1534 Dolby Digital AC-3 Audio AC-3 (backronymed to Audio Codec 3 or Advanced Codec 3) is the common version of Dolby Laboratories' Dolby Digital audio compression technology. 1 Digital Preservation Department / The National Archives 27 Mar 2015 27 Mar 2015 audio/ac3 MIME fmt/735 PUID ac3 File extension 1062 Dolby Digital AC-3 The file consists of repeated frames of audio data. Each frame begins with the 0x0B77 syncword. The size of the frame is determined by the nominal bit rate and sample rate as per Table 5.18 of the Digital Audio Compression Standard specification http://www.atsc.org/cms/standards/a_52-2010.pdf 1 Absolute from BOF 0 0 0B77