AES52

Last updated

AES52 is a standard first published by the Audio Engineering Society in March 2006 that specifies the insertion of unique identifiers into the AES3 digital audio transport structure.

Contents

Background

The AES3 transport stream continues to be used extensively in both discrete and network based audio systems alongside audio stored as files. Audio content is moving towards being handled by asset management systems and descriptive metadata is associated with that content is also being stored within systems. In order to provide a mechanism for AES3 transport streams to have similar abilities to work with content management systems, some form of unique label is required which can provide the link with these systems. One of the unique labels currently standardised in the media industry is the SMPTE UMID (SMPTE 330M-2004) while another commonly used in the Information Technology area is the International Electrotechnical Commission (IEC) UUID.

Operation

The standard specifies the method for inserting unique identifiers into the user data area of an AES3 stream. This specifically covers the use of UUID as well as a basic or extended SMPTE UMID but can be extended to embed other data types into the AES3 stream by registering these with the AES so the standard can be updated to include these by following AES due process.

Related Research Articles

Material Exchange Format (MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards. A typical example of its use is for delivering advertisements to TV stations and tapeless archiving of broadcast TV programs. It is also used as part of the Digital Cinema Package for delivering movies to commercial theaters.

AES3 is a standard for the exchange of digital audio signals between professional audio devices. An AES3 signal can carry two channels of PCM audio over several transmission media including balanced lines, unbalanced lines, and optical fiber.

Universally unique identifier 128-bit label used to identify information in computer systems

A universally unique identifier (UUID) is a 128-bit label used for information in computer systems. The term globally unique identifier (GUID) is also used.

Serial digital interface

Serial digital interface (SDI) is a family of digital video interfaces first standardized by SMPTE in 1989. For example, ITU-R BT.656 and SMPTE 259M define digital video interfaces used for broadcast-grade video. A related standard, known as high-definition serial digital interface (HD-SDI), is standardized in SMPTE 292M; this provides a nominal data rate of 1.485 Gbit/s.

HDCAM Magnetic tape-based videocassette format for HD video

HDCAM is a high-definition video digital recording videocassette version of Digital Betacam introduced in 1997 that uses an 8-bit discrete cosine transform (DCT) compressed 3:1:1 recording, in 1080i-compatible down-sampled resolution of 1440×1080, and adding 24p and 23.976 progressive segmented frame (PsF) modes to later models. The HDCAM codec uses rectangular pixels and as such the recorded 1440×1080 content is upsampled to 1920×1080 on playback. The recorded video bit rate is 144 Mbit/s. Audio is also similar, with four channels of AES3 20-bit, 48 kHz digital audio. Like Betacam, HDCAM tapes were produced in small and large cassette sizes; the small cassette uses the same form factor as the original Betamax. The main competitor to HDCAM was the DVCPRO HD format offered by Panasonic, which uses a similar compression scheme and bit rates ranging from 40 Mbit/s to 100 Mbit/s depending on frame rate.

AES47 is a standard which describes a method for transporting AES3 professional digital audio streams over Asynchronous Transfer Mode (ATM) networks.

A container format or metafile is a file format that allows multiple data streams to be embedded into a single file, usually along with metadata for identifying and further detailing those streams. Notable examples of container formats include archive files and formats used for multimedia playback. Among the earliest cross-platform container formats were Distinguished Encoding Rules and the 1985 Interchange File Format.

Dolby Digital Plus, also known as Enhanced AC-3 is a digital audio compression scheme developed by Dolby Labs for transport and storage of multi-channel digital audio. It is a successor to Dolby Digital (AC-3), also developed by Dolby, and has a number of improvements including support for a wider range of data rates, increased channel count and multi-program support, and additional tools (algorithms) for representing compressed data and counteracting artifacts. While Dolby Digital (AC-3) supports up to five full-bandwidth audio channels at a maximum bitrate of 640 kbit/s, E-AC-3 supports up to 15 full-bandwidth audio channels at a maximum bitrate of 6.144 Mbit/s.

Ancillary data is data that has been added to given data and uses the same form of transport. Common examples are cover art images for media files or streams, or digital data added to radio or television broadcasts.

The Unique Material Identifier (UMID) is a SMPTE standard for providing a stand-alone method for generating a unique label designed to be used to attach to media files and streams. The UMID is standardized in SMPTE 330M.

Program stream is a container format for multiplexing digital audio, video and more. The PS format is specified in MPEG-1 Part 1 and MPEG-2 Part 1, Systems. The MPEG-2 Program Stream is analogous and similar to ISO/IEC 11172 Systems layer and it is forward compatible.

AES53 is a standard first published in October 2006 by the Audio Engineering Society that specifies how the timing markers specified in AES47 may be used to associate an absolute time-stamp with individual audio samples. AES47 specifies a format for the transmission of digital audio over asynchronous transfer mode (ATM) networks. A recommendation is made to refer these timestamps to the SMPTE epoch which in turn provides a reference to UTC and GPS time. It thus provides a way of aligning streams from disparate sources, including synchronizing audio to video, and also allows the total delay across a network to be controlled when the transit time of individual cells is unknown. This is most effective in systems where the audio is aligned with an absolute time reference such as GPS, but can also be used with a local reference.

Dolby E is a lossy audio compression and decoding technology developed by Dolby Laboratories that allows 6 to 8 channels of audio to be compressed into an AES3 digital audio stream that can be stored as a standard stereo pair of digital audio tracks.

A Digital Cinema Package (DCP) is a collection of digital files used to store and convey digital cinema (DC) audio, image, and data streams.

The Entertainment Identifier Registry, or EIDR, is a global unique identifier system for a broad array of audio visual objects, including motion pictures, television, and radio programs. The identification system resolves an identifier to a metadata record that is associated with top-level titles, edits, DVDs, encodings, clips, and mash-ups. EIDR also provides identifiers for video service providers, such as broadcast and cable networks.

Ravenna is a technology for real-time transport of audio and other media data over IP networks. Ravenna was introduced on September 10, 2010 at the International Broadcasting Convention in Amsterdam. Ravenna can operate on most existing network infrastructures using standard networking technology. Performance and capacity scale with network performance. Ravenna is designed to match broadcasters' requirements for low latency, full signal transparency and high reliability. Fields of application include in-house signal distribution for broadcasting houses and other fixed installations, flexible setups at venues and live events, outside broadcasting support, and inter-studio links across wide area network links and production facilities.

The Open Control Architecture (OCA) is a communications protocol architecture for control, monitoring, and connection management of networked audio and video devices. Such networks are referred to as "media networks".

AES67 is a technical standard for audio over IP and audio over Ethernet (AoE) interoperability. The standard was developed by the Audio Engineering Society and first published in September 2013. It is a layer 3 protocol suite based on existing standards and is designed to allow interoperability between various IP-based audio networking systems such as RAVENNA, Livewire, Q-LAN and Dante.

SMPTE 2110 is a suite of standards from the Society of Motion Picture and Television Engineers (SMPTE) that describes how to send digital media over an IP network.

Audio Video Bridging Specifications for synchronized, low-latency streaming through IEEE 802 networks

Audio Video Bridging (AVB) is a common name for the set of technical standards which provide improved synchronization, low-latency, and reliability for switched Ethernet networks. AVB embodies the following technologies and standards: