why no support för other mpeg2 resolutions?

jocks wrote on 8/19/2004, 1:10 AM
hi there,
I can understand if DVDA2 doesn't support SVCD since the audio format isn't standard for mpeg2. But why does it then support mpeg2 at 352x288 but not a 480x480 or 480x576 if one sticks to standard audio format? a lot of people own a TV capture card and wouldn't loose picture quality with a 480x480 resolution. the benefit will also be more recording time on a DVD-R.
/jocks

Comments

bStro wrote on 8/19/2004, 7:57 AM
It's been discussed many times before. Opinions vary among the users, but obviously only Sony would be able to speak as to whether or not DVDA will ever support SVCD resolutions. And they ain't talkin'. So far, there are essentially three sides to the debate:

1. "My player will read SVCD rez on DVD, and other programs do it, so DVDA should, too."
2. "SVCD resolutions are not DVD-compliant, so DVDA should not accept them."
3. "I understand the interest people some people have in this feature, but it's Sony's call and I see no reason to begrudge them for their decision to create only DVD-compliant discs."

Personally, if this thread turns into that discussion, I'll probably sit it out this time. I've taken position #3 before, but some people with position #1 seemed to think I was expressing position #2 no matter how many times I explained otherwise.

If you fancy reading the previous discussions on this, click the Search button up there at the top right, enter SVCD for Search Words and DVD Architect Software for the Search Forum.
jocks wrote on 8/20/2004, 1:31 PM
thanks bStro,
I've already read the discussion about SVCD here, but was curious about other mpeg2 formats as well. for now I'm squeezing in 2h40min on each DVD, by converting 480x576 mpeg2 tv series to standard DVD resolution. the picture quality is however rather grainy...
for a full quality movie, it usually ends up on two discs.
/jocks
bStro wrote on 8/20/2004, 1:57 PM
*shrug* I don't think that changes my answer any. Only in that Sony is even less likely to support those resolutions than they would SVCD ones, I'd think.

Rob
JSWTS wrote on 8/20/2004, 3:41 PM
I'm not sure why Sony has decided not to support anything but full D1 files (720x480 for NTSC and 720x576 for PAL), but that has been their position up to this point in time. The dvd spec allows for mpeg 1 (352x240 NTSC and 352x288 PAL) up to a max of 1.856 Mbps video stream, and half D1 (352x480 NTSC and 352x576 PAL) or broadcast D1 (704x480 NTSC and 704x576 PAL). Since dual layer type discs have not been the norm, or even possible with recordable media until now, many (including in-house instructional business discs) have used mpeg1 and 1/2 D1 discs to fit more content per disc. Absolute image quality is not always the intent of every disc, and the trade off in loss of image quality with some types of material is well worth the extra content that can be put on a single sided disc. With mpeg1 you can fit nearly 8 hours on a disc, and with half D1 you can fit roughly 4 (and even more) hours per disc. To do the same with full D1 would require very low bitrates, and full mpeg is not as efficient as these other image sizes and mpeg type in encoding. The resulting encoded files don't typically look as good as their mpeg1 or half D1 counterparts. All of DVD-A's competing authoring apps support these variations in mpeg files. Very few support non-spec frame sizes like you posted (including SVCD), so I wouldn't hold my breath that they ever will. None of these frame sizes and mpeg types are officially supported, and for that reason, even if DVD-A would accept the files, the discs you create in all likelihood wouldn't play on many, if any, players.

Jim