| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Space savings from new CHD delta feature
#397228 - 10/21/23 08:04 PM
|
|
|
So Vas added the ability to load a delta of a CHD child which could lead to a significant space savings in CHD storage.
https://github.com/mamedev/mame/commit/d1172bf710f2a7b1777ed7687f5ba65748d90ee9
Does anyone have a batch file or similar to automate this across all your CHDs?
Per Vas:
Using sf2049tea and sf2049te as an example, you can create a delta CHD like:
Code:
chdman copy -i sf2049tea.chd -op sf2049te.chd -o sf2049tea-delta.chd
mv sf2049tea.chd sf2049tea-abs.chd
mv sf2049tea-delta.chd sf2049tea.chd
|
john iv
http://www.mameui.info/
|
|
| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397234 - 10/22/23 04:45 AM
|
|
|
Pretty cool, as an example Golden Tee Fore! 2004's clone went from 1GB to 90MB.
It'll be interesting to see if there'll be a new torrent just for deltas.
Note, if you're doing some converting be aware that clrmame will flag the chds as missing and not recognize the delta version.
Edited by John IV (10/22/23 04:48 AM)
|
john iv
http://www.mameui.info/
|
|
| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397235 - 10/22/23 08:56 AM
|
|
|
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397236 - 10/22/23 05:46 PM
|
|
|
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397237 - 10/22/23 05:48 PM
|
|
|
So this only works on clone CHDs?
|
|
|
| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature?
[Re: joey35car]
#397238 - 10/22/23 06:27 PM
|
|
|
Yes, it basically creates a diff between the existing clone and the parent, which can share a lot of data. The space savings can be enormous for a full set collection. I already shaved off 20GB with just four CHDs converted.
Also, Roman just cranked out a test .exe of cmpro if anyone wants to test it before he releases a full build.
https://www.emulab.it/forum/index.php?topic=9148.0
Note the conversions take a while if you haven't dealt with CHD 'editing' in a bit, as it has to do a validate extract and re-compress.
|
john iv
http://www.mameui.info/
|
|
| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397245 - 10/23/23 09:24 AM
|
|
|
|
|
|
Re: Space savings from new CHD delta feature?
[Re: John IV]
#397265 - 10/25/23 06:41 AM
|
|
|
Nice. Hopefully some sites like PD will have these converted one day so we don't have too. 😁
Thanks
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: John IV]
#397270 - 10/25/23 07:36 PM
|
|
|
OK so far I converted one game and works fine. Anyone know how to create a batch file so it can do all the clones automatically instead of renaming the files one by one in the batch file?
Thanks
Edit: Well I guess I'm in the mood to do it one by one.  Not to many.
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: John IV]
#397271 - 10/25/23 09:23 PM
|
|
|
I used this batch file to convert all my ISO and Cue to CHDs automatically. Maybe something similar could be used for the delta.
for /r %%i in (*.cue, *.iso) do chdman createcd -i "%%i" -o "%%~ni.chd"
|
|
|
| John IV |
|
IV/Play, MAME, MAMEUI
|
|
|
|
|
|
Reged: 09/22/03
|
|
Posts: 1967
|
|
Loc: Washington, USA
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature
[Re: joey35car]
#397272 - 10/25/23 09:31 PM
|
|
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: joey35car]
#397278 - 10/26/23 09:01 AM
|
|
|
The problem with a batchfile is that you need to know the parent/clone relationship of sets and the exact storing position of each chd file.
So you need to provide the clone chd filename and the belonging parent chd filename to chdman to create a delta out of it. There is no rule in naming/storing, so a general batchfile is not possible without having the parent/clone relationship accessible from somewhere and the relations can theoretically change with each MAME version.
So...it sounds more like a job for a tool which knows the current -listxml/-listsoftware output, runs through folders collecting chd sha1s, finding the pairs in the xml data and creates an output (either a batchfile or directly calling chdman)....and surely it should also support revert in case a delta chd lost its parent...
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: Roman]
#397279 - 10/26/23 09:35 AM
|
|
|
Thanks for the explanation. Hopefully you can incorporate this in clrmamepro one day.
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: joey35car]
#397280 - 10/26/23 09:58 AM
|
|
|
I did already..need a day or two for some more testing....busy with real life.
https://www.emulab.it/forum/index.php?topic=9148.msg25902#msg25902
Actually writing a standalone tool would be easy, too with the core I already got for the new rebuilder (all the xml loading/parent/clone relationship stuff is in there)...and doing a folder walk and reading chd sha1, storing them in a hashmap plus calling chdman...no big deal...however...no time currently...
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: Roman]
#397284 - 10/26/23 11:42 AM
|
|
|
You’re obviously adding functionality to your own tool, but it would be relatively easy to do in any scripting language with XML DOM support. PowerShell and Python both have everything you’d need to load the XML and drive chdman.
|
|
|
|
Re: Space savings from new CHD delta feature
[Re: Vas Crabb]
#397285 - 10/26/23 11:51 AM
|
|
|
Yes of course it's possible with all kind of solutions which are able to take the XML into account and run through folders...
All I said was that a static batchfile without taking the xml into account or just writing down a for loop or having hardcoded filenames won't generally work.
I'm sure there will be someone who writes a powershell/python/whatever script....feel free
|
|
|
| R. Belmont |
|
Cuckoo for IGAvania
|
|
|
|
|
|
Reged: 09/21/03
|
|
Posts: 9713
|
|
Loc: ECV-197 The Orville
|
|
|
|
Send PM
|
|
|
Re: Space savings from new CHD delta feature
[Re: John IV]
#397288 - 10/26/23 08:10 PM
|
|
|
The usual disclaimer applies: if you're doing this, keep a backup of your original CHDs, or wait for the next MAME to see if the early adopters end up having to redownload their entire set ;-)
|
|
|
Previous 
Index 
Threaded 
Space savings from new CHD delta feature
Reply
[Re: 
Not to many.
