John McGowan's AVI Overview: GLOSSARY

A quick guide to the acronyms, jargon, and techno-babble related to AVI, Video for Windows, ActiveMovie, DirectShow, desktop and networked video.

Audio Compression Manager. The Windows Multimedia software component that manages audio codecs (compressor/decompressors). ACM can also be considered an API specification. A codec must conform to the implicit ACM specification to work with Windows Multimedia.
Microsoft software component for handling and displaying digital video, including AVI, MPEG, and QuickTime, for Windows 95 and Windows NT 4.0. Intended to replace Video for Windows. Renamed DirectShow.
Audio Compression-3. Usually marketed as Dolby Digital. A digital audio compression format from Dolby Laboratories. Incorporates "5.1" audio channels: left, right, center, left surround, right surround, and a base channel for more realistic three-dimensional sound. Used in DVD, GA-HDTV, laser discs, and movie theaters.
Analog to Digital Converter. A device that converts analog signals to digital signals.
Asymmetric Digital Subscriber Line. A technology and standard to enable much higher bitrates between telephone company central offices and homes over the already installed copper telephone lines. One of a family of such technologies and standards collectively referred to as xDSL. May provide sufficient bandwidth for network video to homes.
A mathematical rule or procedure for solving a problem.
American National Standards Institute. A private not-for-profit membership organization that administers the private sector voluntary standards system in the United States. It is the dues paying member and sole U.S. representative to the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).
American Standard Code for Information Interchange. This is the most widely used character set for representing Latin characters and certain control codes using 7 bit codes, that is 0 to 127 (decimal) or 0x00 to 0x7f (hexadecimal). ASCII is an American National Standard: ANSI X3.4-1968 ASCII Character Set. There is an updated standard: ANSI X3.110-1983 ASCII Character Set Revised.
Audio Video Interleave. Microsoft format for digital audio, video, and other multimedia data.
Active Pixel Sensor. A type of image sensor. This usually refers to a CMOS image sensor, as opposed to a CCD image sensor.
Advanced Streaming Format (ASF) Stream Descriptor. .asd files are files that specify encoding parameters for the ASF Real Time Encoder, one of the NetShow Tools.
Advanced Streaming Format (formerly Active Streaming Format). A Microsoft file and data stream format for multimedia data including audio, video, still images, and other data types. Also referred to as Windows Media format.
Active stream redirector (.asx) file. .asx files provide information that a NetShow Player needs to receive either unicast or multicast ASF streams. An .asx file may be encrypted or not. An unencrypted .asx file is simply a text file that contains the URL's for the ASF streams. A .asx file is not a .asf file.
Applications Specific Integrated Circuit. A silicon chip customized for a specific application such as video compression.
Asynchronous Transfer Mode. Networking technology and standard frequently used for implementing high-speed Wide Area Networks over fiber optic cables.
A video tape format used for analog video. This standard from Sony lost out in the commercial market but survived in the professional market where it has been used for television. There is also Digital Betacam.
Bitrate may refer to bits per pixel for compressed images or bits per second (such as 128 Kilobits/second) for compressed video.
Windows Bitmap file format. The most common type of still image on the PC. There are also OS/2 BMP still image files. The OS/2 BMP file format is similar but not identical to the Microsoft Windows BMP file format.
A class of goods identified by name as the product of a single firm or manufacturer. (Merriam-Webster Collegiate Dictionary)
Community Access Television (also known as Cable Television).
Constant Bit Rate. In video coding, the bitrate of the compressed video is fixed at a certain rate. This usually results in variable perceived quality of the video.
Charge Coupled Device. A widely used solid state technology image sensor. A CCD is a silicon chip. CCD's are used in video cameras, digital still cameras, and so forth.
The International Radio Consultative Committee. An international body responsible for a number of video standards, e.g. CCIR-601. Renamed ITU-R (International Telecommunications Union - Radio Standardization Sector).
This is now "Recommendation ITU-R BT.601-5, Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios". This is a standard for high quality uncompressed digital video used in studios and video production. CCIR-601 digital video is frequently stored on D1 digital video tapes.
The International Telephone and Telegraph Consultative Committee. An international body responsible for a number of communications standards, e.g. H.261. Renamed ITU-T (International Telecommunications Union - Telecommunications Standardization Sector).
Common Intermediate Format. A video format. Usually used to refer to video frames with dimensions of 352 pixels by 288 pixels.
Complimentary Metal Oxide Semiconductor. A semiconductor process technology for making chips. Most personal computer and consumer electronics chips are some variant of CMOS. Other semicondcutor technologies include BiCMOS and GaAs (Gallium Arsenide). CMOS is also used to refer a permanent 64 byte piece of CMOS RAM on IBM Personal Computer (PC) compatible computers that contains various parameters used by the PC BIOS, Basic Input Output System.
short for compressor decompressor. Usually a software or hardware component that compresses and/or decompresses audio or video data. A hardware codec is usually a silicon chip.
The legal right granted, as to an author, composer, playwright, or publisher, for exclusive publication, production, sale, or distribution of a literary, musical, dramatic, artistic, or electronically produced work. (Webster's II New Riverside Dictionary, The Riverside Publishing Company, 1984)
Microsoft's code name for its up-coming (March 30, 2002) release of Windows Media Technologies.
Content Scrambling System. This is an encryption system used by DVD movies. Also, see DeCSS.
Discrete Cosine Transform. Mathematical transform used in digital video compression. Used in JPEG, MPEG-1, MPEG-2, H.261, H.263, H.263+, and DV digital video compression.
A program that can decrypt CSS (Content Scrambling System) encrypted material, specifically DVD movies.
de facto
by fact.
de jure
by law.
Device Driver
A software component that handles direct interaction with a piece of hardware.
Microsoft software component for handling and displaying digital video, including AVI, MPEG, and QuickTime, for Windows 95 and Windows NT 4.0. Intended to replace Video for Windows. Originally codenamed Quartz, then released as ActiveMovie. Now DirectShow.
Dynamic Link Library. A type of software library in Microsoft Windows.
Dolby Digital
A standard for compressed digital audio from Dolby Laboratories. Dolby Digital encodes 5.1 channels of digital audio (Left, Right, Center, Left Surround, Right Surround, and a Base Channel). Dolby Digital is used in film, on DVD, in the Grand Alliance High Definition Television (GA-HDTV) standard, and some laser discs. Dolby Digital is also known as AC-3 (Audio Compression 3).
Digital Signal Processor. Usually, a programmable silicon chip optimized to perform digital signal processing. For example, DSP's traditionally have an optimized multiply accumulate (MAC) instruction.
DV is a format for storing digital audio and video used by by the DV-standard digital video cameras such as the DVCam and DVCPro cameras.
Digital Versatile Disc. (Digital Video Disc at one time.) High density optical storage discs. DVD discs are used to distribute movies using MPEG-2 digital video and either Dolby Digital (AC-3) or MPEG-2 (Philips MUSICAM) digital audio.
DVD Video
Sometimes used to refer specifically to DVD discs with video content or to the video compression for video used by DVD Video discs, the ISO MPEG-2 video compression standard.
European Broadcasting Union.
Electronics Industry Association. A trade organization responsible for a number of standards. For example, EIA Standard EIA-189-A, July 1976, Encoded Color Bar Signal
entropy coding
Entropy coding is a fancy name for a variety of methods that seek to compress digital data by representing frequently occuring patterns with few bits and rarely occuring patterns with many bits. Examples include run length encoding, Huffman coding, and arithmetic coding.
Federal Communications Commission. The United States government agency that regulates the television industry. Established the NTSC television standard and the GA-HDTV high definition television standard.
Fibre Channel
Technically, Fibre Channel is a family of standards from the American National Standard Institute (ANSI). The initial core standard is the X.3230-1994 Fibre Channel Physical and Signaling Standard (FC-PH). Fibre Channel is used as an interface to disk arrays that store, for example, high resolution video such as uncompressed CCIR-601 (ITU-R 601) digital video. Fibre Channel can be implemented over optical fibre or copper. See the Fibre Channel Industry Association (FCIA):
The IEEE-1394 High Performance Serial Bus. This standard supports data rates of 100/200/400 Megabits/second. It is used with high quality digital video such as the DV digital video standard and cameras.
Focal Plane Array. An image sensor such as a CCD (Charge Coupled Device) located at the focal plane of an optical system such as a camera.
Frames Per Second. NTSC video is 29.97 or 30 FPS. PAL and SECAM video are 25 FPS. Cinema films are 24 FPS.
Federal Trade Commission. A United States government agency that enforces antitrust laws amongst other things.
Grand Alliance - High Definition Television. The new United States standard for High Definition Television based on the MPEG-2 digital video compression format and the Dolby Digital (AC-3) audio compression format.
General Agreement on Tariffs and Trade. This agreement was first drafted in 1947 to establish "free trade" between nations by limiting or eliminating tariffs and quotas on international trade. The Uruguay Round of the GATT, completed in December of 1993, substantially expanded the scope of the agreement and created the World Trade Organization (WTO). In particular, an Agreement on Technical Barriers to Trade such as technical standards was added. An agreement on Trade Related aspects of Intellectual Property or TRIPs was added.
An ITU-T standard for digital video compression for videoconferencing. Uses the Discrete Cosine Transform (DCT). ITU-T Recommendation H.261 (1993) "Video codec for audiovisual services at px64 kbit/s".
An ITU-T standard for digital video compression for videoconferencing. Uses the Discrete Cosine Transform. ITU-T Recommendation H.263 (199x) "Video Coding for Low Bitrate Communication"
An ITU-T standard for digital videoconferencing over ISDN. ITU-T Recommendation H.320 (1993) "Narrow-band ISDN visual telephone systems and terminal equipment".
An ITU-T standard for digital videoconferencing over TCP/IP networks.
An ITU-T standard for digital videoconferencing over telephone lines. ITU-T Recommendation H.324 (1995) "Terminal for low bitrate multimedia communication".
High Definition Television. Various schemes to increase the resolution of broadcast television. The original schemes were analog, but HDTV now refers almost exclusively to various digital audio and video technologies and standards.
Intel Architecture. This is the instruction set architecture of the series of chips used in IBM PC-compatible computers. This includes the 8080, 8086, 80286, 80386, 80486, Pentium (formerly 80586 or P5), Pentium Pro (formerly 80686 or P6), Pentium with MMX, Pentium II (formerly Pentium Pro with MMX), Pentium II Xeon (TM), Celeron (TM), and Pentium III.

The Intel Architecture is a de facto standard. Intel has repeatedly added new instructions and features to the architecture, although so far maintaining backward compatibility with previous versions. New instructions such as the MMX instructions and the Streaming SIMD Extensions in the Pentium III can be used to accelerate video codecs such as are used in AVI files. Advanced Micro Devices (AMD), National Semiconductor's Cyrix division, and Integrated Device Technology (IDT) manufacture processor chips compatible with the Intel Architecture.

International Electrotechnical Commission. The International Organization for Standardization (ISO) and the IEC work closely together to standardize information technology through the Joint Technical Committee 1 (JTC1). The MPEG digital video standards activities fall under the umbrella of JTC1.
Institute of Electrical and Electronics Engineers. An organization of engineers responsible for a number of electrical and electronics industry standards. IEEE is an international professional society headquartered in the United States. IEEE is responsible for the Firewire (IEEE-1394) High Performance Serial Bus standard used with high quality digital video cameras such as DV cameras.
Internet Engineering Task Force. The body responsible for managing and establishing protocols for the Internet.
Intellectual Property Rights. This usually refers to four major categories of intellectural property: patents, copyrights, trademarks, and trade secrets.
International Organization for Standardization. ISO is a non-governmental organization that was established in 1947. ISO works closely with the International Electrotechnical Commission (IEC) and the International Telecommunications Union (ITU). Note that ISO is not an acronym. It is derived from the Greek isos for "equal". Responsible for many audio, video, and telecommunications standards.
International Telecommunications Union. The ITU has been an agency of the United Nations since 1948. It is older, dating back to 1865. It may be the world's oldest intergovernmental agency.
ITU Radiocommunications Standardization Sector. Formerly known as CCIR, the International Radio Consultative Committee.
ITU Telecommunications Standardization Sector. ITU-T is a permanent organ of the International Telecommunications Union. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. Formerly known as CCITT, the International Telephone and Telegraph Consultative Committee.
Just another Box of Disks. An array of hard disks for storing large amounts of data such as digital video. JBOD arrays do not have any special redundancy features to recover from data corruption unlike RAID disk arrays.
JPEG File Interchange Format. A standard file format for storing JPEG images in a binary data file. When people refer to JPEG images, they are usually refering to JFIF format files. JFIF had some competitors in the early days of JPEG, such as the JPEG TIFF format which has fallen into to disuse.
Joint Photographic Experts Group. A body within the International Organization for Standardization (ISO) that established the JPEG still image compression standard. JPEG is usually used to refer to compression of still images or video frames using the "baseline JPEG" compression algorithm using the Discrete Cosine Transform and Huffman coding. JPEG is the basis of the Motion JPEG used in digital video, where each frame in a video is encoded separately using JPEG. See JFIF.
A new standard for lossless JPEG still image encoding. The original JPEG standard included a lossless still image encoding mode - actually a completely different algorithm from the DCT based "baseline JPEG". JPEG-LS is a new lossless compression algorithm that achieves better compression ratios than the original lossless JPEG.
A new standard under development by the JPEG committee for improved lossy still image compression. JPEG-2000 will probably use a different technology than the Block Discrete Cosine Transform used in baseline JPEG.
Media Control Interface. A Microsoft standard API for software control of multimedia devices and components. MCI includes API's for playback of AVI files and digital video devices (such as laser disc players).
Multipurpose Internet Mail Extensions. An extension to the Internet mail format to allow attaching multimedia data types such as AVI files, word processing documents, sound files, and so forth to Internet electronic mail. MIME is discussed in substantial detail elsewhere in the AVI Overview.
Microsoft Media Server. Network protocol used by Microsoft NetShow Server to communicate with NetShow Players. The actual multimedia data in ASF format may be delivered using HTTP, TCP, or UDP protocols as available.
Motion JPEG
A type of digital video in which the video frames are individually compressed using JPEG still image compression. A standard exists for Motion JPEG stored in AVI files.
Motion Pictures Experts Group. A body within the International Organization for Standardization (ISO) that established the MPEG-1, MPEG-2, and MPEG-4 digital audio and video compression standards. MPEG is also used to refer to video and audio clips compressed using the MPEG standards and the MPEG standards themselves.
A compressed digital audio format. MPEG (Motion Pictures Experts Group) Layer 3 Audio compression.
Mean Squared Error. A statistical measure of error, used to determine quality of compressed images. Mathematically equivalent to Peak Signal to Noise Rate (PSNR).
National Association of Broadcasters. A trade organization for the television broadcast industry in the United States. NAB is involved in standards, lobbying the federal government, sponsors trade shows, and other activities. NAB is known for the annual National Association of Broadcasters Conference, a major industry trade show where new products are oftened announced.
Microsoft videoconferencing software.
Microsoft streaming audio/video/multimedia product for broadcasting multimedia streams over computer networks. Also see ASF, ASX, and MMS.
network effect
The value of a product or service to a buyer increases with the cumulative number of other buyers. Also known as increasing returns to adoption. This usually occurs when the product or service is part of a network of components that must work together to produce a useful result, hence the name network effect. A simple example is a telephone service. If a telephone service has one subscriber, it has no value. The subscriber can communicate with no one else. The more subscribers to the telephone service, the more valuable the service becomes. The subscribers can communicate with more people, the other subscribers. This is a common phenomenon with communication systems and communication technologies. Microsoft's near-monopoly is frequently attributed to network effects. The value of the AVI file format - or Apple's QuickTime file format, or the ISO MPEG format - depends on the number of people who can view the AVI files, the amount of entertaining or useful content available in the format, and the number of applications supporting the format.
National Institute of Standards and Technology. A part of the United States Department of Commerce. NIST was formerly the National Bureau of Standards (NBS).
National Security Agency. A United States agency within the U.S. Department of Defense responsible for signals intelligence, encryption, cryptography, and related topics. NSA was established by a still classified executive order. Thus the full scope of its powers and responsibilities remains secret. NSA is involved in computer security policy and setting computer and communications security standards within the United States. NSA has a long history of relationships with major telecommunications companies.
National Television System Committee. The color analog television standard used in the United States, Japan, and a number of other countries. Adopted by United States in 1953.
Open Media Framework. A standard for high end digital video from Avid. Avid video editing products use OMF as do some products from other companies.
open standard
A standard that is easy for companies to produce and market products or services conforming to the standard. Essentially there is a competitive market without monopoly profits in products or services conforming to the standard. Some standards that are marketed as "open" aren't open in this sense. Some open standards are the 8 1/2 " by 11 " paper size used in the United States and the ASCII (American Standard Code for Information Interchange) used for representing alphanumeric characters on computers and computer networks. Also see standard, de facto, de jure, and specification.
Phase Alternation Line. The analog television standard used in Germany, England, and many other nations.
A grant made by a government to an inventor, assuring the sole right to make, use, and sell the invention for a certain period of time. Many audio and video technologies are covered by patents. This is also true of the underlying technologies for many of the international standards such as MPEG.
Macintosh QuickDraw picture file. The most common type of still image on the Macintosh.
Plain Old Telephone Service. Analog copper wires between telephones and the phone company.
Portable Pixmap. This is a color still image file format that originated on Unix computers. Historically, a number of still image and video research prototypes developed for Unix platforms accepted video input and generated video output as a sequence of PPM images. There are also PGM for Portable Greymap and PBM for Portable Bitmap files.
Peak Signal to Noise Ratio. A statistical measure of error, used to determine the quality of compressed images. Mathematically equivalent to the mean squared error (MSE) and the root mean squared error (RMSE). This is the most commonly used metric of image quality used in the image and video compression literature. The PSNR is usually quoted in decibels, a logarithmic scale. The PSNR has a limited, approximate relationship with the perceived errors noticed by the human visual system.

As a rough rule of thumb, an image with a PSNR of 25 dB (decibels) is usually pretty poor. Anything below 25 dB is usually unacceptable. Perceived quality usually improves from 25 dB to about 30 dB. Above around 30 dB images look pretty good and are often indistinguishable from the uncompressed original image.

The human visual system appears to have sensitivity thresholds. This can be rigorously demonstrated in controlled experiments using sinusoidal gratings against black backgrounds. Because of this thresholding, once the PSNR exceeds some value, the errors become undetectable to human viewers. Hence an image with a PSNR of 35 dB may look the same as an image with a PSNR of 40 dB.

Conversely, the human visual system seems to have a saturation effect as well. Once the image quality falls below a certain level, the image simply looks bad. An image with a PSNR of 15 dB and an image with a PSNR of 10 dB may look equally bad to a viewer. Typically by this point the image appears quite poor.

There is a range where the perceived quality and the PSNR tend to scale.

| ************ Q| ***** u| **** a| *** l| ** i| ** t| *** y|********** | --------------------------------------------- 25 dB 30 db 35 dB (PSNR) Relationship Between Perceived Quality and Image PSNR

The Mean Squared Error is the mean of the squares of the differences between the values of pixels in two images. If i and j are indices of an images and N is the total number of pixels:

MSE = (1 / N) * (Sum[i][j] |P[i][j] - Q[i][j]|^2

Where P and Q are two images. i and j are the horizontal and vertical location of a pixel. P[i][j] is the value of the pixel at location (i,j) in the image. Sum[i][j] indicates a sum over i and j.

The Root Mean Squared Error (RMSE) is:

RMSE = Sqrt(MSE)

The Peak Signal to Noise Ratio expressed in decibels is:

PSNR = 20 log_10(b/RMSE)

Where b is the peak value for a pixel, typically 255 (8 bit pixels).

Patent and Trademark Office, United States Patent and Trademark Office. This is the government office responsible for granting patents and trademarks. Currently (May 10, 1999) the Patent and Trademark Office is part of the United States Department of Commerce. Many audio and video compression technologies are covered by patents.
Quarter CIF, or Quarter Common Intermediate Format. Usually used to refer to video with dimensions of 176 by 144 pixels.
Quarter SIF, or Quarter Source Intermediate Format. Usually used to refer to video with dimensions of 176 by 120 pixels.
Quality of Service. In networking, QoS refers to various schemes to insure a certain quality, such as limiting or eliminating packet loss for video streams.
Microsoft software component for handling and displaying digital video, including AVI, MPEG, and QuickTime, for Windows 95 and Windows NT 4.0. Intended to replace Video for Windows. Originally codenamed Quartz, then released as as ActiveMovie. Now (May, 1998) DirectShow.
QuickTime is Apple's equivalent of Video for Windows for the Macintosh. Apple also makes QuickTime for Windows. QuickTime is also used to refer to the QuickTime Movie file format, a widely used format for digital audio, video, and other multimedia.
Red Green Blue. Color represented as red, green, and blue components. Most computer monitors use RGB pixels.
Original black and white television standard used in the United States. NTSC was designed to be compatible with RS-170 black and white television sets.
scan converter
A hardware device used to convert one video scan format, such as the VGA output to a monitor, to another video scan format such as the NTSC composite video used by televisions in the United States and Japan. Scan converters can be used to output AVI files and other computer video to a video tape.
Software Development Kit. Usually a collection of programming tools, utilities, documentation, and libraries of functions or classes. SDK is a term popularized by Microsoft as in Windows SDK or Windows Media SDK.
Sequentiel Couleur Avec Memoire or Sequential Color with Memory. Analog television standard developed in France. Used in France and some other nations.
Source Intermediate Format. A video format. Usually used to refer to video with video frames with dimensions of 352 by 240 pixels.
Single Instruction Multiple Data. An instruction set for a computer where a single instruction acts on multiple data in parallel. Examples include Intel's MMX and Streaming SIMD, and Sun's VIS instruction set. SIMD is used in image and video processing where a single instruction acts on several pixels or transform coefficients in parallel.
Society of Motion Picture and Television Engineers.
The English word specification has a few meanings, or word senses. The Webster's New World Dictionary gives the following meaning: "2 [usually pl.] a)a detailed description of the parts of a whole b) a statement or enumeration of particulars, as to actual or required size, quality, performance, terms, etc. [specifications for a new building]".
Society of Photo-Optical Instrumentation Engineers. "The International Society for Optical Engineering". A professional organization for scientists and engineers. SPIE sponsors many trade shows and conferences. It publishes Proceedings of its conferences, books, magazines, and so forth. The conferences frequently report work in video, optics, image processing, image compression, and video compression. The SPIE web site is
The English word standard has a large number of meanings, or word senses. The Webster's New World Dictionary gives the following meaning: "4 the type, model, or example commonly or generally accepted or adhered to; criterion set for usages or practices [moral standards]". This is the closest dictionary meaning or word sense to the usage of engineers.

The ISO (International Organization for Standardization) gives the following definition: "Standards are documented agreements containing technical specifications or other precise criteria to be used consistently as rules, guidelines, or definitions of characteristics, to ensure that materials, products, processes and services are fit for their purpose."

Standard can have a precise legal meaning in the context of U.S. law, the laws of foreign nations, treaties and international organizations such as the United Nations. For example, the United States Office of Management and Budget (OMB) Circular A-119, "Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities", Revised and Dated February 10, 1998 provides the following definition of standards (Note: the Act refers to Public Law 104-113, the "National Technology Transfer and Advancement Act of 1995"):


3. What Is A Standard?

a. The term "standard," or "technical standard" as cited in the Act, includes all of the following:

(1) Common and repeated use of rules, conditions,guidelines or characteristics for products or related processes and production methods, and related management systems practices.

(2) The definition of terms; classification of components; delineation of procedures; specification of dimensions, materials, performance, designs, or operations; measurement of quality and quantity in describing materials, processes, products, systems, services, or practices; test methods and sampling procedures; or descriptions of fit and measurements of size or strength.

b. The term "standard" does not include the following:

(1) Professional standards of personal conduct.

(2) Institutional codes of ethics.

c. "Performance standard" is a standard as defined above that states requirements in terms of required results with criteria for verifying compliance but without stating the methods for achieving required results. A performance standard may define the functional requirements for the item, operational requirements, and/or interface and interchangeability characteristics. A performance standard may be viewed in juxtaposition to a prescriptive standard which may specify design requirements, such as materials to be used, how a requirement is to be achieved, or how an item is to be fabricated or constructed.

d. "Non-government standard" is a standard as defined above that is in the form of a standardization document developed by a private sector association, organization or technical society which plans, develops, establishes or coordinates standards, specifications, handbooks, or related documents.

4. What Are Voluntary, Consensus Standards?

a. For purposes of this policy, "voluntary consensus standards" are standards developed or adopted by voluntary consensus standards bodies, both domestic and international. These standards include provisions requiring that owners of relevant intellectual property have agreed to make that intellectual property available on a non-discriminatory, royalty-free or reasonable royalty basis to all interested parties. For purposes of this Circular, "technical standards that are developed or adopted by voluntary consensus standard bodies" is an equivalent term.

(1) "Voluntary consensus standards bodies" are domestic or international organizations which plan, develop, establish, or coordinate voluntary consensus standards using agreed-upon procedures. For purposes of this Circular, "voluntary, private sector, consensus standards bodies," as cited in Act, is an equivalent term. The Act and the Circular encourage the participation of federal representatives in these bodies to increase the likelihood that the standards they develop will meet both public and private sector needs. A voluntary consensus standards body is defined by the following attributes:

(i) Openness.

(ii) Balance of interest.

(iii) Due process.

(vi) An appeals process.

(v) Consensus, which is defined as general agreement, but not necessarily unanimity, and includes a process for attempting to resolve objections by interested parties, as long as all comments have been fairly considered, each objector is advised of the disposition of his or her objection(s) and the reasons why, and the consensus body members are given an opportunity to change their votes after reviewing the comments.

b. Other types of standards, which are distinct from voluntary consensus standards, are the following:

(1) "Non-consensus standards," "Industry standards," "Company standards," or "de facto standards," which are developed in the private sector but not in the full consensus process.

(2) "Government-unique standards," which are developed by the government for its own uses.

(3) Standards mandated by law, such as those contained in the United States Pharmacopeia and the National Formulary, as referenced in 21 U.S.C. 351.

The AVI file format is an example of a standard. AVI would probably be considered a "de facto standard" in the language of the U.S. Federal Government.

streaming video
Streaming video is video that is played over a network. It differs from video that is played from a file on a local storage medium such as a hard disk or video that is downloaded over a network to local storage media such as a hard disk and then played back from the storage media. Typically, streaming media is transferred in packets over the network. A short amount of the video, perhaps one second, is buffered locally in a streaming video player to average out fluctuations in the channel. The streaming video player plays the video from the buffer which is often a block of local memory (RAM).
Sub QCIF, Sub Quarter CIF, or Sub Quarter Common Intermediate Format. A video format. Usually used to refer to video with dimensions of 88 by 72 pixels.
Sub QSIF, Sub Quarter SIF, or Sub Quarter Source Intermediate Format. A video format. Usually used to refer to video with dimensions of 88 by 60 pixels.
The conversion of film, usually shot at 24 frames per second, to television video, usually at 25 frames per second (PAL) or 30 frames per second (NTSC).
A name, symbol, or other device identifying a product, officially registered and legally restricted to the use of the owner or manufacturer. (Webster's II New Riverside University Dictionary, The Riverside Publishing Company, 1984)
Trade Related aspects of Intellectual Property. Term used in the context of the General Agreement on Tariffs and Trade (GATT) and the World Trade Organization (WTO) usually for attempts to harmonize the patents laws of different nations and enforce patent rights internationally. The Uruguay Round of the GATT, an agreement finalized in December of 1993, includes an agreement on TRIPs.
Universal Serial Bus. This is a standard for connecting peripherals to computers including low-bandwidth digital still and video cameras. USB supports low and medium-bandwidth peripherals. There are at least two versions of the USB standard: USB 1.0 and USB 2.0. USB is managed by the Universal Serial Bus Implementers Forum, Inc. (USB-IF), a non-profit corporation founded by the group of corporations that developed the USB specification.
Video Home System. This is the video tape system used in most consumer Video Casette Recorders (VCR). Developed by Matsushita and Japan Victor Corporation (JVC). VHS video tapes are typically used to store NTSC, PAL, or SECAM composite analog television.
Video for Windows (VfW)
Microsoft Windows software component for handling and displaying video. Windows 3.x incorporates a 16-bit Video for Windows. Windows 95 and Windows NT both incorporate a 32-bit Video for Windows.
Variable Bit Rate. In video coding, the bitrate of the encoded video stream varies over time. Sometimes the video is encoded with a fixed quantization factor resulting in varying bitrates and varying perceived quality. Sometimes the video is encoded with a fixed perceived quality which usually results in varying bitrate.
Video Compression Manager. The Microsoft Video for Windows component that manages video codecs (compressor/decompressors). VCM can also be considered a specification for an API. A video codec must conform to VCM to work with Video for Windows.
Video On Demand. Systems where users can demand that a selected video, such as a movie, be played. For example, many hotels now have systems where guests can select a recent movie using a simple menu driven system on the television set in their room.
Video Quality Experts Group. The ITU's Video Quality Experts Group ad hoc committee to establish a standard for objectively measuring video quality. A group of experts from three groups: ITU-R Study Group 11, ITU-T Study Group 9, and ITU-T Study Group 12.
Virtual Device Driver. A type of device driver for Microsoft Windows 3.x and Windows 95.
Windows Media Technologies
Microsoft's brand name for its digital video, audio, and other multimedia software. This seems to be the successor or umbrella for Video for Windows, ActiveMovie, DirectShow, and NetShow. As of May 1, 2000, Windows Media Technologies includes Windows Media Player, Windows Media Services, Windows Media Tools, and Windows Media SDK (Software Development Kit). Windows Media is a trademark of Microsoft.
World Intellectual Property Organization. WIPO is an agency affiliated with the United Nations. Many nations, including the United States, have agreed to try to harmonize their intellectual property laws through various treaties and this organization. In principle, this makes it easier to patent inventions worldwide, not just in one nation. Also see GATT, WTO, and TRIPs.
Windows Media 4 audio file format (Windows Media Audio). This is yet another Microsoft file format.
Windows Media 4 video file format (Windows Media Video). This is yet another Microsoft file format.
World Trade Organization. The successor to GATT, the General Agreement on Tarrifs and Trade. The ostensible goal of the WTO is to reduce or eliminate barriers to free trade between nations such as tariffs. Relevant to the theme of the AVI Overview, WTO and related agreements cover Technical Barriers to Trade (TBT), which include such issues as incompatible technical standards between different nations. European nations and other foreign nations frequently own their national communications businesses, such as telephone and television, and set and mandate technical standards through government or government sponsored organizations. Thus, this is far from an academic issue for companies and organizations seeking to market products and services in Europe and many other nations. Voluntary consensus standards as defined by the WTO related agreements have favored standing under the Agreement on Technical Barriers to Trade. The ISO standards such as MPEG and the ITU standards such as H.261 and H.263 are considered voluntary consensus standards under these agreements. Governments may mandate or encourage the use of such standards. For example, a national government may legally block a company without the ISO 9000 and ISO 9001 quality system standards certification from selling products or servies in their nation.

Under the Uruguay Round agreements that established the WTO, the United States was able to exempt government sponsored research and development of non-commercial working prototypes from treatment as a government subsidy to industry. While the United States has relatively few direct subsidies of companies compared to other nations, many high technology businesses in the United States were built on technologies and non-commercial working prototypes developed with federal funding. The Internet and the Worldwide Web are probably the most prominent example of this currently - with Microsoft licensing the Mosaic Web browser to become Internet Explorer and Netscape hiring several of the Mosaic development team from the federally funded National Center for Supercomputer Applications (NCSA) at the University of Illinois. In the video world, the emerging wavelet technologies were largely developed with federal funding, including the development of working still image prototypes in software.

The color space used in the CCIR-601 digital video specification.
The color space used in the NTSC analog television standard.
The color space used in the PAL analog television standard.
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© 2000 by John F. McGowan, Ph.D.