AC3, or Dolby AC-3, is a lossy audio format created by Dolby Digital that is used in cinemas, television broadcasts, DVDs, Blu-Ray Discs, and game consoles. While AC3 was never designed to replace MP3 files, it has grown in popularity in the PC audio industry and is now recognized and supported by many media players and devices. However, AC3 is mostly used in audio/video recordings and is rarely separated from video files.
How AC3 Works
Because AC3 is a lossy audio format, it discards information when it is compressed. Although this sounds like it would be a disastrous situation, AC3 only discards information that is not really needed in order to reduce the size of the file. While the resulting compressed file is of a much lower quality than the original, human ears cannot distinguish a compressed AC3 file from the original.
AC3 can be used in a number of audio environments, such as Blu-Ray discs, DVDs, and gaming consoles, as well as television broadcasts and cinema film recordings, which it was originally designed for. While AC3 is usually not separated from its corresponding audio file, a PC user can separate the two files and most media players can recognize and playback the AC3 file.
AC3 is advantageous because it can be encoded along with a video recording for use in television broadcasts, digital recordings, and optical film. AC3 files are also much smaller than other audio files because of their lossy compression, allowing for users to obtain the same quality as other audio files from a file that takes up considerably less space.