CDR-RW Over-burning

The Red Book standard for an audio CD specifies a capacity of at least 74 minutes plus a silent lead-out area of approximately 90 seconds, used to indicate the end of a disc. Overburning, also known as oversizing, is basically writing more audio or data to CD than its official capacity by utilising the area reserved for the lead-out and perhaps even a few blocks beyond that. The extent to which this is possible depends on the CD recorder, burning software and media used. Not all CD-RW drives or CD recording software allow overburning, and results will be better with some disc brands than with others.

Overburning requires support the Disc-At-Once mode of writing and for the CD-writer to be capable of ignoring capacity information encoded in the blank media’s ATIP and use instead the information provided by the CD recording application. Many CD-Writers will reject a Cue Sheet that contains track information which claims a capacity greater than that specified by the blank media itself. Those capable of overburning will simply ignore the latter and attempt to burn a disc up to the end of its pre-formed spiral track.

Burn-speed is critical when recording data to the outermost edge of a CD and most CD-writers that are able to overburn a CD can do so only at a low burn speed. Whilst most CD recording applications have been updated to allow overburning, the extent to which they accommodate the practice varies. Some are capable of accurately computing the maximum capacity of a given disc in a recording simulation mode. With others it may be necessary to make a trial recording to establish precisely how much can be successfully written to the media.

However, since the CDs produced by overburning are, by definition, non-standard, there’s no guarantee that they’ll be readable by all CD drives or players. Moreover, users need to be aware that the practice can potentially result in damage to either CD media or the CD-writer itself.