SVCD vs DVD. what makes the difference to the DVD player

[nailbmb]

SVCD and DVD both use the same type of compression (mpeg2), yes?
i understand that dvd differs in resolution and the bitrate is much higher than that of a SVCD but what else?
why is it that my DVD player chokes on SVCD (unless i change the header to VCD)? it can read DVDs (obviously) which are have a MUCH higher data rate yet it can't read lower bitrat SVCDs.
it seems very counter intuitive that this is the case.

so i come to the conclusion that the reason must lie in the structure of the DVD vs the structure of the SVCD and i'm pretty ignorant in this area. DVDs use vobs (correct?) whereas SVCD use dats. so am i to infer that vob files are more efficient in delivering data?

if this is the case, then why don't we use vobs (and hence a DVD structure) when we make SVCDs, but use the regular SVCD bitrate, etc. so we can get more than 15 minutes on a disc?

these are all pretty obvious questions (i'm sure) to one who knows a bit about DVDs but i am not that person; and as i said i am just curious about the issue. so if anyone has some light to shed on the situation then i'd appreciate it.

thnx

[BJ_M]

simple - one is on a cd and one is on a dvd disk .. thats really the answer

[crusty]

It comes down to the pits on the different disks and how th laser reads them. The pits on a DVD are smaller than that of cd hence the reason for greater storage.

[sterno]

why is it that my DVD player chokes on SVCD (unless i change the header to VCD)?

Because the firmware (the software inside the DVD player) supports VCD but not SVCD. In this case, you can trick it in to playing the SVCD if you make it look enough like a VCD. When you load the disc, the player checks to see what kind it is. DVDs are physically different from CDs, the DVD player can tell the difference. As soon as it sees that it's a CD, it checks to see what kind it is. It probably recognizes audio CD and VCD, but can't identify and read the SVCD.

if this is the case, then why don't we use vobs (and hence a DVD structure) when we make SVCDs, but use the regular SVCD bitrate, etc. so we can get more than 15 minutes on a disc?

There are standards that define how VCDs, SVCDs, and DVDs are structured. If you make one that doesn't use the right structure, it's not standard anymore and may or may not work on a player.

Putting a DVD structure on a CD is called a MiniDVD or cDVD, and very few players support them. As soon as the player sees that you've loaded a CD and not a DVD it doesn't check for the DVD structure.

[nailbmb]

thnx all