45 |     means having the right to grant, to the maximum extent possible,
 46 |     whether at the time of the initial grant or subsequently, any and
 47 |     all of the rights conveyed by this License.
 48 | 
 49 | 1.10. "Modifications"
 50 |     means any of the following:
 51 | 
 52 |     (a) any file in Source Code Form that results from an addition to,
 53 |         deletion from, or modification of the contents of Covered
 54 |         Software; or
 55 | 
 56 |     (b) any new file in Source Code Form that contains any Covered
 57 |         Software.
 58 | 
 59 | 1.11. "Patent Claims" of a Contributor
 60 |     means any patent claim(s), including without limitation, method,
 61 |     process, and apparatus claims, in any patent Licensable by such
 62 |     Contributor that would be infringed, but for the grant of the
 63 |     License, by the making, using, selling, offering for sale, having
 64 |     made, import, or transfer of either its Contributions or its
 65 |     Contributor Version.
 66 | 
 67 | 1.12. "Secondary License"
 68 |     means either the GNU General Public License, Version 2.0, the GNU
 69 |     Lesser General Public License, Version 2.1, the GNU Affero General
 70 |     Public License, Version 3.0, or any later versions of those
 71 |     licenses.
 72 | 
 73 | 1.13. "Source Code Form"
 74 |     means the form of the work preferred for making modifications.
 75 | 
 76 | 1.14. "You" (or "Your")
 77 |     means an individual or a legal entity exercising rights under this
 78 |     License. For legal entities, "You" includes any entity that
 79 |     controls, is controlled by, or is under common control with You. For
 80 |     purposes of this definition, "control" means (a) the power, direct
 81 |     or indirect, to cause the direction or management of such entity,
 82 |     whether by contract or otherwise, or (b) ownership of more than
 83 |     fifty percent (50%) of the outstanding shares or beneficial
 84 |     ownership of such entity.
 85 | 
 86 | 2. License Grants and Conditions
 87 | --------------------------------
 88 | 
 89 | 2.1. Grants
 90 | 
 91 | Each Contributor hereby grants You a world-wide, royalty-free,
 92 | non-exclusive license:
 93 | 
 94 | (a) under intellectual property rights (other than patent or trademark)
 95 |     Licensable by such Contributor to use, reproduce, make available,
 96 |     modify, display, perform, distribute, and otherwise exploit its
 97 |     Contributions, either on an unmodified basis, with Modifications, or
 98 |     as part of a Larger Work; and
 99 | 
100 | (b) under Patent Claims of such Contributor to make, use, sell, offer
101 |     for sale, have made, import, and otherwise transfer either its
102 |     Contributions or its Contributor Version.
103 | 
104 | 2.2. Effective Date
105 | 
106 | The licenses granted in Section 2.1 with respect to any Contribution
107 | become effective for each Contribution on the date the Contributor first
108 | distributes such Contribution.
109 | 
110 | 2.3. Limitations on Grant Scope
111 | 
112 | The licenses granted in this Section 2 are the only rights granted under
113 | this License. No additional rights or licenses will be implied from the
114 | distribution or licensing of Covered Software under this License.
115 | Notwithstanding Section 2.1(b) above, no patent license is granted by a
116 | Contributor:
117 | 
118 | (a) for any code that a Contributor has removed from Covered Software;
119 |     or
120 | 
121 | (b) for infringements caused by: (i) Your and any other third party's
122 |     modifications of Covered Software, or (ii) the combination of its
123 |     Contributions with other software (except as part of its Contributor
124 |     Version); or
125 | 
126 | (c) under Patent Claims infringed by Covered Software in the absence of
127 |     its Contributions.
128 | 
129 | This License does not grant any rights in the trademarks, service marks,
130 | or logos of any Contributor (except as may be necessary to comply with
131 | the notice requirements in Section 3.4).
132 | 
133 | 2.4. Subsequent Licenses
134 | 
135 | No Contributor makes additional grants as a result of Your choice to
136 | distribute the Covered Software under a subsequent version of this
137 | License (see Section 10.2) or under the terms of a Secondary License (if
138 | permitted under the terms of Section 3.3).
139 | 
140 | 2.5. Representation
141 | 
142 | Each Contributor represents that the Contributor believes its
143 | Contributions are its original creation(s) or it has sufficient rights
144 | to grant the rights to its Contributions conveyed by this License.
145 | 
146 | 2.6. Fair Use
147 | 
148 | This License is not intended to limit any rights You have under
149 | applicable copyright doctrines of fair use, fair dealing, or other
150 | equivalents.
151 | 
152 | 2.7. Conditions
153 | 
154 | Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
155 | in Section 2.1.
156 | 
157 | 3. Responsibilities
158 | -------------------
159 | 
160 | 3.1. Distribution of Source Form
161 | 
162 | All distribution of Covered Software in Source Code Form, including any
163 | Modifications that You create or to which You contribute, must be under
164 | the terms of this License. You must inform recipients that the Source
165 | Code Form of the Covered Software is governed by the terms of this
166 | License, and how they can obtain a copy of this License. You may not
167 | attempt to alter or restrict the recipients' rights in the Source Code
168 | Form.
169 | 
170 | 3.2. Distribution of Executable Form
171 | 
172 | If You distribute Covered Software in Executable Form then:
173 | 
174 | (a) such Covered Software must also be made available in Source Code
175 |     Form, as described in Section 3.1, and You must inform recipients of
176 |     the Executable Form how they can obtain a copy of such Source Code
177 |     Form by reasonable means in a timely manner, at a charge no more
178 |     than the cost of distribution to the recipient; and
179 | 
180 | (b) You may distribute such Executable Form under the terms of this
181 |     License, or sublicense it under different terms, provided that the
182 |     license for the Executable Form does not attempt to limit or alter
183 |     the recipients' rights in the Source Code Form under this License.
184 | 
185 | 3.3. Distribution of a Larger Work
186 | 
187 | You may create and distribute a Larger Work under terms of Your choice,
188 | provided that You also comply with the requirements of this License for
189 | the Covered Software. If the Larger Work is a combination of Covered
190 | Software with a work governed by one or more Secondary Licenses, and the
191 | Covered Software is not Incompatible With Secondary Licenses, this
192 | License permits You to additionally distribute such Covered Software
193 | under the terms of such Secondary License(s), so that the recipient of
194 | the Larger Work may, at their option, further distribute the Covered
195 | Software under the terms of either this License or such Secondary
196 | License(s).
197 | 
198 | 3.4. Notices
199 | 
200 | You may not remove or alter the substance of any license notices
201 | (including copyright notices, patent notices, disclaimers of warranty,
202 | or limitations of liability) contained within the Source Code Form of
203 | the Covered Software, except that You may alter any license notices to
204 | the extent required to remedy known factual inaccuracies.
205 | 
206 | 3.5. Application of Additional Terms
207 | 
208 | You may choose to offer, and to charge a fee for, warranty, support,
209 | indemnity or liability obligations to one or more recipients of Covered
210 | Software. However, You may do so only on Your own behalf, and not on
211 | behalf of any Contributor. You must make it absolutely clear that any
212 | such warranty, support, indemnity, or liability obligation is offered by
213 | You alone, and You hereby agree to indemnify every Contributor for any
214 | liability incurred by such Contributor as a result of warranty, support,
215 | indemnity or liability terms You offer. You may include additional
216 | disclaimers of warranty and limitations of liability specific to any
217 | jurisdiction.
218 | 
219 | 4. Inability to Comply Due to Statute or Regulation
220 | ---------------------------------------------------
221 | 
222 | If it is impossible for You to comply with any of the terms of this
223 | License with respect to some or all of the Covered Software due to
224 | statute, judicial order, or regulation then You must: (a) comply with
225 | the terms of this License to the maximum extent possible; and (b)
226 | describe the limitations and the code they affect. Such description must
227 | be placed in a text file included with all distributions of the Covered
228 | Software under this License. Except to the extent prohibited by statute
229 | or regulation, such description must be sufficiently detailed for a
230 | recipient of ordinary skill to be able to understand it.
231 | 
232 | 5. Termination
233 | --------------
234 | 
235 | 5.1. The rights granted under this License will terminate automatically
236 | if You fail to comply with any of its terms. However, if You become
237 | compliant, then the rights granted under this License from a particular
238 | Contributor are reinstated (a) provisionally, unless and until such
239 | Contributor explicitly and finally terminates Your grants, and (b) on an
240 | ongoing basis, if such Contributor fails to notify You of the
241 | non-compliance by some reasonable means prior to 60 days after You have
242 | come back into compliance. Moreover, Your grants from a particular
243 | Contributor are reinstated on an ongoing basis if such Contributor
244 | notifies You of the non-compliance by some reasonable means, this is the
245 | first time You have received notice of non-compliance with this License
246 | from such Contributor, and You become compliant prior to 30 days after
247 | Your receipt of the notice.
248 | 
249 | 5.2. If You initiate litigation against any entity by asserting a patent
250 | infringement claim (excluding declaratory judgment actions,
251 | counter-claims, and cross-claims) alleging that a Contributor Version
252 | directly or indirectly infringes any patent, then the rights granted to
253 | You by any and all Contributors for the Covered Software under Section
254 | 2.1 of this License shall terminate.
255 | 
256 | 5.3. In the event of termination under Sections 5.1 or 5.2 above, all
257 | end user license agreements (excluding distributors and resellers) which
258 | have been validly granted by You or Your distributors under this License
259 | prior to termination shall survive termination.
260 | 
261 | ************************************************************************
262 | *                                                                      *
263 | *  6. Disclaimer of Warranty                                           *
264 | *  -------------------------                                           *
265 | *                                                                      *
266 | *  Covered Software is provided under this License on an "as is"       *
267 | *  basis, without warranty of any kind, either expressed, implied, or  *
268 | *  statutory, including, without limitation, warranties that the       *
269 | *  Covered Software is free of defects, merchantable, fit for a        *
270 | *  particular purpose or non-infringing. The entire risk as to the     *
271 | *  quality and performance of the Covered Software is with You.        *
272 | *  Should any Covered Software prove defective in any respect, You     *
273 | *  (not any Contributor) assume the cost of any necessary servicing,   *
274 | *  repair, or correction. This disclaimer of warranty constitutes an   *
275 | *  essential part of this License. No use of any Covered Software is   *
276 | *  authorized under this License except under this disclaimer.         *
277 | *                                                                      *
278 | ************************************************************************
279 | 
280 | ************************************************************************
281 | *                                                                      *
282 | *  7. Limitation of Liability                                          *
283 | *  --------------------------                                          *
284 | *                                                                      *
285 | *  Under no circumstances and under no legal theory, whether tort      *
286 | *  (including negligence), contract, or otherwise, shall any           *
287 | *  Contributor, or anyone who distributes Covered Software as          *
288 | *  permitted above, be liable to You for any direct, indirect,         *
289 | *  special, incidental, or consequential damages of any character      *
290 | *  including, without limitation, damages for lost profits, loss of    *
291 | *  goodwill, work stoppage, computer failure or malfunction, or any    *
292 | *  and all other commercial damages or losses, even if such party      *
293 | *  shall have been informed of the possibility of such damages. This   *
294 | *  limitation of liability shall not apply to liability for death or   *
295 | *  personal injury resulting from such party's negligence to the       *
296 | *  extent applicable law prohibits such limitation. Some               *
297 | *  jurisdictions do not allow the exclusion or limitation of           *
298 | *  incidental or consequential damages, so this exclusion and          *
299 | *  limitation may not apply to You.                                    *
300 | *                                                                      *
301 | ************************************************************************
302 | 
303 | 8. Litigation
304 | -------------
305 | 
306 | Any litigation relating to this License may be brought only in the
307 | courts of a jurisdiction where the defendant maintains its principal
308 | place of business and such litigation shall be governed by laws of that
309 | jurisdiction, without reference to its conflict-of-law provisions.
310 | Nothing in this Section shall prevent a party's ability to bring
311 | cross-claims or counter-claims.
312 | 
313 | 9. Miscellaneous
314 | ----------------
315 | 
316 | This License represents the complete agreement concerning the subject
317 | matter hereof. If any provision of this License is held to be
318 | unenforceable, such provision shall be reformed only to the extent
319 | necessary to make it enforceable. Any law or regulation which provides
320 | that the language of a contract shall be construed against the drafter
321 | shall not be used to construe this License against a Contributor.
322 | 
323 | 10. Versions of the License
324 | ---------------------------
325 | 
326 | 10.1. New Versions
327 | 
328 | Mozilla Foundation is the license steward. Except as provided in Section
329 | 10.3, no one other than the license steward has the right to modify or
330 | publish new versions of this License. Each version will be given a
331 | distinguishing version number.
332 | 
333 | 10.2. Effect of New Versions
334 | 
335 | You may distribute the Covered Software under the terms of the version
336 | of the License under which You originally received the Covered Software,
337 | or under the terms of any subsequent version published by the license
338 | steward.
339 | 
340 | 10.3. Modified Versions
341 | 
342 | If you create software not governed by this License, and you want to
343 | create a new license for such software, you may create and use a
344 | modified version of this License if you rename the license and remove
345 | any references to the name of the license steward (except to note that
346 | such modified license differs from this License).
347 | 
348 | 10.4. Distributing Source Code Form that is Incompatible With Secondary
349 | Licenses
350 | 
351 | If You choose to distribute Source Code Form that is Incompatible With
352 | Secondary Licenses under the terms of this version of the License, the
353 | notice described in Exhibit B of this License must be attached.
354 | 
355 | Exhibit A - Source Code Form License Notice
356 | -------------------------------------------
357 | 
358 |   This Source Code Form is subject to the terms of the Mozilla Public
359 |   License, v. 2.0. If a copy of the MPL was not distributed with this
360 |   file, You can obtain one at http://mozilla.org/MPL/2.0/.
361 | 
362 | If it is not possible or desirable to put the notice in a particular
363 | file, then You may include the notice in a location (such as a LICENSE
364 | file in a relevant directory) where a recipient would be likely to look
365 | for such a notice.
366 | 
367 | You may add additional accurate notices of copyright ownership.
368 | 
369 | Exhibit B - "Incompatible With Secondary Licenses" Notice
370 | ---------------------------------------------------------
371 | 
372 |   This Source Code Form is "Incompatible With Secondary Licenses", as
373 | defined by the Mozilla Public License, v. 2.0.


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