What's in "lead in"?

[moviebuff2]

Hi everyone:

I tried to burn a DVD. That failed during "lead in". So, I took the DVD out and examined the disc. The disc looked cleaned, unburnt. I put the DVD back in and here are what I found:

1) My read-only DVD drive indicated the disc was no longer blank, although it could not read what was on the disc.

2) My computer DVD burner indicated the disc was full. It even showed the entire DVD structure (all .bup, .info, .vob files), just like the whole DVD. But the disc could not be played.

3) My stand alone DVD recorder indicated the was BLANK! But, when I tried to record something on the disc, the machine could not do that. Instead, it gave me a message "failed to pause recording", even though the recording was never initiated.

Apparently, something was written on the disc during "lead in". It was so little to be appeared recorded on the disc. Would someone please tell me what is in the "lead in" and why do 3 machines read the "lead in" differently?

Thanks

[redwudz]

This is perhaps the best explanation I saw at: http://www.pctechguide.com/34DVD_DVD-R.htm

All DVD discs, recordable or not, must have three basic areas recorded on them: lead-in, user data and lead-out. The lead-in and lead-out areas are boundaries that indicate to a playback device where the inner and outer limits of a recording are respectively. They contain no user accessible information, but are critical to the proper functioning of a disc. The basic recording process is similar to that employed by CD-R technology.

This one has a bit more technical info: http://www.cdrinfo.com/Sections/Glossary/Details.aspx?TermId=433

The DVD Lead-in area is the area comprising physical sectors 1.2 mm wide or more adjacent to the inside of the Data area. The area contains the Control data and precedes the Data area.

You probably wouldn't see that small of burn tracks. When a disc is put in a burner, it first does a 'Power Calibration' burn on the very inner part of the disc. This sets the burner power for the media used. Then, if that goes well, it would start the 'Leadin', then burn the data part of the disc, then the leadout to finish the burn.

What program did you use to do the actual burning? Most generate 'burn logs' where you would see a lot more info and possibly the cause of the failure. Nero and ImgBurn both generate these, and probably most all burning programs.

Also, was that a external drive? The error could be caused by loss of communication between the computer and the drive. Or it could be a media problem, or a burner problem, or a burning program problem, or something with the computer.

What burner, what burning program, what brand of DVD media did you use? More info and a burning log would help considerably with better answers to the problem.

[moviebuff2]

Hi redwudz:

Thanks for the info.

I used a blank printable HP disc, a read-only Toshiba DVD drive (it came with the laptop), a Philips DVD burner and a stand-alone Philips DVD recorder. I used Nero to burn the disc.

What perplexed me most is that the data read by the Philips burner had all the DVD files (.bup, .info and .vob) with their true file size (+1GB for a vob file, for example). Yet, the disc looked as if nothing was burnt onto it.

I cannot understand how +3GB of vob files were read as if they were actually burnt onto the disc; yet the disc appeared unrecorded. Perhaps, in the "lead in", there is some data that showed the DVD structure without its actual files? If so, I wonder why that data is read differently by 3 different machines.

[oldandinthe way]

The data may not be read differently, the machines may be reporting different info.

In any case your Phillips burner either has irrevokable problems with the HP media (usually made by CMC), lacks a proper write strategy for the CMC media (i.e. needs a firmware update) or you have defective media.

Many brands of drive have problems with CMC media. And others do not.

You can update your firmware. If that fixes the problem - you win.

Trash your media and buy TY or Verbatim

or Trash Your Burner and buy an LG or Samsung Burner which is more tolerant of such media.

[redwudz]

Thanks for the info. I doubt anything but the leadin was written to the disc.

I'm not that knowledgeable about the DVD structure as far as the actual burning, but I think the leadin probably sets the 'index' size for the data portion of the burn. So it tells the burner that that amount of space is set aside for the data. In most cases, it should say the DVD is full.

But that's not your problem. The problem is why it failed to burn properly. You should be able to get to the Nero burn log for the file. Our friends at Digital-Digest have this guide for that: http://forum.digital-digest.com/showthread.php?t=57213

They also have a fairly extensive list of Nero errors codes and other Nero info.

But if you post your Nero burn log here, we can probably interpret it. Make sure to delete your Nero serial number before posting.

[moviebuff2]

Hi redwudz:

Unfortunately, I don't think I have the burn log from Nero.

Usually, Nero will start the burning process with the "lead in" step. This step should take approximately 1 minute. If Nero cannot finish the "lead in" step in 1 minute, it will give me an error message which had details of the error.

This time, the burning session was locked in the "lead in" step for a long time (more than 10 minutes), I used "super fast restart" to restart my computer. So, I did not get any reports from Nero.

I think it's the defective disc.

I used another HP disc and had no problems recording my DVD.

[moviebuff2]

oldandinthe way, thanks.

I think this one disc is defective. I used another HP disc and everything was OK. The disc was burnt fine. I watched it on 3 different machines without any problem.