optimal script for mpeg-1 vs mpeg-2 ?
 

Hi,

My first post here. I recently used avisynth optimal scripts and I noticed a real quality improvement. So great work !

I was using kvcd matrices for quite a few time now and I always got good quality. And when file prediction was implemented in DVD2SVCD for tmpgenc I completely switched from CCE to tmpgenc as I got much better quality with less blocks..

But now I always read using mpeg-1 with KVCD is better than using mpeg-2.. I did some test and so far, I've got smaller mpeg-2 file at same CQ than mpeg-1! Plus, visually that does not seem to differ much between mpeg-1 and mpeg-2.

So I'd like to know if it is still true than mpeg-1 is better for KVCD than mpeg-2. If true than I might have a closer look at the videos.

If not sure, has anybody tried to test same video with same CQ and same optimal scripts and got smaller mpeg-2 files just like me?

Cheers
toc

Edit: typos

It's better and it's not normal that you have smaller file with MPEG2. Normally the size is quite the same, with a small difference for MPEG1 files that are slightly... smaller !

Okay I guess I'll have another go with my tests then. I must have mixed up some files.

Thanks !

Hi,

I got the chance to do some more testing. Now I use latest script for dvd2svcd tool and I don't know why I got that but still:

- using same CQ value, I got mpeg-2 smaller than mpeg-1
- roughly same quality to my eyes
- same result not using script but only bicubicresize

Has or can somebody test same thing? using dvd2svcd to do kvcd?

I just thought that maybe BBmpeg perform some weird muxing in here.

Cheers

I also would like to know why that the differences are between mpeg1 and mpeg2, since there are official kvcd templates available for both mpeg formats?

Mpeg1 : low bitrate required, no interlace supported, no required high cpu

Mpeg2 : High bitrate required, interlace supported, required high cpu time

Usually I do mpeg1 to put a video on 1 cd-r 80. I f I do the same with the mpeg2 I get a worst quality.

This happens because the mpeg2 has been created kepping in mind the DVD target. So I don't have to care for the bitrate because I have got lots of space. ( see the definition for the mpeg2 on the mpeg site)

You can do ( has I did ) a simple test .

Make a little convertion in mpeg1 format, then do the same clip in mpeg2 but keeping the bitrate under 1150 and the same video resolution. You'll see a lot of blockness in the svcd more than the vcd. I simply saved a frame from both in bmp format and found that the mpeg1 was better.

The reason for have the kvcd in mpeg1 and mpeg2 is because if you want to make a dvd with 2 or 3 movies on it you can do it mpeg2.

But why does the official SKVCD template use mpeg2? By the way, why is there a skvcd template anyway?

For people that cannot play MPEG-1 KVCDs, and to substitute regular SVCDs with equal quality but longer play time per media ;)

-kwag