my file compression considerations

[JB_]

Hello, its my first post here and i'd like to take my considerations on the concept of file compression.
id like to start by making a critique to all the sites that offer file compression tests. I really dont understand why they only show results of a particular extension type of file. by that i mean, one .pdf file result, or one .txt file result, or one .mp3 result. That is really a one-dimensional situation of an filetype. it does not demonstrate how efficient, or capable, or strong a compressor really is. its not the reality of each compressor or each filetype by any means. its logic that all data is not the same and each compressor is coded differently. im talking about *all* the files that sit on your computer, on your collections, on your storage media, everything. why hasn't already been anyone compressing all the files of an particular filetype and showing the results? it may be a huge task to do that sort of operation, because of the operational part, but, the one that would demonstrate, it would be extremely and pretty interesting and it would overall be a reference and validation to each compressor program. for example, this can be done with an automation program sitting on your memory and verifying all your files, sort of like an firewall or an antivirus would do.

[encode]

Actually, we have not only such one-file-based benchmarks:
http://squeezechart.com - A site with large enough data sets
http://www.maximumcompression.com/data/summary_mf.php - MaxumimCompression's MFC - a nice set also

[SvenBent]

There is several multi file type compression tests.

but the single file type compressions tests has indeed its purpose as well.
its gives people a better look into the strengths and weak spots of the different compression programs.
So its easier the developers to see where improvements are needed and easier for the more advanced user to select the best compression programs.


my personally eksampel
7-zip vs winrar

7-zip performance better on generally data, exe and dll files,
but winrar perform better on wave/pcm data

so if i need to compress a cd image with alot of soundtracks or a game folder with a lots of wave files. its better to use winrar.


but to be honest i use them both and just selects the smallest file