hachoir-parser is a package of most common file format parsers written
using hachoir-core. Not all parsers are complete, some are very good
and other are poor: only parse first level of the tree for example.

A perfect parser have no "raw" field: with a perfect parser you are
able to know *each* bit meaning. Some good (but not perfect) parsers:
* Matroska video
* Microsoft RIFF (AVI video, WAV audio, CDA file)
* PNG picture
* TAR and ZIP archive

WWW: http://hachoir.org/wiki/hachoir-parser