Symfony Background Process FFmpeg 视频转换

我正在尝试使用 FFmpeg 转换视频并且一切正常，但现在我正在尝试在后台进行转换过程，所以我不必等待该过程在一分钟左右完成。

对我如何做到这一点有什么建议吗？

这是我在控制器中的当前代码：

$urlGenerator = new urlGenerator();
$user = $this->getUser ();
$userid = $user->getid ();
$username = $user->getFullname ();
$emailcomment = $this->container->getParameter ( 'mailer_sender_address' );
$ffmpeg = $this->get ( 'dubture_ffmpeg.ffmpeg' );
$ffprobe = $this->get ( 'dubture_ffmpeg.ffprobe' );
$currentDateTime = date ( 'YmdHis' );
$upload = new UploadVideo();
$em = $this->getDoctrine ()->getManager ();
$form = $this->createForm ( new UploadVideoType(), $upload );
$userids = $em->getReference ( 'HotelPlanBundle'Entity'User', $userid );
$form->handleRequest ( $request );
if ( $form->isValid () || TRUE ) {
    $upload->upload ($userid);
    // Start transcoding and save video
    $upload->setUserid ( $userids );
    $upload->setTitle ( 'No title' );
    $upload->setCreatedDate ( new 'DateTime() );
    $duration = $ffprobe
        ->format ( $upload->getWebPath () )// extracts file informations
        ->get ( 'duration' );
    $video = $ffmpeg->open ( $upload->getWebPath () );
    $video
        ->frame ( TimeCode::fromSeconds ( 10 ) )
        ->save ( __DIR__ . '/../../../web/uploads/documents/' . $currentDateTime . '.png' );
    $upload->setThumbnail ( $currentDateTime . '.png' );
    //here is where the converting takes too long !!
    $video->save ( new X264(), __DIR__ . '/../../../web/uploads/documents/' . $currentDateTime . '.mp4' );
    $upload->setVideoPath ( $currentDateTime . '.mp4' );
    $upload->setLink ( $urlGenerator->generateUrl () );
    $upload->setResetLink ( $urlGenerator->generateUrl () );
    try {
        $em->persist ( $upload );
        $em->flush ();
    } catch ( 'Exception $e ) {
        if ( $e->getPrevious ()->getCode () == '23000' ) {
            $upload->setLink ( $urlGenerator->generateUrl () );
            $em->persist ( $upload );
            $em->flush ();
    }
}
$em->persist ( $upload );
$em->flush ();
return new JsonResponse( array (
    'message' => 'Sucessfully Uploaded',
    'last_id' => $upload->getId ()
), 200 );
}