CCE SP: 1 Pass VBR vs Multi-Pass VBR?

[KillerBear]

Hey guys, just a quick question here...

I use CCE SP to encode my DivX's to Mpegs that I burn to DVD. I always use multi-pass VBR and always get a Mpeg around 4 gigs.
I was reading a guide on how to encode using CCE, and it recommended you first do a 1 pass VBR first... the result of this is a video information file (you can use to tweak local parts of the mpeg stream) and an mpeg thats about 1.5 gig. And then after that to do the multi-pass VBR.

Can I use this smaller mpeg to burn to DVD? I could fit 2 er 3 movies on a DVD this way.
I watched the file in windows media and could not tell the difference between the 4 gig and the 1.5 gig file.
Also I noticed that when doing a 1 pass VBR, instead of putting an average bitrate, it asks you for the "quantization level" which was preset at 60. What does that mean?

The way I see it is that the DivX's bitrates are usually around 700 kb/s. So as long as the mpeg is at least that rate the quality wont change, is that right? I have no idea, but seems logical to me....
Anyways, thanks in advance.

[guns1inger]

You can't compare bitrates betwen Dix/Xvid and Mpeg2. The encoding algorythms are too different. Simple exercise. Take your Divx and encode it, 2 pass VBR, to get the same output size. Do it again at the same bitrate as the original Divx. I guarantee you that both will look like shite.

I generally do a 2 or 3 pass VBR out of CCE SP 2.67, using the bitrate calculated on this site's BRC. I'm always happy with the results. For some downloaded footage I will do a CBR encode if I'm time constrained.

[KillerBear]

ok... thats all well and good.. but my question still stands....
can i take the mpeg from the 1 pass VBR (the 1.5 gig file) that used a quantization scale of 60 (whatever that means) and burn that to DVD?
It looks great... like I said, cant tell the difference between it and the 4 gig.

[ronnylov]

I think you can. Try it and see what happens.

[guns1inger]

Sorry, I just sort of trailed off there. It happens to us old people

Assuming that a) the bitrates are in spec, and b) you are happy with the quality, then there is no reason you can't use the output. I think, once you get it up on your TV, you will find the output is not up to the same quality as a 2 or 3 pass VBR encode at full bitrate, but then again, some people claim a %50 squeeze with DVD Shrink is the same as the original disk, so who knows.

Ultimately it is up to you, so give it a try. You don't need us to OK what you do. You do know that, don't you ?

[KillerBear]

lol. yeah I do know that thanks.
I just wasnt sure if it was up to spec for dvd burning.

Still no one knows what that "quantization level" means in CCE?
It only says it when you pick a 1 pass VBR.

[adam]

Still no one knows what that "quantization level" means in CCE?
It only says it when you pick a 1 pass VBR.

The manual describes it in some detail. That is the difference between 1 pass and 2 pass VBR. In 2 pass VBR you set the bitrate and allow the quantization level to fluctuate and in 1 pass VBR you set the quantization and allow the bitrate to fluctutate.

It is an oversimplication but you can think of quantization as quality in a sense, and generally lower is better, thus lowering the Q in 1 pass mode will mean more bitrate will be used and you will get a larger filesize.

Quantization is the amount of data thrown out, so like I said lower is better but a high Q is not necessarily a bad thing. Some scenes are highly compressible and you can throw out a lot of data and not notice it, which is really the whole point of allowing Q to vary in multipass encoding.

So just experiment with Q values to find the one you find acceptable but realize that on some sources your output may come out much larger.

[KillerBear]

ah ok cool.. i see now

is there an online manual for CCE somewhere?
I know on the product website theres a brief one, but it doesnt cover a whole lot of stuff in detail.

Thanks again.

[adam]

Your version probably should have come with a hard copy manual, otherwise there is one in the CCE install directory.