Mame with 7-zip support released.

[jelwell]

I'm not interested in this, and it probably won't work with ClrMamePro. But I know I see people asking for 7-zip support in Mame all the time. Apparently this has been around for a while, but I only recently stumbled upon it and I'm sure most people don't know about it. So here it is:

http://web.tiscali.it/u_fleku/eng/mame-7-zip-support.htm

Source code changes are available. They also have binaries of popular Mame derivatives, such as Mame32. They also have a bunch of tools, like a rommanager, and some batch files to convert all your roms into 7z format.
Joseph Elwell.

[JCKnife]

Bottom line, how much space could it save?

[math0ne]

i couldnt tell you off hand but i've been pretty impressed with 7-zip in the past seem like its twice mabey even three times as effecient as zip.

but i may be totally off base.

[SirPeale]

Ooh, MameDev isn't going to like this.  I'll post this link over on the MameWorld forums, see what they say...

[heffe2001]

Why would they have a problem with it, they say the source mods are also there, which is all they require in a project...

[jelwell]

Why would they have a problem with it, they say the source mods are also there, which is all they require in a project...

http://aarongiles.com/weblog/archives/2005/02/why_doesnt_mame.html

I don't know. The Mame trademark agreement seems to discourage features that MAME devs don't want to add. They have, in the past, become very angry at people who add features that are perfectly legal but against their wishes. But maybe their new leader will welcome open source developers - rather than try to discourage and stifle discussion of license abiding features which Haze was accustomed to doing.
Joseph Elwell.

[wpcmame]

i couldnt tell you off hand but i've been pretty impressed with 7-zip in the past seem like its twice mabey even three times as effecient as zip.

but i may be totally off base.

Yes you are. You might save a few percent on big files.

That is why mamedevs don't want to add 7-zip support. Why remove something that works, is stable and gives a very small gain.

[elvis]

That is why mamedevs don't want to add 7-zip support. Why remove something that works, is stable and gives a very small gain.

... and is Win32 only (no real/decent Mac or Linux support yet - MAME is designed to be a portable project), and means people will waste their time fiddling with unimportant things like saving 2% disk space when there are more important things to be done first, like fixing more emulation.

Disk space is now around $0.50 to $0.75 a GB.  It's a struggle to find a new hard disk under 80GB.  7-Zip support is about as useful as chocolate penis.  Sure, it sounds like a neat idea at first, but in the longrun helps no-one.

zlib is free (cost and source) and works.  Adding anything else that complicates the already huge MAME code database really is a non-issue.

[jelwell]

There's been some discussion on whether or not this endeavor is actually open source.

Apparently this is because one of the libraries includes only the C++ files but forgot to include all the relevant headers, and include files. The full source for 7-zip32.dll can be downloaded from the official website here:
http://akky.cjb.net/download/7-zip32.html

It's interesting. The MAME binary doesn't download with all the source. But the MAME license says that "Redistributions that are modified from the original source must include the complete source code". Does this mean that MAME32 needs to bundle the source with their binaries? Because either Mame with 7zip isn't violating the MAME license or MAME32, Mame with 7zip, and every MAME derivative (including no source change distributions like ahtlon optimized) I've ever known is violating the license.

Either way, all the source for MAME with 7zip available.
Joseph Elwell.

[Silver]

i couldnt tell you off hand but i've been pretty impressed with 7-zip in the past seem like its twice mabey even three times as effecient as zip.

but i may be totally off base.

Yes you are. You might save a few percent on big files.

That is why mamedevs don't want to add 7-zip support. Why remove something that works, is stable and gives a very small gain.

Actually the gain from 7-zip over zip is pretty significant. It's also extremely good at things like roms from different countries (ie similar) - this is because unlike rar and zip it can support huge dictionary sizes. This is more signifcant for console or computer roms though.

However there is a *MASSIVE* performance penalty. You will be waiting around for DAYS trying to compress a mame romset at high compression. Unfortunately its also very slow at decompression - this is where rar/zip really shine IMHO.

Anyway, having said that I think that mamedev are correct in sticking to zip - its unbelivably well tested and ported to everything. If rar was open source and ported all over the place, there would be a good argument for it as its significantly better than zip with very little performance loss.

Even is 7-zip had been around for ages, and fully ported to all systems, I would hate to use it with mame as it would probably increase loading times of bigger games by a factor of 50 or more....

[SirPeale]

Well, I posted the link over on MameWorld...

MameWorld.Info Link

Haze was less than pleased with me.

[MrSaLTy]

wow you ain't kidding.... although I got the feeling he thought it was you that did this not just pointed out the post.

[SirPeale]

No, he knows me better than that.  He was just pissed that I posted that link.

[elvis]

Well, I posted the link over on MameWorld...

MameWorld.Info Link

Haze was less than pleased with me.

You certainly know how to prod the hornet's nest, don't you?  Where I come from that's called "**** stirring".

[wpcmame]

Actually the gain from 7-zip over zip is pretty significant. It's also extremely good at things like roms from different countries (ie similar) - this is because unlike rar and zip it can support huge dictionary sizes. This is more signifcant for console or computer roms though.

No, the gain comes from that all files are compressed together and not individually. You get the same effect by first storing all files in a zip archive without compression and then compress it. (The mame source is distributed that way)

The problem with that approach is that it doesn't work well with the mame's random access rom-loading. On average half the archive must be decompressed for each file to load.

To avoid the performance penalty (which can be significant) you must rewrite the mame loading routine to load files as they are decompressed instead of requesting individual files.

[jelwell]

Well, I posted the link over on MameWorld...

MameWorld.Info Link

Haze was less than pleased with me.

Wow, and not surprising Haze jumped to the conclusion that source does not exist. I guess he didn't bother to download the release. Either that or he downloaded it and then ignored the readme file that states where the source is. Too bad no one on mameworld bothered to verify what Haze said.

Joseph Elwell.