Dreamcast : CDI vs GDI vs CHD (vs ISO)

[voljega]

So after a few months of test and for test who played Dreamcast a lot or tested a lot of different games, what is the preferred format :

• CDI seems to offer the best compatibility but it is a degraded / compressed format
• GDI is a full 1:1 format accuretly dumping the game but the compatibility with current emulator isn't very good
• CHD is compatible with the emulator but people doesn't mention it very much : when converting GDI to CDI is the compatibility as least as good as CDI ? also can you convert ISO (which aren't compatible with the emulator) to CHD ?

[dh04000]

I suggest converting gdi into chd. Cleaner and smaller than gdi and without the downsides of needing to manage multiple "Track 01" files.

Google gdi to chd converter program.

[voljega]

@dh04000 yeah I know that but how does the emulator handles CHD files regarding compatibility ? is it at least as good as CDI ?

[abunille]

@voljega

I would say its the same as non converted GDI.
Tested a few games which are in the compatibility list marked at "not working GDI".
Also tested only with v4 CHD files (v5 untested).

EDIT:
Have you only a .iso file or with an .cue?

[voljega]

@abunille I'm talkng about CHD so no Iso and no cue no ? I din't try anything yet

[abunille]

@voljega

You are asking in your first Post:
....also can you convert ISO (which aren't compatible with the emulator) to CHD ?

Thats why i wrote about that

[voljega]

@abunille oh yeah sorry forgot about that.

Well I don't know, I just see full romset of iso (I assume with no cue) so I wanted to know if you could convert that to CHD

[abunille]

@voljega

.iso without .cue i dont know.
With .cue beside the .iso you can "try" chdman (before version 0146, with 0146 comes chd v5).
Create a batch file and try this command inside:
for /r %%x in (*.cue) do chdman -createcd "%%x" "%%x.chd"

Better way is to look for an alternative source