We all listen to them, but do you know how the compression for an MP3 file actually works? [Portalfire] wanted to find out, while honing his Python skills at the same time. He’s been working on an MP3 decoder in the Python language. So far he’s had some success, with the first working decoder clocking in at just 34 times slower than real-time. But since then a bit of optimization improved that to 10 times slower.

Sure, it’s not a usable module yet but his goal of learning the algorithms has been reached. A combination of reading about the standard and looking at code from other projects made that possible. In the future he plans to try the same thing with the H.264 codec.