Multimedia: JPEG compression using packJPG

[M-Gonzalo]

There are some kind of files that are particularly difficult to pack, because they are already compressed. JPEG images figure among the most common of these. Luckily, today exists open source software capable of performing a lossless re-compression on them. Using the proven packJPG library, by Matthias Stirner, we can effectively compress most jpg images in an efficient manner, that is not only stronger than any general purpose algorithm, but also relatively fast.

Combining this with the already implemented parser that allows to find jpg images embedded inside arbitrary data, Fairytale should be capable of reaching world-class ratios on most modern data sets.