Modules

node_modules/node-opus/examples/mp3-to-ogg.js

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+
+"use strict";
+
+var fs = require( 'fs' );
+var lame = require( 'lame' );
+var opus = require( '../' );
+var ogg = require( 'ogg' );
+
+var opusFile = fs.createWriteStream( 'test.opus' );
+
+var mp3Decoder = new lame.Decoder();
+var opusEncoder = new opus.Encoder( 48000, 2 );
+var oggEncoder = new ogg.Encoder();
+
+process.stdin.pipe( mp3Decoder ).pipe( opusEncoder ).pipe( oggEncoder.stream() );
+oggEncoder.pipe( process.stdout );
+

node_modules/node-opus/examples/stream-to-alsa.js

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+'use strict';
+// replace username and password with speech to text credentials
+// audio.wav can be found here: https://github.com/watson-developer-cloud/nodejs-wrapper/blob/master/test/resources/audio.wav?raw=true
+
+var fs = require('fs');
+var opus = require('node-opus');
+var ogg = require('ogg');
+var cp = require('child_process');
+
+var oggDecoder = new ogg.Decoder();
+
+oggDecoder.on('stream', function (stream) {
+
+    var opusDecoder = new opus.Decoder();
+
+    // the "format" event contains the raw PCM format
+    opusDecoder.on('format', function (format) {
+
+        // format example:
+        //{
+        //    channels: 1,
+        //    sampleRate: 24000,
+        //    bitDepth: 16,
+        //    float: false,
+        //    signed: true,
+        //    gain: 0,
+        //    preSkip: 156,
+        //    version: 1
+        //}
+
+        // convert the signed & bitDepth to an alsa compatible format (`aplay --help format` for full list)
+        var alsaFormat;
+        if (format.signed && format.bitDepth == 16) {
+            alsaFormat = 'S16_LE'; // assume Little Endian
+        } else {
+            throw new Error('unexpected format: ' + JSON.stringify(format));
+        }
+
+	// set up aplay to accept data from stdin
+        var aplay = cp.spawn('aplay',['--format=' + alsaFormat, '--rate=' + format.sampleRate, '--channels='+format.channels, '--']);
+        
+        // send the raw PCM data to aplay
+	opusDecoder.pipe(aplay.stdin);
+
+        // or pipe to node-speaker, a file, etc
+    });
+
+    // an "error" event will get emitted if the stream is not a Vorbis stream
+    // (i.e. it could be a Theora video stream instead)
+    opusDecoder.on('error', console.error);
+
+    stream.pipe(opusDecoder);
+});
+
+
+fs.createReadStream('input.opus').pipe(oggDecoder);