Common Questions About DVD-Rs

[slpknt870621345]

I've been sitting around waiting for my DVD-R burner to arrive, via UPS, and have been pondering a few questions about writing on DVD-R media:


1. When I first started out making VCDs, I was using programs like VCD easy, which worked fine, except it seemed to compile part of the operation while you were recording the cd... and I did not realize that for a full cd it added padding of about 88 MB (thinking back, I beleive NERO did this also)- this always resulted in a coastered disc. So my question is when authoring and writing a DVD-R is there a simular padding that is applied? If so, how much extra space does it require on the disc?
Also, I'm using Spruce Up to author right now, it gives the total file size... is this with the padding included? (if padding is applied at all)


2. Is it possible to OVERBURN on a DVD-R like you can on CD-Rs?
If so, what's a good guideline to use? (I did some calculating and turned up the following results- depending of course that you can overburn dvd-rs and the overburning is accuratly scaled up from cd-rs.):

there is approx. 6.7 700mb cdrs in one 4.7gb dvdr (take 4700mb divided by 700mb)

lets say you can safley overburn 25mb on a 700mb cdr... so then you should be able to overburn 167.5 mb on a dvd-r (6.7 cdrs times 25mb) Would these be accurate calculations if you can overburn?

I don't mean to be a pain or anything, I just thought up these questions and wanted to get them out... I read through most of the forum before I signed up and didn't really see any questions of this nature (i'm sure I didnt read every single post, so I'm not saying that there isn't questions like these somewhere on this forum... Thanks to everyone.... Sorry for the long post.

[vic102482]

well.....

overburning completely throws standards set right out hte window, it may be possible to burn on a 4.7 gig disk(really its 4.3 sorry to dissapoint) but dont be surprised if you make a new coaster. You have 4.3 gigs of space to play around with on your dvd-r and yes they do use padding, remrber dvd burners and cd burners are very very simliar in nature, dvds just have smaller bit sizes on them so that they can fit more data onto one disk so MOST of your cd functions are still going to be present. The 2x burn is really somehting like a 9x cd burn, so if you want to calculate how long it would take calculate how long it would take a 9x cd burner to burn about 7 dvds and you have your calc. (bout an hour per disk). The kool thing is that most dvd players will recognize a dvd r (even ps2 and xbox) so you should already be set tomake your movie. Now if you want to backup dvds then there is a whole new chapter to that.

[slpknt870621345]

Thanks for the replay. So you're saying that when you have a DVD-R labled as 4.7gb, you really have a DVD-R that can only hold 4.3gb of stuff... Right? Or were you saying that the extra space was taken up by the padding? Assuming that I can only burn 4.3gb onto a disc period, Why are there guides that tell you that the max size you can rip a movie to is about 4500 mb?

[vic102482]

well

I would say most of it is padding, you have got to remeber what padding is, it is a safety buffer, and dvds and cds are the same size measurments so if they need 0.025 inches of space from the edge to the data to ensure integrity then dvd will lose alot mroe than cds becuase the bits are smaller on the dvd so if you lose 88 million on a cd and the bits on a dvd are like 1 /10th and the area is still the same thats alot more bits that are lost on a dvd. I dont know where in the hell they got the 4.7 gigs to tell you the truth some people say bits vs. byes well 8 bits make one byte so 4.7 gigaBITS or 4700 megabytes translates to 587.5 MEGAbytes smaller than 1 cd so that argument is out the window. I would just say they were a little bit ambitios on the advertising I really couldnt tell you, as far as myself Ulead wont let me burn more than 4.2 gigs i guess it needs its saftey buffer also.

[slpknt870621345]

Hmm... I'm using spruce up for authoring right now, and it gives a total project size. The project I am working on right now (my first project to be honest) Is about 4.09 GB according to what spruce up says. So would this mean that the buffer includes the 4.09 GB, or is the 4.09 the real information I'm putting on the disc and the buffer is added later....undisclosed to the user?

[Nielchiano]

I never burned any DVD, nor have any experiance with DVD. I DO know a bit of CD-stuf, so I suppose this will apply to DVD's too.

On a regulat CD, there is about 3GB of room (yes, that's right, 3000000000 bytes). However, since a fresh-made CD (NOT cd-r, a silver disc) contains abour 500000 errors, and a regular disc at home (with some scratches) about 1 milion, there should be applied some error-correction on the data. This ends up in about 700MB of usable space.

This is the data that a CD-ROM Drive is able to read. This data is still just a LONG string of bytes, without any meaning. To give those bytes some meaning, you should index them: file 1, with name "file.ext" starts at sector 458 and is 186 sectors long.

This index (ISO table) takes up some space (I think about .5MB, but I'm not sure). Also, the CD-reader must be told how long the total disc is (and maybe some multisession info), that is written in the Lead-in/out area, which is again some MB's (i don't know how much).

So I guess that a DVD will waste some space on Lead-in, ISO-index, UDF file system, ...

Cheerz,
Nielchiano