AC3 File Format

Dolby Digital audio files used on DVDs

AC3 is a file extension for surround sound audio files used on DVDs format.  The AC3 file format was created by Dolby Labs for use in a Dolby Digital audio on DVD, Blu-ray and other digital video formats. AC3 stands for Audio Coding 3.

AC3 increases fidelity over its previous surround sound standard, Pro-logic, with independent tracks for each of the 6 speakers, a 16bit sampling at 48khz rate compressed by 10- 12 times, making for a total bit rate of 384kbps.

To reproduce to the full surround sound signal on an AC3 file requires a supported playback device such as DVD player connected to a Dolby Digital-supporting home theater amplifier. It is more common in computer audio for sound cards to interpret AC3 and put out a PCM stream; however some cards can output a Dolby Digital or DTS stream that may be used on with a home theater amplifier.

MIME type: audio/ac3

Learn more about AC3 files:

Search for answers to AC3-related questions at IT Knowledge Exchange.

See our Fast Guide to CD/DVD.

We've put together an introduction to audio.

Visit the Dolby Labs guide on Understanding Dolby Digital.