FILESTREAM and Converted Video Files

My companies application requires a very strong tie between regular/traditional database data and files.  A file is useless without it's data and data is useless without the file.  They are tightly bound to each other.  So I'm thinking about using FileStream datatype.  

I've managed to answer most of my questions regarding how it would work, how to download files to the client machines that need them, etc., but I'm unable to determine one thing.

Often times users will be uploading files that need to be converted first before going into the DB.  The file is of course attached to traditional data, like the name the user gives it, a description, cloud tags attached to it, etc, so I want everything in a transaction that I can rollback if something goes wrong.  

So how the heck would I upload a file, then convert that file to say a swf and still insert it all into the DB?  Would I upload and insert first and then have a second process which selects the data out, converts it to swf and updates the record?

Thanks