extract raw I420 frame from ffmpeg with node.js

ffmpeg-pipe.js

const tmp = require('tmp')
tmp.setGracefulCleanup()
const spawn = require('child_process').spawn
const net = require('net')

async function sleep(t){
  return new Promise((res) => setTimeout(res, t))
}

(async function(){
  const tmpDir = tmp.dirSync({ prefix: 'mytest' })
  const audioSockPath = `${tmpDir.name}/audio.sock`
  const audioServer = net.createServer((c) => {
    c.on('data', (d) => {
    })
  })

  const videoSockPath = `${tmpDir.name}/video.sock`
  const videoServer = net.createServer((c) => {
    let fps = 0
    const init_size = 1920*1080*1.5
    let tmp = init_size
    c.on('data', (d) => {
      tmp -= d.length
      if( tmp < 0 ){
        tmp = init_size - Math.abs(tmp)
        fps++
      }
    })

    setInterval(() => {
      console.log('fps', fps)
      fps = 0
    }, 1000)
  })

  audioServer.listen(audioSockPath)
  videoServer.listen(videoSockPath)

  console.log('server start')
  await sleep(1000)

  const cmd = spawn('ffmpeg', `-re -i /home/bongole/bigbunny.mp4 -an -f image2pipe -pix_fmt yuv420p -vcodec rawvideo unix://${videoSockPath} -vn -f s16le unix://${audioSockPath}`.split(/\s+/))

})()