The Audio Encoders and Decoders are basically compression algorithms for multichannel audio, meant for storing/streaming music and the audio part of movies, with lesser storage place/bandwidth than the original content. Dolby Digital Decoder is one such algorithm developed by Dolby Digital Laboratories. The Encoders are almost, always used at the recording end in the studios, where the sound/music is created, to encode/compress the sound. The Decoders are generally present at the infotainment end, like home theater systems and car infotainment systems. The article here, describes the basic building blocks of the Dolby Digital (AC3) Decoder algorithm.