Compressed CD format

Anyone know how to create compressed CDs? Not a cd full of zips, but something like compressed folders on windows, that let you handle compressed data transparently?

I ask this, cause I found that some MS Office cd’s probably use this. If you copy their content to the hard drive, or when you see the cd properties, the size is much larger than what would fit on a CD. If you make a 1:1 copy of that cd to a 80min media, it fits. If you try to burn the contents using nero (creating a new cd), it wont fit.

I found a software called Paragon CD Emulator that can make compressed images and mount then directly. I could then burn this image and mount the image from the CD into a virtual drive. But this isnt exactly what I want, I wanna be able to create a compressed cd. Also, this software is very buggy and give some system conflicts, and also appearently not being developed anymore.

Anyone know of any software that can create such cd’s. Or also another sw that can do what paragon emulator do (mount compressed images).

Use an imager and then mount it using Daemon Tools.
Makes not much sense to me to compress CDs too, because most of all content on CDs today IS ALREADY compressed. :wink:

My work place has the original MS Office XP & 2003 CD’s and they don’t do this. Maybe they were OEM upgrade CD’s that were incorporated with ‘Publisher’, ‘Visio’ and ‘Project’. They actually use duplicate file links (also called symbolic links under linux). Between those programs the savings is very large because they share the same dlls, activex, etc. So you’d be mistaken that they were using compression.

  • Truman> Thats right, there were publisher, visio, etc. You know how those links are built? If i copied the installation files from the CD, why would they double? This dont happen if you copy windows links. Have to do some tests with the CD (dont have it here right now).

  • Anyone know of a compressed disk image format for other program beside paragon?

patiferoolz, if I understand correctly, here is an example (a stupid one, but…).

Say you have 1 particular file that you want to show up in 2 different folders on the CD. You can either put this file on the CD twice or you can simply use ISO-9660 pointers to point to the same physical location on the CD 2 times. In the latter, the file can appear to be there twice when it really only exists on the CD once. If you rip this to hard drive, you no longer have ISO-9660 (it’s for CD). So, the file will be copied to your hard drive 2 times, once for each folder.

I’m not sure if this is 100% correct. But it is close if I understand ISO-9660 and your question properly.

Hope this helps.

There was another thread with a similar question somewhere…

OK. Anyway, nice description RichMan, it’s exactly what I meant.

Patiferoolz, since there r 4 programs on there, copying to HD is mostly copying 4 duplicate copies for each of those files.

Windows link is the shortcut link right, they r are not the actual file, they r pointers to the files. Copying them only copies the file that points (which is a tiny file).

There is a program, which is written by Microsoft themselves that is for creating CD ISO images, and can do linking of duplicate files for you. Just google for “Microsoft cdimage”.

Thanks for the nfo. I now see the old topics searching for cdimage here (i searched for compressed before, but didnt help me, its too common of a word)

On google i found this:
“Automatically optimizes the ISO image file structure, saves the disc space.”
“Space Optimize for N in 1 CD builder (works like cdimage form Microsoft)”
Seems nice… too bad its shareware

That’s right. The CD file system supports these “hard links”.

The NTFS file system also supports these. Windows calls them “hard links” and “junctions”.

To clarify what someone else said, they are not shortcuts. Hard links are not the same as shortcuts. With symbolic links you have only one file but two entries in the file table pointing to the same file. So for all intents and purposes it looks as if there are two copies of the file when there is only one. So when you ask for the space used up you may get 200KB reported when in reality only 100KB are used.

In contrast, shortcuts are just a different file with a pointer to the real file.

A link is a pointer to another file. Remember that a directory is nothing more than a list of the names and i-numbers of files. A directory entry can be a hard link, in which the i-number points directly to another file. A hard link to a file is indistinguishable from the file itself. When a hard link is made, then the i-numbers of two different directory file entries point to the same inode. For that reason, hard links cannot span across file systems.