The Audio File Library is a C-based library for reading and writing audio files in many common formats.

The Audio File Library provides a uniform API which abstracts away details of file formats and data formats. The same calls for opening a file, accessing and manipulating audio metadata (e.g. sample rate, sample format, textual information, MIDI parameters), and reading and writing sample data will work with any supported audio file format. The Audio File Library lets you work with audio data in whatever format is most convenient for you.

audiofile.68k.org
github.com/mpruett/audiofile