KVCD Classic Templates?

[GFR]

KVCD Museum

If, altough now we have KVCDx3, file prediction, optimized and matched GOP & matrices, cool smoothing filters, etc. you still swear by the original KVCD, here it is.

http://www.gfrhpg.hpg.ig.com.br/kvcdmuseum.html

[kwag]

Great memories GFR

[GFR]

What about these?

Quote:

kwag
Member


Posted: Mar 13 20:23

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To ******* *** ( and others viewing this posts )


I would like to explain "mathematically", that it is now possible to achieve 120 minutes of video on a single 80 minute CD-R, with a quality far above a standard VCD and even visually close DVD.

Let's put the facts on the table!:

A standard VCD ( NTSC ) is 352x240 MPEG-1 at a bitrate of 1,150Kbps. This totals to 84,480 pixels.

In order to use half D1, 352x480, you must double the bitrate ( to 2,300Kbps ) in order to maintain the same ratio of bitrate/pixels, because 352x480 totals 168,960 pixels.

But then, you could only fit about 40 minutes instead of 80, because of the doubling of bitrate.

Now consider this other fact:
MPEG quality is ->NOT LINEAR<- in relationship with bitrate.

If you are watching a low movement scene on a VCD ( MPEG-1 ) at 1,150Kbps, the quality will be sustained, even if the bitrate was around 850Kbps.

Below that, the quality falls off sharply, and blocks appear very clear.

Now this is what I have done, and I'll explain in detail why it works:

With the information above, if you create a VCD with a minimum bitrate of 300Kbps and a maximum of 2,300Kbps using CQ_VBR of 70, you will maintain an average of around 900Kbps for slow moving scenes but on high speed scenes the bitrate will bump up to the maximum which is 2,300Kbps. I use 2,300Kbps max because most DVD/VCD players can play 2,500 ( some can go higher ). But I have 5 different brands of DVD players and they all play this format.

I have also modified the GOP structure to be 1,15,3,1 instead of the standard 1,5,2,1. This enables higher mpeg compression because there are more P frames available to the encoder. Higher values create "ghosts" on images. Specially on anime and computer generated films.

The value of 3 for B is optimal, because increasing it doesn't compress the image anymore.

This values are to be used with the latest TMPGenc 2.53 plus.

The samples I posted above, one is from "Lethal Weapon 4" ( actually the filename is Action Scene Test ) is almost 29 seconds long, but the file size is roughly 4MB!.

If you look at this file, which has raindrops falling, fire and movement, with the bitrate viewer ( http://www.tecoltd.com ), you will see that the average bitrate is 941Kbps and the maximum is a peak of 1489Kbps.

But looking at the file with WinDVD, PowerDVD, or burning it as a non-standard VCD the quality on a regular TV ( 32" CRT ) will look just like a DVD.
Unless you have a HDTV( which I do ) and there you can see some difference. But the quality is far far above any VCD I have done , or even commercial VCD's.

The whole file "Lethal weapon 4" is a bad example, because it's a continuous action movie, and the whole film encoded with this method came out to a size of 1,006,003,824 bytes ( or about 1GB in size ). So I couldn't fit it on one CD. The whole movie is 127 minutes long. But then again, if created as a standard VCD, the size would be over 1.6GB and with less quality!.

As another example, the film "Don't say a word" which is also about 2 hours long, was only 700MB in size!.

I also drop the audio to 128Kbps to save some space.

So, please look at the samples before saying that the quality is below VCD, because it is FAR above VCD and I would dare say that it's equal or better than SVCD.

The real thing here making it possible is the newer version of TMPEG. Older versions of TMPEG never achieved this quality/compression.

The samples are posted at http://briefcase.yahoo.com/mpeg_test under My Documents.

So enjoy! ( and flame me all you wan't )

kwag

[kwag]

Oh yeah , and the quality we are getting now is so far far above those times
That's another good post for the museum

-kwag