[mythtv-users] Transcode HD for SD frontend?

[Dave]

I've got a combo backend/frontend which records and displays HD.  But,
I've also got an SD frontend (XBox), and it doesn't have the
horsepower (or network bandwidth) to display HD recordings.

Is there some way I can tell the backend to transcode (but keep the
original), and "decide" which version to send when a program is
selected on the frontend?

I know I'm asking for a lot here, but I'm guessing someone else must
have this issue.

Thanks
Dave