Olivier Langlois's blog

AAC is a new audio codec standardized to supersede the MP3 codec. When I hear about new technologies, I am always a little skeptic since I have long understood that newer technology is too often not synonym with better technology. However, at the company that I am working for, StreamTheWorld, we have developed the first system that stream AAC through Flash players. On StreamTheWorld website, there is a demo where the player connects to one MP3 stream and to one AAC stream with the same bitrate of 48 kbps. Both streams contain the same song and the demo consists of slider that allows you to switch between the AAC version and the MP3 version. You must absolutely check the demo! (PS: Make sure that you have the latest Adobe Flash player installed as AAC playback as being added only in the latest release which is 9.0.115) The difference is so convincing that you will probably want to start converting all your music to AAC!

One note about AAC, is that there exist many versions of AAC. I am listing them in the order that they have been released:

• MPEG2 AAC
• MPEG4 AAC
• AACPlus
• AACPlus v2

All versions provide improvements over the previous versions and also provide backward compatibility. That is you could listen an AACPlus v2 stream with an MPEG2 AAC decoder. However, the additional information contained for AACPlus v2 will be discarded and the resulting audio will only be as good as an MPEG2 AAC audio stream can be. Players supporting AACPlus v2 includes:

• Adobe Flash player
• WinAmp and every player using the open source AAC decoder FAAD2.

iTunes support AAC but not AACPlus v2. Sony with its PS3 and Nintendo with the Wii gaming console have made AAC their official audio codec but I do not know which version they are supporting.