The MAME CHD V4 format works with Reicast.
Change line 70 in runscript.sh to CDFILE=`zenity --file-selection $OLDSELECT --file-filter=
" "*.cdi" "*.chd" "*.gdi" "*.iso" "` so CHD files show up in the browser.
You can convert GDI folders to the much smaller and singular CHD files using MAME's CHD manager (chdman.exe) version 145 - attached.
\>chdman.exe -createcd Skies1.gdi Skies1.chd
chdman - MAME Compressed Hunks of Data (CHD) manager 0.145 (Feb 5 2012)
CD-ROM Skies1.gdi has 3 tracks and 549150 total frames
Track 01/03 (track01.bin:0,775 frames,194 hunks,swap 0,pregap 0,postgap 0)
Track 02/03 (track02.raw:0,44225 frames,11057 hunks,swap 0,pregap 0,postgap 0)
Track 03/03 (track03.bin:0,504150 frames,126038 hunks,swap 0,pregap 0,postgap 0)
Compression complete ... final ratio = 43%
\>
Skies of Arcadia storage size is reduced from 1.1 GB to 726 MB for disc 1 and is reduced from 1.1 GB to 739 MB for disc 2.
Since they are now single files I can keep both disc images in the same folder. Playing the game seems identical.
Note: MAME moved to CHD V5 in version 146 and CHD V5 files do not seem to work with Reicast.
EDIT: Renamed attached chdman0145.zip to win32_chdman0145.zip.
EDIT2: Posted a Pandora native chdman here
http://boards.openpandora.org/topic/15211-reicast-dreamcast-emulator/?p=300979