I am adding cover art support to the Mixxx DJ mixing software. Code is written in Qt. I don't understand how to write code that will do the exact reading from and writing to files containing cover art. I can use external libraries to perform this task but it is required that the libraries are cross platform and preferably open-source. Libraries can be in any language. Adding dependencies to the existing software is not much of an issue.
Any links, suggestions, code will be greatly appreciated.
I will use taglib to check whether embedded cover art is present. taglib is already a dependency for Mixxx and supports read/write of all the common formats for cover art (mp4,ID3v2).