LZMA2 for compress data in memory, not files.

[iXX]

Hi!

I am looking for code that allows to use LZMA2 compression for data in memory, not for files.

I found only some LZMA UDFs, not LZMA2.

I need LZMA2 because of better compression ratio for badly compressible data.

If there is nothing for compressing data, I could use something for files, teoretically, hypotetically...

ThanX for any info...

[mLipok]

'?do=embed' frameborder='0' data-embedContent>>

edit:

oh.. I see you found this one...

Can you provied any link to any doc ?

Edited February 28, 2015 by mlipok

[mLipok]

You can use 7Zip.dll (I must search some reference)

[iXX]

This one I found, yes.

It is only LZMA, not LZMA2, I thing.

LZMA2 is litle newer, and newest thing I found is: 

But even there is nothing about LZMA2, and it is only for files.

[mLipok]

Start reading from here: Calling 7z.dll.

[UEZ]

You can try LZMAT from here: '?do=embed' frameborder='0' data-embedContent>>

Maybe it's near to LZMA2 compression.

Br,

UEZ

Edited February 28, 2015 by UEZ

[Mugen]

LZMAT is a realtime compression, week but very fast.

LZMA2 only have one improvement over LZMA and that's multi CPU core support.

Question is will this work with single threaded Autoit3?

[mLipok]

With third party dll - 7z.dll ? Why not?

[iXX]

Mugen:

Actually, you not right.

LZMA2, except multithreating, has better compression ratio for data than almost can't be compressed.

That is what I need.

Not fast, but strong for such data.

[Mugen]

@mlipok

I remember Autoit3 could not handle the multi threaded wimgapi.dll.

So we had to run dism.exe and capture output.

Not sure how thread-safe 7z.dll is.

iXX, thanks for info, I wasn't aware of that.

[UEZ]

FYI, LZMA vs. LZMA2

 

Br,

UEZ

[mLipok]

  On 2/28/2015 at 6:38 PM, Mugen said:

@mlipok

I remember Autoit3 could not handle the multi threaded wimgapi.dll.

So we had to run dism.exe and capture output.

Not sure how thread-safe 7z.dll is.

 

Thanks for info.

[keithwalmar]

LZMA2 is faster for 4-threads, if you compress big file (more than 256 MB), so 7-Zip will be able to split it to blocks.  If the zip file exceeds that size, 7-zip will split it into multiple files automatically, such as integration_serviceLog.zip.001, integration_serviceLog.zip.002, etc. (Way back when, PK Zip used this to span zip files across multiple floppy disks.) You'll need all the files to be present to unzip them. LZMA2 was created for XZ format and it includes changes that are good for that stream compression format. Also LZMA2 is better than LZMA, if you compress already compressed data. LZMA decoder is simple. But PPMd decoder is complex. So its not a better  idea of PPMd / LZMA mixing.