HOW IS TRANSPARENT COMPRESSION ACCOMPLISHED FOR BURNING CD ?

suhas_sm · 19-09-2004, 02:30 PM

CAN ANY ONE HELP ME WITH IT

I HAVE SEEN LOADS OF GBS BURNT ON 700 MB CD ... HOWZ THAT "TRANSPARENT DECOMPRESSION" DONE ?

allajunaki · 19-09-2004, 03:01 PM

Sorry cant find out how.
But Transparent Decompression is 'On the Fly Decompression'. That is file is compressed when it is stored on the Secondary Storage (Hdd. Floppy, CdRoms etc.) . When the file is accessed, it is decompressed on the fly and used.
I think NTFS File Compresssion comes under Transparent Decompression
The CDROM transparent compression acheived on Unix Platform (incl. Mac OS X) and Linux Kernels 2.4.19 upwards.
Similar transparent compression is done by a third party software on P800 mobile phones ( Used it on my dad's P800 its called stacker).

Lemme see if i can find out more about this...

suhas_sm · 19-09-2004, 08:29 PM

Quote:

Originally Posted by allajunaki

Sorry cant find out how.
But Transparent Decompression is 'On the Fly Decompression'. That is file is compressed when it is stored on the Secondary Storage (Hdd. Floppy, CdRoms etc.) . When the file is accessed, it is decompressed on the fly and used.
I think NTFS File Compresssion comes under Transparent Decompression
The CDROM transparent compression acheived on Unix Platform (incl. Mac OS X) and Linux Kernels 2.4.19 upwards.
Similar transparent compression is done by a third party software on P800 mobile phones ( Used it on my dad's P800 its called stacker).

Lemme see if i can find out more about this...

even i searchd alot but couldnt gather enough info

[deXter] · 19-09-2004, 09:10 PM

There is no real 'Compression' as such done, its just sector/file optimization. Repeated files/bits are marked and mapped to the CD index database, instead of physically writing them. When your drive copies those files, it just looks up the index and produces / repeats the sectors/bits/files as and when needed.

Of course this would only be applicable only for those CDs that contain a lot of files, for eg, CDs that contain many windows installations in a single disk, multi-boot cds, etc. And yes, it wouldn't work for audio/video CDs or CDs containg a single large file, etc

A few programs such as UltraIso and makeiso.exe support filesystem optimizations.

suhas_sm · 20-09-2004, 09:29 AM

Quote:

Originally Posted by [deXter

]
A few programs such as UltraIso and makeiso.exe support filesystem optimizations.

ultra iso ...........hmmmmmmm i now this software

but can this be accomplished on a normal cd writer ???
and also if u get more info do let us now

theraven · 20-09-2004, 06:01 PM

its not abt accomplishing it
like dexter boy genius said
it happens when files are repeated
again like he said in say for eg. a windows 2003 3in1 cd ... which has all the three versions
we all know the files are extracted from the i386 folder therefore the files are common for all 3 installations.
thers is only one folder but when u examine it ... there are 3 different i386 folders and the copied files shows say abt 1.3GB
but yet it fits on that 700mb cd ...
cuz the i386 folder isnt written 3 times ...
just once ...
therefore it fits on once cd