How can 90 min SVCD quality movie fit on an 80 min CD?

[culttvguy]

OK,I have heard about overburning,but this seems to be more than that. I got a disc image of a 90 minute movie (not made by me) which i burned straight to an 80 min CD. The movie is SVCD quality,and is recognized as,and plays as SVCD in my DVD player.
My question is,how can a 90 minute SVCD quality movie be made to fit on an 80 min CD? I thought that an SVCD could hold only about 40 mins

thanks

[yoda313]

Maybe its an xsvcd. They may use the mpeg2 codec but reduce the bitrate to squeeze more video onto it.

[ZippyP.]

Using a bitrate calculator...Audio at 128 kbps, the video would be 1074 kbps to get 90 minutes on a CD. Far too low for SVCD resolution, more like VCD res.

Perhaps it a KSVCD, They seem to be able to fit ridiculous amounts of video on a CD, but with DVD's so cheap it doesn't make any sense to me.

http://www.kvcd.net/portal/index.php

[Abond]

My question is,how can a 90 minute SVCD quality movie be made to fit on an 80 min CD? I thought that an SVCD could hold only about 40 mins

thanks

SVCD specs allow variable bitrate. 40 min is when the bitrate is at the max allowed, constant.

Maybe its an xsvcd. They may use the mpeg2 codec but reduce the bitrate to squeeze more video onto it.

Nonsense. Are you really think that there is limit at min bitrate for SVCD?

Far too low for SVCD resolution, more like VCD res.

If you mean constant bitrate, yes. If it is variable bitrate it is OK. DVD Players generally would recognise also 352/XXX mpeg2 variable bitrate as SVCD. So if you think that only 480/XXX is SVCD you are wrong.

[vitualis]

Actually, only 480x480/576 is SVCD.

352x480/576 is CVD, a standard that slightly predates SVCD but which SVCD was obliged to be compatible with as CVD compatible players (and discs) had already been released.

I also agree that at SVCD specs, that you are likely to get relatively poor quality video at those bitrates unless you have a particularly MPEG friendly source.

Regards.

[jman98]

It was a few years ago and I think it was in another forum, but I got into an offline discussion with a guy who was given an SVCD of _Kill Bill Volume 1_ that fit on one CD-R. He gave me a 1 minute sample out of it and it was amazing. The guy who originally made it refused to tell his secrets other than to say that he used VBR under CCE to re-encode it from DVD and he used 20 passes! I examined the video clip I was given and it had some really wild GOP sizes. Nothing was more than 15, but some GOPs were only 8 frames, others might be 10 or 11. The GOP size changed constantly during the clip. I have no idea how to do something like that. The bit rate was all over the place, going as low as 400 Kbps and as high as 2400 or so. The quality was not as good as the original as there were some small artifacts, but it looked a lot better than I thought it should have considering how low the bit rate was and I think most people would find it acceptible. If the GOPs of the disc image the original poster talks about are 15 or less, then it's not KSVCD. KSVCD uses insane GOP sizes like 30 or more frames per GOP. If you drop the bit rate low enough, you can make a standard SVCD and fit 90 minutes of movie on one CD-R, but you'll have to do some fancy encoding (like with CCE) to make it look OK.

[culttvguy]

I pulled this from the folder called EXTRA on the disc,don't know if anything can be determined from it...

--------------------------------------------------------
ccefront v1.0 RC3, by Tylo (c) 2005
--------------------------------------------------------
- 2005-10-26 00:13:13
- WIN_XP
--------------------------------------------------------
- Input video : 1:33:49 (140731 frames, 25 fps)
- Input ecl file : C:\Documents and Settings\cw_uk\Application Data\CCEFront\work_dir\v001.ecl
- Input avs file : C:\Encodes\F\Video\Fp.avs
- Output mpv file : C:\Encodes\F\Video\Fp.mpv
- Sample percent : 5.0
- Adjust % : 0.0 (accuracy tweak: yes)
- Sizing pass : Encode if opv sz < -0.0%, or > 0.0% oversize, or Q > 40
- Select ranges : every 300, select 15 frames
- Sample frames : 7050
- Using CCE SP version : 2.67.0.27
--------------------------------------------------------
- Target mpv BR : 1104 (300-9000) kbps, 776835120 bytes
--------------------------------------------------------
Search for Q:
- Sample encode : Q=32: 951 kbps, err=-13.9%, size=669229123, sample sz=33525416
- Sample encode : Q=25: 1109 kbps, err=0.5%, size=780862781, sample sz=39117768
--------------------------------------------------------
- Determined Q : 25 = Round(25 + (0.5/2)) with 0.0% adjustment.
--------------------------------------------------------
- 2005-10-26 01:08:59
- Start movie OPV encoding (Q 25)
- OPV pass result: 101.9% on target (791318192 / 776835120) Speed factor: 0.45
--------------------------------------------------------
- 2005-10-26 04:37:15
- Start VBR sizing pass (1104 kbps)
- Sizing pass result: 100% on target (776485148 / 776835120) Speed factor: 0.46
--------------------------------------------------------
- 2005-10-26 08:02:12
- ccefront successfully finished
--------------------------------------------------------
---------------------------------------------

[offline]

You can do it (kill bill example) by adjusting the quality under CCE in advanced mode after the 1st pass, and then re-passing, editing again, re-passing etc, tweaking the bitrate distribution manually down to the GOP level, but it takes hours of work to get a near perfect result.

[culttvguy]

And only if you are extremely patient