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Demultiplex, Demultiplexing, Demux, Demuxing
Dolby Digital, AC3, AC-3
DVD Studio Pro
DVD+R DL, DVD+R9
DVHS is a digital recording and playback format for High Definition material. It's based on the existing 1/2" VHS-sized cassettes.
http://www.homecinemachoice.com/articles/frame.html?http://www.ho ... lVHS.shtml
A video resolution standard. In the NTSC system, "Full D1" means 720x480 pixels, and in the PAL and SECAM systems full D1 is 720x576. You also see "cropped D1", which is 704xNN, which is useful because the 8 pixels on either edge of the video frame aren't supposed to contain useful information. Therefore, some programs will prefer the cropped D1 resolution to save bandwidth. Other popular resolutions are often described in terms of D1: the SVCD resolution is 2/3 D1 (480xNN) and 352xNN is 1/2 D1. Occasionally you see SIF somewhat inaccurately described as 1/4 D1. videographica
The Discrete Cosine Transform is performed at the Block layer.
For MPEG-2 (ISO/IEC 13818-2), it's specified in the Annex A to the Recommendation.
The input of the DCT and the output of the inverse transform (IDCT) are 8x8 matrices of 9 bits/element, while the DCT coefficients are represented in 12 bits (-2048:+2047).
DCT is used to remove the spatial correlation existing among adjacent pixels in order to allow a more efficient entropy coding.
As DCT is performed to the 8x8 block, only the correlation inside the block can be removed. Besides, the subdivision of the image in 8x8 blocks for the DCT process is the cause of the typical block artifacts of all the DCT based compression algorithms.
If DCT and IDCT processes were performed with infinite precisions, they would be lossless; unfortunatly they are performed with limited integer precision so that, even without quantisation, they can produce some impairment.
The DCT coefficients have a relationship with spatial frequencies and, given that the different components have different subjective importance, DCT gives an important tool to remove also the subjective redundancy.
The first coefficient (0,0) is related to DC component, the coefficients of the first line are related to purely horizontal spatial frequencies, while those of the first column to purely vertical ones, the other coefficients are related to diagonal components.
A representation of DCT coefficients
The image on the left side is the original one, it has been divided in blocks of 8x8 elements for the DCT; the image on the right consists of 8x8 images, each of them represents a coefficient of the DCT and consists of the values that such coefficient takes in all the blocks the DCT has been performed to.
The relevance of the DC values and of the low frequencies values can be noted.
As MPEG-1 and MPEG-2 adopt hybrid DCT compression algorithm, DCT may be applied not only to sample-values (Intra blocks), but also to prediction error values (Non-Intra blocks). For the latter the DC coeffients are no more so important as for the former, but their relevance is quite similar to the other low frequencies coefficients'.
The process of creating a single frame from the 2 interlaced fields of a video frame. Deinterlacing is used to remove the interlacing artifacts if a still frame is required, or if the video is being used at a different rate than it was created. Extensive Info
Demultiplex, Demultiplexing, Demux, Demuxing
Splitting the video and audio to separate files. Also called "Demux".
Camcorder format which allows you to record digital-quality video onto standard Hi8 or 8mm tape. Most Digital8 camcorders also play back analog Hi8 and 8mm recordings, although they do not record in Hi8 or 8mm. A 120-minute Hi8/8mm tape yields one hour of recording when used with a Digital8 camcorder, giving you essentially the same stunning picture quality as you get with Mini DV (500 lines of horizontal resolution).
DiVA is a powerful MPEG-1/MPEG-2 video converter for Mac OS X 10.2 or later. It uses QuickTime, MPEG, MOV, SMP, AltiVec, YUV, Cocoa, Quartz, XML and other amazingly great acronyms and buzzwords. It's also fast, high quality, and integrates extremely well with 3ivx D4 4.5, allowing it to perform automated 2-pass encoding with 3ivx
DivX™ is a new format for digital video, much like MP3 is a format for digital music. DivX™ is the brand name of a patent-pending video compression technology created by DivXNetworks, Inc., (also known as Project Mayo). The DivX™ codec is based on the MPEG-4 compression standard. This codec is so advanced that it can reduce an MPEG-2 video (the same format used for DVD or Pay-Per-View) to ten percent of its original size. DivX.com.
DivX High Definition brings the Hollywood stars to your living room with just the click of a mouse. Supporting resolutions of up to 720p at bit rates as low as 4Mbps, DivX HD delivers astonishing video at one fifth the bit rate of broadcast HD. Download one of the samples from our HD showcase to experience the stunning video and dazzling audio quality of DivX HD today. http://www.divx.com/hd/
Dolby Digital, AC3, AC-3
Dolby Digital, or AC-3, is the common version containing up to 6 total channels of sound, with 5 channels for normal-range speakers (Right front, Center, Left Front, Right Rear and Left Rear) and one channel for the LFE, or subwoofer. The Dolby Digital format supports Mono and Stereo usages as well.
Colour video was slowly introduced into broadcast. It was therefore necessary to make it compatible with black and white receivers and to design colour receivers or televisions to be able to receive black and white programming as well. In order to accommodate the extra information needed for colour the b&w’s 30 frame/second rate was slowed to 29.97 f/s for colour. Although usually not an issue for non broadcast applications, in broadcast, the small difference between real time (or the wall clock) and the time registered on the video can be problematic. Over a period of 1 hour (SMPTE) the video will be 3.6 seconds or 108 extra frames longer in relation to the wall clock. To overcome this discrepancy drop frame is used.
Drop frame: Every frame :00 & :01 are dropped for each minute change (60 X 2 = 120) except for minutes with 0’s (00:, 10:, 20:, 30:, 40: & 50:) (6 X 2 = 12, 120 - 12 = 108)
Double Sided Dual Layer DVD. See DVD-18.
Data Search Information. Information for Fast Forward/Fast Backward and seamless playback. This is real time control data spread throughout the DVD-Video data stream. Along with PGCI, these packets are part of the 1.00 mbit/sec overhead in video applications (Book B). These packets contain navigation information which makes it possible to search and maintain seamless playback of the Video Object Unit (VOBU). The most important field in this packet is the sector address where the first reference frame of the video object begins. Advanced angle change and presentation timing are included to assist seamless playback.
Digital Subscriber Line - a telephone communication line that uses modulation technology to maximize the amount of data that can be sent over copper wires. DSL is used for broadband and voice connections from telephone switching stations to a subscriber with bitrates similar or slightly less than Cable Modem and greater speeds than ISDN.
Double Sided Single Layer DVD. See DVD-10.
Digital Theater Systems Digital Sound. A product of DTS, Inc., DTS is a multichannel audio compression format similar to Dolby Digital used in DVD-video discs, DVD-audio, 5.1 channel audio CDs, and some movie theaters. DTS differs from Dolby Digital in that it generally uses higher data rates and many have the opinion that DTS is better quality. DTS can only be on a DVD-video disc if accompanied by a Dolby Digital or LPCM track (for North America) or mpeg audio and LPCM (European Community) to ensure compatibility, because DVD players are only required to decode those standards in those regions. DTS Website
Digital TV, the standard for broadcasting picture and sound using digital signals, DTV allows for improvements in both picture and sound quality versus conventional Analog TV.
In USA can DTV be delivered in two basic formats: Standard analog Definition (SDTV) or High Definition (HDTV).
In Europe is DTV deliverd in DVB-formats.
USA DTV information.
Digital Video - video captured to a PC from a digital camcorder, often through Firewire. There are two methods of storing DV video data, referred to in this article as type-1 and type-2. Both are stored usually in AVI files. You should be aware of two salient points regarding these respective types to keep in mind when designing multimedia devices and their respective software drivers and utilities:
Any DV stored as type-1 cannot be used with VfW-based editors.
Microsoft provides DV encoder and decoder filters for DirectShow only, and will not provide support for encoding or decoding DV video data for VfW.
It is important to understand the format used to store video and audio in an AVI file for VfW.
Although an AVI file can have n number of streams, the most common case is one video stream and one audio stream. The stream format headers define the format (including compression) of each stream. The existence of one video stream, one audio stream, or both in an AVI file is a de facto standard for VfW.
A native DV stream, on the other hand, interleaves the video and audio data into a single stream. As stated in the introduction, Microsoft is defining two methods (type-1 and type-2) that developers can use for storing DV data in AVI files. The method chosen by a developer will impact the ease with which the data can then be used with current and future video editing applications.
The native DV interleaved stream that is produced and consumed in I/O with a DV device contains DV compressed video and pulse code modulated (PCM) audio data. This single interleaved stream can be stored in an AVI file as "ivas" stream (for interleaved video/audio stream). Microsoft refers to this format as a type-1 DV AVI file.
Because the type-1 format stores data as a single AVI stream, type-1 DV AVI files are not compatible with VfW. DirectShow, however, easily handles type-1 data streams by routing the streams to a DV Splitter filter that produces a DV-encoded video stream and one or more PCM audio streams for playback or subsequent processing.
Interleaved DV data can also be split into a single video stream and one to four audio streams within an AVI file. Microsoft refers to this format of storing DV data as type-2. This format has the advantage of being backward compatible with VfW, because it contains a standard video stream and at least one standard audio stream.
The type-2 file format requires a small amount of additional processing to split and multiplex the DV stream during the functions of capture and transmit to IEEE 1394 DV devices. MS Info
Free Type 1 to Type 2 Converter from Ulead
A device that can capture analog video like VHS, S-VHS, Hi8 and 8mm and convert it to DV. View our Capture Card list for DV Converters.
Also known as DV Time, a DV or MiniDV camcorder starts recording at 00:00:00. The timecode is drop frame for NTSC (minute differences in timing are made to get the film from 30 fps to 29.97 fps). DV Time is carried on the FireWire cable with the video, audio and Device Control. The biggest problem that arises with DV Time is that it resets to zero if the camera operator does not 'hook' to the end of the previously shot footage (there is an unrecorded gap between recordings).
If dealing with a miniDV or DVCAM tape with 'broken' timecode (that is in many parts), either do a clone copy to another DV tape so that the timecode is created continuously for the entire tape, or name each timecode section as a different tape.
DVB is an acronym for "Digital Video Broadcasting". DVB was set up by the EBU (European Broadcast Union) to set the standards for digital video transmission. They have published these via ETSI (European Telecommunications Standards Institute) who also set standards for devices such as GSM telephones. In fact there are several DVB standards for different transmission media.Some of these are:
DVB-SI Specification for Service Information
DVB-CI Common Interface for conditional access
DVD once stood for digital video disc or digital versatile disc, but now it just stands for DVD -- the next generation of optical disc storage technology. DVD is essentially a bigger, faster CD that can hold cinema-like video, better-than-CD audio, and computer data. DVD Demystified FAQ.
A DVD Player that can store 2 or more DVDs (DVD-Video, DVD-Audio) or CDs (CD Audio, VCD, SVCD...) and play them after each other.
DVD Studio Pro
DVD Studio Pro is a software application from Apple that makes it affordable and simple for non-specialists to encode, author, and write professional-quality DVD-Video discs on their Power Mac G4 desktops. If you're shooting and editing using digital video, you can now retain digital quality and precision all the way to the final product. DVD Studio Pro is in a class by itself because it is the only full-featured DVD authoring tool that is both affordable and easy to use.
DVD+Recordable defines a standard for recordable DVD drives and media defined by the DVDRW Alliance. Often called "plus R", the format is write once (compared to DVD+RW wich can be erased and rewritten). The single sided discs can hold 4,700,000,000 bytes (4.38 Gigabytes at 1024 bytes to the kilobyte) with double sided discs holding twice as much. There are no dual layer single sided recordable discs. This format competes with the DVD Forum DVD-R specification. DVDRhelp DVDR information
DVD+R DL, DVD+R9
DVD+R DL or called DVD+R9 is a Dual Layer writeable DVD+R. The dual layered discs can hold 7.95 GB or around 8 540 000 000 bytes (called DVD-9) and a double sided dual layered disc 15.9 GB or around 17 080 000 000 bytes (called DVD-18).
DVD+RW is a ReWriteable media format of the DVD+R standard.
DVD-10 is a double sided single layer DVD which can fit up to 9.4 GB or 8.7 computer GB. Video DVD, DVD-R/W and DVD+R/W supports this format.
DVD-18 is a double sided dual layer DVD which can fit up to 17 GB or 15.9 computer GB which some commercial video DVDs are using today (a DVD-18 is basicly four pressed plastic DVD-5s pressed together, they are not burned). Video DVD supports this format but DVD-R/W and DVD+R/W does not support this format.
DVD-5 is a single sided single layer DVD that stores up to about 4.7 GB = 4 700 000 000 bytes and that is 4.38 computer GigaBytes where 1 kilobyte is 1024 bytes(4 700 000 000B/1024 = about 4 589 843KB/1024 = about 4485MB/1024 = about 4.38GB) . Video DVD, DVD-R/W and DVD+R/W supports this format. Often referred to as "single sided, single layer". DVDRhelp DVD information
DVD-9 is a single sided dual layer DVD which can fit up to 8.5 GB or 7.95 computer GB which many commercial video DVDs are using today (a DVD-9 is basicly two pressed plastic DVD-5s pressed together, they are not burned). Video DVD supports this format but DVD-R/W and DVD+R/W does not support this format.
DVD-Audio or sometimes called DVD-A is a separate format from DVD-Video. It is a format specifically designed to provide the highest possible audio fidelity capable on DVD. DVD-Audio provides for audio in stereo and in multi-channel surround in a wide range of specifications. In addition to audio, a DVD-Audio disk can contain a limited amount of video, which can be used to display text, such as lyrics or notes. DVD-Audio can only be played on DVD Players with DVD-Audio support (most DVD Players do not support this format). DVD-Audio is currently competing with SACD as the new audio defacto standard. DigitalAudioGuide DVD Audio FAQ
This type of disc is created when MP3 audio files are burned on a DVDR/W disc. Very few MP3 capable standalone DVD players supports DVD-MP3 because most players verify DVDR/W as DVD-Video only (compatability list).
DVD-Recordable defines a standard for recordable DVD drives and media defined by the DVD Forum. Often called "minus R", the format is write once (compared to DVD-RW wich can be erased and rewritten). The single sided discs can hold 4,700,000,000 bytes (4.38 Gigabytes at 1024 bytes to the kilobyte) with double sided discs holding twice as much. This format competes with the DVD+R format. DVDRhelp DVDR information
DVD-R DL or called DVD-R9 is a Dual Layer writeable DVD-R. The dual layered discs can hold 7.95 GB or around 8 540 000 000 bytes (called DVD-9) and a double sided dual layered disc 15.9 GB or around 17 080 000 000 bytes (called DVD-18).
A recordable format supported by the DVD Forum. It has superior recording features but it is not compatible with most DVD-ROM drives or DVD Video players. It works well when set up like a removable hard disk.
DVD-RW is a ReWriteable media format of the DVD-R standard.
This is SVCD authored video on a DVDR/W. The DVD standard does not support the SVCD resolution but it may work anyway if the audio has been resampled to 48 khz like the DVD-VCD. Read more here about DVD-SVCD discs.
A DVD Player and a TV in same unit.
Basically this is VCD content authored on a DVDR/W. DVD supports the VCD resolution but the audio has to be resampled to 48 khz. Read more here how to make such a disc.
A DVD Player and VHS Video Recorder in same unit. DVD-VHS Combo DVD Players.
DVD-Video is the video element of the DVD format. DVD Demystified DVD-Video Features.
The format is known as "DVD dash VR" or DVD-VR. Its actually known from the DVD specification as DVD-RTRW for real-time read/write. One thing that makes it different from the "DVD Video" standard which is used by professionally repliacted DVD's is that the indexing for DVD-VR is forward only. This allows the "writing" of the disc image immediately without having to come up with some cludge to try to write a fully index'd DVD Video file. Burnworld DVD-VR Info
A term used to cover both the DVD-R and DVD+R standards in one word.
DVI stands for (D)igital (V)ideo (I)nterface. DVI is a new form of video interface technology made to maximize the quality of flat panel LCD monitors and high- end video graphics cards. It is a replacement for the P&D Plug & Display standard, and a step up from the digital-only DFP format for older flat panels. DVI is becoming increasingly popular with video card manufacturers, and most cards purchased include both a VGA and a DVI output port.
In addition to being used as the new computer interface, DVI is also coming out as the digital transfer method of choice for HDTV, EDTV, Plasma Display, and other ultra-high-end video displays for TV, movies, and DVDs. Likewise, even a few of the top-end DVD players are now featuring DVI outputs in addition to the high-quality analog Component Video. Don't expect to throw away all your old video cables just yet, but keep an eye out for DVI availability in the future.
DVR-MS (Microsoft Digital Video Recording) is a proprietary video and audio file format, developed by Microsoft. Video is encoded using the MPEG-2 standard and audio using MPEG-1 Layer II or Dolby Digital AC-3 (ATSC A/52). The format extends these standards by including metadata about the content and digital rights management.