使用php上传和编码视频

I'm trying to encode video while uploading but not able to do what i want. Here is my code for upload.

if(isset($_FILES['video_profile'])){
                          $errors= array();

                          $file_name = $_FILES['video_profile']['name'];
                          $ext = pathinfo($file_name, PATHINFO_EXTENSION);
                          $newName = time();

                          $file_size =$_FILES['video_profile']['size'];
                          $file_tmp  =$_FILES['video_profile']['tmp_name'];
                          $file_type =$_FILES['video_profile']['type'];
                          $file_ext  =strtolower(end(explode('.',$_FILES['video_profile']['name'])));

                          $expensions = array("webm","mp4", "avi", "mov", "flv", "swf", "mpg", "mpeg", "mpeg-4", "wmv");

                          if(in_array($file_ext,$expensions)=== false){
                           $errors[]="extension not allowed, please choose a JPEG or PNG file.";
                          }

                          if($file_size > 524288000){ // 2097152 //
                           $errors[]='File size must be smaller than 500 MB';
                          }

                          if(empty($errors)==true){
                           move_uploaded_file($file_tmp,"upload_data/site_video/".$newName.'_video.'.$ext);
                           //var_dump($file_tmp,"upload_data/site_video/".$newName.'_video.'.$ext);
                           echo "<p class=\"success\">You have successfully uploaded video</p>";

                           Db::query('INSERT INTO site_video SET table_name = "profile_video", user_id = '.$_SESSION['user']['id'].', video_name = "'.$newName.'_video.'.$ext.'" ');

                           $orderby = Db::insert_id();

                          Db::query('UPDATE site_video SET orderby = '.$orderby.' WHERE id = '.$orderby);
                          }
                          else{
                           //print_r($errors);
                          }
                        }

I was searching and found that I need to place this code somewhere but don't know where and how

 exec("ffmpeg -i video.avi -ar 22050 -ab 32 -f flv -s 320x240 video.flv");

Can someone give me hint! Thank you

It is not really clear, what's your target with the code. I read the following:

1. Upload an video and move it to a specific directory
2. Convert the video to flv-format.
3. Save infos to database

You can try this:

if (move_uploaded_file($file_tmp,"upload_data/site_video/".$newName.'_video.'.$ext)) {
     exec("ffmpeg -i video.avi -ar 22050 -ab 32 -f flv -s 320x240 video.flv");
     echo "<p class=\"success\">You have successfully uploaded video</p>";

     Db::query('INSERT INTO site_video SET table_name = "profile_video", user_id = '.$_SESSION['user']['id'].', video_name = "'.$newName.'_video.'.$ext.'" ');

     $orderby = Db::insert_id();
     Db::query('UPDATE site_video SET orderby = '.$orderby.' WHERE id = '.$orderby);
}

But be careful. Currently you are saving the wrong extension into your database (avi instead of flv). And you should use absolute paths in your exec-command.

To answer on how the ffmmpeg-Command should look like is hard, because this can be very dynamic and depends on the source. https://www.ffmpeg.org/documentation.html should help you more.