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-   -   KVCD/KSVCD: A standard for encode-mux-author ? (http://www.digitalfaq.com/archives/encode/11398-kvcd-ksvcd-standard.html)

absinthe 08-09-2004 02:30 AM

KVCD/KSVCD: A standard for encode-mux-author ?
 
After successfully making a few VCD/SVCD's with "K" standards, I'm wondering if there is some consensus on some things ....

In the world of "ordinary" VCDs and SVCDs, those two formats, obviously , have specific standards. Also obvious is that KVCD deviates from those standards. But I'm confused because KVCD seems to blur the distinction between the two original standards. Let me explain further.

I assumed when starting out that if I was using MPEG2 video, I should mux my audio and video as an "SVCD" (I use bbMPEG) and also author as a noncompliant SVCD. Likewise, for MPEG1 video, I assumed I should mux as VCD and then author (or burn, whatever) the same way.

Then DialHot told me in this forum that he always uses MPEG1 video and burns as SVCD. Well, when it came muxing time I was confused about whether to mux as VCD or SVCD, nevermind the burning phase! I started out muxing my MPEG1 as SVCD and burning the same way. Those disks did in fact work.

Later on, however, I received some errors muxing MPEG1 as SVCD with bbMPEG (the old "can't find I-frame" error). After burning the disc with the resulting .mpg file, my looks-just-fine .m1v video looked awful on TV.

Well, I read a bit more in the bbMPEG forum and of course the first sticky there points out optimal muxing settings for bbMPG. Looks like folks actually mux their video as VCD, too.

So I went to both muxing and burning my MPEG1 as "VCD." This yielded some better results. Interestingly, in that process, I did not receive any errors ... not even the usual compliancy warning from VCDEasy.

I know I tend to blather on, but I'm a person who likes to nail down specific technical details and it's really bugging me that there doesn't seem to be one "best way" to do this sort of thing. In fact, if you consider that you can

a) use MPEG1 or MPEG2 video,
b) mux either of them as VCD or SVCD, and then ...
c) burn any of the above four combination as VCD or SVCD -

... well you've got 8 different definitions right there. And none of that even takes into account such things as aspect ratio, bitrates, etc. that the "K" standard modifies.

I guess what I'm wondering here is whether there is more precise definition of KVCD other than just "whatever you can make work in your player using the the K quant matrix and GOP structure."

Having said all that, I'd just like to hear from others simply how they choose to mux and encode both their MPEG1 and MPEG2 video. And do you do it the same way most every time, or do you vary from job to job?

(Also, if you mux with TMPGEnc, I'd really like to know what setting you use. I've read a lot of posts here about muxing with TMPGEnc, but there are several different options for muxing in TMPGEnc and I'd like to know what people use [i.e. you can also choose to mux as VCD or SVCD in that program as well]).


Thanks,

-abs

Dialhot 08-09-2004 03:12 AM

Re: K(S)VCD: A standard for encode-mux-author ??
 
Quote:

Originally Posted by absinthe
I guess what I'm wondering here is whether there is more precise definition of KVCD other than just "whatever you can make work in your player using the the K quant matrix and GOP structure."

No ! That IS the definition of the KVCD. kvcd is nothing more than the registered Matrix and GOP modified GOP structure. You can read it in good place on the kvcd.net home page.

Whatever is done after that is just implementation that people CHOOSE to have of the KVCD concept. But there are other application than doing DVD backup.

Karl will speak about that better than me.

But this definition of KVCD isn't more "fuzzy" than XSVCD for instance. So that is not really a "new" thing to have so much stuff that can be named "KVCD".

Prodater64 08-09-2004 03:43 AM

1 - This definition is in KVCD.net main page.
Quote:

What is KVCD?

"K Video Compression Dynamics"


KVCD is a modification to the standard MPEG-1 and MPEG-2 GOP structure and Quantization Matrix. It enables you to create over 120 minutes of near DVD quality video, depending on your material, on a single 80 minute CD-R/CD-RW. We have published these specifications as KVCDx3, our official resolution, which produce 528x480 (NTSC) and 528x576 (PAL) MPEG-1 variable bit rate video, from 64Kbps to 3,000Kbps. Using a resolution of 352x240 (NTSC) or 352x288 (PAL), it's possible to encode video up to ~360 minutes of near VCD quality on a single 80 minute CD-R. The mpeg files created will play back in most modern standalone DVD players. You must burn the KVCD MPEG files as non-standard VCD or non-standard SVCD (depends on your player) with Nero or VCDEasy.


Using KVCD parameters to create DVDs (KDVD), will enable you to create 100% DVD compliant MPEG-2 streams, capable of playing on any standard DVD player. This will allow you to put up to about 6 hours Full D-1 720x480 on one DVD, or about 10 hours at Half D-1 352x480.

2 - KVCD is not a standard itself.
3 - You have KVCD mpeg1, and KVCD mpeg2 and KDVD.
4 - Burn techniques are not related to any standard. There is a lot of tricks, that you learn with time and experience, that make your final result better. Many standalones, for example, only supports mpeg1 352*288 as VCD, as standard says, and no other resolution. But mpeg1 encodes, obtained with TMPGEnc gives you an advantage. At low bitrates, his performance is better in high motion scenes, you won't see pixelation as easy than using mpeg2. For this reason, many people prefers mpeg1.
And with mpeg1, the better encoder is TMPGEnc.
In opposite, standalones supports in an easy way mpeg2 at not standard resolutions, and you can take your mpeg1 with other res that 480*576(480), burn it as SVCD (in Nero uncheck standard compliance, in VCDEasy discard advise that SVCD needs mpeg2 files) and play it in your standalone. It don't note any difference.
5 - For any other search of knowledge, search the forum or ask us again.

See you.

absinthe 08-09-2004 03:44 PM

Quote:

Originally Posted by Prodater64
Burn techniques are not related to any standard. There is a lot of tricks, that you learn with time and experience, that make your final result better. Many standalones, for example, only supports mpeg1 352*288 as VCD, as standard says, and no other resolution. But mpeg1 encodes, obtained with TMPGEnc gives you an advantage. At low bitrates, his performance is better in high motion scenes, you won't see pixelation as easy than using mpeg2. For this reason, many people prefers mpeg1.
And with mpeg1, the better encoder is TMPGEnc.
In opposite, standalones supports in an easy way mpeg2 at not standard resolutions, and you can take your mpeg1 with other res that 480*576(480), burn it as SVCD (in Nero uncheck standard compliance, in VCDEasy discard advise that SVCD needs mpeg2 files) and play it in your standalone. It don't note any difference.

Yes, I've found that I have one stubborn player (Apex) that seems to want to only play at fairly standard resolutions. Indeed, the resolution I use seems to be the most important factor in whether something will work or not. I've found I have no trouble getting it to play MPEG1 muxed and burned as VCD at 352x240(288).

What I'm struggling with is getting it to play MPEG2. I think I finally got a small sample to work (honestly, I've burned so many 3-minute samples in the last few days I almost can't remember what I've done :-)). I believe I used the "SKVCD 352 x 480" template, muxing and burning as SVCD. If I try to make a disc using MPEG2 at 528 x 480, I get an odd effect that someone else was talking about in a nearby thread where the video only shows up on the leftmost three-fourths of the screen.

My other little standalone (CyberHome) plays MPEG2 at 528 x 480 (or anything else for that matter) and it looks great! So what I'm really shooting for is the highest standard that is shared between these 2 players.

I'm also having a little trouble getting aspect ratios to look correct inside of some of these more oddly shaped templates (352 x 480 ?). I don't quite grasp the height being greater than the width.

-abs

Prodater64 08-09-2004 04:58 PM

Quote:

Originally Posted by absinthe
... I'm also having a little trouble getting aspect ratios to look correct inside of some of these more oddly shaped templates (352 x 480 ?). I don't quite grasp the height being greater than the width.
-abs

If your movie aspect ratio (AR) isn't correct, it can to be in this way because your source, if it is not DVD, has wrong AR also. Or because your are giving wrong values to resizers if you use another one that Gripcrop in your script. You need to know that picture alway is growed to 704*480(576) when is showed in TV, no matter its original res, and the original AR is restored to show it in a correct way. Think you also that 352*480(576) it is too an official DVD resolution.

absinthe 08-09-2004 07:42 PM

Quote:

Originally Posted by Prodater64
If your movie aspect ratio (AR) isn't correct, it can to be in this way because your source, if it is not DVD, has wrong AR also. Or because your are giving wrong values to resizers if you use another one that Gripcrop in your script. You need to know that picture alway is growed to 704*480(576) when is showed in TV, no matter its original res, and the original AR is restored to show it in a correct way. Think you also that 352*480(576) it is too an official DVD resolution.

I think what is confusing me is that when using a script with TMPGEnc, there is a sort of "doubling" of AR specification. For example, I have an XviD movie that's 640*480 (nice 1.33 AR). If I specify that in both the script with GripCrop and use the 528*480 TMPGEnc template, it looks too tall and fat. But if I load the .avi directly into the 528*480 template, it looks correct under Preview.

I think this is largely a result of my complete lack of understanding of the GripCrop filter :roll:. I've been under the assumption that most of the external filters (the "grip" ones, anyway) that appear in scripts on this website were developed specifically for KVCD. Anyway, I can't find any documentation in the ususal places, or in the forums. If someone could point me to a post/thread/site that describes the use of these filters (GripCrop, GripSize, GripBorders) in a bit more detail, I'd appreesh. I'd mostly just like a simple definition of what what exactly they're supposed to do, and perhaps a list of their parameters. 8)

Thanks for taking the time to give advice :D

-abs

Dialhot 08-10-2004 02:12 AM

Quote:

Originally Posted by absinthe
If someone could point me to a post/thread/site that describes the use of these filters (GripCrop, GripSize, GripBorders) in a bit more detail, I'd appreesh.

You havbe to read all the thread as the first release of the tool works a little differently than now :
http://www.kvcd.net/forum/viewtopic.php?t=2292

Prodater64 08-10-2004 04:10 AM

Quote:

Originally Posted by absinthe
... For example, I have an XviD movie that's 640*480 (nice 1.33 AR). If I specify that in both the script with GripCrop and use the 528*480 TMPGEnc template, it looks too tall and fat. But if I load the .avi directly into the 528*480 template, it looks correct under Preview.
-abs

I don't understand that. If you want a target of 528*480, you need to give these values to gripcrop:
Code:

...
GripCrop(528, 480, source_anamorphic=false)
...

to load the template in TMPGEnc (first) and to load the avs script (second).
If you can see below in the info line that nothing was changed according with your resolution settings all is ok. Yor final mpg will look ok when playing in a TV (or use BSPlayer and select AR 4:3 that is the same as viewing in TV)
But, permit me to say you. Do a complete short sample test, including a CD-RW burn, you will learn much more than with our words.

absinthe 08-12-2004 01:31 AM

Thanks for the above advice. I'll definitely be taking a look at the "Grip" filters thread. I actually had glanced in there before, but I saw that it concerned the "GripFit" filter so I thought that was all. I guess that filter has evolved some.

I've spent quite a bit of time just resizing my movies manually with AviSynth's "LanczosResize" + "AddBorders." Once I figured out how to do this properly (instead of guessing like I always had in the past) it was a breeze. If I can do this on my own with internal filters, do the "grip" filters have any added functionality? ... or is their sole purpose just auto-resizing and border-adding?

Anyway, I've created numerous 90-second samples in the last couple of days, and I've used just about every template. Once I figured out correct resizing, this was a pretty quick process. I played with movies of just about every aspect ratio, both PAL and NTSC, and burned plenty of both MPEG1 and MPEG2 as both KVCD and KSVCD.

I found that probably the most important factor affecting compatability, at least in my stubborn Apex player, was the horizontal resolution (the CyberHome player still plays just about everything). I had originally thought that the Apex just wasn't going to play MPEG2 from CD media, but that didn't make sense anyway since I watch standard SVCDs all the time. But as long as I use a template with a horizontal res. of 352 or less I can get my product to play in either of my standalone machines.

So far, I think the 352 x 480 template is my favorite. Even using MPEG1, the quality is really impressive (not to mention, this is without adding ANY filters to clean up/sharpen/smooth/whatever the image). And best of all, the encode times are QUICK!

I've also started playing with the KDVD templates, which is easy stuff compared with the CD formats.

Thanks for all your work on KDVD/KVCD :-)

-abs

Dialhot 08-12-2004 03:15 AM

Quote:

Originally Posted by absinthe
or is their sole purpose just auto-resizing and border-adding?

That is its only purpose but that includes an auto-detect and crop of previous border if there were present.Something that is hard to do manually.
Quote:

Thanks for all your work on KDVD/KVCD :-)
You're welcome :-)


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