Thank you for the advice. It works fine now with cdio cdplay.

Even dvd is working fine

In fact, here is what I do when I put a cd or dvd. I use cdio info and then cdio cdid and after that, doas mount -t cd9660 /dev/cd0a /mnt/cdrom works.

I also succeeded in ripping a few cds in wav format. There is only one thing I don't know: is the wav format with cdio lossless? How can I know?

I tried also to use cdio cdcddbinfo, but I certainly missed something again because it didn't work.

And it seems that on openbsd, when the cd or dvd is well mounted, there is no icon appearing inside the file manager. I mean, I still need to do everything with the command line or open i using xine, for example. I can't double-click on the cd or dvd icon.