I was wondering if an upconvert DVD player can upconvert the burned DVD's that I have made from my collection. I do not have an upconvert DVD player yet, but was thinking about getting one later this year. Maybe I will get an HD-DVD player or blu-ray player if they come way down in price. The DVD's I have burned from the past are compressed, but over the last year I have started burning DVD's onto dual layer media with no compression of course. Can an upconvert DVD player upconvert burned DVD's? Also, how will they handle a burned DVD that has, lets say 30%-40% of the video compressed?

Nothing changes with a burned disc vs. a pressed disc, it simply upconverts whatever video data exists on the disc. Any time you apply lossy compression on video data you're obviously lowering the quality to varying degrees and artifacts introduced from additional compression may become more obvious with upconverting, but again the process is exactly the same regardless of the video quality.

Yes.
Burned dvd's up-convert quite well.

I have over 400 backups and use the NeoDigits 4000 on our Plasma
and last years Neo 3000 model on another HD tv.

Both upconvert to what looks to me like damn near HD quality...
Good enough that I don't plan to lay out big bucks for a blue ray for quite sometime.. if ever...

http://www.neodigits.com/

Ditto with my OPPO (http://oppodigital.com/) upconverting DVD play. Like rago, I have hundreds of backups and they look great on my 50" Sony HD LCD RPTV. You won't see me buying a Blu-ray anytime soon. I'm quite happy with what I have.

Burned DVD upconvert just fine... I suggest using the Denon 3930CI. I love mine! The image quality is the best I've seen yet from standard DVD.

http://usa.denon.com/ProductDetails/3297.asp