This library has a great concept, but has suffered massive bit rot since it was last maintained in 2006.
Here are my main problems with the library:
1. There is no support for multi-file magic (my system has moved to a directory-based magic file system).
2. No support for newer file(1) magic syntax: cannot detect image/png using system magic from file(1) version 5.04.
2a. Not very code-hardy: code is broken by newer/unrecognized magic file syntax.
3. There are four undocumented subs which show up in the documentation, but tell nothing of their use.
4. No support for character set detection.
5. No support for long file type descriptions ("PNG image data, xxx x yyy, ...").
All in all, I would not recommend using this module until it is maintained; File::LibMagic seems like it will give you better results.
This module is simply-written and provides fast audio data extraction for PCM wav files.
Though the module claims to be incomplete, due to its inability to process a few rarely-used proprietary formats, it's definitely well-written to process the formats it does support.
I've been using this module to perform audio extraction for a scientific audio processing and aggregation and it hasn't failed me yet. The only reason I would have to replace its functionality is to process more types of audio data.
The only complaint I have is that the sample values it returns are in short-integer format, which I have to convert into floating-point values in order to process them.