1、 Copyright 2009 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved May 29, 2009 Table of Contents Page Foreword 2 Intellectual Property 2 1 Scope . 3 2 Conformance Notation 3 3 Normative References 4 4 Definition of Terms 4 5 Ove
2、rview 6 6 Audio Data Packet 9 7 Audio Control Packet 19 Annex A Recommendations for Handling of SMPTE 337 Non-PCM Data (Informative) 25 Annex B Recommendations for Handling Legacy Implementations (Informative) 26 Annex C Bibliography (Informative) 27 Annex D Additional Sampling Frequency (Informativ
3、e) .28 Page 1 of 28 pages SMPTE 299-2009 Revision of SMPTE 299M-2004 SMPTE STANDARD 24-Bit Digital Audio Format for SMPTE 292 Bit-Serial Interface SMPTE 299-2009 Page 2 of 28 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards deve
4、loping organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participat
5、ion in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices.
6、 SMPTE Standard 299 was prepared by Technology Committee 32NF. Intellectual Property SMPTE draws attention to the fact that it is claimed that compliance with this Standard may involve the use of one or more patents or other intellectual property rights (collectively, “IPR“). The Society takes no po
7、sition concerning the evidence, validity, or scope of this IPR. Each holder of claimed IPR has assured the Society that it is willing to License all IPR it owns, and any third party IPR it has the right to sublicense, that is essential to the implementation of this Standard to those (Members and non
8、-Members alike) desiring to implement this Standard under reasonable terms and conditions, demonstrably free of discrimination. Each holder of claimed IPR has filed a statement to such effect with SMPTE. Information may be obtained from the Director, Standards or that a certain course of action is p
9、referred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision t
10、hat is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision will never be defined in the future. A conformant implementation according to this document is one that includes all mandato
11、ry provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may“) and need not implement them as described. SMPTE 299-2009 Page 4 of 28 pages 3 Normative References The following standards conta
12、in provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applyin
13、g the most recent edition of the standards indicated below. AES3-2003, AES Standard for Digital Audio Digital Input-Output Interfacing Serial Transmission Format for Two-Channel Linearly Represented Digital Audio Data (AES3) SMPTE 291M-2006, Television Ancillary Data Packet and Space Formatting SMPT
14、E 292-2008, 1.5 Gb/s Signal/Data Serial Interface SMPTE RP 168-2002, Definition of Vertical Interval Switching Point for Synchronous Video Switching 4 Definition of Terms 4.1 AES audio: All the VUCP (sample validity bit (V), channel status bit (C), user data bit (U), even parity bit (P) data, audio
15、data and auxiliary data, associated with one AES digital stream as defined in AES3. 4.2 AES frame: Two AES subframes: in the 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 success
16、ive samples of the same AES audio signal which is mandatory for 96 kHz application. 4.3 AES subframe: All data associated with one AES audio sample for one channel in a channel pair. 4.4 Ancillary data packet: A data packet as defined by SMPTE 291M. 4.5 audio clock phase data: Audio clock phase is i
17、ndicated by the number of video clocks between the first word of EAV and the video sample appearing at the same time as the audio sample at the input to the formatter. 4.6 audio control packet: An ancillary data packet occurring once a field in an interlaced system and once a frame in a progressive
18、system and containing data used in the process of decoding the audio data stream. 4.7 audio data: 29 bits: 24 bits of AES audio associated with one audio sample, including AES auxiliary data, plus VUCP bits and the Z flag which is derived from the preamble of AES3 stream. The Z bit is common to the
19、two channels of an AES channel pair. 4.8 audio data packet: An ancillary data packet containing audio clock phase data, audio data for 2 channel pairs (4 channels) and error correction code. An audio data packet shall contain audio data of one sample associated with each audio channel. 4.9 audio fra
20、me number: A number, starting at 1, for each frame within the audio frame sequence. For the example in 4.9, 48 kHz sampling at 30.00/1.001 frames/s system, the frame numbers would be 1, 2, 3, 4 and 5. 4.10 audio frame sequence: The number of video frames required for an integer number of audio sampl
21、es in synchronous operation. As an example, the audio frame sequence for synchronous 48 kHz sampling at 30.00/1.001 frames/s system is 5 frames. 4.11 audio group: Consists of two channel pairs that are contained in one ancillary data packet. Each audio group has a unique ID as defined in 6.1 and 7.1
22、. Audio groups are numbered 1 through 4. SMPTE 299-2009 Page 5 of 28 pages 4.12 auxiliary data: Four bits of data associated with one AES audio sample defined as auxiliary data by AES3. The four bits can be used to extend the resolution of the audio sample. 4.13 channel pair: Two digital audio chann
23、els, derived from the same AES audio source. 4.14 data ID: A word in the ancillary data packet that identifies the use of the data therein. 4.15 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 (
24、ADF) through the last word of audio data of channel 4 (CH4) in user data words (UDW) can be corrected or detected within the capability of this code. 4.16 horizontal ancillary data block: An ancillary data space located in the digital line blanking interval of one television line. 4.17 synchronous a
25、udio: Audio is defined as being clock synchronous 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. Examples are shown in Table 1. Table 1 Examples of audio samples per frame for s
26、ynchronous audio Samples/frame Audio sampling rate 30.00 frame/s 30.00/1.001 frame/s 25.00 frames/s 24.00 frames/s 24.00/1.001 frames/s 96.0 kHz 3200/1 16016/5 3840/1 4000/1 4004/1 48.0 kHz 1600/1 8008/5 1920/1 2000/1 2002/1 44.1 kHz 1470/1 147147/100 1764/1 3675/2 147147/80 32.0 kHz 3200/3 16016/15
27、 1280/1 4000/3 4004/3 AES11 provides specific recommendations for audio and video synchronization. Note: Implementations of this standard may achieve synchronous or asynchronous operation through the use of sample rate converters. In the context of this standard, synchronous audio applies to the AES
28、 audio stream that is directly mapped into the ancillary data space, which may or may not be the AES audio stream present on device interfaces. It is recommended that product manufacturers clearly state when sample rate conversion is used to support multiple sample rates and/or asynchronous operatio
29、n. It is also recommended that the use of sample rate conversion be user selectable. For example, when the AES audio data contains SMPTE 337 formatted data the use of sample rate conversion will corrupt the SMPTE 337 data (see Annex A). This recommendation applies to both multiplexing (embedding) an
30、d demultiplexing (receiving) devices. SMPTE 299-2009 Page 6 of 28 pages 5 Overview 5.1 The modes of transmission carried in an audio data packet defined in 6 shall 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
31、sampling frequency of 96 kHz as defined in AES3. Audio data channels 14 (CH1 CH4) defined in 6.2.2 carry two AES audio channel pairs (AES1 channel 1 and 2 and AES2 channel 1 and 2) in the case of 32 kHz to 48 kHz sampling. For 96 kHz sampling, two successive samples of two AES audio channels (AES1 c
32、hannel 1 1stand 2ndsample and AES2 channel 1 1stand 2ndsample) shall be carried. Note: AES3 document allows for different audio samples configurations of the digital audio. Single sample mode or successive sample modes are permitted in AES3 without regard to used sampling frequency. 5.2 The 32 kHz,
33、44.1 kHz or 48 kHz sampling audio data derived from two channel pairs shall be configured in an audio data packet as shown in Figure 1. Both channels of a channel pair are derived from the same AES audio source. The number of samples per channel used for one audio data packet shall be constant and i
34、s equal to one. The number of audio data packets in a given group shall be less than or equal to Na in a horizontal ancillary data block. The definition and examples of Na are described in 6.3.3. 5.3 Figure 2 shows the audio data packet at the sampling rate of 96 kHz. AES subframes 1 and 2 carry suc
35、cessive samples of the same AES audio signal. Both channels shall be derived from the same AES audio source. The number of samples per channel used for one audio data packet shall be constant and equal to two. The number of audio data packets in a given group is less than or equal to Na/2 in a horiz
36、ontal ancillary data block. The definition and examples of Na are described in 6.3.3. 5.4 Two types of ancillary data packets carrying AES audio information are defined and formatted per SMPTE 292. Each audio data packet shall carry all of the information in the AES bit stream as defined by AES3. Th
37、e audio data packet shall be located in the horizontal ancillary data space of the Cb/Crdata stream. An audio control packet shall be transmitted once per field in an interlaced system and once per frame in a progressive system in the horizontal ancillary data space of the second line after the swit
38、ching point of the Y data stream. 5.5 Data ID shall be defined for four separate packets of each packet type. This allows for up to eight channel pairs. In this standard, the audio groups are numbered 1 through 4 and the channels are numbered 1 through 16. Channels 1 through 4 are in group 1, channe
39、ls 5 through 8 are in group 2, and so on. Table 2 defines the relationship between CH1CH4 (UDW2UDW17) in the audio data packet and the channel/sample number for 32 kHz to 48 kHz sampling and 96-kHz sampling respectively. 5.6 The audio data packet and audio control packet shall be located in SMPTE 29
40、2 transport HANC space that is equal to 268 clock pulses at 30 Hz video frame rate. SMPTE 299-2009 Page 7 of 28 pages Figure 1 Relationship between AES audio and audio data packets at sampling rates of 32 kHz, 44.1 kHz or 48 kHz Y channel 2 Z Y Xchannel 1 channel 2 channel 1 Y channel 2AESchannel pa
41、ir 2(AES2)AESsubframe 2AESsubframe 1AESsubframe 2AESsubframe 1AESsubframe 2AES frame 191 AES frame 0 AES frame 1Y channel 2 Z Y Xchannel 1 channel 2 channel 1 Y channel 2AESchannel pair 1(AES1)AESsubframe 2AESsubframe 1AESsubframe 2AESsubframe 1AESsubframe 2AES frame 191 AES frame 0 AES frame 1Pream
42、ble4-bitAES1channel 1(CH1)AES channel pair 1, subframe 2(CH2)Audio data 20-bitV U C PAES subframe 32-bitADF DID DBN DC CLKAUX dataorAudio data4-bitAES1channel 2(CH2)AES2channel 1(CH3)AES2channel 2(CH4)ECC 0ECC 1ECC 2ECC 3ECC 4ECC 5CSA sample of AES audio data istransferred to 4 words in an audio dat
43、a packet3 1 1 1 2 4 4 4 4 6 1Number of wordsSMPTE 299-2009 Page 8 of 28 pages Figure 2 Relationship between AES audio and audio data packets at a sampling rate of 96 kHz Y channel 1 Z Y Xchannel 11st samplechannel 12nd samplechannel 1 Y channel 1AES2nd channel(AES2)AESsubframe 2AESsubframe 1AESsubfr
44、ame 2AESsubframe 1AESsubframe 2AES frame 191 AES frame 0 AES frame 1Y channel 1 Z Y Xchannel 11st samplechannel 12nd samplechannel 1 Y channel 1AES1st channel(AES1)AESsubframe 2AESsubframe 1AESsubframe 2AESsubframe 1AESsubframe 2AES frame 191 AES frame 0 AES frame 1Preamble4-bitAES1channel 11st samp
45、le(CH1)AES channel 1, subframe 2Audio data 20-bitV U C PAES subframe 32-bitADF DID DBN DC CLKAUX dataorAudio data4-bitAES1channel 12nd sample(CH2)AES2channel 11st sample(CH3)AES2channel 12nd sample(CH4)ECC 0ECC 1ECC 2ECC 3ECC 4ECC 5CSA sample of AES audio data istransferred to 4 words in an audio da
46、ta packet3 1 1 1 2 4 4 4 4 6 1Number of wordsSMPTE 299-2009 Page 9 of 28 pages Table 2 Relationship between audio data packets and the channel/sample number of 32 kHz to 48 kHz and 96 kHz sampling 6 Audio Data Packet 6.1 Structure of Audio Data Packet 6.1.1 The structure of the audio data packet sha
47、ll be as shown in Figure 3. Audio data packets shall be formatted according to the requirements of SMPTE 291M and shall include ancillary data flag (ADF), data identification (DID), data block number (DBN), data count (DC), user data words (UDW) and checksum (CS) fields as specified in SMPTE 291M. D
48、C is always 218h. Figure 3 Structure of audio data packets 6.1.2 The DID value shall be defined as 2E7hfor audio group 1 (channel 14), 1E6hfor audio group 2 (channel 58), 1E5hfor audio group 3 (channel 9-12) and 2E4hfor audio group 4 (channel 1316), respectively. Audio Group 132.0 kHz, 44.1 kHz or 4
49、8.0 kHz96.0 kHzUDW2UDW5CH1UDW6UDW9CH2UDW10UDW13CH3UDW14UDW17CH4AES1channel 1AES1channel 2AES1channel 11st sampleAES2channel 1AES2channel 2AES1channel 12nd sampleAES2channel 11st sampleAES2channel 12nd sampleAudio sampling rateAES1channel 1ADF DID DBN DC CLKAES1channel 2AES2channel 1AES2channel 2ECC 0ECC 1ECC 2ECC 3ECC 4ECC 5CS3 1 1 1 2 4 4 4 4 6 1Number of wordsECC protectedUDW0UDW1UDW2UDW3UDW4UDW5UDW6UDW7UDW8UDW9UDW10UDW11UDW12UDW13UDW14UDW15UDW16UDW17UDW18UDW19UDW20UDW21UDW22UDW23AES1channel 11st sampleAES1channel 12nd sampleA
