Listing of missing or half-implemented formats in FFMpeg
approvals
This is a wiki page that links to lists of un/half-implemented audio- and video-formats in FFmpeg, the open source media converter.
This is a really useful list for anyone using ffmpeg to convert 'random' input media in their program or service. The sidebar on the linked page also has lists of codecs that are supported. Both lists have samples. This is perfect for setting up test scripts and for compiling lists of formats you do and do not support.