how can a dvd store more data than its limit

[andreasaspenberg]

i have an issue with my dvd recorders when i combine recordings in EP with recordings in XP, SP or LP that cause the data to exceed the limits of the dvd. how is that even possible?

 

[Dr Super Good]

i have an issue with my dvd recorders when i combine recordings in EP with recordings in XP, SP or LP that cause the data to exceed the limits of the dvd. how is that even possible?

There are several ways it could be possible.

First and most logically is a corrupted partition and controllers. You can make a partition say it is larger than it actually has backing storage for. This trick is used by Chinese fake hard disk manufacturers who use a tiny USB stick (1 GB odd, cheap) and claim the drive has huge capacity (1-2 TB). Once a certain amount of data is written it obviously starts to discard further blocks of data as there is no space. Just because this happens does not mean there will be data loss as one could have implicit data or duplicate data counted as partition size without it actually being present twice on the file storage.

Second could be that the DVD is larger than you think. Usually the amounts given on the box when you buy the disk are rounded units (eg 1,000 instead of 1,024) or include space for file structure etc. As such you actually get more space than specified.

Finally if you are comparing to commercial printed DVDs you have to remember that they are "dual layer" so can store twice as much as the single layer disks the public can buy and write on with a DVDRW. This is why pirated DVDs almost always look rubbish compared with the originals since they have had to have their bit-rate over halved.

 

[andreasaspenberg]

it is possible to buy dual layer dvds though they can only be written to once. i use those to burn out stuff i want to keep on dvd. what appears to be the case with my issue however is that there is duplicates of each recording file.(vob)