The Advanced Television Systems Committee (ATSC) has published two new candidate standards that document enhancements to the AC-3 digital audio compression standard and specify its use in the DTV standard.
The new specifications provide improved performance and flexibility. Enhanced AC-3 gives the industry expanded audio capabilities that can be used for broadcast, cable, satellite and DVD applications, according to ATSC President Mark S. Richer.
ATSC first standardized the AC-3 digital audio system in November 1994. AC-3 is now widely used in digital television systems around the world. The enhancements to AC-3 (E-AC-3) are contained in documents CS/T3-613 and CS/T3-614.
CS/T3-613 provides revisions to the ATSC Digital Audio Compression Standard (A/52) that can be used in a variety of media. CS/T3-614 describes additions to the ATSC DTV Standard (A/53) that specify use of E-AC-3 in the Enhanced VSB (E-VSB) robust mode currently under development in ATSC.
These new candidate standards complement the previously published CS/T3-608 and CS/T3-609 that provide transport specifications for E-VSB and CS/T3-606 that provides enhancements to the ATSC PSIP standard (A/65) for use with E-VSB.
Dolby Laboratories submitted Enhanced AC-3 to the ATSC for consideration in response to a request for information published in December 2002. E-AC-3 can be converted into AC-3 for playback compatibility on consumers’ existing A/V decoders.
The Candidate Standard stage is an explicit call for implementation and technical feedback. Candidate standards are available at www.atsc.org/standards/candidate_standards.html.