xVCD specs - what does it cover? even unofficially?

greenspun.com : LUSENET : Video CD : One Thread

After giving up on SVCD (because I can never get them to burn right (yes, even with VCDimager and Nero5.5)) I found myself in a tough place. I wasn't satisfied with VCD quality so I went hunting around for more options. I've been toying with different xVCD specs (in TMPGenc-b12j) and I've found a couple tweaks that I really like.

First off, instead of plain-old 1152 kbps I upped it to 1500 kbps, which helps a lot. I get about 60 minutes of video per 700MB CD. And with that extra quality I can hold a larger image; so I started using half-d1 480x480 resolution (at fullscreen 4x3 aspect ratio). That looked really good, but even better is using VBR encoding - tmpgenc supports it for mpeg1 as well as mpeg2. So if I average 1400 kbps or so I get a _very_ good picture quality, and if I keep the peak under 2400 (or so; I'm cautious) then it's under SVCD specs and _should_ play on most dvd players.

But that's question; Will this play? I know that "xVCD" is an industry-wide undefined term, but I've been led to believe that it encompasses "higher-than-normal bitrates". Does anyone know if that means VBR? and will the 480x480 resolution mess it up either? Both of the traits are common on all DVDs, and I would think that if it works on mpeg2 - and if the dvd player plays VCDs then it supports mpeg1 - then all should be well, right?

Basically, how far can I push the definition of "xVCD"? Any comments would be most appreciated.

-- Elliot (spam@quasignosis.com), December 11, 2001


oops - 480x480 = 2/3 D1.

-- Elliot (spam@quasignosis.com), December 11, 2001.

XVCD means anything that deviates from VCD specs. Usually it means higher than normal bit rates. What you are doing qualifies. Most DVD players that support VCD don't enforce any of the specs and they'll play XVCDs. Whether they'll play XVCDs with high bit rates and VBR and 480x480 may vary from player to player. I wouldn't be surprised if you found some players that played them fine and others than refused to play them at all. VCDimager sucks big time for SVCD. I use it a little for VCD, but it's a real pain in the butt. If I didn't want to use to make entry points, I wouldn't use it at all. It is absolutely fascist in demanding that your video be totally compliant to use it. If your SVCD or VCD is not compliant by even the slightest bit, it will go nuts. Nero is real simple to use. Were you getting the message from Nero that your video was not compliant? Just check to burn it anyway. Most people don't produce compliant SVCDs anyway and if you just go ahead and burn anyway, most players will play them with no problems. The bad news for you is that it really doesn't get simpler than Nero for SVCD, but it sounds like your XVCD approach is working for you, so that's OK.

-- Jason (Jason.Shumate@equant.com), December 11, 2001.

Moderation questions? read the FAQ