Wow, your post is really scrambled.
From what I understand (English is not my native tongue), you have an HD video in 1080i and want to burn it to a normal Single Layer (SL) DVD and be playable on a normal video DVD player, the ones normally found under a telly for example.
What exact format is that video in and what applications do you have at your disposal?
If you have a Mac, you surely have iLife, thus iDVD, which is able to create video DVDs, but not from every source format.
There is also
Burn, maybe take a look at that.
Then there is
Toast Titanium, but that software costs something, thus iDVD and Burn might be suited better for your purposes.
Has MRoogle brought any useful information?
If all those failed, can you please post more details on that 1080i video, like what suffix the file uses and what codec is used to compress the video?