Progress percentages appear to be incorrect when creating an mpeg video from captured images.

Sometimes percentages greater than 100% are shown.

let ffmpeg_process = spawn('/usr/bin/ffmpeg', [
'-r', 30,
'-f', 'image2',
'-s', '320x200',
'-i', 'image-%04d.jpg',
'-vcodec', 'libx264',
'-crf', '25',
'-pix_fmt', 'yuv420p',
'test.mp4' ], {
detached: true,
windowsHide: true
});

ffmpeg_process.stdout.on('data', console.log);
ffmpeg_process.stderr.pipe(progressStream(120)).on('data', (data) => {
console.log('data.progress =', data.progress, data); // percentages greater than 100% are shown.
});