svcd vbr questions

[vcd4me]

I used to use cbr and have recently switched to vbr.

So, I have a file and just converted it to svcd in vbr

theses are the settings:
minimum - 1150
average - 1900
Max - 2500

Now the file is completed and the size is:
680 MB or 713,296,024 bytes.

Also when I looked at the screen when using nero it shows that the disc is not full?

How come I can't fill the disc or am I missing something?

Please any help would be appreciated.

Signed
VCD4ME

[fingers]

You can actually fit an 800mb mpg file onto a 700 mb CDR, it has to do with the mode that's used when burning (S)VCD's.

I've burned SVCD's as big as 814mb without needing to overburn, you could go even higher depending on how much the CD's overburn capacity is, although there's no guarantee that your CD Writer has the ability to overburn, and no guarantee that your DVD player can read that far out on the disc... 800mb is usually safe..

[vcd4me]

Can you explain how you have done this. I have never heard of this before and have converted around 150 movies.? I do know 80 minutes on 700 mb disc because of vcd is a diffrent mode than data.

When I use tmpgenc it basically does all the calculations for me.

Like I said I have just started doing vbr. I used to use cbr. Everybody kept saying you woulld get better quality with vbr.

Thanks in advance
VCD4ME

[fingers]

All you should have to do with tmpgenc is select 80 minute CD, it will then set the max file size to something like 799mb / 99% of disk capacity...click on the auto setting checkbox.

If you're using the wizard, then it's the 4th of 5 wizard pages. Depending on how you have tmpgenc set up, you may need to change to a different template...

Also I have a difference of opinion on the whole VBR issue... yes VBR does look better than CBR, but that being said I've found that the best setting is CQ encoding, but it's a pain in the ass.

With CQ encoding tmpgenc can not estimate the file size so you have to do test encodes of smaller parts until you get the right cq setting, then you encode the whole thing... if your file ends up being over 813mb, then you have to delete it change your CQ setting and start all over... if it's between 700 and 800 then you can burn it...

I found a really good resource is Dr. Mercury's SVCD movie kit, Doc posts it every friday night on usenet (your ISP should have a usenet server that may or may not support binaries)... it includes all of the free utilities, and a guide, or you can download just the guide... sorry but if I give you any more details than that someone will mistakenly qualify this as a warez post , and delete it...

Doc also runs a site www.svcd.cc , but it's a payed membership, and I found that the free guide is good enough..

[vcd4me]

Fingrers,
As I said I have made plenty of vcds/svcd. Yes I use the wizard and I do set it for 80 minute discs . I don't use it auto setting. I usually set it for a number close to 98% because I have read about problems when you put the setting too close to 100%

you wrote

I've burned SVCD's as big as 814mb without needing to overburn

I think what you were saying about the 814 MB file size that you were talking about is similar to what disc 2 of my example below is.

Now as far as the 814 mb there is two diffrent ways programs use mb . Just look at what GAZORGAN wrote in this post to me https://www.videohelp.com/forum/viewtopic.php?t=151799&highlight=

Let me give you an example of what I am talking about:

Disc 1 (50minutes) projected file size is 773MB
actual size 680MB or 713,296,024 bytes

Disc 2 (50minutes) projected file size 773MB
actual size 768Mb or 806,174,684 bytes

How can the 2 discs be the same in length in time but diffrent sizes?

Thanks for your help Fingers but I am confused about how this can be.

Signed
VCD4ME

[Nitemare]

More than likely one of the discs has more "action" on it than the other. Using VBR more bits will be applied to the high motion scenes and less to low motion scenes. The bigger file has more high motion scenes than the smaller file. That's what VBR is all about (Variable Bit Rate)... not wasting precious bits on scenes that don't need them. With 2 pass VBR, you can accurately predict file sizes but you'll double (at least) your encoding time.

CBR (Constant Bit Rate) applies the same amount of bits throughout the entire movie. Sometimes it's wasted and sometimes it's not quite enough, but the file sizes are predictable.

As near as I can tell, CQ (Constant Quality) is a 1-pass VBR encode. Difficult to predict file sizes but gives excellent results in a short time.

Sorry if you knew all this already.

[fingers]

Nitemare said it all above...

Basically the more action, and not necessarily action, it's the more change in a scene the more bits required to render the scene. For example a panoramic sweep across a field requires a huge amount of bits to encode because just about every pixel on the screen changes.

But a scene where two characters are talking uses very few bits to render as all that's moving are parts of the face, but the background around them is static...

Also if a scene is very dark, then the encoding would require less bits, from what I've read animation compresses quite nicely because colour is usually in large blocks.

Your example below for VBR encoding is fine (I'm assuming that you're using 2 pass VBR).

For 50 minutes a disc I usually use CQ encoding, and depending on how much movement there is I can usually get away with a CQ setting in the low 90's, which results in excellent quality... I've also encoded some stuff at 72 minutes a disc, roughly 104000 frames per disc, and used a CQ setting of 59 for part 1, and 65 for part 2 which came out quite nice... had lots of dark scenes... the reason I can get away with a higher CQ setting for part 2, is that rendering film credits uses very few bits, so more data can be allocated to the movie... or you could even just lop of the credits, and bump the CQ even higher...

If you want to learn more about CQ encoding get DR Mercury's SVCD movie kit, the html guide is excellent, and it comes with some great freeware utilities, assuming that you have access to a decent usenet server... it's posted every friday night on usenet in:

alt.binaries.multimedia.utilities

He uploads a suite of freeware utilities, which includes the guide, or you can dowload just the guide...

[vcd4me]

Thanks guys

I still don't get why it wouldn't use all the disc space ?

But never mind I already burnt this movie.

It is a low action movie.

Thanks again
VCD4ME