importance of (x)vcd overburn lead out?

[sunmanking]

hello,

can anyone please explain what is the REAL importance
of an xvcd (or just vcd) lead out when overburning? is
the same as in a normal burn (no overburning)?

lately, i have overburnt two 99min cd-r but this time
i've pushed the limits a little bit beyond and whereas
lead in and burning have been and 100% perfect, the
lead out has failed and nero has given back an error.
however, when i play the xvcd on the dvd player
everything seems to be fine. so, is there ANY reason
why anyone should be concerned about the lead out?

if i were to make an image of that xvcd, the image would
include the lead out error, wouldn't it? is that relevant?

please, cast some light on this issue as no posting has
dealt with it in depth (i have searched the forums and
the website).

thanks in advance,

sunmanking

[kees1952]

Sunmanking,

a standard CD (74 min, no multisession) has three main blocks: the Lead-In, the Tracks containing data and the Lead-Out. The Lead-Out contains the Table Of Contents plus other miscellaneous info like the disk label, a disk ID number, all stored in the Subcode channels. The data sectors contain digital silence. This Lead-In starts at a fixed radius of the disk.
The Tracks contain the data (audio, data, depending on the mode of the used sectors).
The Lead-Out indicates the end of the information block and contains digital silence in the data sectors and a Lead-Out code in its subcode. The Track number is AA. During the reading of the CD the CD reader finds the start of the Lead-Out and stops reading.

The length of the lead-in is about 25 MB and this space is not available for anything else. The length of the lead-out is about 15 MB and this space is partly used by overburning.
By overburning it is possible to get an error during burning due to the fact that the burning software (Nero etc) wants to write the complete lead-out on the disk and detects not enough space on the CD. But the start of the lead-out has been written so there are no reading problems and the CD looks fine on a normal reader.

An image of a CD contains Lead-in, tracks and Lead-out. Problem by reading the image of an overburned CD is that the software wants to read sectors which are not there due to lack of space. This can be solved by using reading software that has the possibility to put in the number of sectors you want to read from the CD. You will have to find the number of readable sectors of the CD first. After this you have the image and you can replicate the CD.

Hope this helps a bit, regards,

Kees Janssen.