Comments

PeterMac wrote on 3/7/2002, 6:02 AM
That's a good answer, but surely not quite accurate?
If you set a maximum bitrate of, say, 6000 bps, then the CBR setting will encode everything at this rate, but the VBR setting will only use this setting if it has to - lots of movement.
The best you can hope for then is that the two results will be indistinguishable. I cannot see how the VBR can have better quality unless its bitrate is allowed to rise above 6000 bps. More efficient certainly, but not better.
I'd say that provided lack of space is not the enemy, go for CBR every time.

-Pete
mcwill wrote on 3/7/2002, 6:40 AM

But surely you can specify a higher max bps to VBR eg: 7500 and still get an "average" bps of 6000. In that scenario the file size will be the same as a 6000bps CBR but have the quality of a 7500bps CBR?

Iain
owlsroost wrote on 3/7/2002, 7:30 AM
I use VBR with Max=8000000, Av=6000000, Min=4000000 and get very good results.

Using Bitrate Viewer ( http://www.tecoltd.com/bitratev.htm ) to examine the MPEG files, the average bitrate usually comes out at 5.8 Mbps, max about 7 Mbps, min about 5 Mbps. I've yet to see the VV30a encoder use more than about 1.2Mbps 'headroom' above the average rate in VBR mode.

Tony
wvg wrote on 3/7/2002, 10:46 AM
I think Tony is on the right track. After all the whole idea behind VBR is to boost bitrate WHERE the video needs it. Setting some arbitrary bitrate COULD result in a bloated file size resulting in a needlessly high bitrate for static scenes. Of course since we're talking about DVD where bitrates are high to begin with, I doubt you'll get much noticable improvement by tinkering beryond a certain point.
SonyEPM wrote on 3/7/2002, 11:14 AM
Are you getting unacceptable results with the DVD templates (which are VBR) in 3.0a?

You should be reasonably safe if you go CBR at 8,000,000 bits/sec, provided your project fits on a DVD at that bitrate.

My advice: stick with the canned render templates if you can, as those will have ALWAYS undergone the most extensive internal testing.

pdmath wrote on 3/7/2002, 3:50 PM
I have been encoding avi to mpeg2 using the trial version of Ulead DVD Workshop. It seems to me I get better results than vv3. My question is, do both Ulead Workshop and vv3 use the very same Main Concept codec? Or is there a difference?
VidJockey wrote on 3/10/2002, 11:38 PM
Hi,
I beleive that Ulead DVD Workshop uses a MPEG Encoder made by Ligos, not Main Concept. All of Ulead's products as far as I know use Ligos. The encoder that is packaged with Workshop and the new VideoStudio 6 is new, allowing you to encode video straight into MPEG-1 or 2 format directly from a DV source hooked to a firewire card(instead of just an analog source hooked to a capture card). I wouldn't think the results would be quite as good as capturing to the DV-AVI format and then reencoding, but it would definitely save time if quality wasn't an issue. I have actually captured some Mpeg-2 with Workshop and found the results to be satisfactory! But not up to the quality when you let the CPU take it's time with the footage. Hope this helps

P.S. TMPegenc still rules!

VidJockey
owlsroost wrote on 3/12/2002, 7:35 AM
The VideoStudio 6 encoder is definately MainConcept - see http://www.mainconcept.com/ulead.shtml (also the dll names are the same as the VV3 version....)

I think the DVD Workshop encoder is the same - note the Ligos/LSX logo isn't in the setup dialogs any more....

Tony