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-   -   MVCD is VCD 2.0 compliant / Can achieve this with KVCD? (http://www.digitalfaq.com/archives/encode/11195-mvcd-vcd-20-a.html)

trioptic 07-28-2004 05:21 PM

MVCD is VCD 2.0 compliant / Can achieve this with KVCD?
 
I was under the impression that mVCD / mDVD was a hacked kVCD script.

neither are unique codecs, but just tweaks to existing formats, but that makes them compatible with only a select amount of standalone units.

That is the biggest drawback to the tweaks, but I recently came across an mpg file that was encoded as mvcd (I assume mole-vcd, but file said "mini-vcd").

anyways, I usually burn them as non compliant svcd in Nero, but just decided to try as a compliant VCD 2.0 in Nero this time, and it worked.

It works in my standalone, works in all my computers, and any other vcd player I have come across.

When I try to encode kvcd as 2.0 compliant, I of course get an error regarding either the quantization, or Nero asking me to re-encode to a legit mpeg-2 format.

is there something special about mVCD that allows it to do the same thing as kVCD, only stay within the standards?

incredible 07-28-2004 05:43 PM

KVCDs and MVCDs do base on settings/Templates, not scripts.

MVCD keeps the std. GOP length specs. KVCD uses larger GOPs but on the other hand the KVCD NOTCH matrix filters less. So both do end up in almost same compression ratios, ... thats the only difference (said in few words).

You mean probably M-VCD from DaVideo which is very confusing.
M-VCD (not MVCD) means Maxi-VCD and is :arrow: MEGAcrap! And you have even to pay for. ;-)

I never use Nero to author KVCDs or MVCDs but using VCDEasy gives me the option to add chapters! Did you thought about that?

trioptic 07-28-2004 06:01 PM

so to clarify, mvcd is vcd compliant, whereas kvcd is not; and the quality of both are about the same, as are the compression?

what is the main benefit of using kvcd over mvcd?

Dialhot 07-28-2004 06:07 PM

MVCD (and nothing else) can't be VCD compliant AND put 2hour of movies on a CD80min (near 3 hours in VCD resolution !)

To be VCD compliant the video stream must be CBR and at 1150 Kbit/s and you can't put more than 80 minutes on the disc then (do the math if you want).

So either MVCd is not VCD compliant or can't be compared to KVCD.

trioptic 07-28-2004 06:46 PM

i assure you I have put a 1:30 hour video on a single 80 min CD and it checks out as VCD 2.0 compliant in several programs, as well as working in standalone players without and special modifications.

trioptic 07-28-2004 06:48 PM

correction: 137:39 minutes

Dialhot 07-28-2004 06:54 PM

Sorry to disappoint you but you didn't. A CD80 can contain often 84 or 85 minutes (rarely over) with overburning, but not more.

THAT IS THE DEFINITION OF THE COMPLIANCE !

Now, what you probably have, is a "near compliant VCD" that use the compliant video bitrate (that explain why it is readable on more players than KVCd) but with a not compliant audio bitrate (on VCD 2.0 disc the bitrate is 224 Kbit/s. What it is in your MVCD ?)
This way, I agree with you, you can put more than 80 minutes of video. But you are not VCD2.0 compliant. I guess a lot of tools don't care about the audio the same way they do for the video.

But now try to put with MVCD 2h of video in 544x480 on a CD or 3hours in 352*240. It's impossible.

Dialhot 07-28-2004 06:55 PM

Quote:

Originally Posted by trioptic
correction: 137:39 minutes

Definitely NOT compliant !

Go read a little :
http://www.videohelp.com/vcd

Edit: what are these tools where you say you declared the MVCd as compliant ?

trioptic 07-28-2004 06:57 PM

so just a bug in Nero (and other software) then?

Im not on a side here, I just want to know if this could be possible. like I said, the file just says "mvcd" so I dont know which mvcd that means (there apparently are several).

I do know that it burns and plays perfectly, moreso than any other kvcd or one-disc format I have encountered so far.

Is there a program where I can post some kind of header info so I can tell exactly how it was made?

Dialhot 07-28-2004 07:01 PM

Quote:

Originally Posted by trioptic
I do know that it burns and plays perfectly, moreso than any other kvcd or one-disc format I have encountered so far.

The usage of standard GOP (as explained by Inc) can explain the greater compatibility with standalones.

But quality of KVCd if not in the complaince, it is in its KVCDx3 resolution. I repeat : try to put a 2h movie in 544*480 in MVCD (if it is possible) and compare ! Compare also the KVCD of this movie with a "VCD 2.0" compliant MVCD.

Quote:

Is there a program where I can post some kind of header info so I can tell exactly how it was made?
DVD patcher can read the header of the m2v or bitrate viewer.

logan555 08-17-2004 05:15 PM

According to all that you can see on the web the vcd spec talking about a Costant Bitrate for a VCD.
That's not the really true.
According to the original white book , made by philips sony , the mpeg1 video part must be of a maximun of 1151929 bits/sec , but not at CBR.
The CBR definition is not reported on the White book.
The real limitation is in the audio bitrate , that must be 224kbit/sec .
Nor limitaiton on the white book about the gop.
The only limitation is on the the fact that from one i-frame to another, must not be more than 50 frame ( 2 seconds for pal frame rate).
The CBR was assumed on some videocd implementation , because in any case an higher CBR decoding is better than a VBR low than that. ( kvcd wasn't out when the White book was pressed).
I personally made a video part in kvcd ( max bitrate 1150) and the audio part as standard ( 224 kbit/sec). I mux then with the pink software and made a VCD with the videotoolkit original from philips.
Played it on cd-i philips. Worked perfect.
The real problem is the multiplexing. Is there the real constrain of the white book. The mpeg stream can be VBR, but the multiplexing is real hard to bit. If you multiplex a movie of 160 minute you get a final file long 1.6 gigabyte, even if is a 800 M.
This is the real problem.

Dialhot 08-18-2004 02:12 AM

Quote:

Originally Posted by logan555
According to the original white book , made by philips sony , the mpeg1 video part must be of a maximun of 1151929 bits/sec , but not at CBR.
The CBR definition is not reported on the White book.

That's a good info. I didn't know.

Quote:

The CBR was assumed on some videocd implementation , because in any case an higher CBR decoding is better than a VBR low than that. ( kvcd wasn't out when the White book was pressed).
Don't you think is a more technical reason ? With CBR a 1150 + Audio at 224 you match exactly the bitrate delivered by players while reading an audio CD.

logan555 08-18-2004 03:40 AM

That's it!
But this , according to the white book, means that is a maximum. Because the white book standard wanted to make the video streaming be played on the same cd readers that read the audio cd.
But still this is a maximum.
This mean that a true white book standard mpeg file with an audio of 224 kbits and a video part made with the ulbr kvcd is perfectly rigth.

kwag 08-18-2004 08:45 AM

Quote:

Originally Posted by logan555
This mean that a true white book standard mpeg file with an audio of 224 kbits and a video part made with the ulbr kvcd is perfectly rigth.

And that is correct. The problem is that many manufacturers didn't folow the specs, and assumed 1,150Kbps constant bitrate :!:
So many players won't play MPEG-1 VBR, even if the audio is encoded at 224Kbps.
However, they will probably play with a very low video bitrare, IF the video is encoded CBR.

-kwag

logan555 08-19-2004 08:32 AM

I Agree and I want to be absolutely clear on this. THE SPECIFICATION OF VCD 2.0 ARE NOT COSTANT BITRATE.


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