IEC 61937-3 pdf download – Digital audio – Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 – Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats
1 Scope
This part of lEC 61937 describes the method used to convey non-linear PCM bitstreamsencoded according to the AC-3 and enhanced AC-3 formats.
2Normative references
The following referenced documents are indispensable for the application of this document. Fordated references,only the edition cited applies. For undated references, the latest edition ofthe referenced document (including any amendments) applies.
IEC 60958(all parts),Digital audio interface
IEC 61937-1:2007，Digital audio interface for non-linear PCM encoded audio bitstreamsapplying lEC 60958 – Part 1: General
IEC 61937-2:2007，Digital audio interface for non-linear PCM encoded audio bitstreamsapplying lEC 60958- Part 2: Burst-info
ATSC Standard A/52B,Digital Audio Compression (AC-3，E-AC-3), Rev.BETSI TS 102 366,Digital Audio Compression (AC-3,Enhanced AC-3)
3 Terms and definitions
For the purposes of this standard, the following terms,definitions and abbreviations apply.3.1 Terms and definitions
3.1.1
latency
delay time of an external audio decoder to decode an AC-3 or enhanced AC-3 data burst,defined as the sum of two values of the receiving delay time and the decoding delay time.
3.1.2
stream type
an enhanced AC-3 bitstream is constructed from one or more substreams,with eachsubstream being constructed from a sequence of frames. The stream type parameter of anenhanced AC-3 frame identifies the type of substream of which the frame is a part
3.1.3
substream identification
substream identification parameter of an enhanced AC-3 frame which, in conjunction with thestream type parameter,identifies the substream in the bitstream of which the enhanced AC-3frame is a part
3.1.4
converter synchronization flag
flag used for synchronization by a device that converts an enhanced AC-3 bitstream to abitstream compliant with an AC-3 decoder and indicates that the first block in this enhancedAC-3 frame will form the first block of the AC-3 frame output by the conversion process
3.1.5
block identification flag
if the stream type value of an enhanced AC-3 substream is two，indicating that the bitstreamhas been converted from an AC-3 bitstream, this bit is set to 1 to indicate that the first block inthis enhanced AC-3 frame was the first block in the original standard AC-3 frame
3.2Abbreviations
ATSC
Advanced Television Standards Committee
ETSI
European Telecommunication Standards Institute
IEC
lnternational Electrotechnical Commission
lSOnIEC MPEG
Moving Pictures Expert Group, a joint committee of lSO and lEC
4Mapping of the audio bitstream on to lEC 61937-1
4.1General
The coding of the bitstream and data-burst is in accordance with lEC 61937-1 and 61937-2.
4.2AC-3 and enhanced AC-3 burst-info
The 16-bit burst-info contains information about the data which will be found in the data-burst(see Table 1).
IEC 61937-3 pdf download – Digital audio – Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 – Part 3: Non-linear PCM bitstreams according to the AC-3 and enhanced AC-3 formats
