I'm working on a project where I need to parse .avb project files and extract all filenames associated with usage of external audio files (WAV and MP3 files) along with the duration of the usage. Based on this, the application I'm working on should be able to generate a report of the audio used in a production.

How would I best approach this task?

AVB is the file extension of Avid bins. It is a properietary format. You will need to open it within Avid Media Composer. It may contain clips and sequences. If sequence, it will contain all relevant associated clips (Set Bin Display - > Show reference clips). You can create an EDL for your audio report. You can also export the sequence as an AAF that many 3rd party applications can process.