The Advanced Authoring Format (AAF) is a

file format A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free. Some file formats ...

for professional

cross-platform In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software r ...

data interchange, designed for the video

post-production Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments. The ...

and authoring environment. It was created by the Advanced Media Workflow Association (AMWA), and is now being standardized through the

Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the m ...

(SMPTE).

History

AAF was originally created by the AMWA, formerly the AAF Association Inc., a trade association created to develop and promote adoption of specifications and technologies, such as AAF,

Material Exchange Format 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 broadc ...

(MXF), and

Service-oriented architecture In software engineering, service-oriented architecture (SOA) is an architectural style that focuses on discrete services instead of a monolithic design. By consequence, it is also applied in the field of software design where services are provide ...

(SOA), to facilitate the deployment and operation of efficient media workflows. Technical work of the AMWA is through projects that aim to improve compatibility between AAF, Broadcast Exchange Format (BXF), MXF and

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. T ...

. The current projects fall into three categories: data models, interface specifications, and application specifications. AAF was created to help address the problem of multi-vendor, cross-platform interoperability for computer-based digital

video production Video production is the process of producing video content for video. It is the equivalent of filmmaking, but with video recorded either as analog signals on videotape, digitally in video tape or as computer files stored on optical discs, hard dri ...

. The AAF Object Model is now being standardized through SMPTE, including a better definition of the mapping between MXF and AAF essence.

Usage

Capabilities of AAF include the following: * Allows complex relationships to be described in terms of an object model. * Facilitates the interchange of metadata and/or program content. * Provides a way to track the history of a piece of program content from its source elements through final production. * Makes downstream rendering possible (with appropriate equipment). * Provides a convenient way to "wrap" all elements of a project together for archiving. There are two kinds of data that can be interchanged using AAF: * Essence Data:

Audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound ...

(including

music Music is generally defined as the art of arranging sound to create some combination of form, harmony, melody, rhythm or otherwise expressive content. Exact definitions of music vary considerably around the world, though it is an aspect ...

video Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) syste ...

image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensiona ...

graphics Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture ...

text Text may refer to: Written word * Text (literary theory), any object that can be read, including: **Religious text, a writing that a religious tradition considers to be sacred **Text, a verse or passage from scripture used in expository preachin ...

animation Animation is a method by which image, still figures are manipulated to appear as Motion picture, moving images. In traditional animation, images are drawn or painted by hand on transparent cel, celluloid sheets to be photographed and exhibited ...

, and other forms of

multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to tradition ...

data. So named because they are the essential data within a multimedia program that can be perceived directly by the audience. *

Metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

: Data that provides information on how to combine or modify individual sections of essence data, or that provides supplementary information about essence data. The metadata in an AAF file can provide the information needed to combine and modify the sections of essence data in the AAF file to produce a complete multimedia program. By preserving source referencing, and abstracting the creative decisions that are made, AAF tries to improve workflow and simplify project management. AAF's rich data model combining metadata and various types of essence has led to its use in non-broadcast applications as well. For example, AAF has been adopted by the DoD/IC Motion Imagery Standards Board (MISB) for their Aerial Surveillance and Photogrammetry Applications standard (ASPA).

Elements of AAF

The core elements of the AAF specification include: * The AAF Object Specification, which defines the structured container by which AAF stores essence data and metadata using an object-oriented model. It defines the logical contents of the objects and the rules for how the objects relate to each other. *The AAF Low-Level Container Specification, which describes how each object is stored on disk. It uses Structured Storage, a file storage system developed by Microsoft, to store the objects on disk. * The AAF API Specification, which defines how software engineers can write applications. * The AAF Reference Implementation, which implements both these specifications in a completely cross-platform manner. * The AAF

Software Development Kit A software development kit (SDK) is a collection of software development tools in one installable package. They facilitate the creation of applications by having a compiler, debugger and sometimes a software framework. They are normally specific to ...

(SDK), which includes developer utilities and validation test suites. * The AAF Example software, which demonstrates how to use the AAF SDK to produce AAF files. * The AAF Example files, created by working AAF implementations.

Differences from MXF

AAF is designed to be a data representation of works in progress, as compared to

(MXF), which is for exchanging finished media products. While MXF uses a Key Length Value (KLV) format for storage, AAF uses the

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

Structured Storage Structuring, also known as smurfing in banking jargon, is the practice of executing financial transactions such as making bank deposits in a specific pattern, calculated to avoid triggering financial institutions to file reports required by la ...

system.{{Cite web, url=https://www.loc.gov/preservation/digital/formats/fdd/fdd000004.shtml, title=Advanced Authoring Format (AAF) Object, Version 1.1, date=2011-12-16, website=Library of Congress, access-date=2019-02-11 MXF was developed as a subtype of the AAF data model, under a zero-divergence policy, which allows for workflows that mix AAF and MXF. Specifically, all MXF metadata can be understood by AAF, but not all AAF metadata can be understood by MXF (and would be filtered out during encoding as a result).

References

External links