Adam Bower wrote:
Doubling the resolution makes the output 4 times as big...
That's where my 1GB XVID -> full DVD (4.7GB XVID) calculation came from.
Then you have to take into account that most HD-DVD discs have much better audio soundtracks options than normal DVD soundtracks, so these will take up more space.
But a dual-layer DVD is 9GB so still using MPEG4 should be capable of fitting it all onto a single disk.
I can also assure you that playing a full HD source on a good full HD panel you can really see the difference,
Oh I know that there is a hell of an improvement, but it's not just the resolutions that have improved - MPEG4 is a hell of a lot better than MPEG2 too!
I'd also disagree about being able to re-encode a DVD down to 1GB with XVID with no loss of quality, as everything I've ever watched that has been encoded this way looks somewhere about the same level of quality as Freeview ;)
I agree on this but it is largely (I believe) down to the lossy -> lossy transcoding. I would expect (but don't have any figures to prove it) that from the original source, encoding at the same playback quality, MPEG4 should result in a file around half the size of MPEG2. As far as I know most movie disks are only using single layer for the main feature, so that would mean a double-layer DVD should still hold HD quality using MPEG4, and be playable on cheap players. H.264 is considerably better than XVID, but my TV's built in player won't play H/264 :-(
Going beyond HD will need something new, but the combination of MPEG4 and dual layer disks ought to have been enough to delay that next step for some time yet. MPEG4 capable players are around £30 (I bought one in Tesco last week for £15, albeit without an HDMI output), HD (eg Blu-Ray) players are way more expensive and far more limited.
To return to my original questions, what I have is an HD capable TV with a built-in MPEG4 capable player. In order to watch HD-DVD's on that TV I either need to buy an HD-DVD player, which if I can find one will cost me about £100-150 from eBay, or I need to get the HD-DVD converted via my PC down to an MPEG4 file on a single DVD (it can be a dual layer disk). Given I paid no more than £3 for any of the disks, and given that I have an HD/Blu-Ray player waiting to be fitted into my PC, I would like to try that conversion. A loss in quality is acceptable, it should still give me a result way better than I can get from a standard DVD. After all it's only for playback on a TV in my bedroom, not in a home cinema!