CHDman CD/DVD auto-switch?

[VorgonBattlecruiser]

I just learned about the commands "createdvd" and "extractdvd" and i am converting my PS2 dumps from "createcd" to "createdvd", a longwinded process.

Is there no way to automate the detection of the original media-type before the conversion? have CHDman choose the right command for the media the legally dumped ISO originated from?

[angelosa]

1. check for the raw file size, if beyond 700MB (give or take) then that's a DVD.
2. do a reverse search with the SKU (i.e. SLPS 25023 would be Jp The Bouncer).

[VorgonBattlecruiser]

No, sadly not true. I checked every image below 700mb manually in the redump database and several of them were indeed on DVD.
Going by filesize is a good hint of where to start looking, but you still need to verify every image manually because many smaller titles came on DVD later on.

[FoxhackDN]

Absolutely not always the case. I've dumped DVDs that are way smaller than 700 MB, like the Gametrust discs, or DVDs with the remaining files from an 8-ish GB game install:

http://redump.org/disc/88751/
http://redump.org/disc/121757/

It's rare, but it does happen.

[VorgonBattlecruiser]

Absolutely not always the case. I've dumped DVDs that are way smaller than 700 MB, like the Gametrust discs, or DVDs with the remaining files from an 8-ish GB game install:

http://redump.org/disc/88751/ http://redump.org/disc/121757/

It's rare, but it does happen.

yeah, thats what i said and i agree. There is no telling just from the filesize, sadly. Online a lot of people tend to recommend to do that filesize check only and its wrong. Btw, another recommendation is to use a tool called "isobuster" to check and that does not work either. Tells me a lot of games well past 4gb are "CD Media". Extremely unreliable.

[FoxhackDN]

Ah yeah, I was replying to his comment to add a bit more info, but threading here seems to be weirding out for me. Sorry if it seemed like I was correcting you, far from it.

Isobuster is good but it still has its issues, like the one you mentioned. I use it to check for HFS/ISO9660 partitions on older discs, because some of this stuff is just... weird.

[VorgonBattlecruiser]

Ah yeah, I was replying to his comment to add a bit more info, but threading here seems to be weirding out for me. Sorry if it seemed like I was correcting you, far from it.

Isobuster is good but it still has its issues, like the one you mentioned. I use it to check for HFS/ISO9660 partitions on older discs, because some of this stuff is just... weird.

the best option i could think of was to check the redump media database, but im sure there are far smarter people than me that could find a way to check from the dumped file alone, right? or would there be need to compare hash against redump via online connection?

[galibert]

As far as I can tell, there's no visible difference between a dvd dump and a 2048bytes/sector cd dump (as long as the size is compatible with a cdrom of course).

[VorgonBattlecruiser]

As far as I can tell, there's no visible difference between a dvd dump and a 2048bytes/sector cd dump (as long as the size is compatible with a cdrom of course).

From what i read the recommendations online go with createcd for CD-based media and createdvd for DVD-based media. Fairly unilaterally. Thats why i decided to reconvert my dumps.

i DID check the hash of createcd CHD and createdvd CHD and they are not the same, the filesize does not match either.

[FoxhackDN]

DVD discs should have a UDF file system. CDs can also have them, but most of the stuff that usually gets added to MAME (pre-1996) won't normally have one. I'm aware that CHDMAN doesn't take into account any file system info, all it does is compress the sectors on the disc image.

Also, all CD disc images should have been dumped with 2352-byte sectors. I don't think 2048 bytes per sector dumps are allowed, and if there's any they should probably be marked as bad dumps?

[galibert]

DVD discs should have a UDF file system.

That's only valid for video dvds. In data dvds, anything goes. And systems that used both cds and dvds (bemani, hrdvd...) tended to stick to iso9660.