1、 Recommendation ITU-R BT.1365-2 (10/2015) 24-bit digital audio format as ancillary data signals in HDTV and UHDTV serial interfaces BT Series Broadcasting service (television) ii Rec. ITU-R BT.1365-2 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient a
2、nd economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are perfo
3、rmed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms t
4、o be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be fo
5、und. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, ra
6、diodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management
7、 SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2015 ITU 2015 All rights reserved. No part of t
8、his publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BT.1365-2 1 RECOMMENDATION ITU-R BT.1365-2 24-bit digital audio format as ancillary data signals in HDTV and UHDTV serial interfaces (Question ITU-R 130/6) (1998-2010-2015) Scope This Recommenda
9、tion defines the mapping of 24-bit digital audio data conforming with Recommendation ITU-R BS.647 and associated control information into the ancillary data space of serial digital video interfaces conforming to Recommendation ITU-R BT.1120 and Recommendation ITU-R BT.2077. The audio data are derive
10、d from Recommendation ITU-R BS.647, hereafter referred to as Audio Engineering Society (AES). Keywords UHDTV, Serial Interface, AES bit stream The ITU Radiocommunication Assembly, considering a) that many countries are installing digital HDTV and UHDTV production facilities based on the use of digit
11、al video components conforming to Recommendations ITU-R BT.709, ITU-R BT.2020, ITU-R BT.1120 and ITU-R BT.2077; b) that there exists the capacity within the serial digital interface for HDTV and UHDTV for additional data signals to be multiplexed as part of the serial data stream; c) that there are
12、operational and economic benefits to be achieved by the multiplexing of ancillary data signals along with the video data signal; d) that audio is one of the most important uses of the ancillary data packets; e) that audio data may need error correction codes to keep the balance between audio quality
13、 and video quality because errors in audio data are more easily noticed than those of video data; f) that audio equipment with 24-bit accuracy is commonly used in production facilities; g) that some broadcasters have the need to transmit asynchronous audio data by multiplexing into the serial digita
14、l interface, recommends 1 that, for the inclusion of 24-bit digital audio format as ancillary data signals in HDTV and UHDTV serial interfaces, the specification described in Annex 1 and or Annex 2 of this Recommendation should be used; 2 that compliance with this Recommendation is voluntary. Howeve
15、r, the Recommendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. 2 Rec. ITU-R BT.1365-2 Definition of terms Definition of these terms applies to the usa
16、ge made in this Recommendation. AES audio: All the VUCP (sample validity bit (V), user data bit (U), channel status bit (C), even parity bit (P) data, audio data and auxiliary data, associated with one AES digital stream as defined in Recommendation ITU-R BS.647. AES frame: Two AES subframes; in the
17、 case of the 32 kHz to 48 kHz sampling subframes one and two carry AES audio channel 1 and 2 respectively. In the case of 96 kHz sampling subframes one and two carry successive samples of the same AES audio signal which is mandatory for 96 kHz application. AES subframe: All data associated with one
18、AES audio sample for one channel in a channel pair. audio control packet: An ancillary data packet occurring once a field in an interlaced system and once a frame in a progressive system and containing data used in the process of decoding the audio data stream. audio clock phase data: Audio clock ph
19、ase is indicated by the number of video clocks between the first word of EAV and the video sample at the same timing when audio sample appeared at the input to the formatter. audio data: 29 bits: 24 bits of AES audio associated with one audio sample, including AES auxiliary data, plus VUCP bits and
20、the Z flag which is derived from the preamble of AES3 stream. The Z bit is common to the two channels of an AES channel pair. error correction code: BCH (31, 25) code (an error correction method) in each bit sequence of b0-b7. Errors between the first word of ancillary data flag (ADF) through the la
21、st word of audio data of channel 4 (CH4) in user data words (UDW) will be corrected or detected within the capability of this code. audio data packet: An ancillary data packet containing audio clock phase data, audio data for two channel pairs (4 channels) and error correction code. An audio data pa
22、cket should contain audio data of one sample associated with each audio channel. audio frame number: A number, starting at 1, for each frame within the audio frame sequence. audio frame sequence: The number of video frames required for an integer number of audio samples in isochronous operation. aud
23、io group: Consists of two channel pairs that are contained in one ancillary data packet. Each audio group has a unique ID. Audio groups are numbered 1 through 4. channel pair: Two digital audio channels, derived from the same AES audio source. data ID: A word in the ancillary data packet which ident
24、ifies the use of the data therein. Extended audio group: an audio group as defined in Annex 1 of this Recommendation, but numbered from 5 to 8. Extended audio data packet: an audio data packet as defined in Annex 1 of this Recommendation, but with identity corresponding to Extended audio group numbe
25、rs 5 to 8. Extended audio control packet: an audio control packet defined in Annex 1 of this Recommendation, but with identity corresponding to Extended audio group numbers 5 to 8. horizontal ancillary data block: An ancillary data space located in the digital line blanking interval of one televisio
26、n line. Rec. ITU-R BT.1365-2 3 isochronous audio: Audio is defined as being clock isochronous with video if the sampling rate of audio is such that the number of audio samples occurring within an integer number of video frames is itself a constant integer number, as shown in the following example: 4
27、 Rec. ITU-R BT.1365-2 TABLE 1 Examples of samples per frame for synchronous audio Samples-frame/s Audio sampling rate 120 120/1.001 100 60 60/1.001 50 30.00 30.00/1.001 25.00 24.00 24.00/1.001 96.0 kHz 800/1 4004/5 960 1600/1 8008/5 1920 3 200/1 16 016/5 3 840/1 4 000/1 4 004/1 48.0 kHz 400/1 2002/5
28、 480 800/1 4004/5 960 1 600/1 8 008/5 1 920/1 2 000/1 2 002/1 Rec. ITU-R BT.1365-2 5 Annex 1 24-bit digital audio format as ancillary data signals in HDTV and UHDTV serial interfaces 1 Introduction Audio sampled at a clock frequency of 48 kHz locked (synchronous) to video is the preferred implementa
29、tion for intrastudio applications. As an option, this Recommendation supports Audio Engineering Society (AES) audio at synchronous or asynchronous sampling rates from 32 kHz to 48 kHz and 96 kHz. Audio channels are transmitted in groups of four, up to a maximum of 16 audio channels in the case of 32
30、 kHz, 44.1 kHz or 48 kHz sampling, and up to a maximum of 8 audio channels in case of 96 kHz sampling. Each group is identified by a unique ancillary data ID. Audio data packets are multiplexed (embedded) into the horizontal ancillary data space of the CB/CR data stream, and audio control packets ar
31、e multiplexed into the horizontal ancillary data space of the Y data stream. The multiplexed data are converted into serial form according to the HDTV serial digital interfaces defined in Recommendation ITU-R BT.1120. For UHDTV interfaces conforming to Recommendation ITU-R BT. 2077 Parts 1 and 3, th
32、is Recommendation applies to Y data stream and CB/CR data stream, making up the overall multiplex. For UHDTV interfaces conforming to Recommendation ITU-R BT.2077 Part 2, this Recommendation applies to basic stream 1 and basic stream 2 of the interface according to 3.5 and 3.6 in Part 2 of Recommend
33、ation ITU-R BT.2077. 2 References Recommendation ITU-R BT.709 Parameter Values for the HDTV standards for production and international programme exchange. Recommendation ITU-R BT.1120 Digital interfaces for HDTV studio signals. Recommendation ITU-R BS.647 A Digital audio interface for broadcasting s
34、tudios. Recommendation ITU-R BT.2020- Parameter values for ultra-high definition television systems for production and international programme exchange. Recommendation ITU-R BT.2077 Real-time serial digital interfaces for UHDTV signals. Recommendation ITU-R BT.1364 Format of Ancillary Data signals c
35、arried in digital component studios. 3 Overview 3.1 The modes of transmission carried in an audio data packet should be the two channel mode at all sampling frequencies from 32 kHz to 48 kHz and the single channel double sampling frequency mode at the sampling frequency of 96 kHz. Audio data channel
36、s 14 (CH1CH4) carry two AES audio channel pairs (AES1 channel 1 0 asynchronous audio; 1 TABLE 8 Assignment of rate code X2 X1 X0 Sample rate 0 0 0 48.0 kHz 0 0 1 44.1 kHz 0 1 0 32.0 kHz 1 0 0 96.0 kHz 0 1 1 Reserved 1 0 1 Reserved 1 1 0 Reserved 1 1 1 Free running 5.2.3 ACT 5.2.3.1 The word ACT indi
37、cates active channels. Bits a1 to a4 are set to one for each active channel in a given audio group otherwise they are set to zero. The bit-assignment of ACT is shown in Table 9. Rec. ITU-R BT.1365-2 21 TABLE 9 Bit-assignment of ACT Bit number UDW2 ACT b9 (MSB) b8 b7 b6 b5 b4 b3 b2 b1 b0 (LSB) not b8
38、 even parity(1) 0 0 0 0 a4 active: 1, inactive: 0 (CH4) a3 active: 1, inactive: 0 (CH3) a2 active: 1, inactive: 0 (CH2) a1 active: 1, inactive: 0 (CH1) (1) Even parity for b0 through b7. 5.2.4 DELm-n 5.2.4.1 The words DELm-n indicate the amount of accumulated audio processing delay relative to video
39、, measured in audio sample intervals, for each channel pair of CHm and CHn. In the case of 96 kHz sampling, DELm-n should indicate the amount of accumulated audio processing delay relative to video measured in audio sample intervals for the successive two samples of the same AES audio signal carried
40、 in CH1, CH2 and CH3, CH4. 5.2.4.2 The bit-assignment of DELm-n should be as shown in Table 10. The e bit is set to one to indicate valid audio delay data. The delay words are referenced to the point where the AES/EBU data are input to the formatter. The delay words represent the average delay value
41、, inherent in the formatting process, over a period no less than the length of the audio frame sequence plus any pre-existing audio delay. 5.2.4.3 The audio delay data (del 0-del 25) is represented in the format of 26-bit 2s complement. Positive values indicate that the video leads the audio. TABLE
42、10 Bit-assignment of DELm-n Bit number UDW3 UDW4 UDW5 UDW6 UDW7 UDW8 DEL1-2 DEL3-4 b9 (MSB) b8 b7 b6 b5 b4 b3 b2 b1 b0 (LSB) not b8 del 7 del 6 del 5 del 4 del 3 del 2 del 1 del 0 (LSB) e not b8 del 16 del 15 del 14 del 13 del 12 del 11 del 10 del 9 del 8 not b8 del 25 () del 24 (MSB) del 23 del 22
43、del 21 del 20 del 19 del 18 del 17 not b8 del 7 del 6 del 5 del 4 del 3 del 2 del 1 del 0 (LSB) e not b8 del 16 del 15 del 14 del 13 del 12 del 11 del 10 del 9 del 8 not b8 del 25 () del 24 (MSB) del 23 del 22 del 21 del 20 del 19 del 18 del 17 22 Rec. ITU-R BT.1365-2 5.2.5 RSRV 5.2.5.1 The words ma
44、rked RSRV are reserved for future use. 5.2.5.2 The bit-assignment of RSRV word should be as shown in Table 11. TABLE 11 Bit-assignment of RSRV Bit number UDW9 UDW10 RSRV RSRV b9 (MSB) b8 b7 b6 b5 b4 b3 b2 b1 b0 (LSB) not b8 reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to
45、 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) not b8 reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) reserved (set to 0) 5.3 Multi
46、plexing of the audio control packet 5.3.1 The audio control packets should be transmitted once every field in an interlaced system and once per frame in a progressive system. 5.3.2 The audio control packet should be transmitted in the horizontal ancillary data space of the second line after the swit
47、ching point of Y parallel data stream. For example, since the switching point for 1125/60 system exists in Line 7 and 569, the audio control packets are transmitted in the horizontal ancillary data space of Line 9 and Line 571 of the Y data stream. Ancillary data space available for the transmission
48、 of audio control packets is shown in Fig. 9. Rec. ITU-R BT.1365-2 23 FIGURE 9 Ancillary data space of Y data stream available for transmission of audio control packets (1080/60/I system) B T . 1 3 6 5 - 0 9Sw i t ch i n g p o i n tA ct i v e v i d eoV ert i cal b l an k i n gV ert i cal b l an k i
49、n gSw i t ch i n g p o i n tA ct i v e v i d eoSam p l e n u mb erV ert i cal b l an k i n gV ert i cal b l an k i n gV ert i cal b l an k i n gSA VCRCE A V LNA v ai l ab l e areaA v ai l ab l e area1678920215605615685695705715835841 1 2 31 1 2 41 1 2 591920Linenumber1924192619282195219621991919024 Rec. ITU-R BT.1365-2 Annex 2 (Normative) Introduction Annex 1 of this Recommendation defines the 24-bit audio format for up to 16 audio channels at 32, 44.1, or 48 kHz sample rate, or 8 audio channels at 96 kHz sample rate, The intended application is for 1.5 G
