Today is April 17, 1999. Microsoft a few days ago released a proprietary codec, known as "MS Audio v4.0" Nobody's exactly sure what's in it, but it seems to be pretty high-quality. I wanted to investigate how well MS Audio actually works and possibly get a glimpse into how it works as well. I created four test files: a series of pure DTMF tones (like what your telephone does to dial a number), a descending tone and a descending tone at the same time, a short voice clip, and a short music clip. Just because I felt like it, I decided to check a number of different encoding schemes for relative quality, and ended up running a somewhat exhaustive battery of tests on most all of the popular codecs. The results were interesting. I found one codec that could reproduce my speech at 2.5kbps (That's an hour and a half of speech on one floppy disk!) and I found some fascinating hints as to how Xing's Variable Bitrate Coding actually works, as well as some anomalies in the MS Audio codec itself.

As a quick note, I was unfortunately unable to perform comprehensive testing on RealAudio's G2 codec, as their free G2 Encoder (called the RealProducer G2) was extremely limited in what bitrates it would let you encode at. I was somewhat miffed.

UPDATE: Real Networks is sending me a copy of RealProducer G2 to complete the testing. More details when it arrives.