Added sample with static SoX for denoising and normalization

sox-clean-audio/.gitignore

@@ -0,0 +1,67 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+firebase-debug.log*
+
+# Firebase cache
+.firebase/
+firebase.json
+storage.rules
+
+# Firebase config
+
+# Uncomment this if you'd like others to create their own Firebase project.
+# For a team working on the same Firebase project(s), it is recommended to leave
+# it commented so all members can deploy to the same project(s) in .firebaserc.
+# .firebaserc
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env

sox-clean-audio/README.md

@@ -0,0 +1,28 @@
+# Automatically denoise and normalize audio with SoX
+This sample uses a static SoX (Swiss Army knife of sound processing) executable and automatically removes background noise from audio (.WAV format) and then normalizes the audio volume to a given level. The input is supposed to be voice recordings recorded by a smartphone.
+
+## Functions Code
+
+See file [functions/index.js](functions/index.js) for the audio processing code.
+
+The audio processing is performed using a static SoX executable. The audio is first downloaded locally from the Cloud Storage bucket to the `tmp` folder using the [google-cloud](https://github.com/GoogleCloudPlatform/google-cloud-node) SDK.
+
+The dependencies are listed in [functions/package.json](functions/package.json).
+
+## Trigger rules
+
+The function triggers on upload of any file to your Firebase project's default Cloud Storage bucket and perform the process only for .WAV files.
+
+## Deploy and test
+
+To deploy and test the sample:
+
+- Create a Firebase project on the [Firebase Console](https://console.firebase.google.com) and visit the **Storage** tab.
+- Get the code, for instance using `git clone https://github.com/firebase/functions-samples`
+- Enter the correct directory `cd functions-samples/sox-clean-audio`
+- Setup the CLI to use your Firebase project using `firebase use --add` and select your Firebase project
+- Deploy your project's code using `firebase deploy`
+- Go to the Firebase Console **Storage** tab and upload an audio (with .WAV extension). After a short time a converted audio with the same name but a `d_` prefix for denoized audio files and `n_d_` prefix for denoized and normalized audio files will be created in the same folder (make sure you refresh the UI to see the new file).
+
+## Notes
+- The static SoX executable was built on Ubuntu 18.04.03 following [this instruction](https://marcelog.github.io/articles/static_sox_transcoding_lambda_mp3.html).

sox-clean-audio/functions/.eslintrc.json

@@ -0,0 +1,123 @@
+{
+  "parserOptions": {
+    // Required for certain syntax usages
+    "ecmaVersion": 2017
+  },
+  "plugins": [
+    "promise"
+  ],
+  "extends": "eslint:recommended",
+  "rules": {
+    // Removed rule "disallow the use of console" from recommended eslint rules
+    "no-console": "off",
+
+    // Removed rule "disallow multiple spaces in regular expressions" from recommended eslint rules
+    "no-regex-spaces": "off",
+
+    // Removed rule "disallow the use of debugger" from recommended eslint rules
+    "no-debugger": "off",
+
+    // Removed rule "disallow unused variables" from recommended eslint rules
+    "no-unused-vars": "off",
+
+    // Removed rule "disallow mixed spaces and tabs for indentation" from recommended eslint rules
+    "no-mixed-spaces-and-tabs": "off",
+
+    // Removed rule "disallow the use of undeclared variables unless mentioned in /*global */ comments" from recommended eslint rules
+    "no-undef": "off",
+
+    // Warn against template literal placeholder syntax in regular strings
+    "no-template-curly-in-string": 1,
+
+    // Warn if return statements do not either always or never specify values
+    "consistent-return": 1,
+
+    // Warn if no return statements in callbacks of array methods
+    "array-callback-return": 1,
+
+    // Require the use of === and !==
+    "eqeqeq": 2,
+
+    // Disallow the use of alert, confirm, and prompt
+    "no-alert": 2,
+
+    // Disallow the use of arguments.caller or arguments.callee
+    "no-caller": 2,
+
+    // Disallow null comparisons without type-checking operators
+    "no-eq-null": 2,
+
+    // Disallow the use of eval()
+    "no-eval": 2,
+
+    // Warn against extending native types
+    "no-extend-native": 1,
+
+    // Warn against unnecessary calls to .bind()
+    "no-extra-bind": 1,
+
+    // Warn against unnecessary labels    
+    "no-extra-label": 1,
+
+    // Disallow leading or trailing decimal points in numeric literals
+    "no-floating-decimal": 2,
+
+    // Warn against shorthand type conversions
+    "no-implicit-coercion": 1,
+
+    // Warn against function declarations and expressions inside loop statements
+    "no-loop-func": 1,
+
+    // Disallow new operators with the Function object
+    "no-new-func": 2,
+
+    // Warn against new operators with the String, Number, and Boolean objects
+    "no-new-wrappers": 1,
+
+    // Disallow throwing literals as exceptions
+    "no-throw-literal": 2,
+
+    // Require using Error objects as Promise rejection reasons
+    "prefer-promise-reject-errors": 2,
+
+    // Enforce “for” loop update clause moving the counter in the right direction
+    "for-direction": 2,
+
+    // Enforce return statements in getters
+    "getter-return": 2,
+
+    // Disallow await inside of loops
+    "no-await-in-loop": 2,
+
+    // Disallow comparing against -0
+    "no-compare-neg-zero": 2,
+
+    // Warn against catch clause parameters from shadowing variables in the outer scope
+    "no-catch-shadow": 1,
+
+    // Disallow identifiers from shadowing restricted names
+    "no-shadow-restricted-names": 2,
+
+    // Enforce return statements in callbacks of array methods
+    "callback-return": 2,
+
+    // Require error handling in callbacks
+    "handle-callback-err": 2,
+
+    // Warn against string concatenation with __dirname and __filename
+    "no-path-concat": 1,
+
+    // Prefer using arrow functions for callbacks
+    "prefer-arrow-callback": 1,
+
+    // Return inside each then() to create readable and reusable Promise chains.
+    // Forces developers to return console logs and http calls in promises. 
+    "promise/always-return": 2,
+
+    //Enforces the use of catch() on un-returned promises
+    "promise/catch-or-return": 2,
+
+    // Warn against nested then() or catch() statements
+    "promise/no-nesting": 1
+  }
+}

sox-clean-audio/functions/.gitignore

@@ -0,0 +1 @@
+node_modules/

sox-clean-audio/functions/index.js

@@ -0,0 +1,106 @@
+/**
+ * Copyright 2017 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+"use strict";
+const functions = require('firebase-functions');
+const admin = require("firebase-admin"); 
+const gcs = require('@google-cloud/storage')();
+const path = require('path');
+const os = require('os');
+const fs = require('fs');
+const spawn = require('child-process-promise').spawn;
+
+admin.initializeApp(functions.config().firebase);
+
+// Makes a command and return a promise
+function promisifyCommand(command) {
+  return new Promise((resolve, reject) => {
+    command.on('end', resolve).on('error', reject).run();
+  });
+}
+
+exports.denoiseAudio = functions.storage.object().onFinalize(async (object) => {
+  const fileBucket = object.bucket;
+  const filePath = object.name;
+  const fileName = path.basename(filePath);
+  const contentType = object.contentType;
+  const normLevel = "-8";
+
+  if (!contentType.startsWith('audio')) {
+    console.log("This is not an audio")
+    return null;
+  }
+  if (fileName.startsWith('n_') || fileName.startsWith('d_')) {
+    console.log("This file is already processed");
+    return null;
+  }
+
+  // Static executable of SoX built on Ubuntu 18.04.3 LTS (GNU/Linux 5.0.0-25-generic x86_64)
+  const soxPath = [__dirname, 'sox'].join('/');
+  const bucket = gcs.bucket(fileBucket);
+  const tempFilePath = path.join(os.tmpdir(), fileName);
+  const noiseProfPath = path.join(os.tmpdir(), "noise.prof");
+  const denoisedTempFileName = "d_" + fileName;
+  const denoisedTempFilePath = path.join(os.tmpdir(), denoisedTempFileName);
+  const normedTempFileName = "n_" + denoisedTempFileName;
+  const normedTempFilePath = path.join(os.tmpdir(), normedTempFileName);
+  const normedStorageFilePath = path.join(path.dirname(filePath), normedTempFileName);
+
+  // Download the original audio to your temporary directory
+  await bucket.file(filePath).download({destination: tempFilePath});
+  console.log("Audio uploaded locally to ", tempFilePath);
+
+  // Compute a noise profile of the original audio
+  await spawn(soxPath, [
+    tempFilePath, "-n", "noiseprof", noiseProfPath
+  ], {capture : ['stdout', 'stderr']})
+  .catch(err => {
+    console.log(err)
+  })
+  console.log("Noise profile created at", noiseProfPath)
+
+  // Do denoising in your temporary directory
+  await spawn(soxPath, [
+    tempFilePath, denoisedTempFilePath, "noisered", noiseProfPath, "0.1"
+  ], {capture : ['stdout', 'stderr']})
+  .catch(err => {
+    console.log(err)
+  })
+  console.log("Denoised audio created at", denoisedTempFilePath)
+
+  // Do normalization in your temporary directory
+  await spawn(soxPath, [
+    `--norm=${normLevel}`, denoisedTempFilePath, normedTempFilePath
+  ], {capture : ['stdout', 'stderr']})
+  .catch(err => {
+    console.log(err)
+  });
+  console.log('Normalized audio created at', normedTempFilePath);
+
+  // Upload the normalized audio to your storage
+  await bucket.upload(normedTempFilePath, {
+    destination: normedStorageFilePath,
+    metadata: {
+      contentType: "audio/x-wav"
+    }
+  });
+  console.log('Normalized audio uploaded to ', normedStorageFilePath);
+
+  // Once the audio has been uploaded delete the local file to free up disk space
+  fs.unlinkSync(tempFilePath);
+  fs.unlinkSync(normedTempFilePath);
+
+  return console.log('Temporary files removed.', normedTempFilePath)
+});

sox-clean-audio/functions/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "functions",
+  "description": "Apply audio processing to uploads on Firebase",
+  "scripts": {
+    "lint": "eslint .",
+    "serve": "firebase serve --only functions",
+    "shell": "firebase functions:shell",
+    "start": "npm run shell",
+    "deploy": "firebase deploy --only functions",
+    "logs": "firebase functions:log"
+  },
+  "engines": {
+    "node": "8"
+  },
+  "dependencies": {
+    "@google-cloud/storage": "^0.4.0",
+    "firebase-admin": "^8.0.0",
+    "base64url": "^3.0.1",
+    "child-process-promise": "^2.2.1",
+    "core-util-is": "^1.0.2",
+    "firebase-functions": "^3.0.2",
+    "firebase-tools": "^7.2.4"
+  },
+  "devDependencies": {
+    "eslint": "^5.12.0",
+    "eslint-plugin-promise": "^4.0.1",
+    "firebase-functions-test": "^0.1.6"
+  },
+  "private": true
+}