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AVI Graphics Format Overview
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From: jfm@rahul.net Newsgroups: rec.video.desktop, comp.graphics.animation, comp.multimedia, comp.os.ms-windows.video Subject: AVI Graphics Format Overview Date: 3 Aug 1999 21:04:10 GMT Message-ID: <7o7lga$269$1@samba.rahul.net> Summary: Answers to many commonly asked questions about AVI files, Video For Windows, and DirectShow (formerly ActiveMovie). This includes how to convert to and from other video formats, playing, editing, and authoring AVI files as well as information on programming. Archive-name: graphics/avi-faq Posting-Frequency: monthly Last-modified: 1999/8/1 Version: 1.276 URL: http://www.rahul.net/jfm/avi.html Copyright: (c) 1996-1999 John F. McGowan, Ph.D. Maintainer: John F. McGowan, Ph.D. <jfm@rahul.net> <HTML> <META NAME="Description" CONTENT="John McGowan's AVI Overview"> <META NAME="Keywords" CONTENT="AVI, Video, Video for Windows, ActiveMovie, DirectShow, NetShow"> <META HTTP-EQUIV="keywords" CONTENT="AVI, Video, Video for Windows, ActiveMovie, DirectShow, NetShow"> <HEAD><TITLE>John McGowan's AVI Overview</TITLE></HEAD> <BODY BGCOLOR="#FFFFFF"> <PRE> AVI Overview by John F. McGowan, Ph.D. (c) 1996-1999, John F. McGowan http://www.rahul.net/jfm/ ---------------------------------------------------------------------------- </PRE> <!-- This document is best viewed using an HTML browser. However, --> <!-- it has been composed with limited use of HTML so that it can --> <!-- be used as a plain text file as well. --> <!-- Release $Id: avi.html,v 1.276 1999/07/22 17:16:26 jfm Exp $ --> <!-- Permission to copy and distribute this document is granted --> <!-- so long as the title, author's name, and URL are retained --> <!-- Any additions or modifications made to the original should be --> <!-- clearly marked as such. --> <!-- The author welcomes and encourages suggested changes and --> <!-- additions to the overview. Contributors will be credited. --> <PRE> <A NAME="Top"> What is in this Overview? </A> - Overview of Video for Windows, DirectShow (ActiveMovie), and AVI <A HREF="#Definition">What is AVI?</A> <A HREF="#Disclaimer">Disclaimer</A> <A HREF="#Get">How to Get the AVI Overview</A> <A HREF="#New">WHAT'S NEW</A> Brief Table of Contents <A HREF="#Common">Most Common AVI Question: What does "could not find vids:xxxx ..." error mean?</A> <A HREF="#Util">UTILITIES, SYSTEM ADMINISTRATION, AUTHORING, ETC.</A> <A HREF="#Install">Installation, Configuration, and Other Issues</A> <A HREF="#AVIAndWEB">AVI and the WORLDWIDE WEB</A> <A HREF="#Codecs">Audio and Video Codecs</A> <A HREF="#Business">Business and Economics of AVI</A> PROGRAMMING/TECHNICAL TOPICS <A HREF="#WinProg">Microsoft Windows Video Programming</A> <A HREF="#MMProg">Multimedia Technical Information</A> <A HREF="#WinDriver">Microsoft Windows Device Drivers</A> <A HREF="#Glossary">Glossary</A> <A HREF="#Chronology">Chronology</A> Detailed Table of Contents <A HREF="#Common">Most Common AVI Question: What does "could not find vids:xxxx ..." error mean?</A> <A NAME="Util">UTILITIES, SYSTEM ADMINISTRATION, AUTHORING, ETC.</A> - <A HREF="#Play">How to play an AVI file?</A> - DOS - Windows - Macintosh - Unix - VAX/VMS - Amiga - OS/2 - How to convert AVI to various audio/video formats. - <A HREF="#ToMPEG">MPEG (.MPG Files)</A> - <A HREF="#ToMOV">QuickTime (.MOV or .MooV)</A> - <A HREF="#ToGIF89a">Animated GIFs (GIF89a)</A> - <A HREF="#ToASF">Microsoft ASF (Active Streaming Format)</A> - <A HREF="#ToSequence">Sequence of Still Images in Separate Files</A> - <A HREF="#ToSmacker">Smacker (.SMK Files)</A> - <A HREF="#ToRM">Progressive Networks RealMedia Streaming Format (.RM Files)</A> - How to convert other audio/video formats to AVI - <A HREF="#FromMOV">QuickTime (.MOV or .MooV)</A> - <A HREF="#FromSequence">Sequence of Still Images in Separate Files</A> - <A HREF="#FromAutodesk">Autodesk Animation (FLI or FLC)</A> - <A HREF="#FromMPEG">MPEG (.MPG)</A> - <A HREF="#FromGIF89a">Animated GIF (.GIF)</A> - <A HREF="#Bitmaps">How to Convert a Sequence of Still Images in One Format to a Sequence in Another Format</A> - Authoring AVI Files CREATING AVI FILES - <A HREF="#ScreenCapture">How to capture screen to AVI files</A> - <A HREF="#AuthorAVI">Multimedia Authoring Tools to Create AVI Files</A> - <A HREF="#LW">How to import AVI files into Lightwave</A> - <A HREF="#Capture">How to create AVI files from analog video (Video Capture Cards)</A> - From VHS tapes and video cameras - From Hi8 tapes and video cameras - <A HREF="#VfWCapture">Video Capture under Video for Windows</A> - <A HREF="#CaptureCards">Video Capture Cards</A> - <A HREF="#ParCapture">Video Capture through PC Parallel Port - <A HREF="#TBC">What to do about horizontal tearing in the video?</A> - <A HREF="#HDCapture">Hard Drive Video Capture Issues</A> - <A HREF="#NTCapture">Video Capture Cards with Windows NT Drivers</A> - <A HREF="#TV">How to create AVI files from Television</A> - <A HREF="#Morph">How to Create Morph Effects for AVI Files</A> - <A HREF="#Audio">How to compress the audio sound track in AVI files</A> MODIFYING AND EDITING AVI FILES - <A HREF="#FPS">How to change frame rate of AVI files</A> - <A HREF="#Crop">How to crop an AVI file</A> - <A HREF="#Edit">How to edit AVI files</A> - VidEdit - Personal AVI Editor - MGI VideoWave - Corel Lumiere Suite for 32-bit Windows - Ulead Media Studio Pro - Adobe Premiere - in:sync SpeedRazor - Asymetrix Digital Video Producer (DVP) - Fast Movie Processor - Peck's Power Join - <A HREF="#Audio">How to compress the audio sound track in AVI files</A> - <A HREF="#ToNTSC">How to create NTSC (or PAL) Safe AVI</A> - <A HREF="#Phantom">The Phantom Final Frame when Viewing an AVI</A> - <A HREF="#BinEd">Binary File Editors for Viewing and Editing AVI</A> - <A HREF="#VidTrace">RIFF and AVI Parser/Viewers</A> - John McGowan's VidTrace - Microsoft RIFFWALK - Bill Luken's RIFFSCAN - <A HREF="#Wave">Editing and converting WAV files</A> - <A HREF="#MacSound">Editing and converting Sound Files on Macintosh</A> MISCELLANEOUS AUTHORING QUESTIONS - <A HREF="#Output">How to output AVI files to videotape</A> - <A HREF="#Size">Size limits on AVI files</A> - <A HREF="#Corel">How to Fix Problem with AVI files from CorelMove 4.0</A> <A NAME="Install">Installation, Configuration, and Other Issues</A> INSTALLATION AND CONFIGURATION - <A HREF="#VfW16">Where to get the 16-bit Video for Windows for Windows 3.x</A> - <A HREF="#Win95">Reinstalling Microsoft's Video-for-Windows in Windows 95</A> - <A HREF="#GETAM">How to get ActiveMovie 1.0</A> - <A HREF="#NT40">Installing and configuring AVI Codecs in Windows NT 4.0</A> - <A HREF="#Extension">How to give AVI files a different extension in Windows 3.1</A> - <A HREF="#AVI95">How AVI Files are Handled in Windows 95</A> INFORMATION SOURCES - <A HREF="#Biblio">Bibliography of sources of information on Video for Windows and AVI</A> - <A HREF="#News">Internet Newsgroups with Information on AVI and Video </A> - <A HREF="#VideoStandards">Where to find information on digital audio and video standards other than AVI. MISCELLANEOUS QUESTIONS - <A HREF="#VideoChips">PC Video Card and Video Chips</A> - <A HREF="#NTVideo">Video Cards with Windows NT Drivers</A> - <A HREF="#Word">How to embed an AVI file in a Microsoft Word Document</A> - <A HREF="#Names">Microsoft's Changing Names</A> - <A HREF="#Misc">Answers to miscellaneous other frequently asked questions about AVI </A> - <A HREF="#Health"> AVI and Your Health (Eye Strain)</A> <A NAME="AVIAndWEB">AVI and the WORLDWIDE WEB</A> - <A HREF="#Style">Effective use of video on a Web page</A> - <A HREF="#Web">How to embed an AVI file in a Web page</A> - <A HREF="#NS">Configuring Netscape Navigator 3.0x to Display AVI Files</A> - <A HREF="#Plug-ins">Netscape Navigator Plug-ins to play AVI</A> - <A HREF="#IE">Configuring Internet Explorer 3.0x to Display AVI Files</A> - <A HREF="#Mail">Sending AVI by E-Mail or Network News Postings</A> - <A HREF="#Crypto">How to encrypt AVI Files</A> - <A HREF="#MIME">MIME types of AVI</A> - <A HREF="#HTTPD">Configuring Web Servers to Handle AVI Files</A> - Apache - CERN (or W3C) - NCSA HTTPd - Microsoft Internet Information Server 3.0 - Netscape Enterprise Server 3.0 - <A HREF="#Java">AVI and Java</A> - <A HREF="#VRML">AVI and VRML</A> - <A HREF="#NetShow">AVI and NetShow</A> - <A HREF="#ToASF">Converting AVI to Microsoft Active Streaming Format (ASF) Files</A> - <A HREF="#Content">Sources of AVI Video Clips on the Web</A> - <A HREF="#AVILBR">Low Bit Rate AVI for the Web</A> REAL-TIME OR STREAMING VIDEO OVER IP NETWORKS - <A HREF="#Limits">Limitations of AVI and Video for Windows over Networks</A> - <A HREF="#NetShow">NetShow</A> - <A HREF="#Names">Microsoft's Changing Names</A> - <A HREF="#RFC">Internet Video Standards and Pseudo-Standards</A> <A NAME="Codecs">AUDIO and VIDEO CODECS</A> - <A HREF="#Codec">Video for Windows compressors and decompressors</A> WHAT THEY ARE, WHERE TO GET THEM, WHICH WORK BEST! - The Old Guard - <A HREF="#DIB">Full Frames (Uncompressed)</A> - <A HREF="#ColorFormats">Color Formats</A> - <A HREF="#RT21">Intel Real Time Video 2.1 (Indeo 2.1?) (RT21)</A> - <A HREF="#IV32">Indeo 3.2/3.1</A> - <A HREF="#MRLE">Microsoft Run Length Encoding</A> - <A HREF="#MSVC">Microsoft Video 1</A> - <A HREF="#CVID">Cinepak</A> - <A HREF="#MJPG">Motion JPEG</A> - <A HREF="#XMPG">Editable MPEG</A> - The New Wave - <A HREF="#VDOW">VDOWave (VDOLive)</A> - <A HREF="#IV41">Indeo Video Interactive (Indeo 4.1)</A> - <A HREF="#IV50">Indeo Video Interactive (Indeo 5.x)</A> - <A HREF="#UCOD">ClearVideo (aka RealVideo)</A> - <A HREF="#SFMC">SFM (Surface Fitting Method)</A> - <A HREF="#QPEG">QPEG</A> - <A HREF="#H261">H.261</A> - <A HREF="#H263">H.263</A> - Microsoft H.263 - Vivo Software H.263 - Intel I263 H.263 - Shannon Communication Systems (SCS) H.263+ - Telenor R&D H.263 - <A HREF="#MPG4">MPEG-4</A> - <A HREF="#LS">Lightning Strike (Infinop)</A> - <A HREF="#VxTreme">VxTreme</A> Video Codecs NOT Available for AVI - <A HREF="#Sorenson">Sorenson Video</A> - <A HREF="#BestCodec">Which AVI video codec is best?</A> - <A HREF="#CodecPerformance">Performance of the AVI Codecs</A> A table with typical compression ratios of Video for Windows codecs. - <A HREF="#QTCodec">Which Video for Windows codecs are supported by QuickTime on the Apple Macintosh?</A> - <A HREF="#VfWInstalled">How to determine which codecs are installed</A> - <A HREF="#WhichAVICodec">How to determine which codec was used to compress an AVI file</A> - <A HREF="#FourCC">Microsoft Four Character Codes (FOURCC)</A> - <A HREF="#FOURCCGUID">Microsoft GUIDs for Video for Windows Codecs</A> - <A HREF="#ColorFormats">Color Formats</A> - <A HREF="#ALGO">Video Compression Technologies</A> <A HREF="#RLE">Run Length Encoding</A> <A HREF="#VQ">Vector Quantization</A> <A HREF="#DCT">Discrete Cosine Transform</A> <A HREF="#DWT">Discrete Wavelet Transform</A> <A HREF="#Contour">Contour-Based Image Coding</A> <A HREF="#FD">Frame Differencing</A> <A HREF="#Motion">Motion Compensation</A> - <A HREF="#ACM">Audio Codecs</A> - <A HREF="#ACMInstalled">How to determine which Audio Codecs are Installed</A> <A HREF="#Glossary">GLOSSARY</A> <A HREF="#Chronology">CHRONOLOGY</A> PROGRAMMING/TECHNICAL TOPICS <A NAME="WinProg">MICROSOFT WINDOWS PROGRAMMING </A> THE OLD REGIME - <A HREF="#WINMM">Windows Multimedia System</A> - <A HREF="#VFW">Video for Windows</A> - <A HREF="#WAVE">Wave (Waveform Audio)</A> - <A HREF="#Format">AVI file format</A> - RIFF Files - Original AVI File Format - <A HREF="#OpenDML">OpenDML AVI File Format Extensions</A> - <A HREF="#AVISpec">Where to get the exact specification of AVI?</A> - <A HREF="#AVIDIB">AVI and Windows Bitmaps (DDB, DIB, ...)</A> THE NEW WAVE - <A HREF="#ActiveMovie">ActiveMovie</A> - <A HREF="#GUID">GUID's and AVI</A> - <A HREF="#DirectShow">DirectShow (ActiveMovie 2.0)</A> - <A HREF="#DirectDraw">DirectDraw</A> - <A HREF="#MMX">MMX</A> - <A HREF="#ActiveX">ActiveX</A> - <A HREF="#Names">Microsoft's Changing Names</A> HOW TO PROGRAM IN WINDOWS - <A HREF="#AviPlay">Playing an AVI file within a Windows Application</A> - <A HREF="#AviWrite">Reading and Writing an AVI file within a Windows Application</A> <A NAME="MMProg">USEFUL INFORMATION FOR AVI AND VIDEO PROGRAMMING (NOT WINDOWS)</A> SOURCE CODE - <A HREF="#AVISRC">Where to get C source code for an AVI Player Including Many Codecs</A> - <A HREF="#JPEGSRC">Where to get C source code for a JPEG Encoder or Decoder</A> - <A HREF="#H263SRC">Where to get C source code for an H.263 Video Encoder or Decoder</A> - <A HREF="#MPEGSRC">Where to get C source code for an MPEG Video Encoder or Decoder</A> - <A HREF="#WAVELETSRC">Where to get C/C++ Source Code for Wavelet Image Compression</A> TECHNICAL INFORMATION - <A HREF="#COLORFAQ">Where to get an explanation of Color, Color Spaces, Gamma and All That</A> - <A HREF="#FileFormats">Where to get Detailed Information on Graphics File Formats?</A> - <A HREF="#AudioFmts">Where to get Detailed Information on Audio File Formats?</A> USEFUL INFORMATION FOR NETWORKED VIDEO PROGRAMMING - <A HREF="#RFC">Internet Video Standards</A> - MIME - RTP (Real Time Protocol) - RSVP (Resource Reservation Protocol) - IP Multicast - UDP (User Datagram Protocol) <A NAME="WinDriver">WINDOWS DEVICE DRIVERS AND VIDEO</A> - <A HREF="#Driver">What is a driver?</A> - <A HREF="#GDI">GDI Device Drivers</A> - <A HREF="#DHAL">DirectDraw Hardware Abstraction Layer</A> - <A HREF="#VXD">Virtual Device Drivers</A> - <A HREF="#NTDM">Windows NT Driver Model</A> - <A HREF="#WDM">Win32 Driver Model (WDM)</A> - <A HREF="#INF">Setup Information Files</A> <A HREF="#Awards">Awards</A> <A HREF="#Credits">Credits</A> ABOUT THE AUTHOR - John McGowan is a software engineer with experience in digital audio and video on PC/Windows, Unix/X Windows, and PowerMacintosh platforms. He has developed commercial MPEG-1 and MPEG-2 player software. His experience includes development, optimization, and implementation of audio, video, and still image compression and decompression algorithms in C/C++ on Intel, MIPS, SPARC, and PowerPC based platforms. He has also developed Microsoft Windows user interface software. He has a Ph.D. in physics from the University of Illinois at Urbana-Champaign and a B.S. in physics from the California Institute of Technology. - <A HREF="http://www.rahul.net/jfm/index.html">John McGowan's Home Page</A> <A NAME="Disclaimer"> <H2>Disclaimer</H2> In no event shall John McGowan or other contributors be liable for direct, indirect, special, incidental or consequential damages arising out of the use or inability to use information, softwares, bitstreams and other data found on or referenced by the AVI Graphics Overview. Permission to copy and distribute this document is granted so long as the title, author's name, URL, and this disclaimer are retained. Any additions or modifications made to the original should be clearly marked as such. The author welcomes and encourages suggested changes and additions to the overview. Contributors will be credited. <A HREF="#Top">Return to Top</A> <A NAME="Get"> <H2>How to Get the AVI Overview</H2> </A> The AVI Overview is available at: <A HREF="http://www.rahul.net/jfm/avi.html">http://www.rahul.net/jfm/avi.html</A> If you are in a Web Browser such as Internet Explorer or Netscape Navigator, you can save a copy of the page you are viewing to your local hard disk as an HTML File. In Internet Explorer, Select File | Save As... In Netscape Navigator, Select File | Save As... Using FTP (File Transfer Protocol): <A HREF="ftp://ftp.rahul.net/pub/jfm/avi/>ftp://ftp.rahul.net/pub/jfm/avi/avi.html</A> <A HREF="#Top">Return to Top</A> <A NAME="New"> <H2>What's New</H2> </A> (May 11, 1999) Aachen, Germany MainConcept releases Linux verson of Main Actor Video Editor. Linux is a free imlementation of the Unix operating system for the IBM PC-compatible and other platforms. (April 15, 1999) Aachen, Germany MainConcept releases Main Actove Video Editor 3.0 for Microsoft Windows 95/98 and Microsoft Windows NT 4.0. (April 13, 1999) RealNetworks acquires Xing Technology Corporation. (March 21, 1999) XAnim 2.80.1 released on March 21, 1999. XAnim is a video and animation player for the X Windows System and Unix. It includes support for AVI files. XAnim 2.80.1 contains some minor changes to XAnim 2.80.0 which was released on March 14, 1999. (March 14, 1999) XAnim 2.80.0 released on March 14, 1999. XAnim is a video and animation player for the X Windows System and Unix. It includes support for AVI files. According to the XAnim Web site: XAnim 2.80.0 is now ready for consumption. In addition to several new video codecs, the new revision also supports dynamically loadable video decompression libraries. This means you no longer need to recompile xanim each time a new video codec is released or upgraded. There are currently dll's for: Creative CYUV, Radius Cinepak, Intel Indeo 3.2, Intel Indeo 4.1, Intel Indeo 5.0, CCITT H.261 and CCITT H.263. (Feb. 2, 1999) Intel Indeo 5.10 video codec released, supersedes 5.06. (November 5, 1998) Guillaume de Bailliencourt writes: John, I'm an anonymous reader of your FAQ for years. First, congratulation for your work in this FAQ ! I've just released a software MJPEG codec and main features are : Decompress hardware M-JPEG AVI files (Rainbow Runner, DC30, ...) without the capture hardware. Win9x, WinNT, Video for Windows, ActiveMovie & DirectShow compliant. MMX and 3DNow! optimized. DirectDraw YUV accelarated output supported (YUY2 & UYVY). Most of the M-JPEG formats supported (4:2:2, 4:1:1, mjpg, dmb1, jpeg). You can download it at www.morgan-multimedia.com For me it is better than the Paradigm Matrix codec. I'll send you benchmark ... For the moment it has been tested on : Play back (decompression) : Paradigm Matrix software codec compressed AVI Files in every resolutions & compressions. Matrox Rainbow Runner AVI files in every resolutions & compressions. Miro/Pinnacle DC30 AVI files in 384 x 288 & 720x540 Fast Screen Machine II + MJPEG card AVI file in 368 x 276 AVI files created with MainActor "Software & Harware MJPEG output" AVI file converted from a 'jpeg' QuickTime file with SmartVid Compressed with my codec & played back with : Paradigm Matrix software codec Matrox Rainbow Runner Best regards, Guillaume de Bailliencourt (January 6, 1999) Radius Incorporated, the Cinepak company, renames itself Digital Origin Incorporated. (August 24, 1998) jim@shansys.com writes: Hi there, We have an H263+ avi codec and analysis tool at www.shansys.com (August 3, 1998) David Gartner of Equilibrium writes: Equilibrium adds AVI with sound support to DeBabelizer Pro 4.5 ... **AVI Video with Sound** DeBabelizer Pro 4.5's new full AVI support enables users to batch process legacy Video for Windows files for use on most any Macintosh and Windows systems for the Web, CD-ROM or kiosk. Video for Windows (AVI) was built into Windows 95 and NT and runs only on Windows machines. Now, with a few keystrokes, DeBabelizer Pro 4.5 users can automatically optimize, convert, and compress tens, hundreds or thousands of videos to QuickTime 3.0, animated GIFs or a variety of other cross-platform video and animation formats. ... (June 6, 1998) Wolfgang Hesseler writes: Hello, Hello, I just wanted to let you know that I've released the new QuickView 2.30. It now supports a bunch of new video codecs like Motion JPEG, several audio codecs and QuickTime video codecs. Please update your FAQ. Thanks. (May 4, 1998) Microsoft plans to release first public test version of NetShow 3.0 (March 23, 1998) The AVI Overview selected as an 'Outstanding Page' by the PC Webopaedia (November 12, 1997) Microsoft has a new NetShow distribution NetShow 2.1 NetShow 2.1 adds support for RealNetworks (formerly Progressive Networks) RealVideo and RealAudio, NetShow clients for Windows 3.1, MacOS, and the Linux, Solaris, SunOS, and HP-UX versions of Unix, and TheaterServer for streaming broadcast-quality video over highbandwidth networks such as ATM and fast Ethernet. Microsoft has invested in RealNetworks within the last few months. (October 30, 1997) Wolfgang Hesseler writes about his AVI viewer for DOS: Hello, I just wanted to let you know that I've released the new QuickView 2.20. Besides supporting more hardware and MOV files it supports the QPEG codec. Please update your FAQ. Thanks. (September 8, 1997) Microsoft distributes Advanced Streaming Format (ASF) Specification for a "Public Design Review". <A HREF="http://www.microsoft.com/asf/">Microsoft ASF Page</A> (September, 1997) Lernout and Hauspie Speech Products forms a strategic partnership with and receives investment capital from Microsoft. $45 million in some reports. BT Alex Brown acted as financial advisor. Lernout and Hauspie audio codecs are used in Microsoft's NetShow product. (September, 1997) avi2mpg1 released. A Windows 95/NT console application to convert AVI to MPEG-1. (August 5, 1997) Microsoft acquires VxTreme (wavelet based streaming video) for its NetShow product line. <A HREF="http://www.vxtreme.com/">VxTreme Inc.</A> Intel's Indeo Video Interactive 5.0 software is now available on Intel Web site. Wolfgang Hesseler announces version 2.13 of QuickView, an AVI player for DOS (July 28, 1997) MainConcept announces version 1.1 of MainActor shareware. MainActor can convert between AVI and many video, animation, and image formats. (July 9, 1997) Marcus Moenig of MainConcept writes: John, well here comes the press release of v1.1 We now support full MPEG-I and MPEG-II without audio. So you can now convert MPEG into AVI and vice versa. I dont want to get on your nerves on what MainActor can and cannot do but we also support full Motion JPEG for AVIs. Even interlaced JPEG from Miro and FAST hardware can now be read and written by MainActor. ---End--- RAD Game Tools announces a new version of their Smacker utilities, including the ability to read and write AVI files with optimized 8 bit color palettes. (June 27, 1997) <A HREF="#Top">Return to Top</A> <A NAME="Definition"> <H2>What is AVI?</H2> </A> AVI stands for Audio Video Interleave. It is a special case of the RIFF (Resource Interchange File Format). AVI is defined by Microsoft. AVI is the most common format for audio/video data on the PC. AVI is an example of a de facto (by fact) standard. <A HREF="#Top">Return to Top</A> <A NAME="WINMM"> <H2>Windows Multimedia System</H2> </A> In Win16 and Win32, Microsoft created a partially unified system for handling multimedia. This system consists of the high level Media Control Interface or MCI Application Programming Interface (API) and associated MCI drivers. Playback of AVI files can be controlled through the high level MCI API and the MCIAVI.DRV MCI driver. The Windows Multimedia System also provides a number of low level API's such as the WAVE API for waveform audio and associated device drivers such as the WAVE device drivers for sound cards. Under Windows NT 4.0, the MCI and low level API's are stored in the file WINMM.DLL The API's are: MCI (high level API - useful for AVI playback) joy (joystick devices) midi (MIDI devices) mixer (MIXER devices) wave (waveform audio input and output devices) mmio (low level functions to parse RIFF files) time (timers etc.) aux (auxiliary sound device) When a program loads the MCIAVI driver, the Multimedia System has the intelligence to locate and invoke the appropriate MCI driver (MCIAVI.DRV in 16-bit Windows or MCIAVI32.DLL in 32 bit windows) and pass the MCI commands such as MCI_PLAY to the MCI driver. The MCIAVI driver then calls Video for Windows to decompress the video, GDI (or another graphics API) to display the decoded frames, and WAVE to output the decoded audio samples. A dump of the functions exported by winmm.dll under NT 4.0 generated with the Microsoft DUMPBIN.EXE utility follows: Microsoft (R) COFF Binary File Dumper Version 5.00.7022 Copyright (C) Microsoft Corp 1992-1997. All rights reserved. Dump of file winmm.dll File Type: DLL Section contains the following Exports for WINMM.dll 0 characteristics 31EC70B4 time date stamp Tue Jul 16 21:48:52 1996 0.00 version 2 ordinal base 197 number of functions 197 number of names ordinal hint name 3 0 CloseDriver (000026CE) 4 1 DefDriverProc (00005AF4) 5 2 DriverCallback (0000254E) 6 3 DrvGetModuleHandle (00001D37) 7 4 GetDriverModuleHandle (00001D37) 8 5 MigrateAllDrivers (00013E79) 9 6 MigrateMidiUser (00013E60) 10 7 MigrateSoundEvents (00011A3C) 11 8 NotifyCallbackData (0000B2C2) 12 9 OpenDriver (00002036) 13 A PlaySound (00008ACB) 2 B PlaySoundA (00008ACB) 14 C PlaySoundW (00009AE1) 15 D SendDriverMessage (00001000) 16 E WOW32DriverCallback (0000C448) 17 F WOW32ResolveMultiMediaHandle (0000CC3C) 18 10 WOWAppExit (00009D3F) 19 11 aux32Message (0000C507) 20 12 auxGetDevCapsA (0000A3FD) 21 13 auxGetDevCapsW (00008C77) 22 14 auxGetNumDevs (00006AE4) 23 15 auxGetVolume (0000A4A1) 24 16 auxOutMessage (00008BFF) 25 17 auxSetVolume (0000A4C9) 26 18 joy32Message (0000C768) 27 19 joyConfigChanged (0000AE40) 28 1A joyGetDevCapsA (0000A99A) 29 1B joyGetDevCapsW (0000AB40) 30 1C joyGetNumDevs (0000AB96) 31 1D joyGetPos (0000ABAA) 32 1E joyGetPosEx (0000ABFD) 33 1F joyGetThreshold (0000AC5C) 34 20 joyReleaseCapture (0000ACA8) 35 21 joySetCapture (0000ACFC) 36 22 joySetThreshold (0000AE06) 37 23 mci32Message (00007566) 38 24 mciDriverNotify (00007006) 39 25 mciDriverYield (00008727) 40 26 mciExecute (0000D92C) 41 27 mciFreeCommandResource (000035CE) 42 28 mciGetCreatorTask (0000DCD5) 43 29 mciGetDeviceIDA (0000DCA3) 44 2A mciGetDeviceIDFromElementIDA (0000DBC6) 45 2B mciGetDeviceIDFromElementIDW (0000DBF5) 46 2C mciGetDeviceIDW (00005372) 47 2D mciGetDriverData (0000158B) 48 2E mciGetErrorStringA (0000DA46) 49 2F mciGetErrorStringW (0000352F) 50 30 mciGetYieldProc (0000E1F3) 51 31 mciLoadCommandResource (00002A75) 52 32 mciSendCommandA (000015D4) 53 33 mciSendCommandW (000014A1) 54 34 mciSendStringA (00004927) 55 35 mciSendStringW (00004A24) 56 36 mciSetDriverData (000058BD) 57 37 mciSetYieldProc (000034C9) 58 38 mid32Message (0000BDFD) 59 39 midiConnect (0001019E) 60 3A midiDisconnect (0001018C) 61 3B midiInAddBuffer (0001004A) 62 3C midiInClose (0000FF42) 63 3D midiInGetDevCapsA (0000FCCC) 64 3E midiInGetDevCapsW (0000FC71) 65 3F midiInGetErrorTextA (0000FDEB) 66 40 midiInGetErrorTextW (0000FDB2) SetInfo (0000EBF4) 140 8A mmioStringToFOURCCA (0000ED9A) (00008BC5) Under Windows 3.x and Windows 95, the DLL MMSYSTEM.DLL (short for MultiMedia System) contains the multimedia API's. <A HREF="#Top">Return to Top</A> <A NAME="VFW"> <H2>Video for Windows</H2> </A> Video for Windows is an entire system for handling video in Microsoft Windows. It was part of MS Windows 3.1 The original Video for Windows is a collection of 16 bit windows utilities, dynamic link libraries, and other components. The AVI file and file format is a central part of Video for Windows. Microsoft Visual C++ 5.0 has a Video for Windows include file Vfw.h which contains the various API's that make up Video for Windows: * COMPMAN - Installable Compression Manager. * DRAWDIB - Routines for drawing to the display. * VIDEO - Video Capture Driver Interface * * AVIFMT - AVI File Format structure definitions. * MMREG - FOURCC and other things * * AVIFile - Interface for reading AVI Files and AVI Streams * MCIWND - MCI/AVI window class * AVICAP - AVI Capture Window class * * MSACM - Audio compression manager. Microsoft released a Video for Windows 1.0 for Windows 3.1 in November 1992, followed by Video for Windows 1.1. There have been several versions of Video for Windows 1.1 identified by a trailing alphabetical character such as 1.1e The last and most recent version of Video for Windows 1.1 for Windows 3.x is Video for Windows 1.1e This is available by ftp from Microsoft. Microsoft has provided a 32-bit version of Video for Windows for Windows 95, while threatening to replace Video for Windows with ActiveMovie. This version has 32 bit versions of the Video for Windows codecs such as Cinepak. Other DLL's in the Video for Windows 95 are also 32-bit How much of the Video for Windows in Windows 95 is 32 bit code is not clear; many of the codecs are clearly 32 bit codecs. Nor is it clear how much has been changed or modified besides the convesion to 32-bit code. Windows NT 3.5, 3.51 and Windows NT 4.0 include a Video for Windows for NT. Presumably this is strictly 32-bit. It is not clear how much code is shared between the NT Video for Windows and the Windows 95 Video for Windows. Note that hardware device drivers are different between Windows 95 and NT 3.5/3.51/4.0. ActiveMovie 1.0 and DirectShow (formerly ActiveMovie 2.0) are 32-bit successors to Video for Windows for both Windows 95 and Windows NT. These support AVI files. ActiveMovie started out life under the code name Quartz; early Beta releases of ActiveMovie were known as Quartz. ActiveMovie 1.0 is bundled with Windows 95b (OEM Service Release 2.x) and Internet Explorer 3.x/4.x for Windows 95. It can also be downloaded and installed in Windows 95 separately. Note that ActiveMovie 1.0 does NOT completely replace Video for Windows. For example, ActiveMovie 1.0 does not provide a video capture mechanism. Video capture still uses Video for Windows capture drivers. ActiveMovie 1.0 is a 32 bit software component that can run in NT's user mode. It runs under Windows NT 4.0 as well as Windows 95. DirectShow (ActiveMovie 2.0) will supposedly add a number of new features including video capture support, kernel mode streaming, and miscellaneous other features. VIDEO FOR WINDOWS under WINDOWS NT 4.0 Under NT 4.0, Video for Windows is implemented as a collection of 32-bit DLL's in the Microsoft 32-bit Common Object File Format or COFF format. These are usually located in the \WINNT\SYSTEM32 directory where Windows NT stores most of the system DLL's, drivers, and so forth. MSVFW32.DLL ( Microsoft Video for Windows DLL - NT 4.0 ) AVIFIL32.DLL ( AVIFILE API for Reading and Writing AVI Files and Streams ) AVICAP32.DLL ( AVI Capture Window Class ) MCIAVI32.DLL ( Video for Windows MCI Driver ) MSACM32.DRV ( Microsoft Audio Compression Manager ) MSACM32.DLL ( more Microsoft Audio Compression Manager ) MSRLE32.DLL ( Microsoft RLE Video Codec ) IR32_32.DLL ( Intel Indeo 3.2 Video Codec ) MSVIDC32.DLL ( Microsoft Video 1 Codec ) ICCVID.DLL ( Cinepak for Windows 32 - Radius ) What is in MSVFW32.DLL? MSVFW32.DLL includes the DRAWDIB, Installable Compression Manager or ICM, and MCI Windows components of Video for Windows. Other components are stored in other DLL's. This is a dump of the functions exported by MSVFW32.DLL Version 4.00 Microsoft (R) COFF Binary File Dumper Version 5.00.7022 Copyright (C) Microsoft Corp 1992-1997. All rights reserved. Dump of file msvfw32.dll File Type: DLL Section contains the following Exports for MSVFW32.dll 0 characteristics 31EC70E9 time date stamp Tue Jul 16 21:49:45 1996 0.00 version 2 ordinal base 47 number of functions 47 number of names ordinal hint name 3 0 DrawDibBegin (00001E14) 4 1 DrawDibChangePalette (00008C30) 5 2 DrawDibClose (0000888A) 6 3 DrawDibDraw (000010A6) 7 4 DrawDibEnd (00008BEC) 8 5 DrawDibGetBuffer (00008EFC) 9 6 DrawDibGetPalette (00002F97) 10 7 DrawDibOpen (00003E0A) 11 8 DrawDibProfileDisplay (00003EBA) 12 9 DrawDibRealize (00001D49) 13 A DrawDibSetPalette (00001C0D) 14 B DrawDibStart (00002EEB) 15 C DrawDibStop (00002F42) 16 D DrawDibTime (00008C2B) 17 E GetOpenFileNamePreview (0000C7DC) 18 F GetOpenFileNamePreviewA (0000C7DC) 19 10 GetOpenFileNamePreviewW (0000C6A5) 20 11 GetSaveFileNamePreviewA (0000C7EC) 21 12 GetSaveFileNamePreviewW (0000C7CC) 22 13 ICClose (000035E0) 23 14 ICCompress (00004CE5) 24 15 ICCompressorChoose (00005F61) 25 16 ICCompressorFree (00005615) 26 17 ICDecompress (00004D4B) 27 18 ICDraw (0000106A) 28 19 ICDrawBegin (00001B95) 29 1A ICGetDisplayFormat (00004D8E) 30 1B ICGetInfo (00004C60) 31 1C ICImageCompress (00005A96) 32 1D ICImageDecompress (00005D2A) 33 1E ICInfo (00002FEB) 34 1F ICInstall (00004574) 35 20 ICLocate (0000372E) 36 21 ICMThunk32 (0000841C) 37 22 ICOpen (0000337C) 38 23 ICOpenFunction (00003B53) 39 24 ICRemove (0000488B) 40 25 ICSendMessage (00001000) 41 26 ICSeqCompressFrame (000059A7) 42 27 ICSeqCompressFrameEnd (00005907) 43 28 ICSeqCompressFrameStart (000056E4) 44 29 MCIWndCreate (0000C988) 45 2A MCIWndCreateA (0000C988) 46 2B MCIWndCreateW (0000C8CC) 47 2C MCIWndRegisterClass (0000C83F) 48 2D StretchDIB (00009D13) 2 2E VideoForWindowsVersion (000041D1) Summary 8000 .data 3000 .rdata 2000 .reloc 3000 .rsrc 11000 .text VIDEO FOR WINDOWS FOR WINDOWS 95 Microsoft distributed a new Video for Windows for Windows 95 while emphasizing Quartz/ActiveMovie/DirectShow in its marketing. Video for Windows 95 Files MSRLE32.DLL (32-bit Microsoft RLE Video Codec) IR32_32.DLL (32-bit Indeo 3.2 Video Codec) ICCVID.DLL (32-bit Radius Cinepak Video Codec) MSVIDC32.DLL (32-bit Microsoft Video 1 Video Codec ) MSVIDEO.DLL (16-bit Video for Windows DLL) MCIAVI.DRV (16-bit AVI Video MCI Driver) AVIFILE.DLL (16-bit AVIFILE) AVICAP.DLL (16-bit AVICAP) AVICAP32.DLL (32-bit AVICAP) MSVFW32.DLL (32-bit Video for Windows DLL - with VfW API) AVIFIL32.DLL (32-bit AVIFILE) SUMMARY Video for Windows 1.0 (Windows 3.x) Video for Windows 1.1 (a-e) (Windows 3.x) Video for Windows (Windows 95 - has 32-bit codecs and other 32-bit DLL's) Video for Windows (Windows NT 3.5, 3.51, and 4.0) Quartz (Betas of ActiveMovie) (Windows 95) ActiveMovie 1.0 (Windows 95 and NT 4.0) ActiveMovie 2.0 (DirectShow) (probably Windows 97/98/Memphis and NT 5.0) <A HREF="#Top">Return to Top</A> <A NAME="WAVE"> <H2>WAVE</H2> </A> The Microsoft Windows audio (sound) input/output system, commonly referred to as Wave or WAVE, predates Video for Windows, which is wrapped around WAVE in various ways. The audio tracks in AVI files are simply waveform audio (or WAV) data used by the wave system. Video for Windows parses the AVI files, extracts the WAV data, and pipes the WAV data to the WAVE system. Video for Windows handles the video track if present. Traditionally, audio input and output devices such as Sound Blaster Cards have a WAVE audio input/output driver to play WAV (waveform audio) files. The simplest waveform audio files consists of a header followed by Pulse Coded Modulation (PCM) sound data, usually uncompressed 8 or 16 bit sound samples. WAVE also provides a mechanism for audio codecs. See elsewhere in the AVI Overview for further information on audio codecs and audio compression. WAVE is present in Windows 3.1 and Windows 95. A different WAVE system is present in Windows NT 3.5, 3.51, and 4.0 At least the hardware device drivers for sound cards must be different in NT. ActiveMovie appears to be replacing WAVE. <A HREF="#Top">Return to Top</A> <A NAME="Format"> <H2>What is the AVI File Format?</H2> </A> AVI Files are a special case of RIFF files. RIFF is the Resource Interchange File Format. This is a general purpose format for exchanging multimedia data types that was defined by Microsoft and IBM during their long forgotten alliance. Kevin McKinnon writes: In fact, RIFF is a clone of the IFF format invented by Electronic Arts in 1984. They invented the format for Deluxe Paint on the Amiga, and IFF quickly became the standard for interchange on that platform, maintained eventually by Commodore right up 'til it's demise. EA also ported Deluxe Paint to the PC platform and brought IFF with it. IFF even used the 4-character headers (FourCC), though at the time it was simply called a LONGWORD that some clever people decided to pair into four charcter because they looked good in #define's. ;) RIFF is so close to IFF that the good IFF parser routines will (mostly) correctly parse RIFF files. ----End of Kevin---- Further information on the IFF format is available at: <A HREF="http://www.ipahome.com/gff/textonly/summary/iff.htm">http://www.ipahome.com/gff/textonly/summary/iff.htm</A> <H3>RIFF Files</H3> RIFF files are built from (1) RIFF Form Header 'RIFF' (4 byte file size) 'xxxx' (data) where 'xxxx' identifies the specialization (or form) of RIFF. 'AVI ' for AVI files. where the data is the rest of the file. The data is comprised of chunks and lists. Chunks and lists are defined immediately below. (2) A Chunk (4 byte identifier) (4 byte chunk size) (data) The 4 byte identifier is a human readable sequence of four characters such as 'JUNK' or 'idx1' (3) A List 'LIST' (4 byte list size) (4 byte list identifier) (data) where the 4 byte identifier is a human readable sequence of four characters such as 'rec ' or 'movi' where the data is comprised of LISTS or CHUNKS. <H3>AVI File Format</H3> AVI is a specialization or "form" of RIFF, described below: 'RIFF' (4 byte file length) 'AVI ' // file header (a RIFF form) 'LIST' (4 byte list length) 'hdrl' // list of headers for AVI file The 'hdrl' list contains: 'avih' (4 byte chunk size) (data) // the AVI header (a chunk) 'strl' lists of stream headers for each stream (audio, video, etc.) in the AVI file. An AVI file can contain zero or one video stream and zero, one, or many audio streams. For an AVI file with one video and one audio stream: 'LIST' (4 byte list length) 'strl' // video stream list (a list) The video 'strl' list contains: 'strh' (4 byte chunk size) (data) // video stream header (a chunk) 'strf' (4 byte chunk size) (data) // video stream format (a chunk) 'LIST' (4 byte list length) 'strl' // audio stream list (a list) The audio 'strl' list contains: 'strh' (4 byte chunk size) (data) // audio stream header (a chunk) 'strf' (4 byte chunk size) (data) // audio stream format (a chunk) 'JUNK' (4 byte chunk size) (data - usually all zeros) // an OPTIONAL junk chunk to align on 2K byte boundary 'LIST' (4 byte list length) 'movi' // list of movie data (a list) The 'movi' list contains the actual audio and video data. This 'movi' list contains one or more ... 'LIST' (4 byte list length) 'rec ' // list of movie records (a list) '##wb' (4 byte chunk size) (data) // sound data (a chunk) '##dc' (4 byte chunk size) (data) // video data (a chunk) '##db' (4 byte chunk size) (data) // video data (a chunk) A 'rec ' list (a record) contains the audio and video data for a single frame. '##wb' (4 byte chunk size) (data) // sound data (a chunk) '##dc' (4 byte chunk size) (data) // video data (a chunk) '##db' (4 byte chunk size) (data) // video data (a chunk) The 'rec ' list may not be used for AVI files with only audio or only video data. I have seen video only uncompressed AVI files that did not use the 'rec ' list, only '00db' chunks. The 'rec ' list is used for AVI files with interleaved audio and video streams. The 'rec ' list may be used for AVI file with only video. ## in '##dc' refers to the stream number. For example, video data chunks belonging to stream 0 would use the identifier '00dc'. A chunk of video data contains a single video frame. Alexander Grigoriev writes ... John, ##dc chunk was intended to keep compressed data, whereas ##db chunk nad(sic) to be used for uncompressed DIBs (device independent bitmap), but actually they both can contain compressed data. For example, Microsoft VidCap (more precisely, video capture window class) writes MJPEG compressed data in ##db chunks, whereas Adobe Premiere writes frames compressed with the same MJPEG codec as ##dc chunks. ----End of Alexander The ##wb chunks contain the audio data. The audio and video chunks in an AVI file do not contain time stamps or frame counts. The data is ordered in time sequentially as it appears in the AVI file. A player application should display the video frames at the frame rate indicated in the headers. The application should play the audio at the audio sample rate indicated in the headers. Usually, the streams are all assumed to start at time zero since there are no explicit time stamps in the AVI file. The lack of time stamps is a weakness of the original AVI file format. The OpenDML AVI Extensions add new chunks with time stamps. Microsoft's ASF (Advanced or Active Streaming Format), which Microsoft claims will replace AVI, has time stamp "objects". In principle, a video chunk contains a single frame of video. By design, the video chunk should be interleaved with an audio chunk containing the audio associated with that video frame. The data consists of pairs of video and audio chunks. These pairs may be encapsulated in a 'REC ' list. Not all AVI files obey this simple scheme. There are even AVI files with all the video followed by all of the audio; this is not the way an AVI file should be made. The 'movi' list may be followed by: 'idx1' (4 byte chunk size) (index data) // an optional index into movie (a chunk) The optional index contains a table of memory offsets to each chunk within the 'movi' list. The 'idx1' index supports rapid seeking to frames within the video file. The 'avih' (AVI Header) chunk contains the following information: Total Frames (for example, 1500 frames in an AVI) Streams (for example, 2 for audio and video together) InitialFrames MaxBytes BufferSize Microseconds Per Frame Frames Per Second (for example, 15 fps) Size (for example 320x240 pixels) Flags The 'strh' (Stream Header) chunk contains the following information: Stream Type (for example, 'vids' for video 'auds' for audio) Stream Handler (for example, 'cvid' for Cinepak) Samples Per Second (for example 15 frames per second for video) Priority InitialFrames Start Length (for example, 1500 frames for video) Length (sec) (for example 100 seconds for video) Flags BufferSize Quality SampleSize For video, the 'strf' (Stream Format) chunk contains the following information: Size (for example 320x240 pixels) Bit Depth (for example 24 bit color) Colors Used (for example 236 for palettized color) Compression (for example 'cvid' for Cinepak) For audio, the 'strf' (Stream Format) chunk contains the following information: wFormatTag (for example, WAVE_FORMAT_PCM) Number of Channels (for example 2 for stereo sound) Samples Per Second (for example 11025) Average Bytes Per Second (for example 11025 for 8 bit sound) nBlockAlign Bits Per Sample (for example 8 or 16 bits) Each 'rec ' list contains the sound data and video data for a single frame in the sound data chunk and the video data chunk. Other chunks are allowed within the AVI file. For example, I have seen info lists such as 'LIST' (4 byte list size) 'INFO' (chunks with information on video) These chunks that are not part of the AVI standard are simply ignored by the AVI parser. AVI can be and has been extended by adding lists and chunks not in the standard. The 'INFO' list is a registered global form type (across all RIFF files) to store information that helps identify the contents of a chunk. The sound data is typically 8 or 16 bit PCM, stereo or mono, sampled at 11, 22, or 44.1 KHz. Traditionally, the sound has typically been uncompressed Windows PCM. With the advent of the WorldWide Web and the severe bandwidth limitations of the Internet, there has been increasing use of audio codecs. The wFormatTag field in the audio 'strf' (Stream Format) chunk identifies the audio format and codec. <A NAME="OpenDML"> <H3>OpenDML AVI File Format Extensions</H3> </A> The Open Digital Media (OpenDML) Consortium has defined an OpenDML AVI File Format Extensions which extend AVI to support a variety of features required for professional video production. These include support for fields (not just frames), file sizes larger than 1 GB, timecodes, and many other features. Microsoft has reportedly incorporated OpenDML AVI support in DirectShow 5.1 (ActiveMovie 5.1). It is also used by various professional video applications for the PC, in particular Matrox's DigiSuite software. The Open Digital Media Consortium AVI File Format Extensions add new lists and chunks to the AVI file which contain extra data such as timecodes not incorporated in the original AVI standard. OpenDML appears to have been spearheaded by Matrox to improve AVI for professional video authoring and editing. Matrox makes a variety of PC video products such as DigiSuite for professional and broadcast video authoring and editing. The OpenDML AVI File Format Extensions are primarily for the Motion JPEG AVI files used for professional video authoring and editing. The OpenDML effort seems to have been pushed to one side with the advent of ActiveMovie, NetShow, Advanced (formerly Active) Streaming Format (ASF) Files, and other Microsoft initiatives. On Oct. 2, 1997, the OpenDML AVI File Format Extensions Version 1.02 specification document (dated February 28, 1996) was available at the Matrox Electronic Systems, Ltd. Web site at: <A HREF="http://www.matrox.com/videoweb/odmlff2.htm">http://www.matrox.com/videoweb/odmlff2.htm</A> The specification is in Adobe Portable Document Format (PDF). Since Matrox seems to rearrange their site from time to time and one can't always find the specification, I've included a link to a copy of the PDF version of the specification on my Web site. <A HREF="http://www.rahul.net/jfm/odmlff2.pdf">PDF OpenDML AVI File Format Extensions Specification Document</A> <A HREF="http://www.adobe.com/prodindex/acrobat/readstep.html">Get Adobe Acrobat Reader (PDF Viewer)</A> <A NAME="AVISpec"> <H3>Where to get the exact AVI specification?</H3> </A> Microsoft Visual C++ 5.0 has a Video for Windows include file Vfw.h which gives the exact AVI data structures such as the various headers used in AVI files. The file also has comments explaining the structure of the AVI file. Video for Windows refers to the AVI Format by the mnemonic AVIFMT. At one time, the format information was apparently stored in an AVIFMT.H header file. The format information now appears consolidated in Vfw.h In addition to the Video for Windows header files, Chapter Four of the Video for Windows Programmer's Guide, "AVI Files", gives a detailed specification of the AVI file format. <A HREF="#Top">Return to Top</A> <A NAME="AVIDIB"> <H2>AVI and Windows Bitmaps (DDB, DIB, ...)</H2> </A> Microsoft Windows represents bitmapped images internally and in files as Device Dependent Bitmaps (DDB), Device Independent Bitmaps (DIB), and DIB Sections. Uncompressed 'DIB ' AVI files represent video frames as DIB's. Various multimedia API's that work with AVI use Windows bitmapped images. Prior to Windows 3.0, Windows relied on Device Dependent Bitmaps for bitmapped images. A DDB is stored in a format understood by the device driver for a particular video card. As the name suggests, DDB's are not generally portable. The structure of a DDB is: typedef struct tagBITMAP { // bm LONG bmType; /* always zero */ LONG bmWidth; /* width in pixels */ LONG bmHeight; /* height in pixels */ LONG bmWidthBytes; /* bytes per line of data */ WORD bmPlanes; /* number of color planes */ WORD bmBitsPixel; /* bits per pixel */ LPVOID bmBits; /* pointer to the bitmap pixel data */ } BITMAP; Usually the pixel data immediately follows the BITMAP header. (BITMAP header)(Pixel Data) The HBITMAP handles used by GDI are handles to Device Dependent Bitmaps. The GDI function BitBlt and StretchBlt are actually using Device Dependent Bitmaps. With Windows 3.0, Microsoft introduced the Device Independent Bitmap or DIB, the reigning workhorse of bitmapped images under Windows. The DIB provided a device independent way to represent bitmapped images, both monochrome and color. Windows retains DDB's despite the introduction of the DIB. For example, to use a DIB, you might call: hBitmap = CreateDIBitmap(...) CreateDIBitmap creats a DDB from a DIB, returning the GDI HBITMAP handle of the DDB for further GDI calls. At a low level, Windows and GDI are still using DDB's. The DIB files have a standard header that identifies the format, size, color palette (if applicable) of the bitmapped image. The header is a BITMAPINFO structure. typedef struct tagBITMAPINFO { BITMAPINFOHEADER bmiHeader; RGBQUAD bmiColors[1]; } BITMAPINFO; The BITMAPINFOHEADER is a structure of the form: typedef struct tagBITMAPINFOHEADER{ // bmih DWORD biSize; LONG biWidth; LONG biHeight; WORD biPlanes; WORD biBitCount DWORD biCompression; /* a DIB can be compressed using run length encoding */ DWORD biSizeImage; LONG biXPelsPerMeter; LONG biYPelsPerMeter; DWORD biClrUsed; DWORD biClrImportant; } BITMAPINFOHEADER; bmiColors[1] is the first entry in an optional color palette or color table of RGBQUAD data structures. True color (24 bit RGB) images do not need a color table. 4 and 8 bit color images use a color table. typedef struct tagRGBQUAD { // rgbq BYTE rgbBlue; BYTE rgbGreen; BYTE rgbRed; BYTE rgbReserved; /* always zero */ } RGBQUAD; A DIB consists of (BITMAPINFOHEADER)(optional color table of RGBQUAD's)(data for the bitmapped image) A Windows .BMP file is a DIB stored in a disk file. .BMP files prepend a BITMAPFILEHEADER to the DIB data structure. typedef struct tagBITMAPFILEHEADER { // bmfh WORD bfType; /* always 'BM' */ DWORD bfSize; /* size of bitmap file in bytes */ WORD bfReserved1; /* always 0 */ WORD bfReserved2; /* always 0 */ DWORD bfOffBits; /* offset to data for bitmap */ } BITMAPFILEHEADER; Structure of Data in a .BMP File (BITMAPFILEHEADER)(BITMAPINFOHEADER)(RGBQUAD color table)(Pixel Data) The Win32 API documentation from Microsoft provides extensive information on the data structures in a DIB. In Windows 95 and Windows NT, Microsoft added the DIBSection to provide a more efficient way to use DIB's in programs. The DIBSection was originally introduced in Windows NT to reduce the number of memory copies during blitting (display) of a DIB. <A HREF="#Top">Return to Top</A> <A NAME="Codec"> <H2>Meet the Codecs</H2> </A> The video data in an AVI file can be formatted and compressed in a variety of ways. Video for Windows 1.1e comes with several compressors: Intel Indeo (version 3.2) Microsoft Video 1 Microsoft RLE (Run Length Encoding) Cinepak AVI is not restricted to these compressors. They are the compressors provided with Video for Windows. These compressors are the Old Guard, the video codecs from the early days of Video for Windows and QuickTime (Cinepak originated with the Macintosh and QuickTime). During this period the focus of video was playback from hard drives and CD-ROM's. The advent of the WorldWide Web and Internet Mania has created a New Wave of audio and video codecs, trying to apply "advanced" technologies such as sophisticated motion estimation and compensation, wavelets, fractals, and other techniques to achieve extremely low bitrates (such as 28.8 Kbits/second for phone lines) for the Internet. <H3>The Old Guard</H3> <A NAME="DIB"> <H4>Full Frames (Uncompressed)</H4> </A> Users can store AVI files with uncompressed frames. No codec is required for this. The Four Character Code (FOURCC) for this is 'DIB ', DIB for the Microsoft Device Independent Bitmap. NOTE: Unfortunately, at least three other Four Character Codes are somtimes used for uncompressed AVI videos: 'RGB ' 'RAW ' 0x00000000 ( a FOURCC whose hexadecimal value is 0 ) <A NAME="ColorFormats"> <H5>Color Formats</H5> </A> Not all uncompressed bitmap images and AVI frames are the same! A variety of color formats for image pixels exist. Some of these color formats are essentially standard and supported on all systems. Some color formats (such as 8 bit grayscaleY8) require special drivers to display or capture. Color Formats are also known as IMAGE FORMATS or PIXEL FORMATS. Some components of Microsoft Windows identify Color Formats with a Four Character Code (FOURCC) such as 'RGB8' or 'YUY2'. Some components such as the Windows Device Independent Bitmap or DIB do not use Four Character Codes for color formats. 24 BIT RGB (DE FACTO STANDARD) 24-bit RGB is the most well-known color format. All common graphics programs support 24-bit RGB. In 24 bit RGB a pixel is represented as three bytes, one byte for the red component, one byte for the green component, and one byte for the blue component. 255 0 0 (a bright red pixel in 24 bit RGB) 0 255 0 (a bright green pixel in 24 bit RGB) 0 0 255 (a bright blue pixel in 24 bit RGB) 0 0 0 (a black pixel in 24 bit RGB) 255 255 255 (a white pixel in 24 bit RGB) 128 128 128 (a gray pixel in 24 bit RGB) ... and so forth. Other color formats include: 8 bit grayscale Y8 9 bit YUV9 12 bit BTYUV 4:1:1 12 bit YUY12 16 bit YUY2 4:2:2 8 bit RGB (uses a color palette) 15 bit RGB (16 bits with most significant bit zero, 5 bits for red, 5 bits for green, and 5 bits for blue) 16 bit RGB (16 bits with 5 bits for red, 6 bits for green, and 5 bits for blue) (24 bit RGB - described above) 32 bit RGB (most significant byte is zero, 8 bits for red, 8 bits for green, and 8 bits for blue) <H6>Original DIB Color Formats</H6> In the Windows 3.1 Software Development Kit, DIB's were defined to allow values of 1,4,8, and 24 bits per pixel in the biBitCount field of the BITMAPINFOHEADER. The biCompression field was allowed the values BI_RGB, BI_RLE4 (for run length encoding of 4 bit per pixel images), and BI_RLE8 (for run length encoding of 8 bit per pixel images). That was it. This original specification of the DIB provided the 8 bit RGB and 24 bit RGB color formats described above. The original DIB specification had no support for 16 bit per pixel formats, 32 bit per pixel formats, or special encodings like YUV. Not surprisingly, the original formats and specification of the DIB are the most widely supported in software. <H6>New DIB Color Formats and More Complexity</H6> Microsoft added support for 16 bit per pixel and 32 bit per pixel images to the DIB specification. These formats are identified by setting the biBitCount field in the BITMAPINFOHEADER of the DIB to 16 or 32. An uncompressed AVI file that stores images using the RGB 15, RGB 16, or RGB 32 color formats stores the video frames as DIB's using these "new" color formats. By default, the Microsoft 16 bit per pixel format is actually RGB 15 where one bit is unused, 5 bits for red, 5 bits for green, and 5 bits for blue. This was done because the 15-bit RGB or 5-5-5 format was used in 16-bit-per-pixel color video cards. Hardware designers found it easier to build chips using a 5-5-5 pixel format with one bit unused than the slightly higher resolution 5-6-5 color format. The Microsoft 32 bit per pixel format has the most significant byte of the pixel set to zero. Then 8 bits for red, 8 bits for green, and 8 bits for blue. This is RGB 32 bit. Why do this? The 32-bit pixels in this format are DWORD aligned on 32 bit boundaries in this format which is more efficient for operations and memory transfers under a 32 bit processor architecture than the unaligned 24-bit RGB format. Microsoft also added a new value for the biCompression field of the BITMAPINFOHEADER called BI_BITFIELDS. If biCompression is set to BI_BITFIELDS, then the color table is three DWORD (32 bit) masks giving the bits used for the red, green, and blue components of a pixel. In this way, a "custom" format such as RGB 5-6-5 (5 bits for Red, 6 bits for Green, and 5 bits for Blue) can be defined. This is 16-bit RGB. Although Four Character Codes (FOURCC's) such as 'RGB8' are used to identify different Color Formats in some parts of Microsoft Windows, the DIB data structures don't use FOURCC's, rather they use combinations of biBitCount and biCompression. In addition to 16-bit and 32-bit formats, Microsoft also defined a mechanism for custom encodings such as YUV, YUY2, and so forth. Manufacturers can register the new format with Microsoft. Microsoft also concocted a JPEG-DIB specification for wrapping the JPEG still image compression standard in a DIB. The JPEG DIB specification is virtually unused, having lost to the JFIF JPEG file format. JPEG images in general use, such as on Web pages, are JFIF's not JPEG DIB's. <H6>YUV Color Space and Color Formats</H6> YUV is the color space used in the European PAL broadcast television standard. PAL was originally introduced in Britain and Germany in 1967. PAL is used by most European nations and many nations around the world. The United States and Japan use the NTSC standard. France and a few other nations use the SECAM standard. Y refers to the luminance, a weighted sum of the red, green, and blue components. The human visual system is most sensitive to the luminance component of an image. Analog video systems such as NTSC, PAL, and SECAM transmit color video signals as a luminance (Y) signal and two color difference or chrominance signals (the U and V above). If, R, G, and B are the red, green, and blue values, then: Y = 0.299 R + 0.587 G + 0.114 B U = 0.493 (B - Y) V = 0.877 (R - Y) U is very similar to the difference between the blue and yellow components of a color image. V is very similar to the difference between the red and green components of a color image. There is evidence that the human visual system processes color information into something like a luminance channel, a blue - yellow channel, and a red - green channel. For example, while we perceive blue-green hues, we never percieve a hue that is simultaneously blue and yellow. This may be why the YUV color space of PAL is so useful. To exploit this, digital color formats such as YUV9 or YUY2 exist that represent pixels as levels of Y, U, and V. <H6>Summary</H6> Both BMP still image files and AVI files may be saved in many different color formats. While 24 bit RGB is almost universally supported, there is no guarantee that your graphics software or AVI playback drivers will support some of the less well-known color formats. You may need to get special software, drivers, or even hardware to use some of these formats. For example, all of the color formats listed above are supported by hardware and software drivers with the miro miroMEDIA PCTV TV Tuner and Video Capture card. Some of these, like 8 bit grayscale Y8, are not widely known or supported. In general, video capture drivers allow selection of the color format used when the video (AVI file) is captured. These color format options should be accessible through the video capture software application. In Microsoft's VidCap and VidCap32 video capture applications, the user may select the color format through Options | Video Format... <A HREF="#Top">Return to Top</A> <A NAME="MRLE"> <H4>Microsoft Run Length Encoding</H4> </A> Microsoft Run Length Encoding uses the Four Character Code MRLE [drivers32] VIDC.MRLE=MSRLE32.DLL in Windows 95 [drivers] VIDC.MRLE=MSRLE.DLL in Windows 3.x Microsoft Run Length Encoding usually appears with the name "Microsoft RLE" in lists of Video Compression options. 8 BIT ONLY Microsoft RLE only supports 8 bit color, a maximum of 256 colors using a color lookup table. It does NOT support 16 bit color, also known as "High Color" or "Thousands of Colors", or 24 bit color, also known as "True Color" or "Millions of Colors". WHERE TO GET Microsoft RLE Historically, Microsoft RLE has been one of the standard Video for Windows codecs from Microsoft. The 16 bit Microsoft Video for Windows 1.1e installs a 16 bit version of the Microsoft RLE video codec. The Microsoft Windows 95 CD-ROM installs a 32 bit Microsoft RLE video codec. The Microsoft Windows NT Workstation Operating System Version 4.0 installs a 32 bit Microsoft RLE video codec. <A HREF="#Top">Return to Top</A> <A NAME="MSVC"> <H4>Microsoft Video 1</H4> </A> Microsoft Video uses the Four Character Code MSVC [drivers32] VIDC.MSVC=MSVIDC32.DLL in Windows 95 [drivers] VIDC.MSVC=MSVIDC.DLL in Windows 3.x <B>NOTE:</B> The Four Character Code CRAM is also used for Microsoft Video 1. 8 OR 16 BIT ONLY Microsoft Video 1 supports only 8 bit or 16 bit color. 16 bit color is also known as "High Color" or "Thousands of Colors". Microsoft Video 1 does not support 24 bit color, also known as "True Color" or "Millions of Colors". WHERE TO GET Microsoft Video 1 Historically, Microsoft Video 1 has been one of the standard Video for Windows codecs from Microsoft. The 16 bit Microsoft Video for Windows 1.1e installs a 16 bit version of the Microsoft Video 1 video codec. The Microsoft Windows 95 CD-ROM installs a 32 bit version of the Microsoft Video 1 video codec. The Microsoft Windows NT Workstation Operating System 4.0 CD-ROM installs a 32 bit version of the Microsoft Video 1 video codec. <A HREF="#Top">Return to Top</A> <A NAME="RT21"> <H4>Intel Real Time Video 2.1 (Indeo 2.1?) (RT21) </H4> </A> RT21 is the Microsoft Four Character Code for the Intel Real Time Video 2.1 (Indeo 2.1?) video compressor-decompressor (codec). Microsoft's 16-bit Video for Windows Version 1.1e for Windows 3.x includes a 16-bit Video for Windows codec for RT21. WHERE TO GET Intel Real Time Video 2.1 Microsoft appears to have discontinued support for RT21 in the 32-bit Video for Windows in Windows 95 and Windows NT 4.0. There are 32-bit Video for Windows codecs for Indeo 3.1/3.2, Indeo 4.x, and Indeo 5.0. For example, the Microsoft Windows NT Workstation Operating System Version 4.0 CD-ROM DOES NOT install RT21. It DOES install Intel Indeo R 3.2 See the <A HREF="#VfW16">Where to get the 16-bit Video for Windows</A> section. <A HREF="#Top">Return to Top</A> <A NAME="IV32"> <H4>Intel Indeo 3.1/3.2</H4> </A> Indeo uses the Microsoft Four Character Codes IV31 and IV32, originally for Indeo 3.1 and Indeo 3.2, but these are usually now mapped to Indeo 3.2 [drivers32] VIDC.IV31=IR32_32.DLL VIDC.IV32=IR32_32.DLL in Windows 95 [drivers] VIDC.IV31=IR32.DLL VIDC.IV32=IR32.DLL in Windows 3.x Indeo 3.x uses Vector Quantization based image compression. WHERE TO GET INDEO 3.x Indeo R3.2 is one of the default standard Video for Windows codecs. Microsoft's 16 bit Video for Windows 1.1e includes a 16 bit Indeo 3.2 codec (the IR32.DLL above). The Microsoft Windows 95 CD-ROM installs a 32 bit Indeo 3.2 video codec. Microsoft Windows NT Workstation Operating System 4.0 CD-ROM installs a 32 bit Indeo R3.2 video codec. <A HREF="#Top">Return to Top</A> <A NAME="CVID"> <H4>Cinepak</H4> </A> Cinepak is the most widely used Video for Windows codec. Cinepak reportedly provides the fastest playback of video. While Indeo 3.2 provides similar or slightly superior image quality for same compression, Indeo decompression is much more CPU intensive than Cinepak. Cinepak was originally developed for the Mac and licensed to Apple by SuperMac Technology Inc. It is now free with Video for Windows. It is also free with Apple's QuickTime. There are at least three Cinepak Video for Windows codecs in existence: Cinepak by SuperMac (the original, 16 bit) Cinepak by Radius (newer, better?, 16 bit) Cinepak by Radius[32] (32 bit version of Radius Cinepak, shipped with Windows 95) Peter Plantec's Caligari TrueSpace2 Bible strongly recommends using the Radius codec for superior results when generating AVI files from TrueSpace. Cinepak uses the Microsoft Four Character Code CVID [drivers32] VIDC.CVID=ICCVID.DLL in Windows 95 [drivers] VIDC.CVID=ICCVID.DRV in Windows 3.x Apple QuickTime supports Cinepak. Mark Podlipec's XAnim Unix X11 video player supports Cinepak. Cinepak uses Vector Quantization based image compression and frame differencing. Historical Note: On or about Jan. 6, 1999, Radius Inc. renamed itself Digital Origin Inc.. SuperMac Technology, the original owner of Cinepak, was a predecessor to Radius. WHERE TO GET CINEPAK Cinepak is one of the default standard video codecs in Video for Windows. A 16-bit version of Cinepak is included in the 16 bit Video for Windows 1.1e The Microsoft Windows 95 CD-ROM installs a 32 bit Cinepak by Radius video codec. Microsoft Windows NT Workstation Operating System Version 4.0 CD-ROM installs a 32 bit Cinepak by Radius video codec. CINEPAK PRO Compression Technologies Inc. Oakland, CA <A HREF="mailto:info@cinepak.com">E-Mail: info@cinepak.com</A> <A HREF="http://www.Cinepak.com/">http://www.Cinepak.com/</A> sells an improved Cinepak compressor that purportedly can fix some common problems with video encoded with Cinepak. They say their product, CinepakPro, generates 100 percent completely Cinepak compatible movies. These movies will play back using all existing native Cinepak decompressors. CinepakPro and Cinepak Toolkit (Macintosh OS 7.5 or newer and QuickTime 2.5 or 3) CinepakPro QTX (Windows 95/98/NT and QuickTime 3.0 for Windows) CinepakPro AVI (Windows 95/98/NT and Video for Windows/ ActiveMovie) An updated AVI Cinepak codec for Windows is available at the Compression Technologies Inc. Web site (May 12, 1999). <A HREF="#VQ">Vector Quantization</A> <A HREF="#Top">Return to Top</A> <A NAME="MJPG"> <H4>Motion JPEG</H4> </A> Most PC video capture and editing systems capture video to AVI files using Motion JPEG video compression. In Motion JPEG, each video frame is compressed separately using the JPEG still image compression standard. No frame differencing or motion estimation is used to compress the images. This makes frame accurate editing without any loss of image quality during the editing possible. The standards situation for Motion JPEG is complicated since at one time there was no industry standard for Motion JPEG. Microsoft has a Microsoft Motion JPEG Codec and a JPEG DIB Format. The OpenDML Avi File Format Extensions (another standard for extending AVI to support professional video features) includes Motion JPEG support. See the Paradigm Matrix site below for more information on these standards. Motion JPEG codecs usually use the Four Character Code 'MJPG'. Motion JPEG is used for editing and authoring, but rarely for distribution. Usually, once the video has been edited, it is compressed further using Cinepak or another codec for distribution. Because Motion JPEG does not use frame differencing or motion estimation, better compression is possible with other codecs. A software Motion JPEG codec for Windows NT and Windows 95 is available from Paradigm Matrix at: <A HREF="http://www.pmatrix.com/Goodies.htm">http://www.pmatrix.com/Goodies.htm</A> The Paradigm Matrix Motion JPEG codec uses the Four Character Code MJPG. A 32-bit software Motion JPEG codec for Windows NT and Windows 95 is available from Morgan Multimedia at: <A HREF="http://www.morgan-multimedia.com/">http://www.morgan-multimedia.com/</A> A 32-bit software Motion JPEG codec for processors with MMX instructions (MainConcept Motion JPEG Codec) is available from MainConcept at: <A HREF="http://www.mainconcept.com/">http://www.mainconcept.com/</A> Motion JPEG uses the Block Discrete Cosine Transform (DCT) for image compression. <A HREF="#Top">Return to Top</A> <A NAME="XMPG"> <H4>Editable MPEG</H4> </A> At least two companies defined schmes to wrap editable MPEG (I frames only MPEG) in AVI files. Xing Technology's editable MPEG AVI uses the Four Character Code XMPG. Sigma Designs defined an AVI format using the Four Character Code MPGI. Editable MPEG consists of only MPEG I frames. This omits the MPEG motion estimation. It is very similar to Motion JPEG. By wrapping I frames only MPEG in AVI, editable MPEG works with standard Video for Windows editing and authoring applications such as Adobe Premiere. Xing Technologies <A HREF="http://www.xingtech.com/">http://www.xingtech.com/</A> Sigma Designs <A HREF="http://www.graphcomp.com/info/specs/ms/editmpeg.htm">MPEG Extensions to AVI File Format (Draft 1.1 by Sigma Designs)</A> <A HREF="#Top">Return to Top</A> <H3>The New Wave</H3> Recently (5/18/97), there has been a proliferation of new Video for Windows codecs. A few like H.261 have been around for a while, but most represent implementations of new or improved technologies such as wavelets. Many are targetted toward low bitrate video over the Internet. For lack of better terminology, I refer to these as the New Wave to differentiate them from the older codecs like Cinepak included with Video for Windows 1.1e (the last release prior to Windows 95). Microsoft appears to be developing or licensing some of these codecs as part of NetShow, NetMeeting, and other Microsoft initiatives. <A NAME="VDOW"> <H4>VDOWave or VDOLive from VDONet</H4> </A> VDONet <A HREF="http://www.vdo.net/">http://www.vdo.net/</A> 4009 Miranda Ave., Suite 250 Palo Alto, CA 94304 Voice: (415) 846-7730 FAX: (415) 846-7900 markets a wavelet based video codec which includes a Video for Windows (32 bit) implementation. Microsoft has licensed VDOWave as part of the NetShow product. There are two versions of the VDOWave codec. VDOWave 2.0 is a fixed rate video codec which uses the Microsoft Four Character Code VDOM. This codec adds the line [drivers32] vidc.vdom=vdowave.drv to the SYSTEM.INI file in Windows 95. VDOWave 3.0 is a "scalable" video codec. This codec uses the Microsoft Four Character Code (FOURCC) VDOW and adds the line [drivers32] VIDC.VDOW=vdowave.drv to the Windows 95 SYSTEM.INI files. In NetShow 2.0, the standalone Client Setup installs a VDOWave decode-only codec. The NetShow 2.0 Tools Setup installs a VDONet VDOWave encoder. In some of my tests, VDOWave appears significantly superior to MPEG-1 and the other block Discrete Cosine Transform based codecs at low bitrates. VDONet uses the trademark VDOWave for its wavelet based video codec. VDONet uses the trademark VDOLive for its VDOLive On-Demand Product Line. This includes the VDOLive On-Demand Server, the VDOLive tools including VDOCapture and VDOClip, and the VDOLive Player. Sometimes VDOLive and VDOWave are used interchangably by users and in some company literature. VDONet also has a VDOPhone product for real-time videoconferencing. Based on the company documentation, published reports, and viewing the technology, VDOWave appears to be a combination of wavelet based image compression and motion compensation or frame differencing. <A HREF="#Top">Return to Top</A> <A NAME="IV41"> <H4>What is Indeo Video Interactive?</H4> </A> Indeo Video Interactive, Indeo 4.1, is a new version of Indeo from Intel based on a "hybrid wavelet algorithm" according to Intel. This is a different compression algorithm than Indeo 3.2 which is included with Video for Windows. Indeo 3.2 uses Vector Quantization. Indeo Video Interactive supports a number of features in addition to the new compression algorithm such as transparency. Indeo Video Interactive can be installed as a Video for Windows codec or in the new ActiveMovie environment from Microsoft. For further information on Indeo Video Interactive <A HREF="http://www.intel.com/pc-supp/multimed/indeo/index.htm"> http://www.intel.com/pc-supp/multimed/indeo/index.htm</A> How to program "sprites" in Indeo Video Interactive? Some of Intel's marketing material touts the ability to add sprites to applications using Indeo Video Interactive. Most of Intel's technical documentation on Indeo and the API's for using Indeo Video Interactive neglects to explain what Intel means by "sprite". There is a brief mention in the Overview document for Indeo Video Interactive. Indeo "sprite" means TRANSPARENCY. Indeo Video Interactive supports TRANSPARENCY. Indeo has transparent pixels to create transparent backgrounds to implement effects such as chroma-keying. The well-known example of chroma-keying is the television weather forecaster standing in front of a satellite weather picture. The forecaster stands in front of a blue screen (sometimes a green screen) and video gadgetry replaced the blue color with another video signal. Anything that is not the blue "key" color is left unchanged. In Indeo jargon a "video sprite" is a foreground object such as the mythical weather-caster on a transparent background. Your application can then provide a bitmap image or even another video as a background in the transparent areas of the image. This provides a crude mechanism for the video to change depending on interactions with a user. Look up the API's in Intel's documentation for TRANSPARENCY to implement video sprites. How to identify an AVI file that uses Indeo Video Interactive for the video compressor? Video for Windows identifies different video compressors through four character codes. For example, 'cvid' is the four character code for the widely used Cinepak compressor. The four character code is found in the video stream header 'strh' in the AVI file. Indeo Video Interactive (Indeo 4.1) uses the four character code 'iv41' If Indeo Video Interactive is not installed installed Video for Windows will report an error, indicating that it cannot find the compressor for 'iv41'. The specific message appears to be: "Video not available, cannot find 'vids:iv41' decompressor." <B>NOTE:</B> Indeo 4.1 claims to implement a hybrid wavelet transform. Some of the behavior of the codec at low bitrates differs from other wavelet based image and video compressors such as VDOWave, Infinop's Lightning Strike, and some public domain wavelet compression software. In particular, at low bitrates, I have seen the characteristic checkerboard pattern of 8x8 pixel blocks seen in block based transform coding methods such as MPEG-1. I'm not sure what Intel means by hybrid wavelet transform. In general, at low bitrates, image and video compression schemes using the Discrete Wavelet Transform (DWT) exhibit a blurring at the edges of objects and also "ringing" artifacts near edges. They do not exhibit the blocking artifacts, checkerboard pattern in extreme cases, seen in block Discrete Cosine Transform based image and video compression. <A HREF="#Top">Return to Top</A> <A NAME="IV50"> <H4>Indeo Video Interactive 5.0</H4> Intel is now (2/22/99) distributing an Indeo Video Interactive 5.10 software on their Web site. Indeo 5.0 claims to use a new better wavelet compression algorithm for improved video quality. Indeo 5 includes features such as progressive download for the Internet, transparency, sprites, etc. As of 2/22/99, the latest version of Intel Indeo Video appears to be Indeo Video 5.10. The latest version of Intel Indeo Audio appears to be Indeo Audio 2.5 The previous version of Intel Indeo Video was Indeo 5.06 <A HREF="http://developer.intel.com/ial/indeo/video/">http://developer.intel.com/ial/indeo/video/</A> Known releases of Indeo Video 5.x Intel Indeo 5.10 (02-Feb-1999) Intel Indeo 5.06 (1998) Intel Indeo 5.0 (1997????) NOTE: All releases of Indeo 5.x appear to use the Four Character Code IV50 Apple QuickTime 4 includes support for Indeo 5, allowing playback on Apple Macintosh platforms. <A HREF="http://www.apple.com/quicktime/technologies/indeo/">http://www.apple.com/quicktime/technologies/indeo/</A> <A HREF="#Top">Return to Top</A> <A NAME="UCOD"> <H4>ClearVideo (aka RealVideo)</H4> </A> ClearVideo is a video codec from Iterated Systems(<A HREF="http://www.iterated.com/"> http://www.iterated.com</A> Iterated has also licensed the ClearVideo technology to Progressive Networks, makers of RealAudio, under the name RealVideo. You can (or could at one time) download a Video for Windows demo of ClearVideo from the Iterated Web site. This includes a demo Video for Windows codec that allows both encoding and decoding The video can only be played on the same machine with the demo encoder. This codec works with Video for Windows applications such as Media Player and VidEdit. Fractal video encoding appears to be very slow (computationally intensive). The video is similar or somewhat superior to MPEG-1 in quality. ClearVideo uses Fractal Image Compression. Iterated is the main (only?) producer of commercial fractal image and video compression technology. The Video for Windows evaluation version of ClearVideo installs [drivers32] VIDC.UCOD=CLRVIDCD.DLL in SYSTEM.INI in Windows 95. <A HREF="#Top">Return to Top</A> <A NAME="SFMC"> <H4>SFM (Surface Fitting Method)</H4> </A> Crystal Net Corporation (<A HREF="http://www.crystalnet.com/">http://www.crystalnet.com/</A> seeks to license a technology called SFM or Surface Fitting Method. This is supposed to be a low bitrate video technology for ISDN and POTS (Plain Old Telephone Service) bitrates. They have a Video for Windows demo to download from their Web site. SFM used the Microsoft Four Character Code (FOURCC) SFMC. The demo installs (actually the instructions tell you to manually install): [drivers32] VIDC.SFMC=SFMdemo.dll in Windows 95. The demo does not include an encoder which presents problems in evaluating the technology. However, SFM appears to be some sort of edge detection based encoding technology. White Pine's Enhanced CU-See Me desktop videoconferencing product uses Crystal Net's SFM under the name White Pine Color Software Codec. NEC has reportedly licensed SFM for its Network Video Audio Tool (NVAT). (February, 1998) Crystal Net also reportedly has relationships with Shepherd Surveillance and Winnov. (February, 1998) <A HREF="#Top">Return to Top</A> <A NAME="QPEG"> <H4>QPEG</H4> </A> Q-Team Dr. Knabe produces a Video for Windows codec known as QPEG. Currently (6/27/97), QPEG supports 8 bit color. Q-Team plans 16 and 24 bit color, MMX support, and other additional features in the future. Sample AVI/QPEG files and Video for Windows QPEG codecs for Windows 3.x and Windows 95/NT are available at the Q-Team Web site. <A HREF="http://www.q-team.de/">http://www.q-team.de/</A> Q-Team is also working on MPEG-4 for the PC. <A HREF="#Top">Return to Top</A> <A NAME="H261"> <H4>H.261</H4> </A> H.261 is an international standard, widely used for video conferencing in the 128 Kbits/second to 384 Kbits/second range. This is a block Discrete Cosine Transform method. Actually, H.261 was the first international standard developed using the block Discrete Cosine Transform and motion compensation. MPEG-1, which is probably better known, followed the H.261 effort. Intel's ProShare videoconferencing product installs a Video for Windows H.261 codec. <B>NOTE:</B> I've never generated an AVI files with Intel's H.261, so it may only be used for Intel ProShare videoconferencing and not with AVI. Microsoft has a Microsoft H.261 Video for Windows 32 bit codec. [drivers32] VIDC.M261=MSH261.DRV in Windows 95. <A HREF="#Top">Return to Top</A> <A NAME="H263"> <H4>H.263</H4> </A> H.263 is another international standard, based on the Block Discrete Cosine Transform (DCT) and motion compensation. H.263 has a number of improvements, mostly in the area of motion compensation, over the earlier H.261 standard. It is targeted toward very low bitrate video compression. Microsoft's NetShow 2.0 installs a Microsoft H.263 video codec. Microsoft H.263 uses the Four Character Code M263. [drivers32] VIDC.M263=msh263.drv in Windows 95. The Microsoft H.263 video codec is one of several "keyed" codecs installed by NetShow. Others are Vivo H.263 and Duck's TrueMotion 2.0. These codecs will not encode video as AVI files, although they apparently will create Microsoft ASF files or provide compression for streaming video products such as Microsoft's NetMeeting videoconferencing. See the section on NetShow for more information on the NetShow video codecs. Some versions of the msh263.drv driver will crash when trying to encode an AVI file from VidEdit or similar applications. Other versions of msh263.drv don't crash but give an "Unable to begin compression" message box. Vivo Software Inc. markets streaming H.263 and G.723 audio for the Web under the brand name VivoActive. Vivo has its own file format called .VIV which can be embedded in Web pages. Vivo provides a player called VivoActive player and an authoring tool for creating .VIV files called VivoActive Producer. Microsoft NetShow installs a "keyed" codec that identifies itself as Vivo H.263 Video Codec[32] which installs [drivers32] VIDC.VIVO=IVVIDEO.DLL in Windows 95. Vivo H.263 uses the four character code 'VIVO'. The Vivo Software Web Site: <A HREF="http://www.vivo.com/">http://www.vivo.com/</A> Intel distributes an Intel "I263" H.263 video codec at there Web site as part of the NetCard product. This installs [drivers32] VIDC.I263=C:\WINDOWS\I263_32.DLL VIDC.I420=C:\WINDOWS\I263_32.DLL in Windows 95. As of June 18, 1998, this codec could be found at: <A HREF="http://support.intel.com/support/createshare/camerapack/CODINSTL.HTM">http://support.intel.com/support/createshare/camerapack/CODINSTL.HTM</A> Note that Intel, like Microsoft, seems to rearrange their Web site constantly. Unlike the keyed Microsoft H.263 video codecs, this codec can be used to encode AVI's through Microsoft VidEdit 1.1 (and presumably other video editing products). How well this codec in fact implements the H.263 standard is not clear. Shannon Communication Systems (SCS) has an H.263+ AVI codec and analysis tool available for download at their Web site: <A HREF="http://www.shansys.com/">http://www.shansys.com/</A> Telenor R&D of Norway distributes the source code for an H.263 encoder and decoder that will reportedly compile and run under Windows. This is a standalone application not a Video for Windows codec or ActiveMovie filter. See elsewhere in the AVI Overview for a link to the Telenor Web site. <A HREF="#Top">Return to Top</A> <A NAME="MPG4"> <H4>MPEG-4</H4> </A> Microsoft's NetShow 2.0 installs a Video for Windows codec for MPEG-4. MPEG-4 is a new international standard that has not been officially released as yet. Microsoft is deeply involved in the MPEG-4 standardization effort. Microsoft has been using its MPEG-4 for the Microsoft NBC Business Video broadcasting over the Internet. The Microsoft MPEG-4 Video for Windows Codec identifies itself as "MPEG-4 High Speed Compressor" in Control Panel | Multimedia | Devices | Video Compression Codecs. Adding to confusion in true Microsoft fashion, there are two versions of each NetShow video codec. The NetShow 2.0 Player (Client) installation program installs codecs that provide only decoding functionality. The MPEG-4 video codec installed by NetShow 2.0 Player can only play back an MPEG-4 AVI. The MPEG-4 video codec installed by the NetShow 2.0 Tools can encode AVI files with MPEG-4 video compression. If you want to author MPEG-4 compressed AVI, make sure to get and install the NetShow 2.0 Tools, not just the NetShow 2.0 Player. The Microsoft MPEG-4 High Speed Compressor Video Codec installed by the NetShow 2.0 Tools will not encode arbitrary dimension video. The video must have the dimensions 176 x 144 (QCIF). In Microsoft VidEdit, "MPEG-4 High Speed Compressor" becomes visible in the list of compression options only if the video is sized to 176x144. MPEG-4 uses the Microsoft Four Character Code (FOURCC) MPG4. [drivers32] VIDC.MPG4=msscrc32.dll <A HREF="#Top">Return to Top</A> <A NAME="LS"> <H4>Lightning Strike (Infinop)</H4> </A> Infinop markets a wavelet based video codec called Lightning Strike Streaming Video. A Lightning Strike video decoder compatible with Microsoft NetShow can be dowloaded from the Infinop Web site. There are several sample Lightning Strike Video files at the Infinop site. The Lightning Strike encoder does not seem to be generally available. <A HREF="http://www.infinop.com/">http://www.infinop.com/</A> <A HREF="#Top">Return to Top</A> <A NAME="VxTreme"> <H4>VxTreme</H4> </A> VxTreme was acquired by Microsoft in September of 1997. Microsoft has invested in numerous low bitrate audio and video companies during the second half of 1997, include VxTreme, VDONet, Progressive Networks/RealNetworks, and Lernout and Hauspie Speech Products. Although I have not seen a Video for Windows implementation of VxTreme (12/20/97), I thought that I should include this codec. Undoubtedly, it will be ported to Video for Windows and/or ActiveMovie if this has not already happened. VxTreme(<A HREF="http://www.vxtreme.com/">http://www.vxtreme.com/</A> markets a video codec that is usually identified as a wavelet based codec. A VxTreme player, a Plug-In for Internet Explorer and Netscape, is available at the VxTreme Web site. VxTreme has some very impressive demos of QCIF (160x120) talking heads material on their Web sites. The subjective image quality during scenes with small changes is quite good, much superior to the block Discrete Cosine Transform based codecs and probably VDONet's VDOWave. Text such as movie titles and credits appears to encode very well. Preserving the sharp edges of text is a major problem in block Discrete Cosine Transform based encoders such as the JPEG still image compression standard and the MPEG video compression standard. In general, wavelet image compression encounters problems with sharp edges as well. VxTreme clearly uses some sort of motion compensation or frame differencing. Image quality drops dramatically during periods with rapid changes. I viewed a number of movie trailers encoded with VxTreme for 28.8 Kbits/second such as the trailer for "Goldeneye". These trailers contain many scene changes and motion. Video quality is poor, hardly superior to competitors such as H.261 or Microsoft's MPEG-4. The talking heads material at 28.8 looks almost natural. VxTreme may be a combination of the Discrete Wavelet Transform (??) and motion compensation. The preservation of sharp edges suggests something beyond the vanilla Discrete Wavelet Transforms described in the technical literature on wavelet based image and video compression. <A HREF="#Top">Return to Top</A> <A NAME="#Sorenson"> <H2>Sorenson Video</H2> </A> Sorenson Video, from Sorenson Vision, is a low bitrate video codec that appears to be available only for Apple QuickTime as of May 10, 1999. Sorenson Video was used to compress the Star Wars trailer for "Star Wars Episode I: The Phantom Menace" distributed over the Internet as a QuickTime file in the spring of 1999. No Video for Windows Sorenson Video codec appears to be available. Sorenson Video is reportedly based on some kind of vector quantization technology that can achieve very high compression. According to Mark Podlipec's XAnim site (May 10, 1999), he contacted Sorenson Vision to find out if he could license Sorenson Video for incorporation in the XAnim Unix X11 animation, audio, and video player. According to his Web site, Sorenson replied that Apple will not allow Sorenson to license Sorenson Video to others. <A HREF="http://www.s-vision.com/">http://www.s-vision.com/</A> <A HREF="#Top">Return to Top</A> <A NAME="VfWInstalled"> <H2>How to determine which Video for Windows decompressors are installed on a PC?</H2> </A> In the SYSTEM.INI file, there is a section [drivers] which will contain some lines as follows: [drivers] VIDC.MSVC=msvidc.drv VIDC.YVU9=isvy.drv VIDC.IV31=indeor3.drv VIDC.RT21=indeo.drv VIDC.CVID=iccvid.drv VIDC.MRLE=msrle.drv AVI files contain a four character code (such as 'IV31' or 'CVID') in the stream header for the video stream. This four character code identifies the video compressor used for the video stream. For example, 'CVID' is the identifier for Cinepak (formerly Compact Video) compression. Video for Windows prefixes the four character code with VIDC. and uses it to look up the video decompressor driver in SYSTEM.INI iccvid.drv is the driver for Cinepak in the example above. Note: These are 16-bit drivers. Windows 95 adds a section [drivers32] for 32 bit drivers. There are 32 bit versions of the Video for Windows drivers. See below (and notice that the 32 bit drivers have different names from the 16 bit drivers). [drivers32] vidc.cvid=iccvid.dll ; Cinepak for Windows 32 vidc.iv31=ir32_32.dll vidc.iv32=ir32_32.dll vidc.msvc=msvidc32.dll vidc.mrle=msrle32.dll WINDOWS 95 In Windows 95: (1) Open the Control Panel (2) Double click on the Multimedia Icon (applet) (3) Select the "Advanced" Tab (4) Under the Multimedia Drivers icon, double click on the Video Compression Codecs icon to open it. This gives a list of installed video codecs. <A HREF="#Top">Return to Top</A> <A NAME="WhichAVICodec"> <H3>How to determine which codec was used to compress an AVI file</H3> </A> LOW LEVEL WAY THAT WORKS ON ANY OPERATING SYSTEM WITH A FILE EDITOR! A low level way to find out is to view the avi file with an editor, for example the standard EDIT command in DOS will work. Search for the four character code vids (usually lower case). vids indicates a VIDeo Stream. vids is immediately followed by the four character code for the compressor used for the AVI file. For example, a full frames (uncompressed) AVI will contain the string: vidsDIB An AVI compressed using Microsoft Video 1 will contain the string: vidsmsvc And so forth. See elswhere in this overview for information on the Microsoft Four Character Codes. WINDOWS 95 In Windows 95 (or Windows NT 4.0): Right click on the avi file's icon. This brings up a menu of items. Select Properties. Click on the Details tab in the Properties sheet. Look under Video Format in the Details. This will list the compression used. The compression is identified using an explanatory human-readable string such as "16 x 16, 24 Bits, 8 Frames, 60.150 Frames/Sec, 76 KB/Sec, Uncompressed". The Microsoft Four Character Code is not used. NOTE: Windows 95 needs to have the Video for Windows codec installed to correctly identify the codec used in the AVI file. If you have an AVI that Windows 95 can't play because the codec is not installed, you will have to use another method. <A HREF="#Top">Return to Top</A> <A NAME="BestCodec"> <H3>Which AVI video compressor is best?</H3> </A> "Best" depends on what the user is trying to do. Selection of a video codec depends on several variables: time to encode the video, how widely known and available the video codec is, compression ratios that can be achieved for a target subjective quality level. The <A HREF="#CodecPerformance">Performance of AVI Codecs</A> section gives detailed information on the performance, compression ratios, video quality, etc. of AVI video codecs. Cinepak is the most widely used AVI video codec. Cinepak reportedly provides the fastest playback of video. While Indeo 3.2 provides similar or slightly superior image quality for same compression, Indeo decompression is much more CPU intensive than Cinepak. Cinepak was originally developed for the Mac and licensed to Apple by SuperMac. It is now free with Video for Windows. It is also free with Apple's QuickTime. There are at least three Cinepak codecs in existence: Cinepak by SuperMac (the original, 16 bit) Cinepak by Radius (newer, better?, 16 bit) Cinepak by Radius[32] (32 bit version of Radius Cinepak, shipped with Windows 95) Peter Plantec's Caligari TrueSpace2 Bible strongly recommends using the Radius codec for superior results when generating AVI files from TrueSpace. Cinepak is the best codec to use to insure ease of playback. Few people will have problems or need to install special codecs or software to play an AVI compressed with Cinepak. Cinepak is based on Vector Quantization and Frame Differencing to achieve video compression. Other technologies such as the Block Discrete Cosine Transform and Motion Compensation can achieve superior compression (smaller files for the same subjective visual quality). Codecs that beat Cinepak H.263 (probably H.261) Block DCT/Motion Compensation MPEG-4 Video Verification Model Block DCT/Motion Compensation Indeo Video Interactive (Indeo 4.x) "hybrid wavelet" VDONet's VDOWave Discrete Wavelet Transform/Motion Compensation Iterated System's RealVideo or ClearVideo Fractal Compression Although not integrated into AVI, the MPEG-1 digital video standard with IPB frames outperforms Cinepak. The block DCT/Motion Compensation based codecs seem to perform 1.5 - 2.0 times better than Cinepak. VDOWave, a wavelet based codec, seems somewhat better than this. <A HREF="#Top">Return to Top</A> <A NAME="CodecPerformance"> <H2>Performance of AVI Codecs</H2> </A> <H3>How do the Video Codecs Perform on Typical Video?</H3> To test the performance of the many Video for Windows codecs, I created a ten second video of myself using the U.S. Robotics Bigpicture video capture card which is based on the Brooktree Bt848 chip. I am talking, picking up a microphone, and waving my hands against an essentially static background. This sequence was captured at: 30 frames per second, 320 by 240 pixels, with 24 bit RGB color, no frames dropped during video capture. Note that 320 by 240, RGB 24, at 30 frames per second is similar to a single field of NTSC television video and to the spatial resolution and frame rates of the successful VideoCD products based on MPEG-1 digital video compression. I then compressed the video using different codecs and Microsoft's VidEdit 1.1 video editor. A table of results follows. Except where noted, the video resembles the original uncompressed video closely. In case where the video was significantly degraded, this is noted IN CAPS. The encoders for most codecs have an adjustable quality factor, frequently displayed as a value between 0 and 100. A higher quality factor means the compressed video looks better but has a higher bitrate, a lower compression ratio. There is a trade-off between quality and bitrate. In the technical literature on image and video compression this is known as the rate-distortion function R(D). In the table below, the entries give the quality factor used to encode the test video where appropriate. Results: Codec File Size Compression Ratio/ Bitrate -------------------------------------------------------------------------- Raw 24 bit RGB (Full Frames Uncompressed) 66.187 MB 1:1 / 53 Mbps 30 frames per second 320 by 240 pixels a talking head with some hand waving Radius Cinepak (32-bit) 6.92 MB 9.6:1 / 5.5 Mbps Quality Factor 100, keyframe every 15 frames Compression Technology: Vector Quantization Intel Indeo 5.1 (32-bit) 4.41 MB 15.0:1 / 3.5 Mbps Quality Factor 85, keyframe every 15 frames Compression Technology: Wavelet Intel Indeo 5.1 (32-bit) 0.98 MB 67.8:1 / 784 Kbps Quality Factor 50, keyframe every 15 frames Compression Technology: Wavelet Intel Indeo 5.1 (32-bit) 0.81 MB 81.7:1 / 648 Kbps Quality Factor 25, keyframe every 30 frames Compression Technology: Wavelet Intel Indeo 4.3 (32-bit) 2.46 MB 26.9:1 / 2 Mbps Quality Factor 85 Compression Technology: "Hybrid Wavelet" Intel Indeo R3.2 (32-bit) 3.93 MB 16.8:1 / 3.1 Mbps Quality Factor 65, keyframe every 4 frames Version 3.24.15.03 Compression Technology: Vector Quantization Microsoft Video 1 (32-bit) 3.16 MB 20.7:1 / 2.5 Mbps Microsoft Video 1 Compressor Version 1.0 LOW QUALITY - NOTICABLY GRAINY Microsoft MPEG-4 (32-bit) 0.625 MB 105.9:1 / 500 Kbps MPEG-4 Video High Speed Compressor keyframe every 3600 frames Compression Control 0 Data Rate 128 Kilobits/second LOW QUALITY - BLOCKING ARTIFACTS Compression Technology: Block Discrete Cosine Transform Motion Compensation Intel Indeo Raw R1.2 (32-bit) 24.6 MB 2.7:1 / 19.7 Mbps Version 1.20.15.01 Intel I.263 H.263 (32-bit) 0.764 MB 86.6:1 / 612 Kbps keyframe every 15 frames Quality Factor 50 % LOW QUALITY - BLOCKING ARTIFACTS Compression Technology: Block Discrete Cosine Transform Motion Compensation Intel I.263 H.263 (32-bit) 1.99 MB 33.2:1 / 1.6 Mbps keyframe every 15 frames Quality Factor 100 % Compression Technology: Block Discrete Cosine Transform Motion Compensation Brooktree YUV 411 Raw 32.6 MB 2.0:1 / 26 Mbps BtV MediaStream Verson: 2.01 With a 160 by 120, 30 frames per second, 239 frame (7.996) second, 24 bit color video "Space Shuttle" sequence, from a NASA promotional video showing the launch of the space shuttle and some crowds watching and cheering. Here I was able to calculate and report the <A HREF="#PSNR">Peak Signal to Noise Ratio</A> (in dB, decibels), an objective measure of image and video quality. Codec File Size Compression Ratio/ Bitrate/<A HREF="#PSNR">PSNR</A> ----------------------------------------------------------------------- Full Frames (Uncompressed) 13.1 MB 1 : 1 / 13.5 Mbps 24 bits, 160 x 120, 30 fps / INFINITE Cinepak Codec by Radius [32] 0.85 MB 15.9 : 1 / 848 Kbps Version 1.8.0.12 / 31.08 dB Key frame every 15 frames Quality Factor 100 (DEFAULT ENCODING PARAMETERS) Cinepak Codec by Radius[32] 0.78 MB 17.7 : 1 / 780 Kbps Version 1.8.0.12 / 30.49 dB Key Frame every 15 frames Target Data Rate 100 KBytes/sec Quality Factor 100 Cinepak Codec by Radius[32] 0.42 MB 32.93 : 1 / 420 Kbps Version 1.8.0.12 / 27.087 dB Key Frame every 15 frames Target Data Rate 50 KBytes/sec Quality Factor 100 VISIBLE BLOCKING Cinepak Codec by Radius[32] 0.23 MB 59.6 : 1 / 231 Kbps Version 1.8.0.12 / 23.762 dB Key Frame every 15 frames Target Data Rate 25 KBytes/sec Quality Factor 100 HEAVY BLOCKING/UNACCEPTABLE VIDEO Intel Indeo 5.10 0.993 MB 13.2 : 1 / 992 Kbps Key frame every 15 frames / 32.43 dB Quality Factor 85 (DEFAULT ENCODING PARAMETERS) Intel Indeo 5.10 0.22 MB 59.6 : 1 / 216 Kbps Key frame every 15 frames / 29.6 dB Quality Factor 50 RINGING ARTIFACTS JUST VISIBLE Intel Indeo 5.10 0.177 MB 74 : 1 / 176 Kbps Key frame every 15 frames / 28.4 dB Quality Factor 25 RINGING ARTIFACTS Intel Indeo 5.10 0.158 MB 82.9 : 1 / 152 Kbps Key frame every 15 frames / 27.82 dB Quality Factor 10 RINGING ARTIFACTS Intel Indeo Video Interactive[32] 1.564 MB 8.8 : 1 / 1.564 Mbps Indeo V 4.11.15.62 / 28.686 dB Key frame every 15 frames Target Data Rate 1687 KBytes/sec Quality Factor 85 (DEFAULT) Intel Indeo Video Interactive[32] 0.732 MB 18.9 : 1 / 732 Kbps Indeo V 4.11.15.62 / 28.284 dB Key frame every 15 frames Target Data Rate DISABLED Quality Factor 85 Intel Indeo Video Interactive[32] 0.297 MB 46.5 : 1 / 297 Kbps Indeo V 4.11.15.62 / 26.622 dB Key frame every 15 frames Target Data Rate DISABLED Quality Factor 50 BLOCKING AND RINGING ARTIFACTS Intel Indeo Video Interactive[32] 0.256 MB 53.9 : 1 / 256 Kbps Indeo V 4.11.15.62 / 25.389 dB Key frame every 15 frames Target Data Rate DISABLED Quality Factor 25 HEAVY BLOCKING AND RINGING ARTIFACTS/UNACCEPTABLE Microsoft Video 1 5.198 MB 2.7 : 1 / 5.198 Mbps Key frame every 15 frames / 32.209 dB Quality Factor 100 SLIGHTLY GRAINY Microsoft Video 1 0.79 MB 17.5 : 1 / 790 Kbps Key frame every 15 frames / 30.286 dB Quality Factor 75 (DEFAULT) BANDING AND BLOCKING Microsoft Video 1 0.17 MB 82.8 : 1 / 166 Kbps Key frame every 15 frames / 23.915 dB Quality Factor 50 VERY BLOCKY/UNACCEPTABLE Microsoft Video 1 0.08 MB 163.7 : 1 / 84 Kbps Key frame every 15 frames / 18. 524 dB Quality Factor 25 VERY VERY BLOCKY/UNACCEPTABLE With a 160 by 120 pixel, 15 frames per second, 24 bit color version of the "Talking Head" 10 second video sequence, created by downsampling in space and time with Microsoft VidEdit 1.1 Codec File Size Compression Ratio/ Bitrate ------------------------------------------------------------------------ Full Frames Uncompressed 8.53 MB 1:1 / 6.816 Mbps 24 bit RGB 160 x 120 pixels 15 frames per second Cinepak from Radius (32 bit) 1.20 MB 7.1:1 / 960 Kbps Version 1.10.0.6 Quality Factor 100 Keyframe every 15 frames Intel Indeo 4.5 (32 bit) 0.677 MB 12.6:1 / 541 Kbps Quality Factor 85 Keyframe every 15 frames Intel Indeo R3.2 (32 bit) 0.98 MB 8.7:1 / 784 Kbps Version 3.24.15.03 Quality Factor 65 Keyframe every 4 frames Microsoft Video 1 0.947 MB 9:1 / 758 Kbps Quality Factor 75 SOME BLOCKING ARTIFACTS Intel Indeo Raw 1.2 3.25 MB 2.6:1 / 2.6 Mbps Intel I.263 H.263 0.67 MB 12.8:1 / 535 Kbps Intel Indeo 5.10 (32 bit) 0.973 MB 8.8:1 / 778 Kbps Quality Factor 85 Keyframe every 15 frames Intel Indeo 5.10 (32 bit) 0.367 MB 23.2:1 / 294 Kbps Quality Factor 50 Keyframe every 15 frames Intel Indeo 5.10 (32 bit) 0.339 MB 25.2:1 / 271 Kbps Quality Factor 25 No fixed keyframes LOW QUALITY - BLURRY Brooktree YUV 411 Raw 4.42 MB 1.9:1 / 3.536 Mbps <A HREF="#Top">Return to Top</A> <A NAME="QTCodec"> <H2>Which Video for Windows Codecs are Available for QuickTime on Apple Macintosh?</H2> </A> As of June 24, 1998, this is an incomplete list: Cinepak (formerly Apple Compact Video) The Video for Windows 1.1 Apple Macintosh utilities include QuickTime system extensions for: Microsoft Video 1 Microsoft Full Frames (uncompressed) Microsoft RLE (Run Length Encoding) Intel provided a QuickTime system extension for Intel Indeo 3.2. As of June 24, 1998 this was available at: <A HREF="http://developer.intel.com/ial/indeo/video/driver.htm"> http://developer.intel.com/ial/indeo/video/driver.htm</A> As of June 24, 1998 Intel did NOT provide QuickTime versions of Indeo 4.x or 5.x for the Apple Macintosh. Intel did provide a version of Indeo 4.4 for QuickTime for Windows. <A HREF="#Top">Return to Top</A> <A NAME="FourCC"> <H2>Microsoft Four Character Codes (FOURCC)</H2> </A> A Four Character Code or FOURCC is a four byte code defined by Microsoft as part of Video for Windows to identify various types of video data. Microsoft defined FOURCC's to uniquely identify pixel layouts and video compressor types in Video for Windows. For example, the FOURCC 'CVID' identifies the Cinepak (formerly Compact Video) video compressor. AVI files contain the FOURCC for the video compressor in the video stream header. In addition to codecs, Four Character Codes identify the pixel layouts used in uncompressed images and video. For example, codes such as 'YUY2' identify layouts of pixels in YUV space (as opposed to RGB). These codes are used in interfacing with graphics cards. For example, the S3 ViRGE/VX chip supports the YUY2 pixel layout. YUY2 is popular because it refers to the 4:2:2 format used in <A HREF="#CCIR601">CCIR-601</A> (D1) digital video. Video for Windows, Display Control Interface (DCI), and Direct Draw all use FOURCC's. Incomplete List of Four Character Codes for Video for Windows Codecs (This is followed by a list of Codes Registered with Microsoft) DIB Full Frames (Uncompressed) RGB Full Frames (Uncompressed) RAW Full Frames (Uncompressed) 0x00000000 Full Frames (Uncompressed) 0x00000000 indicates the hexadecimal value of the Four Character Code is zero. A Four Character Code 'AAAA' has hexadecimal value 0x41414141 where 0x41 is the ASCII code for 'A'. Some video capture and editing products will use the non-standard FOURCC 0x00000000 for uncompressed AVI video instead of the easier to understand 'DIB ' or 'RGB ' or 'RAW '. MSVC or CRAM or WHAM Microsoft Video 1 MRLE Microsoft Run Length Encoding IV31 Indeo 3.1/3.2 IV32 Indeo 3.1/3.2 CVID Cinepak (Radius) ULTI Ultimotion (IBM) MJPG Motion JPEG (Microsoft, Paradigm Matrix, video capture companies) IJPG Intergraph JPEG CYUV Creative YUV YVU9 Intel Indeo Raw YUV9 XMPG Editable (I frames only) MPEG (Xing) MPGI Editable MPEG (Sigma Designs) VIXL miro Video XL MVI1 Motion Pixels SPIG Radius Spigot PGVV Radius Video Vision TMOT Duck TrueMotion S DMB1 Custom Format Used by Matrox Rainbow Runner. This appears to be a type of Motion JPEG IV41 Indeo Interactive (Indeo 4.1 from Intel) IV50 Indeo 5.x, including 5.0, 5.06, and 5.10 UCOD ClearVideo (Iterated Systems) VDOW VDOWave (VDONet) SFMC Surface Fitting Method (CrystalNet) QPEG Q-Team Dr.Knabe 's QPEG video compressor H261 H.261 M261 Microsoft H.261 VIVO Vivo H.263 M263 Microsoft H.263 I263 Intel "I.263" H.263 MPG4 Microsoft MPEG-4 LIST OF CODES REGISTERED WITH MICROSOFT ( July 19, 1999 ) Compressor Code Description ANIM Intel - RDX AUR2 AuraVision - Aura 2 Codec - YUV 422 AURA AuraVision - Aura 1 Codec - YUV 411 BT20 Brooktree - MediaStream codec BTCV Brooktree - Composite Video codec CC12 Intel - YUV12 codec CDVC Canopus - DV codec CHAM Winnov, Inc. - MM_WINNOV_CAVIARA_CHAMPAGNE CPLA Weitek - 4:2:0 YUV Planar CVID Supermac - Cinepak CWLT reserved DUCK Duck Corp. - TrueMotion 1.0 DVE2 InSoft - DVE-2 Videoconferencing codec DXT1 reserved DXT2 reserved DXT3 reserved DXT4 reserved DXT5 reserved DXTC DirectX Texture Compression FLJP D-Vision - Field Encoded Motion JPEG With LSI Bitstream Format GWLT reserved H260 Intel - Conferencing codec H261 Intel - Conferencing codec H262 Intel - Conferencing codec H263 Intel - Conferencing codec H264 Intel - Conferencing codec H265 Intel - Conferencing codec H266 Intel - Conferencing codec H267 Intel - Conferencing codec H268 Intel - Conferencing codec H269 Intel - Conferencing codec I263 Intel - I263 I420 Intel - Indeo 4 codec IAN Intel - RDX ICLB InSoft - CellB Videoconferencing codec ILVC Intel - Layered Video ILVR ITU-T - H.263+ compression standard IRAW Intel - YUV uncompressed IV30 Intel - Indeo Video 3 codec IV31 Intel - Indeo Video 3.1 codec IV32 Intel - Indeo Video 3 codec IV33 Intel - Indeo Video 3 codec IV34 Intel - Indeo Video 3 codec IV35 Intel - Indeo Video 3 codec IV36 Intel - Indeo Video 3 codec IV37 Intel - Indeo Video 3 codec IV38 Intel - Indeo Video 3 codec IV39 Intel - Indeo Video 3 codec IV40 Intel - Indeo Video 4 codec IV41 Intel - Indeo Video 4 codec IV42 Intel - Indeo Video 4 codec IV43 Intel - Indeo Video 4 codec IV44 Intel - Indeo Video 4 codec IV45 Intel - Indeo Video 4 codec IV46 Intel - Indeo Video 4 codec IV47 Intel - Indeo Video 4 codec IV48 Intel - Indeo Video 4 codec IV49 Intel - Indeo Video 4 codec IV50 Intel - Indeo 5.0 MP42 Microsoft - MPEG-4 Video Codec V2 MPEG Chromatic - MPEG 1 Video I Frame MRCA FAST Multimedia - Mrcodec MRLE Microsoft - Run Length Encoding MSVC Microsoft - Video 1 NTN1 Nogatech - Video Compression 1 qpeq Q-Team - QPEG 1.1 Format video codec RGBT Computer Concepts - 32 bit support RT21 Intel - Indeo 2.1 codec RVX Intel - RDX SDCC Sun Communications - Digital Camera Codec SFMC Crystal Net - SFM Codec SMSC Radius - proprietary SMSD Radius - proprietary SPLC Splash Studios - ACM audio codec SQZ2 Microsoft - VXtreme Video Codec V2 SV10 Sorenson - Video R1 TLMS TeraLogic - Motion Intraframe Codec TLST TeraLogic - Motion Intraframe Codec TM20 Duck Corp. - TrueMotion 2.0 TMIC TeraLogic - Motion Intraframe Codec TMOT Horizons Technology - TrueMotion Video Compression Algorithm TR20 Duck Corp. - TrueMotion RT 2.0 V422 Vitec Multimedia - 24 bit YUV 4:2:2 format (CCIR 601). For this format, 2 consecutive pixels are represented by a 32 bit (4 byte) Y1UY2V color value. V655 Vitec Multimedia - 16 bit YUV 4:2:2 format. VCR1 ATI - VCR 1.0 VIVO Vivo - H.263 Video Codec VIXL Miro Computer Products AG - for use with the Miro line of capture cards. VLV1 Videologic - VLCAP.DRV WBVC Winbond Electronics - W9960 XLV0 NetXL, Inc. - XL Video Decoder YC12 Intel - YUV12 codec YUV8 Winnov, Inc. - MM_WINNOV_CAVIAR_YUV8 YUV9 Intel - YUV9 YUYV Canopus - YUYV compressor ZPEG Metheus - Video Zipper The following list shows the FOURCC values for DIB compression. Compressor Code Description CYUV Creative Labs, Inc - Creative Labs YUV FVF1 Iterated Systems, Inc. - Fractal Video Frame IF09 Intel - Intel Intermediate YUV9 JPEG Microsoft - Still Image JPEG DIB MJPG Microsoft - Motion JPEG DIB Format PHMO IBM - Photomotion ULTI IBM - Ultimotion VDCT Vitec Multimedia - Video Maker Pro DIB VIDS Vitec Multimedia - YUV 4:2:2 CCIR 601 for V422 YU92 Intel - YUV Extensive information on Microsoft's Four Character Codes (FOURCC) may be found at <A HREF="http://www.webartz.com/fourcc">Dave Wilson's The Almost Definitive FOURCC Definition List</A> Microsoft maintains a web page of FOURCC's for video, both pixel layouts and compression, with the FOURCC's registered with Microsoft. <A HREF="http://www.microsoft.com/hwdev/devdes/fourcc.htm">http://www.microsoft.com/hwdev/devdes/fourcc.htm</A> Microsoft has defined 128-bit (16 byte) identifiers known as Globally Unique Identifiers (GUIDs) to identify virtually everything in the Microsoft Universe. Microsoft has defined mappings from the Four Character Codes used for video and audio codecs to GUID's. <A HREF="#FOURCCGUID">GUIDs for Video for Windows Codecs</A> <A HREF="#Top">Return to Top</A> <A NAME="ALGO"> <H2>Video Compression Technologies</H2> </A> There are several underlying technologies used by different Video for Windows Codecs. For example, Indeo 3.2 and Cinepak both use Vector Quantization. The international standards MPEG-1, MPEG-2, MPEG-4, H.261, and H.263 all use a combination of the block Discrete Cosine Transform (DCT) and motion estimation/compensation. Several of the New Wave codecs use wavelet transform based image compression (the Discrete Wavelet Transform or DWT). Other technologies include Fractal Image Compression, represented by Iterated Systems. Some general comments on image and video compression: (1) Image compression may be lossless where no information is lost during the compression process. The image produced by the decompression (also known as decoding) process is identical bit by bit with the original image. The widely used GIF format is a lossless image and video (GIF89a or animated GIF) compression format. LOSSLESS COMPRESSION (2) Image compression may be lossy where information is lost during the compression process. These schemes exploit limitations of the human visual system. Some errors are undetectable by the human eye. Even though two images are different at the bit by bit level, the human viewer cannot distinguish them. Some errors are detectable by the human eye but acceptable. Some errors are detectable and very annoying. The widely used JPEG image compression standard is a lossy compression scheme. LOSSY COMPRESSION (3) Within lossy image and video compression, a compression scheme may be perceptually lossless, in which case the human viewer cannot distinguish between the original image or video and the decompressed compressed image or video which has errors introduced by the lossy compression. Most lossy image and video compression have some sort of quality factor or factors. If the quality is good enough, then the image will be perceptually lossless. PERCEPTUALLY LOSSLESS COMPRESSION (3) JPEG's and MPEG's and other lossy compression of images and video are often compressed beyond the point of perceptual losslessness, but the compressed images and video are still a