MAME will soon have 7zip support ... UGH! And I just got my roms in order....

[Howard_Casto]

I was browsing haze's wip page and noticed a little blurb about mame getting 7zip support in the next u-build.

Now I was never a fan of 7zip... I always thought rar files were better BUT I'd be a fool not to upgrade my roms to 7z when this release comes out.... they unzip faster and it saves a ton of space. 

So everybody will finally have that excuse to upgrade mame and their rom collection.

[drventure]

I just wish I knew enough about the config functionality to roll my controller remap directly into mame.

I started down that road at one point, but, damn my C skills are a tad too rusty (plus, well, I have a cabinet to work on <sigh>)

But saving space in the rom collection sounds great.

[nick3092]

I read they were also playing around with using LZMA (the algorithm behind 7zip) for compressing CHD's. They were seeing about a 5% reduction, I believe. May not seem like much, but if you consider the size of a full CHD collection, that could save some room.

[DaveMMR]

I'm curious, and you would know better than me, why the sudden about-face of their stance on supporting a different compression algorithms? 

Why doesn't MAME support RAR/7-Zip/xxxx compression?
ZIP is extremely well-supported through a free, cross-platform library, and has been a standard for at least a decade. Yes, there are many new up-and-coming compression algorithms that squeeze an extra few percent out of things, but they are generally (a) strictly coded for a particular platform, like 7-Zip (though this is apparently changing), or (b) proprietary, like RAR. Furthermore, what most people really fail to realize is that there is absolutely no incentive for the MAME developers to add support for another compression format. For one thing, it only makes the MAME core more complicated, dependent on more external libraries, and prone to bugs.
But even beyond that, what is the real benefit of getting those extra few percentage points of compression? While we realize there are plenty of people out there who feel that life is not worthwhile unless they have an absolutely perfect, audited collection of ROMs on their machines, we honestly don't see why MAME should bend over backwards to ensure that they can accomplish this in a few less MB. If you're really so cheap that you have to pirate all your software, you can at least cough up a few extra dollars to buy a bigger hard disk.
In short, ZIP is good enough, and has a ton of benefits to it. Adding support for anything else merely says, "Hey, we're in it for the ROMz." And quite frankly, we don't think that benefits MAME in any way.

Unless they were looking to implement 7-Zip for a while (based on their statement about support for the format changing - see bolded italics)? 

I can see the benefits of course, and I'm not opposed to the change - but again, just curious.

[nitz]

BUT I'd be a fool not to upgrade my roms to 7z when this release comes out....

I read Haze's page and it sounds like you could actually make your own 7-zips...though I guess that wouldn't be an "offical" pack if that's important to you.

It also sounds like zip would still be supported, so no need to change if you don't want to (though I think the benefits would be worth it too).

Thanks for the heads up Howard... I was planning to update to 0.145 this week, but now I'm on the fence...Should I just wait and download an entire set in 7-zip? Should I upgrade to 0.145, make my own 7-zips and then just get the few changes I need when 0.146 comes out? What to do...

[Howard_Casto]

Most of your rom managers support re-compression and they will be getting 7z support, so what I'm going to do is get the whole .145 set together, chds and all and just sit on it until they implement the changes and have my favorite rom manager re-zip everything.

Btw, 145 is causing all sorts of havoc with the rom managers as well.  Samples are now available in flc flavor (again, more compression) and because of it romcenter is having a kiniption fit.  Clrmampro seems to be having similar problems with some of the list xml changes due to recent EM additions. 

I'm having to bounce back between the two to rebuild my set. 


Dave:

The difference is cube quest.  Prior to the inclusion of laserdisc games, the average chd not to mention the complete mame set was drastically smaller.  Now the mame set is well over 100 gigs, which makes it problematic simply from a managment standpoint.  But I don't think the devs are overly concerned about storage, what they are concerned about is the loading of roms.  When you play a game it is unzipped in memory, decompressed, and loaded.  Again, it used to be that a "huge" game was 50 or 60 megs.  Arcana Hearts was recently added to mame.  It's a 134 meg rom that decompresses to over 200 megs!  Ever unzipped a 200 meg zip?  It takes a while!  7zip is 64 bit so it helps with the loading time. 

[DaveMMR]

Ahh, makes sense.  Thank you Howard. 

[Cakemeister]

I have no intention of redumping all the roms off my original PCBs. That was a pain.

[newmanfamilyvlogs]

Now if I could just find an elegant solution to quickly mount ISOs from within 7z files for an arbitrary program.

[Haze]

Most of your rom managers support re-compression and they will be getting 7z support, so what I'm going to do is get the whole .145 set together, chds and all and just sit on it until they implement the changes and have my favorite rom manager re-zip everything.

Btw, 145 is causing all sorts of havoc with the rom managers as well.  Samples are now available in flc flavor (again, more compression) and because of it romcenter is having a kiniption fit.  Clrmampro seems to be having similar problems with some of the list xml changes due to recent EM additions.  

I'm having to bounce back between the two to rebuild my set.  


Dave:

The difference is cube quest.  Prior to the inclusion of laserdisc games, the average chd not to mention the complete mame set was drastically smaller.  Now the mame set is well over 100 gigs, which makes it problematic simply from a managment standpoint.  But I don't think the devs are overly concerned about storage, what they are concerned about is the loading of roms.  When you play a game it is unzipped in memory, decompressed, and loaded.  Again, it used to be that a "huge" game was 50 or 60 megs.  Arcana Hearts was recently added to mame.  It's a 134 meg rom that decompresses to over 200 megs!  Ever unzipped a 200 meg zip?  It takes a while!  7zip is 64 bit so it helps with the loading time.  

It's actually more about convenience and future-proofing than any performance, memory, or space reasons.  I don't think 7-zip is quicker to decompress (speed is comparable), and it does require a little more memory (or a lot more if you use 'solid' compression)

BTW even if LMZA compression is added to CHDs the LD ones won't change, what a lot of people don't realise is those are already compressed with a dedicated lossless A/V codec.  If they'd been done as plain zip-based compression they'd probably be closer to 100gig each ;-)

A CHD set for MESS on the other hand is enormous, around 1.5TB, and that's without even the PSX being covered yet (which is around 2TB on it's own)  CHDs of CD images will benefit greatly from integrated FLAC and LMZA compression.

It's all about making sensible choices based on the technology currently available (both hardware and software)

7Zip has long been requested (hence the FAQ entry for it) but it's only recently really started making sense.  The format is 'mature' at this stage, the limits of plain zips are starting to show, and it's effectively become the standard, modern, *open* way of compressing data.  Even Mamedev have been using 7-zip to compress their distributed binaries for a while now.

Nobody is being forced to use .7z files anyway, it's presented entirely as an option.

I know some people seem to handily ignore any real progress made in the last few years, and think we should have all called it quits at 0.36, but if that had happened MAME would just be one of those long dead emulators like Retrocade, virtually impossible to run on a modern system, and we'd all be talking about the same progress in some other emulator instead.

[Howard_Casto]

I know some people seem to handily ignore any real progress made in the last few years, and think we should have all called it quits at 0.36, but if that had happened MAME would just be one of those long dead emulators like Retrocade, virtually impossible to run on a modern system, and we'd all be talking about the same progress in some other emulator instead.

I really need to make a macro so I don't have to keep constantly typing it but:

Ignore PBJ... we're having him tested. 


Thanks for the explaination. 

Just for the record, I think most of the BEST things in mame have happened post ver 36.....  MAME is becoming less rigid in scope and more flexible.  Dual screen support, the new artwork system, the output system....  cleaner code....ect.  MAME/MESS now has the potential to emulate virtually anything with electronic components and for earlier versions it was pretty much video games and that's it.  Mind you I like video games, but there really aren't any mame-like emulators that are trying to preserve the oddball stuff like EM machines, and hybird machines ect...  MAME isn't going anywhere, while these fly-by-night operations could fall off the face of the earth whenever the author decides to quit.  So adding more stuff to mame is just giving developers a bigger tool box to work with and in the end, that means more games are preserved.

[Vigo]

Looking forward to 7z support. Have projects with very limited HD space. Now I have to figure out if it would be easier to batch convert my set, or if I should just re-acquire....

[elkameleon]

Looking forward to 7z support. Have projects with very limited HD space. Now I have to figure out if it would be easier to batch convert my set, or if I should just re-acquire....

batch convert would probably be the better route, i'm picky though, I don't like thinking someone else may of been zipping my ---steaming pile of meadow muffin---...

[abispac]

I have no intention of redumping all the roms off my original PCBs. That was a pain.

[Gray_Area]

I don't like thinking someone else may of been zipping my ---steaming pile of meadow muffin---...

Yeah, they might get it caught in there....