I need to compress an HD timeline from Final Cut Studio to DVD Studio Pro. The project is a 90-minute feature length shot in 1080i 24p. I realize this issue has been posted before, but I would appreciate as in depth a response as you can offer. I know there are many different codecs and compression settings, and I have experiment with many but have yet to find one that is compatible with a home DVD player or a copy that looks good on a HD TV. Thank you for your time and expertise.
I think you're missing one very important piece of your puzzle: DVD is Standard Def. All DVD players are SD. DVD format is an MPEG 2 (not a very efficient codec) wrapped in a .VOB container. Your 1080 sequence is going to be down-scaled to SD frame sizes for DVD formatting.
Sure, you can get a DVD player that will have a DVI or HDMI port on it but it is just up-scaling the 720 x 480 (or 720 x 404) NTSC Video to 1280 x 720 or 1920 x 1080. Your $1,000 TV probably has a slightly better scaler than a $100 DVD player but that is arguable.
1080i @ 24p? How was your footage shot? Just curious, this sounds like contradiction in formats.
An MPEG2 HD @ 20 Mbps will only fit roughly 30 minutes on a 4.7 GB DVD. Are you working with blu-ray by chance?
It sounds like you may need to invest in a Blu-Ray burner or consider other options for your HD distribution.