Optical Media Size Clarification 1

[Glenn9999]

I'm not finding good specific resources, so I'm asking here if anyone knows: Is there a reference which indicates to the byte the maximum sizes of various optical media according to standards? (eg CD-R 74 min, CD-R 80 min, DVD-5, DVD-9)

I'm waiting for the white paper entitled "Finding Employment in the Era of Occupational Irrelevancy

 

[xwb]

The size is in Mb or Gb: not minutes. The number of minutes is approximate depending on what you are recording. Data and videos have different number of minutes.

 

[Glenn9999]

All the CD spec documents I do find are labeled in minutes (CD-DA), which is one of the reasons why this question is being asked. This is also how all the disks I've seen and purchased have been marketed, but I need a clear spec indicating actual numbers of bytes for a project I'm working on. The DVD spec is at least more clear about things, but what I found isn't very clear either.

So any ideas on the real numbers for these things and not vague approximations like I've been finding?

I'm waiting for the white paper entitled "Finding Employment in the Era of Occupational Irrelevancy

 

[Nelviticus]

Have you come across the Rainbow books? They're the various-coloured books that define the spec of optical media.

However I don't think that a maximum byte size is specified because in burning programs such as Nero there's an option to 'over burn', i.e. attempt to fit more on the disc than is specified. If I remember correctly the warning dialog that pops up mentions something about discs generally having a small variable amount of space over the amount specified. This leads me to guess that the spec defines a standard capacity and disc makers have to meet or exceed it, rather than exactly match it.

Nelviticus

 

[rclarke250]

Per the cd-r wiki.

A standard CD-R is a 1.2 mm (0.047 in) thick disc made of polycarbonate with a 120 mm (4.7 in) or 80 mm (3.150 in) diameter. The 120 mm disc has a storage capacity of 74 minutes of audio or 650 MiB of data. CD-R/RWs are available with capacities of 80 minutes of audio or 737,280,000 bytes (703 MiB), which they achieve by molding the disc at the tightest allowable tolerances specified in the Orange Book CD-R/CD-RW standards. The engineering margin that was reserved for manufacturing tolerance has been used for data capacity instead, leaving no tolerance for manufacturing; for these discs to be truly compliant with the Orange Book standard, the manufacturing process must be perfect.

 

[Sympology]

To be labelled and carry the Compact Disk logo, they must conform to the Red book standard. That's why many crippled Sony DRM junk cd's (audio) don't actually carry the Cd logo.

I know as I got Philips to have a major slanging match with Sony once

Robert Wilensky:
We've all heard that a million monkeys banging on a million typewriters will eventually reproduce the entire works of Shakespeare. Now, thanks to the Internet, we know this is not true.

 

[vacunita]

The "Minutes" is mostly used when burning media (music or video) discs.

For Data its mostly irrelevant.

Here's one good reading on the different types of DVD's:

http://www.afterdawn.com/glossary/term.cfm/dvd-5

and there sizes.

However For basic usage its 4.5GB for a regular single layered DVD, and about twice that for double layered DVDs

CD's for the most part hold about 700MB of data.

While Blue-Ray discs will hold about 25GB of data in single layer and 50Gb in dual layer. So far no real upper limit has been defined. So as technology progresses they'll likely be able to hold more data.

----------------------------------
Phil AKA Vacunita
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Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.

 

[Glenn9999]

Okay, the link that vacunita posted is consistent with what else I've found, so that seems to be fine for the project I'm working on. To clarify I'm looking for the numbers that meet the standards exactly.

The real problem I'm having, though, is with the CD-Rs. There are so many numbers being tossed around that I'm not finding anything certain. Right now I'm using (650 * 1024 * 1024) for the 74 min CD-Rs, and (700 * 1024 * 1024) for the 80 min CD-Rs but I get "put a disk with the right amount of space in the drive" messages and "do you wish to overburn?" messages out of the burner software I'm trying.

I'm waiting for the white paper entitled "Finding Employment in the Era of Occupational Irrelevancy

 

[Glenn9999]

And I've already seen the resources the other posters have linked to.

I'm waiting for the white paper entitled "Finding Employment in the Era of Occupational Irrelevancy

 

[rclarke250]

What kind of data are you trying to burn? i've seen issues like that when burning mp3s. Have to watch how it tries to burn the data, if it tries to turn it into an audio cd, it will convert the mp3s into audio format which is huge compared to mp3s.

anything over the 650mb limit will ask if you want to overburn. In some versions of nero you can change the limit, and in some it reads the blank and changes it for you. don't know about other progs.

 

[Glenn9999]

Just a random data file. I'm wanting to generate a file of the exact standard size and then burn it to media as a burn-in or test for a drive. And then optionally I want to be able to compare the burned media against the random data file in the case of rewritable media.

I'm waiting for the white paper entitled "Finding Employment in the Era of Occupational Irrelevancy

 

[rclarke250]

well part of the problem is the way disks are made, you can have cds with different size by a few bytes to a meg or so even in the same lot from the same manufacturer.

The best way to fill the disk is to use something like nero, and as you add stuff to the project it tells you how many megs you have left to fill the disk.

 

[cdogg]

Glenn9999,
What is the exact size of the data file or files you're trying to burn? What software are you using to burn the CD (Roxio, Nero, Sonic, etc.)?

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Einstein
[tab][navy]For posting policies, click [/navy]here.

 

[vacunita]

file of the exact standard size

Nothing is going to be exact. The 700, 4.5 etc.. are just approximate numbers, because there's always going to be slight differences.

Your burning software should be capable of telling you how much free space you have in your given media, as you add files to it.





----------------------------------
Phil AKA Vacunita
----------------------------------
Ignorance is not necessarily Bliss, case in point:
Unknown has caused an Unknown Error on Unknown and must be shutdown to prevent damage to Unknown.