$bin_string = file_get_contents($_FILES['creo']['tmp_name']);
$base64 = base64_encode($bin_string);
..........
curl_setopt($curl, CURLOPT_RETURNTRANSFER,true);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, 'bytes='.$base64.'&access_token='.$access_token);