Add Typescript support

.gitignore

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

lib/pcm.d.ts

@@ -0,0 +1,33 @@
+export declare type PcmOptions = {
+    stereo?: boolean;
+    sampleRate?: number;
+    ffmpegPath?: string;
+};
+export declare type PcmSampleCallback = (value: number, channel: number) => void;
+export declare type PcmEndCallback = (err: string | null, output: string | null) => void;
+/**
+ * Takes a file containing an audio stream and returns raw PCM data
+ * asynchronously using ffmpeg.
+ * @param {String} filename file to extract audio from.
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
+ *        sampleRate parameters.
+ * @param {PcmSampleCallback} sampleCallback(sample, channel) called each time a sample
+ *        is read. sample ranges from [-1.0...1.0] and channel is 0 for left
+ *        channel, 1 for right channel.
+ * @param {PcmEndCallback} endCallback(err, output) called when all samples have been
+ *        read or an error occurred. err is the ffmpeg error output or null,
+ *        output is the ffmpeg output on success.
+ */
+export declare const getPcmData: (filename: string, options: PcmOptions | null | undefined, sampleCallback: PcmSampleCallback, endCallback: PcmEndCallback) => void;
+/**
+ * Takes a file containing an audio stream and returns a stream that will emit
+ * raw PCM data asynchronously using ffmpeg.
+ * @param {String} filename file to extract audio from.
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
+ *        sampleRate parameters.
+ * @returns {Stream} readable stream. Emits a data event with (sample, channel)
+ *          parameters. sample ranges from [-1.0...1.0] and channel is 0 for
+ *          left channel, 1 for right channel. Also emits an end event with err
+ *          and output string parameters.
+ */
+export declare const getPcmStream: (filename: string, options: PcmOptions) => any;

lib/pcm.js

@@ -1,101 +1,93 @@
-var spawn = require('child_process').spawn;
-var stream = require('stream');
-
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.getPcmStream = exports.getPcmData = void 0;
+let spawn = require('child_process').spawn;
+let stream = require('stream');
 /**
  * Takes a file containing an audio stream and returns raw PCM data
  * asynchronously using ffmpeg.
  * @param {String} filename file to extract audio from.
- * @param {Object} options optional object holding boolean stereo and integer
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
  *        sampleRate parameters.
- * @param {Function} sampleCallback(sample, channel) called each time a sample
+ * @param {PcmSampleCallback} sampleCallback(sample, channel) called each time a sample
  *        is read. sample ranges from [-1.0...1.0] and channel is 0 for left
  *        channel, 1 for right channel.
- * @param {Function} endCallback(err, output) called when all samples have been
- *        read or an error occurred. err is the ffmpeg error output or null, 
+ * @param {PcmEndCallback} endCallback(err, output) called when all samples have been
+ *        read or an error occurred. err is the ffmpeg error output or null,
  *        output is the ffmpeg output on success.
  */
-exports.getPcmData = function(filename, options, sampleCallback, endCallback) {
-  var outputStr = '';
-  var oddByte = null;
-  var channel = 0;
-  var gotData = false;
-
-  options = options || {};
-  var channels = 2;
-  if (typeof options.stereo !== 'undefined')
-    channels = (options.stereo) ? 2 : 1;
-  var sampleRate = 44100;
-  if (typeof options.sampleRate !== 'undefined')
-    sampleRate = options.sampleRate;
-  var ffmpegPath = 'ffmpeg';
-  if (typeof options.ffmpegPath !== 'undefined')
-    ffmpegPath = options.ffmpegPath;
-
-  // Extract signed 16-bit little endian PCM data with ffmpeg and pipe to
-  // stdout
-  var ffmpeg = spawn(ffmpegPath, ['-i',filename,'-f','s16le','-ac',channels,
-    '-acodec','pcm_s16le','-ar',sampleRate,'-y','pipe:1']);
-
-  ffmpeg.stdout.on('data', function(data) {
-    gotData = true;
-
-    var value;
-    var i = 0;
-    var dataLen = data.length;
-
-    // If there is a leftover byte from the previous block, combine it with the
-    // first byte from this block
-    if (oddByte !== null) {
-      value = ((data.readInt8(i++, true) << 8) | oddByte) / 32767.0;
-      sampleCallback(value, channel);
-      channel = ++channel % 2;
+const getPcmData = (filename, options, sampleCallback, endCallback) => {
+    let outputStr = '';
+    let oddByte = null;
+    let channel = 0;
+    let gotData = false;
+    options = options || {};
+    let channels = 2;
+    if ((options === null || options === void 0 ? void 0 : options.stereo) !== undefined) {
+        channels = (options.stereo) ? 2 : 1;
     }
-
-    for (; i < dataLen; i += 2) {
-      value = data.readInt16LE(i, true) / 32767.0;
-      sampleCallback(value, channel);
-      channel = ++channel % 2;
+    let sampleRate = 44100;
+    if (options === null || options === void 0 ? void 0 : options.sampleRate) {
+        sampleRate = options.sampleRate;
     }
-
-    oddByte = (i < dataLen) ? data.readUInt8(i, true) : null;
-  });
-
-  ffmpeg.stderr.on('data', function(data) {
-    // Text info from ffmpeg is output to stderr
-    outputStr += data.toString();
-  });
-
-  ffmpeg.stderr.on('end', function() {
-    if (gotData)
-      endCallback(null, outputStr);
-    else
-      endCallback(outputStr, null);
-  });
+    let ffmpegPath = 'ffmpeg';
+    if (options === null || options === void 0 ? void 0 : options.ffmpegPath) {
+        ffmpegPath = options.ffmpegPath;
+    }
+    // Extract signed 16-bit little endian PCM data with ffmpeg and pipe to
+    // stdout
+    let ffmpeg = spawn(ffmpegPath, ['-i', filename, '-f', 's16le', '-ac', channels,
+        '-acodec', 'pcm_s16le', '-ar', sampleRate, '-y', 'pipe:1']);
+    ffmpeg.stdout.on('data', function (data) {
+        gotData = true;
+        let value;
+        let i = 0;
+        let dataLen = data.length;
+        // If there is a leftover byte from the previous block, combine it with the
+        // first byte from this block
+        if (oddByte !== null) {
+            value = ((data.readInt8(i++) << 8) | oddByte) / 32767.0;
+            sampleCallback(value, channel);
+            channel = ++channel % 2;
+        }
+        for (; i < dataLen; i += 2) {
+            value = data.readInt16LE(i) / 32767.0;
+            sampleCallback(value, channel);
+            channel = ++channel % 2;
+        }
+        oddByte = (i < dataLen) ? data.readUInt8(i) : null;
+    });
+    ffmpeg.stderr.on('data', function (data) {
+        // Text info from ffmpeg is output to stderr
+        outputStr += data.toString();
+    });
+    ffmpeg.stderr.on('end', function () {
+        if (gotData)
+            endCallback(null, outputStr);
+        else
+            endCallback(outputStr, null);
+    });
 };
-
+exports.getPcmData = getPcmData;
 /**
  * Takes a file containing an audio stream and returns a stream that will emit
  * raw PCM data asynchronously using ffmpeg.
  * @param {String} filename file to extract audio from.
- * @param {Object} options optional object holding boolean stereo and integer
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
  *        sampleRate parameters.
  * @returns {Stream} readable stream. Emits a data event with (sample, channel)
  *          parameters. sample ranges from [-1.0...1.0] and channel is 0 for
  *          left channel, 1 for right channel. Also emits an end event with err
  *          and output string parameters.
  */
-exports.getPcmStream = function(filename, options) {
-  var sampleStream = new stream.Stream();
-  sampleStream.readable = true;
-
-  exports.getPcmData(filename, options,
-    function(sample, channel) {
-      sampleStream.emit('data', sample, channel);
-    },
-    function(err, output) {
-      sampleStream.emit('end', err, output);
-    }
-  );
-
-  return sampleStream;
+const getPcmStream = (filename, options) => {
+    let sampleStream = new stream.Stream();
+    sampleStream.readable = true;
+    (0, exports.getPcmData)(filename, options, function (sample, channel) {
+        sampleStream.emit('data', sample, channel);
+    }, function (err, output) {
+        sampleStream.emit('end', err, output);
+    });
+    return sampleStream;
 };
+exports.getPcmStream = getPcmStream;

package.json

@@ -1,9 +1,17 @@
 {
   "name": "pcm",
-  "version": "1.0.3",
-  "main": "./index",
-  "dependencies": {
+  "version": "1.0.4",
+  "main": "./lib/pcm.js",
+  "scripts": {
+    "compile": "npx tsc"
   },
   "devDependencies": {
-  }
+    "@types/node": "^18.11.3",
+    "typescript": "^4.8.4"
+  },
+  "files": [
+    "examples/**/*",
+    "lib/**/*",
+    "misc/**/*"
+  ]
 }

src/pcm.ts

@@ -0,0 +1,117 @@
+let spawn = require('child_process').spawn;
+let stream = require('stream');
+
+export type PcmOptions = {
+    stereo?: boolean,
+    sampleRate?: number,
+    ffmpegPath?: string,
+}
+
+export type PcmSampleCallback = (value: number, channel: number) => void;
+export type PcmEndCallback = (err: string | null, output: string | null) => void;
+
+/**
+ * Takes a file containing an audio stream and returns raw PCM data
+ * asynchronously using ffmpeg.
+ * @param {String} filename file to extract audio from.
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
+ *        sampleRate parameters.
+ * @param {PcmSampleCallback} sampleCallback(sample, channel) called each time a sample
+ *        is read. sample ranges from [-1.0...1.0] and channel is 0 for left
+ *        channel, 1 for right channel.
+ * @param {PcmEndCallback} endCallback(err, output) called when all samples have been
+ *        read or an error occurred. err is the ffmpeg error output or null, 
+ *        output is the ffmpeg output on success.
+ */
+export const getPcmData = (
+    filename: string,
+    options: PcmOptions | null | undefined,
+    sampleCallback: PcmSampleCallback,
+    endCallback: PcmEndCallback,
+) => {
+  let outputStr = '';
+  let oddByte: number | null = null;
+  let channel = 0;
+  let gotData = false;
+
+  options = options || {};
+  let channels = 2;
+  if (options?.stereo !== undefined) {
+    channels = (options.stereo) ? 2 : 1;
+  }
+  let sampleRate = 44100;
+  if (options?.sampleRate) {
+    sampleRate = options.sampleRate;
+  }
+  let ffmpegPath = 'ffmpeg';
+  if (options?.ffmpegPath) {
+    ffmpegPath = options.ffmpegPath;
+  }
+
+  // Extract signed 16-bit little endian PCM data with ffmpeg and pipe to
+  // stdout
+  let ffmpeg = spawn(ffmpegPath, ['-i',filename,'-f','s16le','-ac',channels,
+    '-acodec','pcm_s16le','-ar',sampleRate,'-y','pipe:1']);
+
+  ffmpeg.stdout.on('data', function(data: Buffer) {
+    gotData = true;
+
+    let value;
+    let i = 0;
+    let dataLen = data.length;
+
+    // If there is a leftover byte from the previous block, combine it with the
+    // first byte from this block
+    if (oddByte !== null) {
+      value = ((data.readInt8(i++) << 8) | oddByte) / 32767.0;
+      sampleCallback(value, channel);
+      channel = ++channel % 2;
+    }
+
+    for (; i < dataLen; i += 2) {
+      value = data.readInt16LE(i) / 32767.0;
+      sampleCallback(value, channel);
+      channel = ++channel % 2;
+    }
+
+    oddByte = (i < dataLen) ? data.readUInt8(i) : null;
+  });
+
+  ffmpeg.stderr.on('data', function(data: Buffer) {
+    // Text info from ffmpeg is output to stderr
+    outputStr += data.toString();
+  });
+
+  ffmpeg.stderr.on('end', function() {
+    if (gotData)
+      endCallback(null, outputStr);
+    else
+      endCallback(outputStr, null);
+  });
+};
+
+/**
+ * Takes a file containing an audio stream and returns a stream that will emit
+ * raw PCM data asynchronously using ffmpeg.
+ * @param {String} filename file to extract audio from.
+ * @param {PcmOptions} options optional object holding boolean stereo and integer
+ *        sampleRate parameters.
+ * @returns {Stream} readable stream. Emits a data event with (sample, channel)
+ *          parameters. sample ranges from [-1.0...1.0] and channel is 0 for
+ *          left channel, 1 for right channel. Also emits an end event with err
+ *          and output string parameters.
+ */
+export const getPcmStream = (filename: string, options: PcmOptions) => {
+  let sampleStream = new stream.Stream();
+  sampleStream.readable = true;
+
+  getPcmData(filename, options,
+    function(sample, channel) {
+      sampleStream.emit('data', sample, channel);
+    },
+    function(err, output) {
+      sampleStream.emit('end', err, output);
+    }
+  );
+  return sampleStream;
+};