Haha-Yes/node_modules/node-opus/test/old/app.js

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2018-09-09 21:20:36 +02:00
"use strict";
var opus = require('../../');
var fs = require('fs');
//
// Generate a sin tone.
//
var freq = 123;
var time = 5;
var rate = 48000;
// Allocate a buffer for the tone. We use 16-bit samples.
var samples = rate*time;
var length = samples*2;
var b = Buffer.alloc(length);
// Generate the tone.
for( var i = 0; i < rate*time; i++ ) {
var value = Math.round( Math.sin( 2*Math.PI*i*freq/rate ) * Math.pow( 2, 14 ) );
b.writeInt16LE( value, i*2 );
}
//
// Create the encoder.
//
// Use 20ms frames.
var frame_size = rate * 0.02;
var encoder = new opus.OpusEncoder( rate );
// Open the output streams.
var output = fs.createWriteStream( 'out.opus' );
var input_raw = fs.createWriteStream( 'in.pcm' );
var output_raw = fs.createWriteStream( 'out.pcm' );
var read = 0;
while( b.length > 0 ) {
var size = Math.min( b.length, frame_size );
// If the input buffer is smaller than the frame_size, copy it into a new 0-padded buffer.
if( size < frame_size ) {
var temp = Buffer.alloc( frame_size );
temp.fill(0);
b.copy( temp );
b = temp;
}
// We encode frame_size 16-bit samples. This requires a frame_size*2 buffer of bytes.
var bufferSize = frame_size * 2;
var toEncode = b.slice(0, bufferSize);
console.log( frame_size );
// Encode and decode.
var encoded = encoder.encode( toEncode );
var decoded = encoder.decode( encoded );
// Write the results in the output files.
input_raw.write( toEncode );
output.write( encoded );
output_raw.write( decoded );
// Move the buffer forward by the buffer size.
b = b.slice( bufferSize );
}
output.end();
input_raw.end();
output_raw.end();
console.log( 'Wrote following files.' );
console.log( 'in.pcm : Input PCM signal' );
console.log( 'out.opus : OPUS encoded input signal' );
console.log( 'out.pcm : Decoded PCM signal' );