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Video Guide(S)VCD Guide DivX Guide XviD Guide Other Guide Dictionaries Site References last modified : 11 October 2006 DVD Guide
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3GP Stands for Third Generation Partnership Project sometimes called 3GPP it is a multimedia container format defined by 3GPP for use on 3G mobile phones. It is a simplified version of MPEG-4 Part 14 (MP4). 3GP files have the filename extension .3gp or .3g2. 3GP stores video streams as MPEG-4 or H.263, and audio streams as AMR-NB or AAC-LC formats. 3GP files are always big-endian, storing and transferring the most significant bytes first. 3GP also describes image sizes and bandwidth, so content is correctly sized for mobile display screens. Advanced Systems Format (formerly Advanced Streaming Format) is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media. ASF is part of the Windows Media framework. The format does not specify how the video or audio should be encoded; it just specifies the structure of the video/audio stream. This means that an ASF file could be encoded with virtually any audio/video codec. This is similar to the function performed by the QuickTime, AVI, or Ogg formats. One of the objectives of ASF was to support playback from digital media servers, HTTP servers, and local storage devices. ASF is based on serialized objects which are essentially byte sequences identified by a GUID marker. The most common filetypes contained within an ASF file are Windows Media Audio (WMA) and Windows Media Video (WMV). Before a movie can be played the player and the disc have to establish a secured communication line on which they can transfer the actual movie. Before they can establish that line they need to make sure that the right "person" is on the other side - this is done via several key exchanges, verifications, etc. Audio Video Interleave, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of the Video for Windows technology. AVI files contain both audio and video data in a standard container that allows simultaneous playback. Like DVDs, AVI files support multiple audio and video streams, although these features are rarely used. Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are known unofficially as "AVI 2.0". AVI is considered by many to be an outdated container format. There is significant overhead when used with popular MPEG-4 codecs (XviD and DivX, for example), increasing file size more than necessary. The container has no native support for those codecs' modern features like B-Frames. To circumvent this problem, cumbersome hacks (programming) are used, causing incompatibilities in some players. Hacks are also used to implement subtitles. The highly efficient H.264 codecs add even more compression tricks to the mix, and thus are even more ill-suited to the format, particularly Main and High Profile. is an image from a CD. Great for distributing a VCD on the web. BIN is the main file to create VCD by burning it to CD-R(W) with a burn program. The name Blu-ray Disc is derived from the blue-violet laser it uses to read and write to the disc. A Blu-ray Disc can store substantially more data than a DVD, because of the shorter wavelength (405 nm) of the blue-violet laser (DVDs use a 650-nm-wavelength red laser and CDs use an infrared 780 nm laser), which allows more information to be stored digitally in the same amount of space. In comparison to HD DVD, which also uses a blue laser, Blu-ray Disc has more information capacity per layer (currently 25GB, but test media is up to 200GB). Sony has released 50GB recordable BDs and will soon be releasing 50GB BD media discs. In August 2006, TDK developed a Blu-ray Disc with a 200GB capacity. A bup file is a Back UP file of an IFO file. These files are commonly found on DVDs. A cell is the smallest video unit on a DVD. Normally used to contain a chapter it can also be used to contain a smaller unit in case of multiangles or seamless branching titles. is a codec is a piece of software that allows you to encode something - usually audio or video - to a specific format and can decode media encoded in this specific format again. Popular Codecs: MPEG1, MPEG2, MPEG-4, Indeo, etc. AVI, ASF, etc is not a codec but a format - that can be encoded using different codecs. Content Scrambling System. Prioprietary scrambling system for video DVDs. Designed to stop people from making copies of DVDs, most commercial DVDs are encrypted using CSS. During playback, DVDs are then decrypted on the fly. Only parts of the DVD are encrypted (for instance all IFO and BUP files are not encrypted, and VIDEO_TS.VOB often isn't encrypted either) and the encryption scheme is rather weak and was quickly defeated. If you want to know what CSS does, insert a DVD video disc into your PC, start playing the disc using a software DVD player, then close the player. Now copy a 0.99GB VOB file from the disc to your harddisk and try to play back that VOB file in your software DVD player. You'll see a lot of funny colored blocks all over the picture making the movie unwatchable. But you'll also see parts of the movie (the parts that are not encrypted). stands for Display Aspect Ratio and indicates the dimension of a screen. Most PC screens have a DAR of 4:3, meaning that the horizontal size is 4/3 as large as the vertical size. For TVs we have a lot of old 4:3 displays and more and more 16:9 displays. As you can guess from the numbers 16:9 displays are broader than 4:3 displays having the same diagonal size. 16:9 screens are more suited to display Hollywood movies which are usually shot with an aspect ratio of 1:2.35 or 1:1.85 (meaning that the horizontal size of the picture is 1.85 times as wide as the vertical size). is the file that you see on the VCD. The DAT doesn't differs much from a MPG but you should always convert the DAT to MPG to edit or so. Discrete Cosine Transform is used for JPEG and MPEG. Deinterlacing is the process of creating a single frame from two fields (one contains odd lines and the other the even lines). is the opposite of multiplexing. In this process a combined audio/video stream will be separated into the number of streams it consists of (a video stream, at least one audio stream and a navigational stream). Every VOB encoder demultiplexes the VOB files before encoding and every DVD player does the same (audio and video are being treated by different circuits, or decoded by different filters on a pc). DVDs are usually CSS scrambled - imagine you decide to give a number to each letter, starting with 1 for a, etc. A sentence would become a couple of digits - that's what we call scrambled. Of course CSS is much better than that but it's still quite easy to crack. Descrambling means reversing the scrambling process, rendering our digits to a sentence again, or making our movie playable again - you can try to copy a movie to your hard disk when you've authenticated your DVD drive and play it, you'll get a garbled picture because it's still scrambled. Common CSS descramblers either use a pool of known descrambling keys (DeCSS or DODSrip - they contain a large number of keys but not all of them) or try to derive the key by a cryptographic attack (VobDec - that's why it works on most disc since it's not dependent on a pool of discs). is usually compressed since it'd take Terabytes - thousands of Gigabytes or for the mathematicians among you : 10^12 Bytes) to store a movie uncompressed. Since standard loss less compression is insufficient for video, the video codecs have to get rid of unimportant information - stuff the human eye won't see or is unlikely to see. Since that is still not enough modern compression algorithms use keyframes, I and P frames in order to save space. Digital8 is a cassette format to record DV on a Hi8 cassette. The speed is higher than normal Hi8 so on a 60-minute Hi8 tape, one can record 40 minutes. DirectX is an application program interface developed by Microsoft, first for Windows 95, for creating and managing graphic images and multimedia effects in applications such as games and active Web pages. It includes the DirectDraw API for direct access to video memory. obsolete DIVX (DIgital Video eXpress) system introduced by Circuit City '98. There are 2 flavors of DivX today: DivX ;) is the name of the hacked Microsoft Mpeg4 codecs (Windows Media Video V3). Those codecs were developed by Microsoft for use in its proprietary Windows Media architecture and initially supported encoding AVIs and ASFs but all non-beta versions included an AVI lock, making it impossible to use them to encode to the AVI format - and only a few tools support ASF today. What the makers of DivX did is remove that AVI lock making it possible to encode to AVI again, and changed the name to DivX video in order to prevent confusion of codecs, since it's possible to have both the unhacked and hacked codecs on the same computer if you use the Windows Media Encoder. The latest releases of DivX also include a hacked Windows Media Audio Codec called DivX audio - the hack of that codec is not perfect yet and its use is limited for higher bitrates. This codec is also known as DivX3. The other DivX is a brand-new MPEG-4 video codec developed by DivXNetworks. It offers much advanced encoding controls and 2 pass encoding. Furthermore the codec can play the old DivX ;) (DivX3) movies. The codec is commonly called DivX4. Dynamic Range Compression. AC3 Tracks contain a much larger dynamic range that most audio equipment can handle, therefore most standalone and software DVD player will compress the dynamic range somewhat, according to the actual dynamic range. In layman terms the volume will be augmented dymanically, e.g. explosions won't become louder or only a bit louder, whereas in normal dialogues the volume will be augmented quite a bit. Since your player will do the same this is the way to go to have augmented volume. DV is an acronym for Digital Video as a broad domain. DV is also a video standard used for mini-DV and Digital8 camcorders. DV is also a video cassette standard (60-180 minutes). DV is also used to describe camcorders that use the standard DV video cassettes. DVB is an acronym for Digital Video Broadcasting (transmission over satellite, terrestrial , cable, telco networks and IP-networks). An elementary stream is a single (video or audio) stream without container. For instance a basic MPEG-2 video stream (.m2v or .mpv) is an MPEG-2 ES, and on the audio side we have AC3, MP2, etc files that are ES. Most DVD authoring program require ES as input. The process of taking a raw uncompressed file and compressing it to an encoded form while maintaining the quality. A field is half the image in an interlaced frame. A field occupies alternate horizontal lines in a frame and is displayed for half the time of the frame. The Apple name for IEEE1394. Fast interface (100, 200 and 400Mbps) for transferring digital video. Also known as Firewire in the Apple world or i-Link for Sony products. IEEE1394 devices are "hot-swappable", allowing you to plug devices in and out without having to reboot your system. is a controller software which resides on a programmable chip within the drive itself (DVD/CD/Hard Drives). It's upgradable through Firmware Patch such as BIOS at PCs. stands for four character code and is a code that uniquely identifies a video data stream format. A movie player will look up the FourCC code then look for the codec associated to the FourCC code in order to play a certain video stream. A few examples: DIV3 = DivX Low-Motion, DIV4 = DivX Fast-Motion, DIVX = DivX4. A frame is the name for a picture in a movie. The basic source of a movie; one frame represents one image. A movie usually runs at 24 frames per second, equaling 24 different images per second. Imagine 24 images with a bird on it. In the first image, the bird is on the left, gradually moving to the right. On the 24th frame the bird is on the right end of the image. When these 24 images are played in sequence fast enough, the human eye sees a bird flying from left to right. Frameserving is using one utility to decode or read a video file and after it has been decoded, sending it straight to any other video editing or encoding application. The number of frames displayed per second. The standard frame rate for NTSC is 29.97fps, for PAL is 25fps and for FILM is 24fps. H.264, MPEG-4 Part 10, or AVC, for Advanced Video Coding, is a digital video codec standard which is noted for achieving very high data compression. It was written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). The ITU-T H.264 standard and the ISO/IEC MPEG-4 Part 10 standard (formally, ISO/IEC 14496-10) are technically identical. The final drafting work on the first version of the standard was completed in May of 2003. The intent of the H.264/AVC project was to create a standard that would be capable of providing good video quality at bit rates that are substantially lower (e.g., half or less) than what previous standards would need (e.g., relative to MPEG-2, H.263, or MPEG-4 Part 2), and to do so without so much of an increase in complexity as to make the design impractical (excessively expensive) to implement. An additional goal was to do this in a flexible way that would allow the standard to be applied to a very wide variety of applications (e.g., for both low and high bit rates, and low and high resolution video) and to work well on a very wide variety of networks and systems (e.g., for broadcast, DVD storage, RTP/IP packet networks, and ITU-T multimedia telephony systems). The HD DVD name is derived from its origination as a high-definition extension of the DVD optical disc format. A HD DVD disc can store substantially more data than a standard DVD, because of the shorter wavelength (405 nm) of the blue-violet laser (DVDs use a 650-nm-wavelength red laser and CDs an infrared 780 nm laser), which allows more information to be stored digitally in the same amount of physical space. In comparison to Blu-ray, which also uses a blue laser, HD DVD has less information capacity per layer (15 gigabytes instead of 25). HD DVD shares the same basic disc structure as a standard DVD: back-to-back bonding of two 0.6 mm thick, 120 mm diameter substrates. The 30 GB dual-layer HD DVDs have been used on nearly every movie released in this format. On the other hand, Blu-ray has only released movies on 25 GB single layer discs. High-definition television (HDTV) is a television broadcasting system with a significantly higher resolution than traditional formats (NTSC, SECAM, PAL) allow. Except for early analog formats in Europe and Japan, HDTV is broadcast digitally, and therefore its introduction sometimes coincides with the introduction of digital television (DTV): this technology was first introduced in the USA during the 1990s, by the Digital HDTV Grand Alliance (grouping together AT&T, General Instrument, MIT, Philips, Sarnoff, Thomson, and Zenith) While a number of high-definition television standards have been proposed or implemented on a limited basis, the current HDTV standards are defined in ITU-R BT.709 as 1080 active interlaced or progressive lines, or 720 progressive lines, using a 16:9 aspect ratio. The term "high-definition" can refer to the resolution specifications themselves, or more loosely to media capable of similar sharpness, such as photographic film. Hue is the overall gradation of color. Interlacing is the process of building a single video frame from two fields. The two fields are placed on alternate lines and are displayed in sequence at twice the frame rate. Frame describing only the differences to the frame before. Say we have a keyframe with a bird before a cloudy sky. Then we can use I frames which say something like this: move the bird an inch to the left and one inch to the bottom. The video information inside MPEG files is stored in the frequency domain rather than in the spatial domain (the images we see). That way, the information is compacted and that compactation can be used to compress (reduce) the amount of information you have to send over the transmission channel. MPEG uses the DCT (Discrete Cosine Transform) to translate spatial information into frequency information. To bring back the spatial information from the MPEG stream you have to apply the iDCT, that is, the Inverse Discrete Cosine Transform, that undoes the DCT that was used during encoding. DCT and iDCT are basically the same as DFT (discrete fourier transforms) but the results are integers rather than complex reals you get in i/DFT. For more info please refer to a university-level book about DSP, communication systems, or similar. Wavelets are an alternative basis space. There are infinitely many wavelet bases (Daubechies, Haar, Mexican Hat, "Spline", Zebra, etc.), but their primary feature is that they are localized. Fourier basis functions span all space (from negative to positive infinity). Wavelets are basically individual pulses of waves (at various positions and scales). Their value in compression stems from factors like the grouping, which generally shows that a good 90% of the data is modeled by the low-pass filters, with the high-pass filters generally showing very small values that are mostly details. (Of course, this is not true if the source is noisy in the first place). For images, the greatest value comes from localization of the basis, which means that we can model discontinuities (e.g. edges) VERY well with wavelets. You will NOT get those weird JPEG halos if you use wavelets InFOrmation file commonly found on DVDs. Such files contain navigational information for your DVD player. Interlaced is a video storage mode. An interlaced video stream doesn't contain frames (pictures as we know them) but fields with each field containing half of the lines of one frame (all even or all odd lines). Describes the process of gluing together the audio and the video track at defined points. The player will recognize the interleave points and make sure that both audio and video are played in a manner that the "glued" points match throughout the movie. The inverse of Telecine. This process is performed to extract the original 24fps of a 29.97fps source. JPEG is a acronym for Joint Picture Experts Group. JPEG is a bitmap file format which is popular for storing full color images. The format uses a user defined amount of lossy compression, meaning that there is a trade off between file size and image quality in that the more compression is used (smaller file sizes), the lower the quality of the image. A complete frame but heavily compressed. Black bars added on the top and the bottom of the pictue to display a large format (16:9, 2.35) on a 4:3 display. These two terms are used as extensions for MPEG-1 respectively MPEG-2 video data (video only, without any audio). Matroska (common file extensions being .mkv and .mka) is a project to develop an open source multimedia container format similar to Apple's QuickTime, MPEG's MP4 or Microsoft's Advanced Streaming Format. It is named after the Matryoshka doll. The Russian ???????? would be transliterated into the Roman alphabet as Matryoshka. The official playback solution for the Windows operating system is the Combined Community Codec Pack. Mini-DV is a video cassette standard identical to DV but for smaller cassettes (60 minutes). basically is a DVD on a CD-R(W). JPEG is an acronym for Motion Joint Picture Experts Group. Video compression format which compresses each frame individually with a technique very similar to the JPEG bitmap format. Multiple Mpeg 4: A combination of different bitrate encoded files. For instance you could take a 2000kbit/s encode, a 910kbit/s encode and combine the files together, use the lower bitrate file and replace scenes where the quality gets too bad due to a lot of action with the parts taken from the 2000kbit/s one. It also includes the use of both DivX codecs: You can combine DivX low motion and DivX high motion files (and once again you can choose different bitrates). MPEG-4 Part 14, formally, ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. It is most-commonly used to store digital audio and digital video streams, especially those defined by MPEG, but also can be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. The official filename extension for MPEG-4 Part 14 files is .mp4, thus the container format is often referred to simply as MP4. Devices that play .mp4 files are referred to as MP4 players. MPEG-4 Part 14 was based on Apple's QuickTime container format. Although MPEG-4 Part 14 still resembles the QuickTime format, it has been improved upon in many different ways. which stands for Moving Picture Experts Group, is the name of familly of standards (joint of the International Organization for Standardization [ISO]) used for coding audio and video data in a digital compressed format including data transmission across digital networks. MPEG Video files have the .mpg or .dat extension and MPEG Audio files generally have the extension .mp1, .mp2, .mp3. MPEG is cross-platform compatible and can be played on all popular computer systems. The major advantage of MPEG compared to other video and audio coding formats is that MPEG files are much smaller for the same quality (eg, mp3 size is about 1:10 compared to Audio CD). This is because MPEG uses very sophisticated compression techniques. MPEG-2: Transport, video and audio standards for broadcast-quality television. Used for over-the-air digital television ATSC, DVB and ISDB, digital satellite TV services like Dish Network, digital cable television signals, and (with slight modifications) for DVDs. MPEG-3: Originally designed for HDTV, but abandoned when it was discovered that MPEG-2 was sufficient for HDTV. MPEG-4: Expands MPEG-1 to support video/audio "objects," 3D content, low bitrate encoding and support for Digital Rights Management. Several new (newer than MPEG-2 Video) higher efficiency video standards are included (an alternative to MPEG-2 Video), notably, Advanced Simple Profile and Advanced Video Coding. MPEG-4 may be used on HD-DVD and Blu-Ray discs. MPEG-7: A formal system for describing multimedia content. MPEG-21: MPEG describes this standard as a multimedia framework. Multiangle is a special feature of the DVD format, allowing the viewer to switch between different views of the same scene. For instance, let's assume your favorite sport on TV is hockey. You've certainly noticed that there are many cameras recording a hockey game. And while the game is interrupted, you usually get to see slowmo scenes from different angles, be it of a goal scene, a foul or whatnot. While watching the game on TV, you only get the see the picture from the camera that the guy in the cutting room wants you to see. Now, if you get your favorite Stanley Cup final on DVD, the disc could include not only the game as seen on TV, but using the multiangle feature, contain the games from all the different perspectives it was recorded from (camera from the ceiling, cameras on the side, cameras from behind the goal), and while you're watching the game, you can press the Angle button on your remote to switch from one camera to another, or in DVD language, switch from one angle to another, and that's what multiangles is all about. A multimedia framework is a software structure (usually a set of software libraries) that handles media on a computer and through a network. A good multimedia framework offers an intuitive API and a modular architecture to easily add support for new codecs or container formats. It is meant to be used by applications such as media players and audio or video editors True multipass encoding is currently available only for WM8 and MPEG-2 (SVCD & miniDVD). An encoder supporting multipass will, in a first pass, analyze the video stream to be encoded and write down a log about everything it encounters. Let's assume we have a short clip that starts out in a dialog scene where we have few cuts and the camera remains static. Then it leads over to a karate fight with lots of fast cuts and a lot of action (people flying through the air, kicking, punching, etc.). In regular CBR, encoding every second gets more or less bitrate (it's hard to stay 100% CBR but that's a detail) whereas in multipass VBR mode the encoder will use the bitrate according to his knowledge about the video stream, i.e. the dialog part gets the available bitrate and the fighting scene gets allotted more bitrate. The more passes, the more refined the bitrate distribution will be. In single pass VBR, the encoder has to base his decisions on where to use how much bitrate solely on the knowledge of the stuff it previously has encoded. Video and audio are usually encoded separately. You have to join them to make a movie you can play (you can play audio and video separately in two players but to get synch would be rather hard). During multiplexing, the audio and video tracks are combined into one audio/video stream. The audio and video stream will be woven together and navigational information will be added so that the player can, for example fast forward/backward and still retain synch audio/video. Material eXchange Format (MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards. NTSC is an acronym for National Television Standards Committee. The standard for television pictures in the USA (525 lines, 29.97fps). The digital resolution of NTSC is 720x480. The acronym is also for Never The Same Colour which represents the weakness of this analog standard. NUT is a patent-free, multimedia container format originally conceived by a few MPlayer and FFmpeg developers that were dissatisfied with the limitations of all currently available multimedia container formats such as AVI or Matroska. It aims to be simple, extensible, compact and error resistant, thus addressing most if not all of the shortcomings present in alternative formats, like excessive CPU and size overhead, file size limit, inability to allow fine grained seeking or restrictions on the type of data they can contain. OGM stands for OGg Media which is the name of the Ogg container implementation by Tobias Waldvogel. OGM can be used as an alternative to the AVI container and it can contain Ogg Vorbis, MP3 and AC3 audio, all kinds of video formats, chapter information and subtitles. Fundamentally, the format is a hack of the Ogg container format, which has only been designed to support encoders endorsed by Xiph.org (website), the creators of Ogg. It is most likely going to be viewed as a temporary solution, to be phased out when other media container formats (for example, Matroska) mature and come to support the same services. PAL is an acronym for Phase Alternate Line. PAL is the standard for television pictures in most of Europe (625 lines, 25fps). The digital resolution of PAL is 720x576. As you know from going to the movie theater, movies are not shot in the format of your traditional computer screen (I say computers on purpose because in many European countries, the widescreen 16:9 TVs outsell traditional 4:3 format TVs these days - something which is not yet the case for computer screens). When movies are prepared for DVD or video (especially video), they can be presented either in the original widescreen 16:9 format, which leaves large black bars on top and bottom of the picture (but looks much better on widescreen TVs), or the picture can be resized and cut at the sides so that it will fill a 4:3 screen. The process of turning the original widescreen movie into one that fits your 4:3 screen is called pan & scan. stands for ProGram Chain. It is a term often used in DVD authoring it's basically one concurrent playback item. For instance the main movie has its own PGC, each trailer on a DVD usually has its own PGC. The studio logo that comes up when you enter the disc has its own PGC, etc. Both SmartRipper in Movie mode and DVD Decrypter in IFO mode will show you all PGCs a DVD has. For more info about PGCs visit MPUCoder's DVD information site. A program stream is a combination of elementary video and audio streams (ES). An MPEG-1 program stream contains MPEG-1 video and MPEG1 layer 2 audio (mp2) whereas an MPEG-2 program stream contains MPEG-2 video and MPEG1 layer 2 audio (mp2). The opposite of interlaced. A video stream consisting of only full frames is considered progressive. means Prohibited User Operations. It's a feature of the DVD format, allowing the person doing the authoring to prevent the user from executing certain functionality. For instance, you could activate a PUO that prevents people from fast forwarding / skipping an FBI warning before the main movie starts. Or, it could be used to force you to use the menu of the disc to change the audio language, by setting the PUO for audio switching (so the audio button on your remote won't do anything). To truly understand this term you'd have to take a course in signal processing. In laymen's terms it means compression factor. The higher this value the more compressed an image is (and therefore a high quantizer means low quality picture and small size whereas low quantizers means high quality picture and larger size). QuickTime is a multimedia framework developed by Apple Computer, capable of handling various formats of digital video, media clips, sound, text, animation, music, and several types of interactive panoramic images. The ability to contain abstract data references for the media data, and the separation of the media data from the media offsets and the track edit lists means that QuickTime is particularly suited for editing, as it is capable of importing and editing in place (without data copying) other formats such as AIFF, DV, MP3, MPEG-1, and AVI. Other later-developed media container formats such as Microsoft's Advanced Streaming Format or the open source Ogg and Matroska containers lack this abstraction, and require all media data to be rewritten after editing. RCE means Region Code Enhancement. Using the programming options that the DVD format offers (reading and writing to a number of registers available in all players), RCE is a more advanced version of region codes. It's a way studios try to prevent you from playing discs that are not sold in your region (don't have a matching region code). Old regionfree hardware players might have problems with RCE discs, but most modern regionfree players have no trouble playing such discs. Currently, discs using RCE use RCE-3 but I don't know if this means it's the 3rd version, or if the 3 has another meaning. Rendering is the process of drawing a video frame or calculating an audio ouput when editing video files. Refers to the number of pixels that an image has. For example, an image which has 720 pixels across and 480 pixels down is said to have a resolution of 720x480. RFF means repeat first frame, it's a technique used to make the necessary 29.97 frames per second out of a 24 frames per second source - the movie like it was recorded. Movies that are encoding using the rff flag - the flag tells the player to repeat one field. Tff means top field first and is also used to perform a telecine to make a 24fps movie into 29.97fps. Basically ripping means copying a DVD movie to your hard disk. This includes the authentication process for the DVD Drive (try to copy a file off a DVD and you'll get a message that this operation is not supported if your drive hasn't been authenticated) and the actual CSS Descrambling. CSS (Content Scrambling System) is a copy protection scheme designed to prevent unauthorized copying of DVD movies, although many argue that it was also designed to control where DVD movies can be played since without a CSS license you essentially have to crack the encryption to play a DVD movie. The term "ripping" is also often used (even on this site) to describe the whole process of descrambling a DVD, then convert the audio and video into another - lesser - format. RealMedia is a multimedia container format created by RealNetworks. It is typically used in conjunction with RealVideo and RealAudio and is popular for streaming content over the internet. Typically these streams are in CBR (constant bit rate). Recently RealNetworks has developed a new container for VBR (variable bit rate) streams, named RealMedia variable bitrate Support of RealMedia is available in a wide variety of multimedia players for different architectures/platforms. Some people who have found the RealMedia player to be too invasive, have created alternative software such as Real Alternative. Saturation is the strength of the colors in a video. Smart Bitrate Control. A new way to encode DivX;-). Using Nandub, it can modify many internal codec parameters on the fly during compression, giving you better quality and more control over the encoding. SMPTE, which stands for the Society of Motion Picture and Television Engineers, is a method of displaying time in the timecode. There are two ways that SMPTE can be displayed; non-drop or drop frame. Is represented by the display; hours, minutes, seconds and frame number, or 0:00:00:00. This format works the best when the source and destination video has a "whole number" for the number of frames per second. When using the NTSC frame rate (29.97 frames per second), time slipping is a potential problem. TIs represented by the display; hours, minutes, seconds and frame number, or 0:00:00:00. This format is only available for the NTSC frame rate of 29.97 frames per second to avoid the time slipping problems of SMPTE non-drop timecode. A streamlist is an ASCII test file that contains the pathnames and filenames of your VOB files, one file on every line. Here's a small example: e:\video_ts\vts_01_1.vob e:\video_ts\vts_01_2.vob e:\video_ts\vts_01_3.vob e:\video_ts\vts_01_4.vob e:\video_ts\vts_01_5.vob Save this file as streamlist.txt, or streamlist.lst. Make sure that you save it as unformatted ASCII text, we suggest you use notepad to edit your streamlists, since notepad won't save in another format. Mpeg2avi needs the streamlist to have the extension lst, whereas you're free to chose any other extension for other programs that use a streamlist. However the GUI is kind of limited in its choice for input files/extensions, therefore you might have to rename your streamlist, if it doesn't show up in the file selection dialog. Super Video CD, mainly used in Asian countries. Uses MPEG2 Video and therefore much better image quality - LaserDisc-like and also offers High quality surround sound. Furthermore it can take advantage of hardware decoders and there are players for many operating systems. However there are only a few - mostly Asian made low-end - DVD player that can play SVCD and other than SVCD player which are not sold in the US and Europe you can only play SVCDs on your computer. Video is MPEG2 at up to 2600kbit/s and audio MPEG1 audio layer 2 up to 224kbit/s. MPEG2 multichannel audio is also possible, but most players will only output 2 channels and those that will pass through 5.1 audio still require that you have an mpeg2 multichannel capable receiver. Process to transfer film (cinema) to video. It generates interlaced frame (3:2 for NTSC), a 24fps source to 29.97 for 29.97x2 interlaced fields per second. Timecode is how the running time of a file is shown; such as SMPTE (non-drop) and SMPTE (drop-frame). When using the NTSC frame rate of 29.97 frames per second, and the SMPTE non-drop timecode, the timecode will shift from "real" time due to the fact that there are only 29.97 frames per second in NTSC instead of the normal 30. This is called time slip. A video codec is a device or software module that enables video compression or decompression for digital video. The compression usually employs lossy data compression. Historically, video was stored as an analog signal on magnetic tape. Around the time when the compact disc entered the market as a digital-format replacement for analog audio, it became feasible to also begin storing and using video in digital form, and a variety of such technologies began to emerge. Video coding is the field in computer science that deals with finding efficient coding formats for digital video. Video data usually not only contains visual information but also audio. Therefore, it is often referred to as multimedia. Modern video coding standards even include other multimedia data such as synthetic computer graphics, text and meta information for searching/browsing and digital rights management. They also often provide mechanisms for user interaction. However, the most intensive parts of video data in terms of data size (memory demand, transmission bandwidth) remain (visual) video and audio data. These parts have to be compressed. Unfortunately, this can hardly be done without loss of quality (lossy compression), because of the enormous size of a lossless video stream. There are two special research areas that deal with multimedia compression: video compression and audio compression. Video coding has two distinct goals: storing and transmission of video data. These two goals have much in common. Therefore, video file formats usually have the same structure as streaming video formats with just a little header information added. Video compression refers to reducing the quantity of data used to represent video content without excessively reducing the quality of the picture. Digital video requires high data rates - the better the picture, the more data is ordinarily needed. This means powerful hardware, and lots of bandwidth when video is transmitted. However much of the data in video is not necessary for achieving good perceptual quality, e.g., because it can be easily predicted - for example, successive frames in a movie rarely change much from one to the next - this makes data compression work well with video. Video compression can make video files far smaller with little perceptible loss in quality. For example, DVDs use a video coding standard called MPEG-2 that makes the movie 15 to 30 times smaller while still producing a picture quality that is generally considered high quality for standard-definition video. Without proper use of data compression techniques, either the picture would look much worse, or one would need more such disks per movie. Video quality is a characteristic of video passed through a video processing system. Since the time when the first video sequence was recorded, lots of video processing systems have been designed. Different systems may have different influence on a video sequence, so video quality evaluation is a very important task. Video CD, works on many DVD players, there are software players on almost every operating systems, doesn't need a fast computer but the image is VHS-like. Video is MPEG1 at 1150kbit/s and audio MPEG1 audio layer 2 at 224kbit/s. Variable Keyframe Interval. Basically that means that keyframes will not be inserted in regular intervals as in the regular DivX codecs but where they are needed. There are 2 ways of VKI: The first is that the encoder analyzes the compressed frame, compares it against the original and reencodes the frame again as a keyframe if the quality difference is higher than a set threshold. This way of encoding is only possible with a certain special application: m4c. There's a command line based version and a plugin for AviUtl available (the latter is described in detail in the AviUtl guide). If you set the treshold too high you'll end up with a lot of keyframes. Then there's the 2nd way which is basically keyframe insertion at scene changes. In order to do that the encoding program or the codec will detect when there's a cut (as it's called by movie makers) occurr and make the first frame of the new scene a keyframe. This can be achieved by using mpeg2aviAr (part of AviRevolution 2.1), m4c or by installing the DivX VKI codec. If you use the latter you don't have to worry about the encoder... every program that can encode to DivX will then result in files that has keyframes at scene changes. VKI, when properly used (that applies to the first way), can help you increase quality and reduce the amount of keyframes, which may lead to higher quality again because especially at lower bitrates too many keyframes will give you a worse quality. Shorts version of VKI + MM4 + VBR MP3 VOB IDs are used to internally group cells in a PGC on a DVD. All DVD movies are stored in so-called VOB files. Vob files usually contain multiplexed Dolby Digital Audio and MPEG2 video. Vob Files are called as follows: vts_XX_y.vob where XX represents the title and Y the part of the title. There can be 99 titles and 10 parts, although VTS_XX_0.VOB does never contain any video, usually just menu or navigational information. There's 2 ways to find out which files contain the main movie: First: Play the movie in any DVD player and watch the LED on a standalone or the status window on a software player. Second: The main movie is the largest number of consecutively numbered VOB files. For instance it's vts_05_1.vob, vts_05_2.vob.... vts_05_8.vob VTS stands for Video TitleSet and means a set of consecutively named VOB files with the corresponding IFO and BUP files. For instance VTS2 would be VTS_02_0.VOB (containing the menus), VTS_02_1.VOB, VTS_02_2.VOB, etc, VTS_02_0.IFO and VTS_02_0.BUP. VTS are used to group video stuff together that belongs together. For instance one VTS is usually used for the main movie (sometimes including the trailer and some studio logos), other VTS are used for extras. Wavelets are an alternative basis space. There are infinitely many wavelet bases (Daubechies, Haar, Mexican Hat, "Spline", Zebra, etc), but their primary feature is that they are localized. Fourier basis functions span all space (from negative to positive infinity). Wavelets are basically individual pulses of waves (at various positions and scales). Their value in compression stems from factors like the grouping which generally shows that a good 90% of the data is modelled by the low-pass filters, with the high-pass filters generally showing very small values that are mostly details. (of course, this is not true if the source is noisy in the first place). For images, the greatest value comes from localization of the basis, which means that we can model discontinuities (e.g. edges) VERY well with wavelets. You will NOT get those weird JPEG halos if you use wavelets. is a Microsoft's proprietary architecture for audio and video on the pc. It's based on a collection of codecs which can be used by the WindowsMedia Player to play files encoded in any supported format. The current release of the Windows Media Player is version 7.0. WindowsMedia 7.0 offers a new set of codecs, among them a fully ISO compliant MPEG4 codec (called MS Windows Video V1), an improved MPEG-4 codec called MS Video V7, an encoder that supports Deinterlacing and Inverse Telecine. eXtended CD is an upcoming CD format which allows your CDs to be written in mode2 form 2 mode which basically means that it contains less error correction codes thus allowing you to store more data onto a single CD. XCD allows you to store 800 MB of data on a regular 700 MB CD. But as there's less error correction on the discs, XCDs are not very scratch resistant and it's suggested that you only put data that has additional error correction in the container (for instance OGM) on such CDs. XviD is a word play, read it the reverse way and you might find a familiar term. XviD is an open source MPEG-4 codec which depending on whom you're asking yields even better quality than the best DivX codec. Official XviD site. Site ReferencesMPEG-4 File Formats white paper |
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