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29-541: AES3 is a standard for the exchange of digital audio signals between professional audio devices. An AES3 signal can carry two channels of pulse-code-modulated digital audio over several transmission media including balanced lines , unbalanced lines , and optical fiber . AES3 was jointly developed by the Audio Engineering Society (AES) and the European Broadcasting Union (EBU) and so

58-417: A coordination problem : it emerges from situations in which all parties realize mutual gains, but only by making mutually consistent decisions. Examples : Private standards are developed by private entities such as companies, non-governmental organizations or private sector multi-stakeholder initiatives, also referred to as multistakeholder governance . Not all technical standards are created equal. In

87-443: A frame . Frames contain 64 bit periods and are produced once per audio sample period. At the highest level, each 192 consecutive frames are grouped into an audio block . While samples repeat each frame time, metadata is only transmitted once per audio block. At 48 kHz sample rate, there are 250 audio blocks per second, and 3,072,000 time slots per second supported by a 6.144 MHz biphase clock. The synchronisation preamble

116-399: A 75-ohm BNC electrical variant of AES3. This uses the same cabling, patching and infrastructure as analogue or digital video, and is thus common in the broadcast industry. AES3 was designed primarily to support stereo PCM encoded audio in either DAT format at 48 kHz or CD format at 44.1 kHz. No attempt was made to use a carrier able to support both rates; instead, AES3 allows

145-509: A custom, convention, company product, corporate standard, and so forth that becomes generally accepted and dominant is often called a de facto standard. A technical standard may be developed privately or unilaterally, for example by a corporation, regulatory body, military, etc. Standards can also be developed by groups such as trade unions and trade associations. Standards organizations often have more diverse input and usually develop voluntary standards: these might become mandatory if adopted by

174-434: A government (i.e., through legislation ), business contract, etc. The standardization process may be by edict or may involve the formal consensus of technical experts. The primary types of technical standards are: Technical standards are defined as: Technical standards may exist as: When a geographically defined community must solve a community-wide coordination problem , it can adopt an existing standard or produce

203-658: A joint effort between the Audio Engineering Society and the European Broadcasting Union, and culminated in the publishing of AES3 in 1985. The AES3 standard has been revised in 1992 and 2003 and is published in AES and EBU versions. Early on, the standard was frequently known as AES/EBU. Variants using different physical connections are specified in IEC 60958. These are essentially consumer versions of AES3 for use within

232-505: A large user base, doing some well established thing that between them is mutually incompatible. Establishing national/regional/international standards is one way of preventing or overcoming this problem. To further support this, the WTO Technical Barriers to Trade (TBT) Committee published the "Six Principles" guiding members in the development of international standards. The existence of a published standard does not imply that it

261-412: A new one. The main geographic levels are: National/Regional/International standards is one way of overcoming technical barriers in inter-local or inter-regional commerce caused by differences among technical regulations and standards developed independently and separately by each local, local standards organisation , or local company. Technical barriers arise when different groups come together, each with

290-602: A number of papers in relation to the proliferation of private food safety standards in the agri-food industry, mostly driven by standard harmonization under the multistakeholder governance of the Global Food Safety Initiative (GFSI). With concerns around private standards and technical barriers to trade (TBT), and unable to adhere to the TBT Committee's Six Principles for the development of international standards because private standards are non-consensus,

319-545: A single international standard ; ISO 9001 (quality), ISO 14001 (environment), ISO 45001 (occupational health and safety), ISO 27001 (information security) and ISO 22301 (business continuity). Another example of a sector working with a single international standard is ISO 13485 (medical devices), which is adopted by the International Medical Device Regulators Forum (IMDRF). In 2020, Fairtrade International , and in 2021, Programme for

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348-534: A total of 192 bits or 24 bytes for each channel in each block. Between the AES3 and S/PDIF standards, the contents of the 192-bit channel status word differ significantly, although they agree that the first channel status bit distinguishes between the two. In the case of AES3, the standard describes, in detail, the function of each bit. SMPTE timecode data can be embedded within AES3 signals. It can be used for synchronization and for logging and identifying audio content. It

377-466: Is a specially coded preamble that identifies the subframe and its position within the audio block. Preambles are not normal BMC-encoded data bits, although they do still have zero DC bias . Three preambles are possible: The three preambles are called X, Y, Z in the AES3 standard; and M, W, B in IEC 958 (an AES extension). The 8-bit preambles are transmitted in the time allocated to the first four time slots of each subframe (time slots 0 to 3). Any of

406-496: Is also known as AES/EBU . The standard was first published in 1985 and was revised in 1992 and 2003. AES3 has been incorporated into the International Electrotechnical Commission 's standard IEC 60958 , and is available in a consumer-grade variant known as S/PDIF . The development of standards for digital audio interconnect for both professional and domestic audio equipment, began in the late 1970s in

435-404: Is always useful or correct. For example, if an item complies with a certain standard, there is not necessarily assurance that it is fit for any particular use. The people who use the item or service (engineers, trade unions, etc.) or specify it (building codes, government, industry, etc.) have the responsibility to consider the available standards, specify the correct one, enforce compliance, and use

464-502: Is an AES information document published by the Audio Engineering Society for digital audio engineering—Guidelines for the use of the AES3 interface. This document provides guidelines for the use of AES3, AES Recommended Practice for Digital Audio Engineering, Serial transmission format for two-channel linearly represented digital audio data. This document also covers the description of related standards used in conjunction with AES3 such as AES11 . The full details of AES-2id can be studied in

493-534: Is embedded as a 32-bit binary word in bytes 18 to 21 of the channel status data. The AES11 standard provides information on the synchronization of digital audio structures. the AES52 standard describes how to insert unique identifiers into an AES3 bit stream. SMPTE 2110 -31 defines how to encapsulate an AES3 data stream in Real-time Transport Protocol packets for transmission over an IP network using

522-580: The WTO does not rule out the possibility that the actions of private standard-setting bodies may be subject to WTO law. BSI Group compared private food safety standards with "plugs and sockets", explaining the food sector is full of "confusion and complexity". Also, "the multiplicity of standards and assurance schemes has created a fragmented and inefficient supply chain structure imposing unnecessary costs on businesses that have no choice but to pass on to consumers". BSI provide examples of other sectors working with

551-462: The Endorsement of Forest Certification (PEFC) issued position statements defending their use of private standards in response to reports from The Institute for Multi-Stakeholder Initiative Integrity (MSI Integrity) and Greenpeace. Private standards typically require a financial contribution in terms of an annual fee from the organizations who adopt the standard. Corporations are encouraged to join

580-547: The SMPTE 2110 IP based multicast framework. SMPTE 302M -2007 defines how to encapsulate an AES3 data stream in an MPEG transport stream for television applications. AES3 digital audio format can also be carried over an Asynchronous Transfer Mode network. The standard for packing AES3 frames into ATM cells is AES47 . Technical standard It is usually a formal document that establishes uniform engineering or technical criteria, methods, processes, and practices. In contrast,

609-443: The board of governance of the standard owner which enables reciprocity. Meaning corporations have permission to exert influence over the requirements in the standard, and in return the same corporations promote the standards in their supply chains which generates revenue and profit for the standard owner. Financial incentives with private standards can result in a perverse incentive , where some private standards are created solely with

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638-457: The data to be run at any rate, and encoding the clock and the data together using biphase mark code (BMC). Each bit occupies one time slot . Each audio sample (of up to 24 bits) is combined with four flag bits and a synchronisation preamble which is four time slots long to make a subframe of 32 time slots. The 32 time slots of each subframe are assigned as follows: Two subframes (A and B, normally used for left and right audio channels) make

667-457: The development of a technical standard, private standards adopt a non-consensus process in comparison to voluntary consensus standards. This is explained in the paper International standards and private standards . The International Trade Centre published a literature review series with technical papers on the impacts of private standards and the Food and Agriculture Organization (FAO) published

696-447: The domestic high fidelity environment using connectors more commonly found in the consumer market. These variants are commonly known as S/PDIF. IEC 60958 (formerly IEC 958) is the International Electrotechnical Commission 's standard on digital audio interfaces . It reproduces the AES3 professional digital audio interconnect standard and the consumer version of the same, S/PDIF . The standard consists of several parts: AES-2id

725-411: The item correctly. Validation of suitability is necessary. Standards often get reviewed, revised and updated on a regular basis. It is critical that the most current version of a published standard be used or referenced. The originator or standard writing body often has the current versions listed on its web site. In social sciences , including economics , a standard is useful if it is a solution to

754-413: The protocol level, but at the physical level, they specify different electrical signalling levels and impedances , which may be significant in some applications. AES/EBU signals can also be run using unbalanced BNC connectors a with a 75-ohm coaxial cable. The unbalanced version has a very long transmission distance as opposed to the 150 meters maximum for the balanced version. The AES-3id standard defines

783-500: The standard connector for AES3. The hardware interface is usually implemented using RS-422 line drivers and receivers. IEC 60958 Type II defines an unbalanced electrical or optical interface for consumer electronics applications. The precursor of the IEC 60958 Type II specification was the Sony/Philips Digital Interface, or S/PDIF . Both were based on the original AES/EBU work. S/PDIF and AES3 are interchangeable at

812-534: The standards section of the Audio Engineering Society web site by downloading copies of the AES-2id document as a PDF file. The AES3 standard parallels part 4 of the international standard IEC 60958. Of the physical interconnection types defined by IEC 60958, two are in common use. Type I connections use balanced , three-conductor, 110-ohm twisted pair cabling with XLR connectors . Type I connections are most often used in professional installations and are considered

841-456: The three marks the beginning of a subframe. X or Z marks the beginning of a frame, and Z marks the beginning of an audio block. In two-channel AES3, the preambles form a pattern of ZYXYXYXY..., but it is straightforward to extend this structure to additional channels (more subframes per frame), each with a Y preamble, as is done in the MADI protocol. There is one channel status bit in each subframe,

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