AviSynth is a frameserver program for Microsoft Windows developed by Ben Rudiak-Gould, Edwin van Eggelen, Klaus Post, Richard Berg, Ian Brabham and others. It is free software under GNU GPL license. Image File history File links Avisynth-logo-gears. ... Software development is the translation of a user need or marketing goal into a software product. ... A software release refers to the creation and availability of a new version of a computer software product. ... January 7 is the seventh day of the year in the Gregorian calendar. ... 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the CE era. ... An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Digital video is a type of video recording system that works by using a digital, rather than analog, representation of the video signal. ... A frameserver is a computer program that acts as a source of video data; use of frameservers allows the user to pass video/audio streams between programs without creating temporary files. ... A software license is a legal agreement which may take the form of a proprietary or gratuitous license as well as a memorandum of contract between a producer and a user of computer software. ... The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely-used free software license, originally written by Richard Stallman for the GNU project. ... A website (or Web site) is a collection of Web pages, images, videos and other digital assets and hosted on a particular domain or subdomain on the World Wide Web. ... A frameserver is a computer program that acts as a source of video data; use of frameservers allows the user to pass video/audio streams between programs without creating temporary files. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Prolific wargame designer and winner of the Charles S. Roberts Lifetime Achievement Award in 1989. ... GPL redirects here. ...

Scripting video editor

AviSynth acts as a non-linear video editor (without a GUI) controlled entirely by scripting. It stands as an intermediary between a digital video source, like an AVI or MPEG, and a VFW receiving program, which is typically a media player, video editing software, or an encoder. A non-linear editing system is a video editing or audio editing system that can perform random access on the source material. ... A graphical user interface (GUI, often pronounced gooey) is a type of user interface which allows people to interact with a computer and computer-controlled devices which employ graphical icons, visual indicators or special graphical elements called widgets, along with text labels or text navigation to represent the information and... This article or section should be merged with script programming language In computer applications, a script, roughly speaking, is a computer program that automates the sort of task that a user might otherwise do interactively at the keyboard. ... Digital video is a type of video recording system that works by using a digital, rather than analog, representation of the video signal. ... AVI, an acronym for Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992, as part of the Video for Windows technology. ... The Moving Picture Experts Group or MPEG is a working group of ISO/IEC charged with the development of video and audio encoding standards. ... Video for Windows was a multimedia technology developed by Microsoft that allowed Microsoft Windows to play digital video. ... Media Player was a media player originally included in Windows 3. ... Video editing software is application software which handles the editing of video sequences on a computer. ... An encoder is a device used to encode a signal (such as a bitstream) or data into a form that is acceptable for transmission or storage. ...

AviSynth communicates with any program that supports AVIs through the video for windows system by acting as a "fake" AVI file. It can apply a large variety of editing and processing functions (called filters) to a video stream before passing along the results as if it were a legitimate file being read. Filter capabilities include trimming, cropping, deinterlacing, inverse telecine, loading and splicing still images, doing colour corrections, denoising, and many other things. AVI, an acronym for Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992, as part of the Video for Windows technology. ... Video for Windows was a multimedia technology developed by Microsoft that allowed Microsoft Windows to play digital video. ... Deinterlacing the process of converting interlaced video (a sequence of fields) into a non-interlaced form (a sequence of frames). ... It has been suggested that multiple sections of 24p be merged into this article or section. ... In common usage, an image (from Latin imago) or picture is an artifact that reproduces the likeness of some subject—usually a physical object or a person. ... In science, and especially in physics and telecommunication, noise is fluctuations in and the addition of external factors to the stream of target information (signal) being received at a detector. ...

Technically, it acts as a codec for AviSynth scripts, which are text files written in the AviSynth scripting language. The scripting language can be extended through the use of plugins. A plugin list is maintained at AviSynth Filter Collection. A codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... A plugin (plug-in, addin, add-in, addon or add-on) is a computer program that interacts with a main (or host) application (a web browser or an email program, for example) to provide a certain, usually very specific, function on demand. ...

AviSynth filters work in several colour spaces including RGB, YUY2 and YV12. This is necessary to allow all kinds of video input and output. Also, certain functions only work on certain colour spaces, making conversion mandatory. A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e. ... The RGB color model utilizes the additive model in which red, green, and blue light are combined in various ways to create other colors. ... Example of U-V color plane, Y value = 0. ... Example of U-V color plane, Y value = 0. ...

For example, say the script "myAvi.avs" (just a plain text-file saved with the extension "avs") contains the following:

 AviSource("myAvi.avi") Crop(0, 0, 320, 240) Blur(0.1) 

This script file can be opened in most media players (such as Windows Media Player). The program will play the video file "myAvi.avi" trimmed down to precisely 320 pixels by 240 pixels and blurred by a small amount. Operations occur in sequential order, so the Cropping occurs first, then the Blurring. Windows Media Player (WMP) is a digital media player and media library application developed by Microsoft that is used for playing audio, video and images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices. ... A pixel (a contraction of picture element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ...

AviSynth Scripting Language

The scripting language is a powerful programming language in its own right, containing many features familiar to programmers, including variables, distinct datatypes, conditionals, and complex expressions. A programming language is an artificial language that can be used to control the behavior of a machine, particularly a computer. ... In computer science and mathematics, a variable (IPA pronunciation: ) (sometimes called a pronumeral) is a symbolic representation denoting a quantity or expression. ... In computer science, a datatype or data type (often simply a type) is a name or label for a set of values and some operations which one can perform on that set of values. ... An expression in a programming language is a combination of values and functions or procedures, interpreted according to the particular rules of precedence and of association for a particular programming language, which computes and then returns another value. ...

The language deals primarily with videos, as a primitive data type. A typical script loads a video as input, applies processing to it, and then "returns" that video in the same way functions return values. The returned video is the output of the script, which is seen as the video by the program running the script.

The language also has several other more standard data types, including int, float, bool and string. These can be used to perform calculations, decisions, and write text such as subtitles to the video.

The processing work is largely done by functions or filters (the two terms are interchangeable). The programmer can pass arguments to one of many built-in functions, and a value may be returned. Also, many functions take a video stream as an argument, and make changes to this stream.

Programmers may be unaware that they are constantly passing video streams into functions, since convention suggests that the video is not explicitly passed. If no video is passed into a function, it simply takes the last video used.

Additional functions/filters are available through plugins. The use of plugins is encouraged to extend the capabilities of AviSynth. (See AviSynth Filter Collection link for a list of plugins). A plugin (plug-in, addin, add-in, addon or add-on) is a computer program that interacts with a main (or host) application (a web browser or an email program, for example) to provide a certain, usually very specific, function on demand. ...

"Hello World"

This example is a "Hello World" program - it simply creates a video containing the words "Hello, world!". A hello world program is a software program that prints out Hello world! on a display device. ...

 BlankClip() Subtitle("Hello, world!") 

The BlankClip function is necessary to create a new video, before having a subtitle displayed on top of it. The brackets at the end of the word are optional, since no arguments are being passed, but are given in this case to indicate it is a function and not a variable.

The Subtitle function draws the words "Hello, world!" on top of the previously-created blank video.

Although the BlankClip and Subtitle functions both accept many more arguments (for example, controlling the size and length of the video, and the positioning, font, and colour of the subtitle), this example leaves them out, so AviSynth simply uses its built-in defaults.

If the above text is entered into a .avs file, it can be opened in Windows Media Player or any of the other programs in the list above, and a video containing the text will be displayed. Windows Media Player (WMP) is a digital media player and media library application developed by Microsoft that is used for playing audio, video and images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices. ...

Video-processing

This example takes an actual video, applies some simple processing, and returns it to the output.

 AviSource("C:Example.avi") ReduceBy2() GreyScale() 

The AviSource function is used to load a video from a real location. The DirectShowSource function could also be used. ReduceBy2 divides the vertical and horizontal size of the video in half, and GreyScale forces the video to greyscale colours. In computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample. ...

Again, the above script can be entered into a .avs file and opened in a video player or editor. Assuming C:Example.avi exists, it will play a copy of that file, except that it will be half the size and greyscale. In computing, a grayscale or greyscale digital image is an image in which the value of each pixel is a single sample. ...

User defined

The AviSynth scripting language allows for users to define their own functions.

This is an example of a function that allows you to dissolve from one clip to another without damaging interlacing lines.

 clip1 = AVISource("video1.avi") clip2 = AVISource("video2.avi") return interlaced_dissolve(clip1,clip2,30) # dissolve from clip1 to clip2 over 30 frames function interlaced_dissolve(clip clip1, clip clip2, int iter) { clip1 = clip1.SeparateFields() evn1 = clip1.SelectEven() odd1 = clip1.SelectOdd() clip2 = clip2.SeparateFields() evn2 = clip2.SelectEven() odd2 = clip2.SelectOdd() evn = Dissolve(evn1,evn2,iter) odd = Dissolve(odd1,odd2,iter) return Interleave(evn,odd).Weave().DoubleWeave.SelectOdd() }  

AviSynth 3.0 code rewrite

AviSynth 3.0 is a complete rewrite of AviSynth 2.5 and is still in development. It aims at overcoming limitations of AviSynth 2.x and editing and processing videos in a non-linear manner. It is being developed to offer more powerful frameserving capabilities through improvements such as an abstracted color space model, in which new colour spaces can be supported through a plug-in mechanism, better cache management for better performance, and a more powerful scripting language. AviSynth 3 will also be available for other operating systems than Windows, and it will rely on gstreamer. Therefore, it will theoretically be compilable on every OS supported by gstreamer, such as Mac OS X or BSDs. A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e. ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... GStreamer is a multimedia framework written in the C programming language with the type system based on GObject. ... Mac OS X (official IPA pronunciation: ) is a line of proprietary, graphical operating systems developed, marketed, and sold by Apple Inc. ... BSD redirects here; for other uses see BSD (disambiguation). ...

AviSynth compatible programs

In addition, several programs have now been created which accept only AviSynth scripts as input - thereby simplifying the program itself but giving users the full power of AviSynth for input. VirtualDub is an open source video capture and linear processing tool for Microsoft Windows. ... VirtualDub is an open source video capture and linear processing tool for Microsoft Windows. ... VirtualDubMod is an open source video capture and linear processing tool for Microsoft Windows. ... VirtualDubMod is an open source video capture and linear processing tool for Microsoft Windows. ... VirtualDubMod is an open source video capture and linear processing tool for Microsoft Windows. ... Windows Media Player (WMP) is a digital media player and media library application developed by Microsoft that is used for playing audio, video and images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices. ... Media Player Classic (MPC) is a compact free software media player for Microsoft Windows. ...

Some examples of this type of program are xvid_encraw - which is a command line encoder for the Xvid codec, and x264, which natively comes as a command line encoder. Both accept YV12 (4:2:0) input, and will produce MPEG-4 / MPEG-4 AVC compliant output. Xvid (formerly XviD) is a video codec library following the MPEG-4 standard. ... x264 is a free software library for encoding H.264/MPEG-4 AVC video streams. ...

There are also several batch encoding applications that tie together AviSynth with command line audio and video encoders and muxers to provide an all in one modular, customizable video encoding application. MeGUI is an example of this kind of application

See also

• List of video editing software

The following is a list of video editing software. ...

External links

• AviSynth home page
• AviSynth Filter Collection
• AviSynth scripting language
• Doom9's AviSynth Forums
• AviSynth 3.0 development homepage
• AviSynth 3 FAQ