Data corruption on VCD problem

[Graham Meredith]

Does anyone have experience with my problem making VCDs? I am getting occasional freezing of frames on my home made VCDs after burning them. I make an .mpg of a movie using the TMPEGEnc VCD PAL compliant template. I play both the source AVI and also the resultant .mpg movie and there are no frozen frames, I also run them through VirtualDub freeze-frame checker, and all is well.

I then burn them as a compliant VCD using Easy CD 4.0. When I go to play them on my AKAI ADV8000 standalone player, every so often the movie freezes for about half a second (the audio continues OK). When the picture starts moving again, all is OK, sound and picture are all in sync. I might typically get 5 or 6 of these frames in an hour movie, so they're not bad really. I thought it might be my Akai, but if I rewind, the glitch happens on the same spot on the CD every time, so it must be the disk. It happens when I play the CD on my computer as well.

I am aware that when you burn a VCD for a standalone player, the .mpg file is stripped of its error correction padding (which is why you can fit 740MB source mpg onto a 650 MB CD). I suspect that having no error correction on the VCD is what is allowing these glitches on the CD, but how do I get around this issue?

Can you control the amount of error correction that is burnt, and if so, can set top units use it? Or is it a media related issue? I have a P3 450 and a Ricoh MP6200a burner, burning at 2x, onto Ricoh CD-R disks from a bulk ream of 100 CDs.

Again, I say that the source and mpg file are OK, its only when they get burnt as a VCD that they glitch, and ten, only a couple of times, and some, not at all. If I burn the mpg as a data CD, it is OK.

Does anyone else experience this?

Thanks, Graham

[vitualis]

The most likely reason you are having this problem is that your DVD player cannot read the CD-R disc properly. It is unlikely that there is actually any read data corruption on the disc, or else you wouldn't be able to read it properly on your PC either.

MPEG files don't have "error correction". Rather, data burnt onto a CD as a CD-ROM (i.e., MODE1 or MODE2 Form1) have additional error correction (ECC) put in. A 74min/650MB CD actually can contain about 747MB of raw data -- the 650 MB limit is because part of this capacity is taken up by ECC.

That is, an MPEG file is not striped of anything when you burn it as a VCD as you implied. MODE2 Form2 sectors are simply burnt without the additional ECC. This cannot be changed without turning your VCD into something that probably will not be recognised on anything.

Your best option is to test out other brands of CD-R media to see if one works without this problem. CD-RW may work better.

Regards.

[Graham Meredith]

Thanks, Michael, for the quick reply. OK, I understand now about the error correction stuff. I thought it was already there, and stripped off going to VCD. So it may be a media problem. I remember trying CDRW's (cheap "Lazer" brand)and seeing it do it as well. I'll try others. Would it have to do with Easy CD 4?

Graham

[vitualis]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR size=1 color=black></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2001-10-08 17:03:04, Graham Meredith wrote:
I remember trying CDRW's (cheap "Lazer" brand)and seeing it do it as well. I'll try others. Would it have to do with Easy CD 4?
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR size=1 color=black></TD></TR></TABLE>

I wouldn't think that it would be an Easy CD 4 problem... but if it was, it also wouldn't surprise me.

If you try a couple of other brands of media and they all do exactly the same thing, then there is something either wrong with Easy CD Creator, or the MPEG...

Regards.

[Buffy_Fisk]

Hello, i viewed this with great attention.. I have got a similiar problem right now. Exactly what kind of problems do you have on your stand alone player? I have burned own VCD for a year for use with two different DVD-players. All my old VCD seems to work, but the new ones looks too crappy. There is annoying pixelation effects all over the TV..

Could it be the CDR's? No, because Im using the same CDR's like I always had.

Anyone knows what this is all about. I am using W2k and the latest TPMG encoder. My writer is a Sony CDRW CRX160E.

Someone told me that I could have to defrag my harddisk.. but honestly, burning works, what about it..

I think I will try an older TPMGenc version, it might be the problem..

[iant]

Here's another possibility for you. I recently upgraded my burner to an LG 32x8x4. Started noticing intermittent problems with playback. Wasn't media as I was using the same CD-RWs as in the old one. ( And I do mean the same. Just erased one and reburned it. ) Put the old burner back in ( Wearnes 6x2x2 ) and got a perfect result. I now use the LG for everything else but stick with the old one for VCDs.

First off, check the encoded mpg for glitches before burning it. That way, you can at least confirm whether it's being encoded correctly. Then burn it and check that out. Should be the same. Can't help betting it will not be. After that, once you have a glitch free MPG, experiment with a couple of different burning programs. You might even try copying the mpg onto a CD-RW as a normal CD, take it to a friend and have them burn it as VCD and test that. Heck of a muckaround but will probably isolate just where in the process it's fouling up.

Good Luck,
Ian

[Buffy_Fisk]

thank you! I will try some of that! I should get back my old good RICOH 4X scsi writer, and try it out.

[cman01]

You could always try to burn at 1x, it solved my problems which were very similar to yours.

[Graham Meredith]

Buffy_fisk,
Regarding the pixellation you are getting on your TV. Is your TV an old one, and you're running your DVD player into a video cassette player, then into your TV because your TV is so old it only has coax 75 ohm input, not RCA?

That is my setup. I get the pixellation problems all over the VCD, but it's not the VCD or my Akai ADV8000 DVD player. Its because my TV is so old (25 yrs) and badly shielded that it gets RF interference from the DVD player. I get faint diagonal lines, as well as faint pixellation on the TV. This occurs even when I'm watching TV broadcasts, not watching a DVD, but still have the DVD unit switched on. As soon as I switch off the DVD, the lines and pixellation disappear. Besides, which, I took one of my homemade VCD's into the shop to test out DVD players when I was looking to buy one, and tested the Akai plugged into a big, brand new TV in the shop, and the picture was perfect.

Your TV may not be as old as mine, but still might not be shielded for new equipment interference standards. Just check by watching a TV broadcast while leaving your DVD switched on and see if you still get it. As for me I'll just have to wait until I can afford a new TV

Graham