Plot audio data from wav file

gistfile1.txt

/*
$ sox -V -r 16000 -n -b 32 -c 1 -e float test.wav synth 30 sin 440 vol -10dB
sox:      SoX v14.4.2

Input File     : '' (null)
Channels       : 1
Sample Rate    : 16000
Precision      : 32-bit


Output File    : 'test.wav'
Channels       : 1
Sample Rate    : 16000
Precision      : 25-bit
Sample Encoding: 32-bit Floating Point PCM
Endian Type    : little
Reverse Nibbles: no
Reverse Bits   : no
Comment        : 'Processed by SoX'

sox INFO sox: effects chain: input        16000Hz  1 channels
sox INFO sox: effects chain: synth        16000Hz  1 channels
sox INFO sox: effects chain: vol          16000Hz  1 channels
sox INFO sox: effects chain: output       16000Hz  1 channels


$ sox --i test.wav 

Input File     : 'test.wav'
Channels       : 1
Sample Rate    : 16000
Precision      : 25-bit
Duration       : 00:00:30.00 = 480000 samples ~ 2250 CDDA sectors
File Size      : 1.92M
Bit Rate       : 512k
Sample Encoding: 32-bit Floating Point PCM


*/

const pl = require( 'nodeplotlib')

const fs = require('fs');
const wav = require('wav');

const rs = fs.createReadStream('./test.wav')
const reader = new wav.Reader()

const buf = []

var samples = 512

reader.on('format', function(format) {
    console.log(format)

    reader.on('data', (data) => {
		buf.push(data)
    })

	reader.on('end', () => {
		console.log('end')
		var data = Buffer.concat(buf)

		var y = new Array()

		for(var i=0 ; i<samples ; i++) {
			y.push( data.readFloatLE(i*4) )
		}

		var x = [...Array(y.length).keys()];

		//console.log(y)
		//console.log(x)

		var data =  [{x: x.slice(0, samples), y: Array.from(y).slice(0, samples), type: 'line'}]

		pl.plot(data)
	})
})

rs.pipe(reader)

// CLI output:
/*
{ audioFormat: 3,
  endianness: 'LE',
  channels: 1,
  sampleRate: 16000,
  byteRate: 64000,
  blockAlign: 4,
  bitDepth: 32,
  signed: true,
  float: true }
end
*/