If I remember correctly, MAME's most recent 0.145 revision (might have been .145u1) completely updated the CHD specifications.
Here's what the release notes specified about it:
See if you can download MAME 0.145u1, as that might fix it. If you can't get it, I can compile you a copy and upload it.
Here's what the release notes specified about it:
Code:
Major CHD/chdman update: [Aaron Giles]
The CHD version number has been increased from 4 to 5. This means any
diff CHDs will no longer work. If you absolutely need to keep the
data for any existing ones you have, find both the diff CHD and the
original CHD for the game in question and upgrade using these
commands:
rename diff\game.dif diff\game-old.dif chdman copy -i
diff\game-old.dif -ip roms\game.chd -o diff\game.dif -op roms\game.chd
-c none
Specifics regarding this change:
Defined a new CHD version 5. New features/behaviors of this version:
* support for up to 4 codecs; each block can use 1 of the 4
* new LZMA codec, which tends to do better than zlib overall
* new FLAC codec, primarily used for CDs (but can be applied
anywhere)
* upgraded AVHuff codec now uses FLAC for encoding audio
* new Huffman codec, used to catch more nearly-uncompressable blocks
* compressed CHDs now use a compressed map for significant savings
* CHDs now are aware of a "unit" size; each hunk holds 1 or more
units (in general units map to sectors for hard disks/CDs)
* diff'ing against a parent now diffs at the unit level, greatly
improving compression
Rewrote and modernized chd.c. CHD versions prior to 3 are
unsupported, and version 3/4 CHDs are only supported for reading.
Creating a new CHD now leaves the file open. Added methods to read
and write at the unit and byte level, removing the need to handle
this manually. Added metadata access methods that pass astrings and
dynamic_buffers to simplify the interfaces. A companion class
chd_compressor now implements full multithreaded compression,
analyzing and compressing multiple hunks independently in parallel.
Split the codec implementations out into a separate file chdcodec.*
Updated harddisk.c and cdrom.c to rely on the caching/byte-level
read/ write capabilities of the chd_file class. cdrom.c (and chdman)
now also pad CDs to 4-frame boundaries instead of hunk boundaries,
ensuring that the same SHA1 hashes are produced regardless of the
hunk size.
Rewrote chdman.exe entirely, switching from positional parameters to
proper options. Use "chdman help" to get a list of commands, and
"chdman help <command>" to get help for any particular command. Many
redundant commands were removed now that additional flexibility is
available. Some basic mappings:
Old: chdman -createblankhd <out.chd> <cyls> <heads> <secs> New: chdman
createhd -o <out.chd> -chs <cyls>,<heads>,<secs>
Old: chdman -createuncomphd <in.raw> <out.chd> .... New: chdman
createhd -i <in.raw> -o <out.chd> -c none ....
Old: chdman -verifyfix <in.chd> New: chdman verify -i <in.chd> -f
Old: chdman -merge <parent.chd> <diff.chd> <out.chd> New: chdman copy
-i <diff.chd> -ip <parent.chd> -o <out.chd>
Old: chdman -diff <parent.chd> <compare.chd> <diff.chd> New: chdman
copy -i <compare.chd> -o <diff.chd> -op <parent.chd>
Old: chdman -update <in.chd> <out.chd> New: chdman copy -i <in.chd>
-o <out.chd>
Added new core file coretmpl.h to hold core template classes. For now
just one class, dynamic_array<> is defined, which acts like an array
of a given object but which can be appended to and/or resized. Also
defines dynamic_buffer as dynamic_array<UINT8> for holding an
arbitrary buffer of bytes. Expect to see these used a lot.
Added new core helper hashing.c/.h which defines classes for each of
the common hashing methods and creator classes to wrap the
computation of these hashes. A future work item is to reimplement the
core emulator hashing code using these.
Split bit buffer helpers out into C++ classes and into their own
public header in bitstream.h.
Updated huffman.c/.h to C++, and changed the interface to make it
more flexible to use in nonstandard ways. Also added huffman
compression of the static tree for slightly better compression rates.
Created flac.c/.h as simplified C++ wrappers around the FLAC
interface. A future work item is to convert the samples sound device
to a modern device and leverage this for reading FLAC files.
Renamed avcomp.* to avhuff.*, updated to C++, and added support for
FLAC as the audio encoding mechanism. The old huffman audio is still
supported for decode only.
Added a variant of core_fload that loads to a dynamic_buffer.
Tweaked winwork.c a bit to not limit the maximum number of processors
unless the work queue was created with the WORK_QUEUE_FLAG_HIGH_FREQ
option. Further adjustments here are likely going to be necessary.See if you can download MAME 0.145u1, as that might fix it. If you can't get it, I can compile you a copy and upload it.