KVCD: is the Bitrate Actually Running at 1800kbs?

Fistandantilus · #1 09-11-2003, 03:53 PM

I've been defending the KVCD format tooth and nail at another forum.
Here's a little discussion:

Quote:

KVCD = XVCD, i.e. an extension to the allowable standard for VCD. Therefore, many standalone DVD players won't play them.

I have never made one myself so I can't comment on quality, but at that low a bitrate, surely they must be macroblocks/pixellation all over the place?

Quote:

You cannot change the amount of data a 700MB CD-R can store, and you cannot change the runtime of a movie (except maybe by removing the credits). Therefore, if you want to use fewer discs for your backup, you will have to use a lower bitrate.

OK if your source is the original DVD, I concede that it probably is possible, with a lot of tweaking and hard work, to get a result that is of comparable quality to a VCD or SVCD that conforms to standards. (If however your source is a 700kbps DivX-encoded AVI file, it's very likely going to look blocky before you even start re-encoding.)

However, what happens when you buy a new DVD player, and find that it won't play these KVCDs you have encoded? You have to go through the whole process again to make a standards-compliant disc.

It's just my opinion, but KVCD is really not worth the effort.

Did you see the thread on VCDQuality about KVCD?
"KVCD - does it suck?"
Over the top as usual, but entertaining stuff nonetheless.

One other thing, there is a certain person on another forum who is a big proponent of KVCD, even written some guides on the subject. Not naming any names, but this is the same guy who, when he first joined that forum, didn't even know the difference between bitrate and framerate!

Quote:

Call them what you want, they are XVCD non standard nothing more and nothing less, most of the time people come to a forum, wanting to cram 2/3 hours onto a 80 min disk, a forum with any sense will tell them they cannot do this without loss of quality.

Quote:

There you go, quality and bitrate go hand in hand, lower it by 1 bit per second and the quality has dropped. The old saying of crap in crap out still stands, and if you did a DVD rip and placed it on an XVCD then the watchable quality perceived by you would be just fine.

The vast majority of people here are downloading AVI's which are Mpeg 4, already the quality has gone and there is nothing you can do to put it back, converting it to mepeg 1 will reduce the quality down further, these are facts, dropping the bitrate even lower and the quality is going to be much lower.

There is no way you can say the quality has not dropped, we are not talking about what your seeing and find to be exceptable. On cheaper DVD players and TV's it will look crap, if it plays at all

Yes all my VCD's look like DVD quality, but they are not and played on the average player you will see bad artefacts, they are present the moment you did any conversion

Now let me ask you a question KWAQ.When I use the 352x480 template is the bitrate actually running at 1800kbs?When I do a 352x480 is the bitrate running at 2500kbs?

From what I percieved in this little argument,as I didn't quote it all they seem to think that all the templates run at a bitrate the same as a vcd.Does it?Because from what I have seen both on my computer,on my home DVD player,on my laptop and 2 other friends laptops(different specs as well) the quality doesn't change.It seems hard for these people to belive that a 2 cd-r kvcd is just as good if not better than a 3 cd-r Svcd.
My main question is the bitrate.If I use the 352x480(running at 2500kbs) and am able to compress it to one cd-r is the bitrate actually running at 2500 or is it running at 1150 like a vcd?From what I have seen,I have tested the exact same rip,using smartripper,dvd-avi turned into a KVCD and an SVCD and the quality of a 2cd-r kvcd was exactly the same as a 3-4 cd-r SVCD.

kwag · #2 09-11-2003, 04:50 PM

Quote:

Originally Posted by Fistandantilus

Now let me ask you a question KWAQ.When I use the 352x480 template is the bitrate actually running at 1800kbs? When I do a 352x480 is the bitrate running at 2500kbs?

Depends of how you set your MIN and MAX bitrates, and what average bitrate is used while encoding (CQ in our case).
Why do we use MIN=300, MAX=2,500

The reason is, because the bitrate is variable, we take that to our advantage. So to answer your questions, no matter what resolution you encode, if you set MIN=300 and MAX=2,500, that is the bracket range that the bitrate will fluctuate. So you'll get maximum ox 2,500Kbps on high action peaks, and the bitrate will go down to 300Kbps on low action/dark scenes.

Quote:

From what I percieved in this little argument,as I didn't quote it all they seem to think that all the templates run at a bitrate the same as a vcd.Does it?

No. A standard VCD bitrate is constant at 1,150Kbps. Not variable, as we do here.

Quote:

Because from what I have seen both on my computer,on my home DVD player,on my laptop and 2 other friends laptops(different specs as well) the quality doesn't change.It seems hard for these people to belive that a 2 cd-r kvcd is just as good if not better than a 3 cd-r Svcd.

Well, you have to consider that some people are happy with (sub quality) standards. I'm not

I have a rough idea where you quoted those lines

You are correct, that KVCDs quality is 2 CDs, can only be achieved in about 4 SVCD disks. This has been proven here over and over again. Bit some people "there" at that other site, just seem to ignore this reality.
They'll tell you that they rather make standard VCDs and SVCDs, so they can play them years from now on standalones. And they say KVCD, because are non-standard, can't be guaranteed to play on future players.
My answer to that has always been simple: I rather encode KVCD (higher quality that VCDs or SVCDs) and in the future, I'll test my KVCD collection on a player that plays them, and buy that one. Not the other way around

Quote:

My main question is the bitrate.If I use the 352x480(running at 2500kbs) and am able to compress it to one cd-r is the bitrate actually running at 2500 or is it running at 1150 like a vcd?

As I said above. If you encode VBR, it's variable bitrate. So it will fluctuate. And yes, the best example is a KVCDx3 encode, where you can put ~2 hours on one CD-R, with bitrates from 300Kbps to 2,500Kbps.

Quote:

From what I have seen,I have tested the exact same rip,using smartripper,dvd-avi turned into a KVCD and an SVCD and the quality of a 2cd-r kvcd was exactly the same as a 3-4 cd-r SVCD.

Exactly

But hard habits are hard to kick, and some people just don't want to believe it

-kwag

Fistandantilus · #3 09-11-2003, 05:05 PM

Actually Kwaq the site you have an idea of probably isn't the site that it is.I can tell you that it is an ex member of that site and another one called fasttrack but now he has his own site.Initials KJ.I'm sure you know by now who I speak of.
All I can say is that i'm freaking impressed and will stick with it.Plus the next time I buy a DVD player I'll check out the compatability list here and just pick up one that is on here.I saw a philips in wal-mart,think it was a 723(something).I think it does most templates and was on sale for $169 Canadian.Pretty good price.

zes · #4 09-12-2003, 03:39 AM

i don't want to confuse Fistandantilus in any way, but weren't we encoding at MIN 0.57*avg_in_moviestacker and MAX 2000 bitrate? just a detail probably

kvcd's are simply the best, but seems to me they are very 'detail-dependant'. like what script to use, bitrates, all kinds of settings and the latest i hadn't a clue about before: divx decoder settings

it's almost as if this is a PRO-format. let the newbs have their svcd's