WHAT IS AC3?
It is the Dolby Digital 5.1 audio track that you find on DVD-videos. You can also find AC3 on some divx-like video files. Usually, the audio track of divx-like video files are encoded with the MP3 codec, which offers stereo only. Using the AC3 codec in divx-like video files, you can get a 5.1 surround sound. There is no much difference between the AC3 of DVD’s and the AC3 of DIVX-like video files.