Okay I am trying to do this in php

Upload a video make sure the extension is in a text file of acceptable extensions.
if it fails exit
or
if successful continue

convert the video using php's exec and ffmpeg
if it fails
exit or
if it is successful continue
write the data to mysql
if it fails
exit or
if it is successful show success
this is my model


>>Upload
>>>Is there an error? If so stop. If not continue
>>Convert
>>>Is there an error? If so stop. If not continue
>>Write to mysql
>>>Is there an error? If so stop. If not continue

For on how to upload see here http://us.php.net/features.file-upload
For how to confirm it's the correct file type:
<?php
function image_valid($type)
{
$file_types = array(
'image/pjpeg' => 'jpg',
'image/jpeg' => 'jpg',
'image/jpeg' => 'jpeg',
'image/gif' => 'gif',
'image/X-PNG' => 'png',
'image/PNG' => 'png',
'image/png' => 'png',
'image/x-png' => 'png',
'image/JPG' => 'jpg',
'image/GIF' => 'gif',
'image/bmp' => 'bmp',
'image/bmp' => 'BMP',
);

if(!array_key_exists($type, $file_types))
{
return "FALSE";
}
else
{
return "TRUE";
}
}

if(image_valid($_FILES['user_file']['type']) === "FALSE")
{
die("Image file is not valid");
}
?>
Just replace the correct video/BLANK
I don't know about file converting, but this should allow you to upload.

What exactly you cannot perform?