



To an extent, these costs reduce as you gain more users (e.g. Each user costs the person distributing the software money. The most common ones (H.264, MP3 and AAC) are what I would call "proprietary" media codecs because they are patented and hence require various licenses to distribute software that can decode them. HTML5 media (audio and video) allows for the use of several different codecs. If you are unsure, it is always best to ask.
