get PJ64 to play .7z files... read why inside

[zilmar]

only advantage of 7z over other versions is when you compress two files that are very similar. If you have 4 different versions of mario and compress those, you will see that 7z archieve is basicly the same size of just one version compressed. There is already basic 7z support in 1.7.

 

[smcd]

Yes but my point was that (in 7z at least) using "ultra" profile might result in a larger end file than using a "normal" profile and tweaking a few settings...

 

[Poobah]

only advantage of 7z over other versions is when you compress two files that are very similar. If you have 4 different versions of mario and compress those, you will see that 7z archieve is basicly the same size of just one version compressed. There is already basic 7z support in 1.7.

That's called solid archiving, and WinRAR and WinACE also support it. I only recently discovered this, because the name "solid archive" isn't self-descriptive at all.

Now what were the last few posts all about? I already demonstrated that 7-zip is still overall Number 1. Profiles, options, settings -- you can call them whatever you want, but they're all pretty-much the same. What were you guys trying to prove? I'm aware of how basic archiving works.

 

[Smiff]

seeing as this has become about compression tech, can someone tell me how to get solid archiving in 7z to produce significantly smaller files:

sum size of Mario E U and J in seperate 7z files: 16MB
size of those files in one solid 7z archive: 16MB
wooah! look solid saved no space at all.

7z settings kept contant: 7z, Normal, LZMA, 4MB, 32 word, createsolid ON
all ROMS in same byte order (v64)
what dumbass thing am i missing?

this was with 7z 4.3x and now 4.41

 

[KingVendrSnatch]

Just increase your Dictionary size to 12MB if you can. You should get around a 6.4 MB compressed file.

Heres a minor comparison using the same 3 files. I used the same settings that you did I just tweaked the dictionary size:

6 MB - 15.8
8 MB - 14.6
12 MB - 6.4
16 MB - 6.4
24 MB - 5.96

Everything past 24MB produced the same result.

 

[Smiff]

KingVendrSnatch
yup thanks youre exactly right.. changing compression level from Normal to Maximum did the trick - dictionary size has to larger than filesize or something?
6.62MB on Max
6.13 MB on Ultra.
not bad

 

[Doomulation]

Well... from the help file:

Dictionary size
Specifies Dictionary size for compression method.

Usually higher Dictionary size gives more compression ratio. But compressing can be slower and it can require more memory.

Memory (RAM) usage for LZMA compressing is about 11 times more than dictionary size. Memory usage for LZMA decompressing is close to value of dictionary size. Memory usage for PPMd compressing and decompressing is almost equal to dictionary size.

Word size
Specifies the length of words, which will be used to find identical sequences of bytes for compression.

Usually for LZMA and Deflate big Word size gives a little bit better compression ratio and slower compression process. Big Word size parameter can significantly increase compression ratio in case when files contain long identical sequences of bytes. For PPMd Word size has big meaning. It strongly affects both compression ratio and compression/decompression speed.

 

[nevinsb]

Yeah, I have been repacking my 7zips using the "maximum" setting, removing the versions of roms I wasn't using. There wasn't much gain between "Max" and "Ultra." There was a big difference (Extracting, deleting, and recompressing) between Max and Normal. Recompressing with normal would make the 7z file twice the size! There was so many names in the ROM browser, I couldn't stand it. So far, I have been VERY happy with the 7z support of PJ64 1.7.