Reicast CHD support


Hi there, I’ve tested the new reicast oit updated core with a bunch of games. It works really well, indeed, it has worked perfectly for every gamje I’ve tested. So, I’ve decided to migrate from demul to retroarch for dreamcast emulation.

I’ve noted this core accepts chd loading, so I tried to convert some of my GDIs to CHD, and they crashed the emu. Browsing the forum, I’ve found a thread talking about this core supporting only OLD chd format. So I tried downloading an old chdman from an old mame version (its from around 2010) and the converted CHDs with this old version seem to work ok on reicast.

So my question is, given that recently you are doing a lot of work on reicast, am I safe to expect support for actual CHD format in the next weeks (or soon) on this core? Are there any p`lans for it? If it has to happen sooner than later, I would not lose my time converting all my games with the old version of chdman and would wait for proper support of recent CHD.

Besides that, do you plan to add lightgun support on this core?

Congratulations for all your continued work on this and all other cores and retroarch itself.


According to a comment on this issue, libchdr support is implemented in upstream Reicast, which supports the newest CHD format. So hopefully it won’t be too long until it trickles down into the libretro port.


Lot of Updates Been Added so yeah Hopefully not too long away until they Add this Feature


Thank you both guys. Yeah, the recent progress on reicast core is being amazing. I’ll cross my fingers for the lightgun support too.


Is there a method to upgrade your existing CHDs? If not, is it possible to convert them back to GDI and then to CHD with the new format?

Or is it best to just download an entirely new GDI set and convert to the ‘new’ CHDs?


Supposedly you’ve already lost data in the conversion to the old CHD format. So it’s best to use fresh Redump verified GDI dumps and convert them to CHD V5.


What is the difference between v4 and v5 CHDs? I think all my CHDs are v4. Just wondering if it is worth to do the re download and conversion of my game library.


According to this comment, CHDv4 was not lossless for GDI while v5 is.


Got it, but in terms of playability/experience, would a user notice a difference and/or improvement?


Probably not, but I don’t know the specifics of the compression used between versions (besides v5 using FLAC for redbook audio) or what data isn’t included in v4. I’m guessing CHDv4 isn’t as bad as CDI dumps that recompress or even remove audio and/or FMVs to fit on a CD :stuck_out_tongue:


hi, so the v5 chd is compatible now with the reicast ? thanks


Damn, that’s depressing lol It took me 2 months to get those GDI’s with my damn 1TB data limit.

Guess I’ve got a new project hahaha - thanks for the info awakened.


Nah, I updated the core yesterday to test some chdv5 converted games, and it still crashes trying to load’em. So CHDv5 is still not featured on the Reicas OIT core. I guess it will happen sooner than later though.


ok thanks we will wait


CHD v5 seem to work after the last update. Some games don’t start (actually most of them), but it doesn’t crash anymore when loading chd.


Hey guys,

Just wanted to share I’ve been testing my chd v5 collerction against latest reicast core (updated from Core updater today)and ALL my games worked perfectly. No problems at all. So CHDv5 seems to be completely added to the core.

Thanks devs.


I already reported this on github, but the only issue I’ve noticed left is the CDDA music tracks in Bangai-O (USA) not looping in CHDv5 format. They loop fine in gdi format. Curious if anyone finds the same problem in any other games that use CDDA audio.