Forum: UltraISO
Topic: Target Size
started by: mtobc
Posted by mtobc on Jan. 29 2010,01:22
So...I came across two .iso files that have the exact same number of bits, however they contain slightly different content. This made me curious.

Can .iso files be created to a target size, regardless of their actual content?
Can UltraISO be used to specify a target size?
Posted by xoben on Jan. 29 2010,02:35
Sorry, it is not possible to do so.
Posted by mtobc on Jan. 29 2010,02:55
Thank you for the reply.

Do you mean, not possible in UltraISO or impossible all together?
Posted by ThetaSigma on Feb. 09 2010,00:37
If a file is 3,300,000 bytes in size, it will always be that size unless you either modify the actual content of the file or compress it with a compression utility such as WinRAR, WinZIP, etc. before burning it (or a codec in the case of audio/video).

However, keep in mind that many file types will benefit very little or not at all from compression. This is particularly true for images & video since they are already compressed and can rarely be compressed any further (a few kilobytes of size reduction at best).

For example, JPEG is a compression method used to compress raw image data, AVI is a container containing audio & video that (in most cases) has already been compressed with an audio/video codec such as Xvid, DivX, AC3 etc. Since they have already been compressed, further compression using a utility such as WinRAR is pointless from a file size viewpoint.

In other words, it is physically impossible to decrease the size of a file while retaining the original content without some form of compression. Furthermore, whether or not you will benefit from compression depends entirely on the particular file type & content you are working with.