upload video clips display video thumb images not working?

Hi

I have created an upload_video.php page and having issues with it. Hoping that some PHP genius    can help me out a little for which I would be ever so grateful.

Change my video page does not display video thumb images. Linked to include/generatevideothumb.php

In my upload_video.php page I have defined thumb variables as follows

            // Thumb size
            $th_max_height1 = 150;
            $th_max_width1 = 250;
            $th_max_width = 55;
            $th_max_height = 55;
            $thumb_dir="upload/video/thumbs/";
            $thumb_dir1="upload/video/thumbs1/";
 

             // Thumb
             $thumb_video_name=$video_name;
             generatevideothumb($dir,$th_max_width, $th_max_height,$thumb_dir,$thumb_video_name);
             generatevideothumb($dir,$th_max_width1, $th_max_height1,$thumb_dir1,$thumb_video_name);
 

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Complete code from generatevideothumb.php below

<?php
function generatevideothumb($im_file,$th_max_width, $th_max_height,$thumb_dir,$thumb_video_name)
{
         @chmod($im_file,0777);
         $image_attribs = getimagesize($im_file);
                         
         if($image_attribs[0]>$th_max_width)
         {
             $ratio = $th_max_width/$image_attribs[0];
             $th_width = $image_attribs[0] * $ratio;
             $th_height = $image_attribs[1] * $ratio;
         }
         elseif($image_attribs[1]>$th_max_height)
         {
             $ratio = $th_max_height/$image_attribs[1];
             $th_width = $image_attribs[0] * $ratio;
             $th_height = $image_attribs[1] * $ratio;
         }
         else
         {
             $th_width = $image_attribs[0];
              $th_height = $image_attribs[1];
         }
                                                    //This code below is where I get that error saying invalid image dimensions
         $im_new = imagecreate($th_width,$th_height); //returns an image identifier representing a black image of size x_size by y_size.
         $th_file_name = $thumb_dir.$thumb_video_name;
         @chmod($th_file_name,0777);
        
         if($image_attribs[2]==2)
         {
             $im_old = imageCreateFromJpeg($im_file);
            imagecopyresized($im_new,$im_old,0,0,0,0,$th_width,$th_height, $image_attribs[0], $image_attribs[1]);
            imagejpeg($im_new,$th_file_name,100);
         }
         elseif($image_attribs[2]==1)
         {
             $im_old = imagecreatefromgif($im_file);
             imageCopyResampled($im_new,$im_old,0,0,0,0,$th_width,$th_height, $image_attribs[0], $image_attribs[1]);
            imagegif($im_new,$th_file_name,100);
        }  
        
 }
?>