ffmeg nodejs

ffmpeg.js

var fs = require('fs'),
  videoName = './record_10.mp4',
  child_process = require("child_process"),
  exec = child_process.exec;

/*This works like a charm*/
var ffmpeg = child_process.spawn("ffmpeg", [
  '-i', videoName, // path
  '-vf', 'thumbnail,scale=640:360',
  '-r', '1',
  '-frames:v', '1',
  '-f', 'mjpeg',
  'pipe:1'
]);
ffmpeg.on('error', function(err) {
  console.log(err);
})
ffmpeg.stderr.on('data', function(data) {
  console.log('stderr: ' + data);
})
ffmpeg.on('close', function(code) {
  console.log('child process exited with code ' + code);
});
var ws = fs.createWriteStream('./thumb_out.jpg');
ws.on('error', function(err) { console.log('stream err: ',err); });
ffmpeg.stdout.pipe(ws);

/*This return error: 
stderr: [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7ffbb1020800] stream 0, offset 0x30: partial file
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7ffbb1020800] Could not find codec parameters for stream 0 (Video: h264 (avc1 / 0x31637661), none, 1920x1080, 15873 kb/s): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
*/

var readStream = fs.createReadStream(videoName);
readStream
  .on('data', function(chunk) {
    //console.log(chunk)
  })
  .on('end', function() {
    console.log('finished...');
  });

var writeStream = fs.createWriteStream('woop.jpg');
writeStream.on('error', function(err) {
  console.log('stream err: ', err);
});

var ffmpeg = child_process.spawn("ffmpeg", [
  '-i', 'pipe:0', // path
  '-f', 'yuyv422',
  '-vf', 'thumbnail,scale=640:360', // bitrate to 64k
  '-r', '1',
  '-frames:v', '1',
  '-f', 'mjpeg',
  '-pix_fmt', 'yuyv422',
  'pipe:1'
]);
ffmpeg.on('error', function(err) {
  console.log(err);
})
ffmpeg.stderr.on('data', function(data) {
  console.log('stderr: ' + data);
})
ffmpeg.on('close', function(code) {
  console.log('child process exited with code ' + code);
});

writeStream.on('error', function(err) {
  console.log('stream err: ', err);
});

readStream.pipe(ffmpeg.stdin)
ffmpeg.stdout.pipe(writeStream);