Originally posted by: Alan Partridge
The source doesn't need to be deinterlaced before transferring to DVD.

But it should be inverse-telecined (IVTC) before transferring to DVD.
Ohterwise you're wasting bit-budget by encoding the same fields twice.
Yes, DVD stores fields not frames, but there's not much point wasting space storing two copies of the same field.
If you store telecined "frames" (two fields from different film frames) on your DVD, it'll look crap needlessly on progressive displays (computer screen, plasma TV, projector, etc.)
Not to mention, color correction routines will work best on progressive frames.

Fortunately, the X0 team members already understand the benefits of IVTC'ing their sources.