Digital Video (DV) is a digital video format launched in 1996, and, in its smaller tape form factor MiniDV, has since become a standard for home and semi-professional video production; it is sometimes used for professional purposes as well, such as filmmaking and electronic news gathering (ENG). Digital video is a type of Video recording system that works by using a Digital rather than an analog video signal Filmmaking is the process of making a Film, from an initial story idea or commission through scriptwriting shooting editing and finally distribution to an audience ENG is a Broadcasting (usually Television) industry acronym which stands for electronic news gathering. The DV specification (originally known as the Blue Book, current official name IEC 61834) defines both the codec and the tape format. The International Electrotechnical Commission ( IEC) is a not-for-profit, non-governmental international Standards organization that prepares and publishes A codec is a device or program capable of encoding and/or decoding a Digital Data stream or signal. Features include intraframe compression for uncomplicated editing, a standard interface for transfer to non-linear editing systems (IEEE 1394, also known as FireWire), and good video quality, especially compared to earlier consumer analog formats such as Video8, Hi8 and VHS-C. Video compression refers to reducing the quantity of Data used to represent video images and is a straightforward combination of Image compression and Motion "NLE" redirects here For the standardized test see National Latin Examination. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently The 8 mm video format refers informally to three related Videocassette formats for the NTSC and PAL / SECAM television systems The 8 mm video format refers informally to three related Videocassette formats for the NTSC and PAL / SECAM television systems VHS-C is the compact VHS format introduced in 1982 and used primarily for consumer-grade compact Camcorders. DV now enables filmmakers to produce movies inexpensively, and is strongly associated with independent film and citizen journalism. An independent film, or indie film, is a film that is produced outside of the Hollywood Studio system, a series of oligopolistic practices by several Citizen journalism, also known as public or participatory journalism or democratic journalism, is the act of citizens "playing an active role in the

The high quality of DV images, especially when compared to Video8 and Hi8 which were vulnerable to an unacceptable amount of video dropouts and “hits", prompted the acceptance by mainstream broadcasters of material shot on DV. The low costs of DV equipment and their ease of use put such cameras in the hands of a new breed of videojournalists. Video journalism is a form of Broadcast journalism, where the production of video content in which the journalist shoots edits and often presents his or her own material Programs such as TLC’s Trauma: Life in the E.R. and ABC News’ Hopkins: 24/7 were shot on DV. Trauma Life in the ER is a medical-based Television Reality show that formerly ran on TLC from 1997 to 2002 and now CNN’s Anderson Cooper is perhaps the best known of the generation of reporter/videographers who began their professional careers shooting their own stories. Anderson Hays Cooper (born June 3 1967 is an American Emmy Award -winning Journalist, author and television personality

There have been some variants on the DV standard, most notably Sony's DVCAM and Panasonic's DVCPRO formats targeted at professional use. Sony's consumer Digital8 format is another variant, which is similar to DV but recorded on Hi8 tape. Digital8 (or D8) is a consumer digital videotape format developed by Sony, and introduced in 1999 Other formats such as DVCPRO50 utilize DV25 encoders running in parallel.

MiniDV tapes can also be used to record a high-definition format called HDV in cameras designed for this codec, which differs significantly from DV on a technical level as it uses MPEG-2 compression. HDV is a High-definition_video format that uses MPEG2 compression to record HD content onto tapes originally designed for standard definition DV recording MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" MPEG-2 is more efficient than the compression used in DV, in large part due to inter-frame/temporal compression. ^[1] This allows for higher resolution at bitrates similar to DV. On the other hand, the use of inter-frame compression can cause motion artifacts and complications in editing. ^[2] Nonetheless, HDV is being widely adopted for both consumer and professional purposes and is supported by many editing applications using either the native HDV format or intermediary editing codecs. ^[3]

Contents 1 Technical standards 1.1 Before compression 1.2 Video compression 1.3 Chroma subsampling 1.4 Audio 1.5 Connectivity 2 Physical format 2.1 MiniDV 2.2 DVCAM 2.3 DVCPRO 3 Memory in cassette 4 Other digital formats 5 Application software support 6 Mixing tapes from different manufacturers 7 See also 8 References 9 External links

Technical standards

Before compression

To avoid aliasing, optical low pass filtering is necessary (although not necessarily implemented in all camera designs). This article applies to signal processing including computer graphics Essentially, blurry glass is used to add a small blur to the image. This prevents high-frequency information from getting through and causing aliasing. Low-quality lenses can also be considered a form of optical low pass filtering.

Before arriving at the codec compression stage, light energy hitting the sensor is transduced into analog electrical signals. These signals are then converted into digital signal by an analog to digital converter (ADC or A/D). An analog-to-digital converter (abbreviated ADC, A/D or A to D) is an electronic integrated circuit which converts continuous signals to This signal is then processed by a digital signal processor (DSP) or custom ASIC and undergoes the following processes:

Processing of raw input into (linear) RGB signals: For Bayer pattern-based sensors (i. A digital signal processor ( DSP or DSP micro) is a specialized Microprocessor designed specifically for Digital signal processing, generally e. sensors utilizing a single CCD or CMOS and color filters), the raw input has to be demosaiced. A demosaicing Algorithm is a digital image process used to interpolate a complete image from the partial raw data received from the color-filtered For Foveon-based designs, the signal has to be processed to remove cross-talk between the color layers. The Foveon X3 sensor is a CMOS Image sensor for digital cameras designed by Foveon Inc In pixel-shifted 3CCD designs, a process somewhat similar to de-mosaicing is applied to extract full resolution from the sensor. Three-CCD or 3CCD is a term used to describe an imaging system employed by some still cameras Video cameras Telecine and Camcorders

Matrix (for colorimetry purposes): The digital values are matrixed to tweak the camera's color response to improve color accuracy and to make the values appropriate for the target colorimetry (SMPTE C, Rec. 709, or EBU phosphor chromaticities). ITU-R Recommendation BT709, more commonly know by the abbreviations Rec For performance reasons, this matrix may be applied after gamma correction and combined with the matrix that converts R'G'B' to Y'CbCr. YCbCr or Y'CbCr is a family of Color spaces used as a part of the Color image pipeline in Video and Digital photography systems

Electronic white balance may be applied in this matrix, or in the matrix operation applied after gamma correction.

Gamma correction: Gamma correction is applied to the linear digital signal, following the Rec. 601 transfer function (a power function of ^{1/0. 45}). Note that this increases the quantization error from before.

Matrix (R'G'B' to Y'CbCr conversion): This matrix converts the gamma-corrected R'G'B' values to Y'CbCr color space. YCbCr or Y'CbCr is a family of Color spaces used as a part of the Color image pipeline in Video and Digital photography systems YCbCr or Y'CbCr is a family of Color spaces used as a part of the Color image pipeline in Video and Digital photography systems Y'CbCr color space facilitates chroma subsampling. Chroma subsampling is the practice of encoding images by implementing less resolution for chroma Information than for luma information This operation introduces yet more quantization error, in large part due to a difference in the scale factors between the Y' and Cb and Cr components.

Chroma Subsampling: Since human vision has greater acuity for luminance than color, performance can be optimized by devoting greater bandwidth to luminance than color. Chroma subsampling approximates this by converting R'G'B' values into Y'CbCr color space. The Cb and Cr color difference components are stored at a lower resolution than the Y' (luma) component.

Sharpening is often used to counteract the effect of optical low pass filtering. Sharpening can be implemented via finite impulse response filters. A finite impulse response (FIR filter is a type of a Digital filter.

The data is now compressed using one of several algorithms including discrete cosine transform (DCT), adaptive quantization (AQ), and variable-length coding (VLC). A discrete cosine transform ( DCT) expresses a sequence of finitely many data points in terms of a sum of Cosine functions oscillating at different frequencies In Digital signal processing, quantization is the process of approximating a continuous range of values (or a very large set of possible discrete values by a relatively-small In Coding theory a variable-length code is a Code which maps source symbols to a variable number of bits

Video compression

DV uses DCT intraframe compression at a fixed bitrate of 25 megabits per second (25. A discrete cosine transform ( DCT) expresses a sequence of finitely many data points in terms of a sum of Cosine functions oscillating at different frequencies In Telecommunications and Computing, bitrate (sometimes written bit rate, data rate or as a Variable R or f b A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) 146 Mbit/s), which, when added to the sound data (1. 536 Mbit/s), the subcode data, error detection, and error correction (approx 8. 7 Mbit/s) amounts in all to roughly 36 megabits per second (approx 35. A megabit is a unit of Information or computer storage abbreviated Mbit (or Mb) 382 Mbit/s). At equal bitrates, DV performs somewhat better than the older MJPEG codec, and is comparable to intraframe MPEG-2. In Multimedia, Motion JPEG ( M-JPEG) is an informal name for multimedia formats where each Video frame or Interlaced field of a Digital video MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" (Note that many MPEG-2 encoders for real-time acquisition applications only use intraframe compression [I-frames only], but not interframe compression [P and B frames]. ) DCT compression is lossy, and sometimes suffers from artifacting around small or complex objects such as text. A lossy compression method is one where compressing data and then decompressing it retrieves data that may well be different from the original but is close enough to be useful The DCT compression has been specially adapted for storage onto tape. The image is divided into macroblocks, each consisting of 4 luminance DCT blocks and 1 chrominance DCT block. Furthermore 6 macroblocks, selected at positions far away from each other in the image, are coded into a fixed amount of bits. Finally, the information of each compressed macroblock is stored as much as possible into one sync-block on tape. All this makes it possible to search video on tape at high speeds, both forward and reverse, as well as to correct very well faulty sync blocks.

Chroma subsampling

The chroma subsampling is 4:1:1 for NTSC, 4:1:1 for DVCPRO PAL, and 4:2:0 for other PAL. Chroma subsampling is the practice of encoding images by implementing less resolution for chroma Information than for luma information NTSC ( National Television System Committee) is the Analog television system used in the United States, Canada, Japan, Mexico PAL, short for Phase Alternating Line, is a colour -encoding system used in Broadcast television systems in large parts of the world Not all analog formats are outperformed by DV. The Betacam SP format, for example, can still be desirable because it has slightly greater chroma fidelity and no digital artifacts. Betacam is a family of half-inch professional Videotape products developed by Sony from 1982 onwards

Low chroma resolution is a reason why DV is sometimes avoided in applications where chroma-key will be used. Chroma Key is the name under which ex- Dream Theater Keyboardist Kevin Moore records Nevertheless, advances in keying software (i. e. the combination of chroma keying with different keying techniques,^[4] chroma interpolation^[5]) allows for reasonable quality keys from DV material.

Audio

DV allows either 2 digital audio channels (usually stereo) at 16 bit resolution and 48 kHz sampling rate, or 4 digital audio channels at 12 bit resolution and 32 kHz sampling rate. Stereophonic sound, commonly called stereo, is the reproduction of Sound, using two or more independent audio channels through a Symmetrical Sampling theorem The Nyquist–Shannon sampling theorem states that perfect reconstruction For professional or broadcast applications, 48 kHz is used almost exclusively. In addition, the DV spec includes the ability to record audio at 44. 1 kHz (the same sampling rate used for CD audio), although in practice this option is rarely used. DVCAM and DVCPRO both use locked audio while standard DV does not. This means that at any one point on a DV tape the audio may be +/- ⅓ frame out of sync with the video. However, this is the maximum drift of the audio/video sync; it is not compounded throughout the recording. In DVCAM and DVCPRO recordings the audio sync is permanently linked to the video sync.

Connectivity

The FireWire (aka IEEE 1394) serial data transfer bus is not a part of the DV specification, but co-evolved with it. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently Nearly all DV cameras have an IEEE 1394 interface and analog composite video and Y/C outputs. Composite video is the format of an Analog television (picture only signal before it is combined with a sound signal and modulated onto an RF Super Video or Separated Video abbreviated S-Video and also known as Y/C is an analog video signal that carries the video data as two separate High end DV VTRs may have additional professional outputs such as SDI, SDTI or analog component video. VTR redirects here For other meanings see VTR (disambiguation. Serial digital interface (SDI refers to a family of Video interfaces standardized by SMPTE. Serial Data Transport Interface is a way of transmitting data packets over a Serial Digital Interface datastream This article is about analog component video for the processing of color components in digital video see Digital video, Chroma subsampling and YCbCr All DV variants have a timecode, but some older or consumer computer applications fail to take advantage of it. Some camcorders also feature a USB2 port for computer connection, but these are sometimes not capable of capturing the DV stream in full detail, and are instead used primarily for transferring certain digital data from the camcorder such as still pictures and computer-format video files (such as MPEG4-encoded video). MPEG-4 is a collection of methods defining compression of audio and visual (AV digital data This carries Audio Video and Control Signals.

On computers, DV streams are usually stored in container formats such as MOV, MXF, AVI or Matroska. Material eXchange Format ( MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards The Matroska Multimedia Container is an Open standard free Container format, a File format that can hold an unlimited number of video audio

Physical format

The DV format uses "L-size" cassettes, while MiniDV cassettes are called "S-size". Both MiniDV and DV tapes can come with a low capacity embedded memory chip (MIC) (most commonly, a scant 4 Kbit for MiniDV cassettes, but the system supports up to 16 Kbit). This embedded memory can be used to quickly sample stills from edit points (for example, each time the record button on the camcorder is pressed when filming, a new "scene" timecode is entered into memory). DVCPRO has no "S-size", but an additional "M-size" as well as an "XL-size" for use with DVCPRO HD VTRs. All DV variants use a tape that is ¼ inch (6. Inches redirects here To see the Les Savy Fav album see Inches. 35 mm) wide.

MiniDV

The "L" cassette is about 120 × 90 × 12 mm and can record up to 4. VHS-C is the compact VHS format introduced in 1982 and used primarily for consumer-grade compact Camcorders. 6 hours of video (6. 9 hours in EP/LP). The better known MiniDV "S" cassettes are 65 × 48 × 12 mm and hold either 60 or 90 minutes of video (13 or 19. 5 GB) depending on whether the video is recorded at Standard Play (SP) or Extended Play (sometimes called Long Play) (EP/LP). 80 minute tapes that use thinner tape are also available and can record 120 minutes of video in EP/LP mode. The tapes sell for as little as US$3. 00 each in quantity as of 2006. DV on SP has a helical scan track width of 10 micrometres, while EP uses a track width of only 6. Helical scan is a method of recording high bandwidth signals onto Magnetic tape. A micrometre ( American spelling: micrometer; symbol µm) is one millionth of a Metre, or equivalently one thousandth of a Millimetre 7 micrometres. Since the tolerances are much tighter, the recorded tape may not play back properly or at all on other devices.

Software is currently available for ordinary home computers which allows users to record any sort of computer data on MiniDV cassettes using common DV decks or camcorders. Though originally intended for the consumer market as a high-quality replacement for VHS, L-size DV cassettes are largely nonexistent in the consumer market, and are generally used only in professional settings. Even in professional markets, most DV camcorders support only MiniDV, though many professional DV VTRs support both sizes of tape.

DVCAM

Sony's DVCAM is a professional variant of the DV standard that uses the same cassettes as DV and MiniDV, but transports the tape 33% faster. Digital Video (DV is a Digital video format created by Sony JVC Panasonic and other video camera procuers and launched in 1995 and in its smaller tape Form factor This leads to a higher track width of 15 micrometres. This variant uses the same codec as regular DV. However, the greater track width lowers the chances of dropout errors. The LP mode of consumer DV is not supported. All DVCAM recorders and cameras can play back DV material, but DVCPRO support was only recently added to some models like DSR-1800, DSR-2000, DSR-1600. Digital Video (DV is a Digital video format created by Sony JVC Panasonic and other video camera procuers and launched in 1995 and in its smaller tape Form factor DVCAM tapes (or DV tapes recorded in DVCAM mode) have their recording time reduced by one third.

Because of wider track DVCAM has the ability to do a frame accurate insert tape edit. DV will vary by a few frames on each edit compared to the preview. Another feature of DVCAM is locked audio. If several generations of copies are made on DV, the audio sync may drift. On DVCam this does not happen. ^[6]

DVCPRO

Panasonic specifically created the DVCPRO family for electronic news gathering (ENG) use, with better linear editing capabilities and robustness. ENG is a Broadcasting (usually Television) industry acronym which stands for electronic news gathering. Linear video editing is the process of selecting arranging and modifying the images and sound recorded on Videotape whether captured by a Video camera, generated It has an even greater track width of 18 micrometres and uses another tape type (Metal Particle instead of Metal Evaporated). Additionally, the tape has a longitudinal analog audio cue track. Audio is only available in the 16 bit/48 kHz variant, there is no EP mode, and DVCPRO always uses 4:1:1 color subsampling (even in PAL mode). Apart from that, standard DVCPRO (also known as DVCPRO25) is otherwise identical to DV at a bitstream level. However, unlike Sony, Panasonic chose to promote its DV variant for professional high-end applications.

DVCPRO50 is often described as two DV-codecs in parallel. The DVCPRO50 standard doubles the coded video bitrate from 25 Mbit/s to 50 Mbit/s, and uses 4:2:2 chroma subsampling instead of 4:1:1. DVCPRO50 was created for high-value ENG compatibility. The higher datarate cuts recording time in half (compared to DVCPRO25), but the resulting picture quality is reputed to rival Digital Betacam. Betacam is a family of half-inch professional Videotape products developed by Sony from 1982 onwards

DVCPRO HD, also known as DVCPRO100, uses four parallel codecs and a coded video bitrate of approximately 100 Mbit/s, depending on the format flavour. DVCPRO HD encodes using 4:2:2 color sampling. DVCPRO HD prefilters the 720p image from the DSP to a recorded size of 960x720, and 1080i is prefiltered to 1280x1080 for 59. 94i and 1440x1080 for 50i. This is a common technique, utilized in most tape-based HD formats such as HDCam and HDV. The final DCT compression ratio is approximately 6. 7:1. To maintain compatibility with HDSDI, DVCPRO100 equipment upsamples video during playback. Serial digital interface (SDI refers to a family of Video interfaces standardized by SMPTE. A camcorder using a special variable-framerate (from 4 to 60 frame/s) variant of DVCPRO HD called VariCam is also available. All these variants are backward compatible but not forward compatible. In Technology, especially Computing (irrespective of platform a product is said to be backward compatible when it is able to take the place of an older product Forward compatibility (sometimes confused with Extensibility) is the ability of a system to gracefully accept Input intended for later versions of itself DVCPRO-HD is codified as SMPTE 370M; the DVCPRO-HD tape format is SMPTE 371M, and the MXF Op-Atom format used for DVCPRO-HD on P2 cards is SMPTE 390M.

DVCPRO cassettes are always labeled with a pair of run times, the smaller of the two being the capacity for DVCPRO50. A "M" tape can hold up to 66/33 minutes of video. The color of the lid indicates the format: DVCPRO tapes have a yellow lid, longer "L" tapes made specially for DVCPRO50 have a blue lid and DVCPRO HD tapes have a red lid. The formulation of the tape is the same, and the tapes are interchangeable between formats. The running time of each tape is 1x for DVCPRO, ½x for DVCPRO 50, ½x for DVCPRO HD EX, and ¼x for DVCPRO HD, since the tape speed changes between formats. Thus a tape made 126 minutes for DVCPRO will last approximately 32 minutes in DVCPRO HD.

Memory in cassette

Some MiniDV cassettes have a small memory chip referred to as memory in cassette (MIC). Cameras and recording decks can record any data desired onto this chip including a contents list, times and dates of recordings, and camera settings used. It is EEPROM memory using the I²C protocol. I²C ( Inter-Integrated Circuit) is a multi-master serial Computer bus invented by Philips that is used to attach low-speed peripherals The members of the MIC range are available in two forms:

The MIC-R family 

The MIC-R family works with serial EEPROM capacities between 1 Kbit and 8 Kbit (the I²C-compatible EEPROM devices: M24C01, M24C02, M24C04 and M24C08).

The MIC-S family 

The MIC-S family works with serial EEPROM capacities greater or equal to 16 Kbit (the XI2C-compatible EEPROM devices: M24C16, M24C32 and M24C64).

Both families are compliant with the DV standard. For detailed information see datasheet: Serial I²C bus EEPROM (STMicroelectronics).

MIC functionality is not widely used on the consumer level; most tapes available to consumers do not even include the chip, which adds substantially to the price of each cassette. Most consumer equipment includes the circuitry to read and write to the chip even though it is rarely used.

Other digital formats

Digital video dates back to 1986, with the creation of the uncompressed D-1 format for professional use (although several professional video manufacturers such as Sony, Ampex, RCA, and Bosch had experimentally developed prototype digital video recorders dating back to the mid-to-late 1970s). is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with Ampex ( is an American electronics company founded in 1944 by Alexander M RCA Corporation, founded as Radio Corporation of America, was an electronics company in existence from 1919 to 1986 Robert Bosch GmbH is a German diversified technology-based corporation which was started in 1886 by Robert Bosch in Stuttgart Germany.

Sony has several digital specifications for professional use, the most common for standard definition use being Digital Betacam, a distant descendant of the Betamax products of the 1970s thru 1990s from which it received only some mechanical aspects, notably the form of the cassette. Betacam is a family of half-inch professional Videotape products developed by Sony from 1982 onwards ---- Betamax is a home Videocassette tape recording format developed by Sony, and released on May 10, 1975. (Betamax itself descended from Sony's U-Matic ¾ inch videocassette system. )

JVC's D-9 format (also known as Digital-S) is very similar to DVCPRO50, but records on videocassettes in the S-VHS form factor. ( usually referred to as JVC, is an International consumer and professional electronics Corporation based in Yokohama, Japan which was founded D-9 or Digital S as it was originally known is a professional digital videotape format created by JVC in 1995 D-9 or Digital S as it was originally known is a professional digital videotape format created by JVC in 1995 Introduced in Japan in 1987, S-VHS ( Super VHS) is an improved version of the VHS standard for consumer Video cassette recorders (NOTE: D-9 is not to be confused with D-VHS, which uses MPEG-2 compression at a significantly lower bitrate. D-VHS is a Digital video format developed by JVC, in collaboration with Hitachi, Matsushita, and Philips. MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information" )

The Digital8 standard uses the DV codec, but replaces the recording medium with the older Hi8 videocassette. Digital8 (or D8) is a consumer digital videotape format developed by Sony, and introduced in 1999 A codec is a device or program capable of encoding and/or decoding a Digital Data stream or signal. The 8 mm video format refers informally to three related Videocassette formats for the NTSC and PAL / SECAM television systems Digital8 theoretically offers DV's digital quality, without sacrificing playback of existing analog Video8/Hi8 recordings. However, in practice the maximum quality of the format is unlikely to be achieved, since Digital8 is largely confined to low-end consumer camcorders. It is also a semi-proprietary format, being manufactured exclusively by Sony (although Hitachi also made Digital8 camcorders briefly).

DVD was originally created as a distribution format, but recordable DVDs quickly became available. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is DVD recordable and DVD rewritable refer to DVD Optical disc formats that can be recorded (written "burned" either write once Camcorders using miniDVD media are fairly common on the consumer level, but due to difficulties with editing the MPEG-2 data stream, they are not widely used in professional settings. There are two types of MiniDVDs. 80 mm DVD, which are smaller versions of the 120 mm DVD cDVD, which are standard

Sony also made a format called MicroMV, which stored MPEG-2 video on a matchbox-sized tape. MicroMV was a videotape format introduced in 2001 by Sony. This cassette is physically smaller than a Digital8 or DV cassette Due to lack of platform support and the difficulties of editing MPEG-2 video, MicroMV never became popular and was discontinued by 2005.

Ikegami's Editcam System can record in DVCPRO or DVCPRO50 format on a removable hard disk. Editcam is a professional digital camera system manufactured by Ikegami and first introduced in 1995, available both as professional Camcorders and modular A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device

Panasonic's P2 system uses recording of DV/ DVCPRO/ DVCPRO50/ DVCPROHD streams in an MXF wrapper on PC card-compatible flash memory cards. DVCPRO P2 (P2 is short form for "Professional Plug-In" is a professional digital video storage media format introduced by Panasonic in 2004, and especially In Computing, PC Card (originally '''PCMCIA''', or PCMCIA Card is the Form factor of a peripheral interface designed for Laptop computers Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed

Sony's XDCAM format allows recording of MPEG IMX, DVCAM and low resolution streams in an MXF wrapper on a Sony ProDATA disc, an optical medium similar to a Blu-ray Disc. XDCAM is tapeless professional video system introduced by Sony in 2003 Material eXchange Format ( MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards Sony has also, in cooperation with Panasonic, created AVCHD, a medium-independent codec for consumer high definition video; it is currently used on camcorders containing hard disks, SD cards and DVD-R drives for storage. AVCHD ( Advanced Video Codec High Definition) is a high-definition and Standard-definition recording format for use in digital Tapeless camcorders A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device Secure Digital ( SD) is a non-volatile Memory card format developed by Matsushita, SanDisk, and Toshiba for use in DVD-R is a DVD recordable format A DVD-R typically has a storage capacity of 4

Application software support

Most DV players, editors and encoders only support the basic DV format, but not its professional versions. DV Audio/Video data can be stored as raw DV data stream file (data is written to a file as the data is received over FireWire, file extensions are . dv and . dif) or the DV data can be packed into AVI container files. The DV meta-information is preserved in both file types.

Most Windows video software only supports DV packed into AVI containers, as they use Microsoft's avifile. Microsoft Windows is a series of Software Operating systems and Graphical user interfaces produced by Microsoft. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer dll, which only supports reading avi files. A few notable exceptions exist:

• The Apple Inc.'s QuickTime Player: QuickTime by default only decodes DV to half of the resolution to preserve processing power for editing capabilities. Apple Inc, ( formerly Apple Computer Inc, is an American Multinational corporation with a focus on designing and manufacturing Consumer electronics QuickTime is a Multimedia framework developed by Apple Inc, capable of handling various formats of Digital video, Media clips sound text However, in the "Pro" version the setting "High Quality" under "Show Movie Properties" enables full resolution playback.

• DVMP Basic & DVMP Pro: full decoding quality. Plays AVI (inc DVCPRO25 and DVCAM) and . dv files. Also displays the DV meta-information (e. g. timecode, date/time, f-stop, shutter speed, gain, white balance etc)
• The VLC media player (Free software): full decoding quality
• MPlayer (also with GUI under Windows): full decoding quality
• muvee Technologies autoProducer 4. Free software or software libre is Software that can be used studied and modified without restriction and which can be copied and redistributed in modified or unmodified MPlayer is a free and Open source media player. The program is available for all major Operating systems including Linux muvee Technologies is a Singapore -based software company that produces automated video editing software for the consumer PC market 0: Allows editing using FireWire IEEE 1394
• Quasar DV codec (libdv) - open source DV codec for Linux

Type 1 and Type 2 DV AVI files

There are two types of DV-AVI files:

• Type 1: The multiplexed Audio-Video is kept in its original multiplexing and saved together into the Video section of the AVI file
  • Does not waste much space (audio is saved uncompressed, but even uncompressed audio is tiny compared to the video part of DV), but Windows applications based on the VfW API do not support it. The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently Video for Windows (VfW also referred to as Video Compression Manager (VCM was a Multimedia framework developed by Microsoft that allowed Microsoft Windows
• Type 2: Like type 1, but audio is also saved as an additional audio stream into the file.
  • Supported by VfW applications, at the price of little increased file size.

Type 1 is actually the newer of the two types. Microsoft made the "type" designations, and decided to name their older VfW-compatible version "Type 2", which only furthered confusion about the two types. In the late 1990s through early 2000s, most professional-level DV software, including non-linear editing programs, only supported Type 1. One notable exception was Adobe Premiere, which only supported Type 2. Adobe Premiere Pro is a Real-time, timeline based Video editing software application High-end FireWire controllers usually captured to Type 1 only, while "consumer" level controllers usually captured to Type 2 only. Software is and was available for converting Type 1 AVIs to Type 2, and vice-versa, but this is a time-consuming process.

Many current FireWire controllers still only capture to one or the other type. However, almost all current DV software supports both Type 1 and Type 2 editing and rendering, including Adobe Premiere. Thus, many of today's users are unaware of the fact that there are two types of DV AVI files. In any event, the debate continues as to which – Type 1 or Type 2 – if either, is better.

Mixing tapes from different manufacturers

There is controversy over whether or not using tapes from different manufacturers can lead to dropouts. [1][2][3] The problem theoretically occurs when incompatible lubricants on tapes of different types combine to become tacky and deposit on tape heads. This problem was supposedly fixed in 1997 when manufacturers reformulated their lubricants, but users still report problems several years later. Much of the evidence relating to this issue is anecdotal or hearsay. In one case, a representative of a manufacturer (unintentionally) provided incorrect information about their tape products, stating that one of their tape lines used "wet" lubricant instead of "dry" lubricant. [4] The issue is complicated by OEM arrangements: a single manufacturer may make tape for several different brands, and a brand may switch manufacturers. An original equipment manufacturer, or OEM is typically a company that uses a component made by a second company in its own product or sells the product of the second company

It is unclear whether or not this issue is still relevant, but as a general rule many DV experts recommend sticking with one brand of tape.

See also

• Digital8
• Camcorder
• MPEG
• Video quality
• Formats:
  • HDV and its variant, ProHD
  • MicroMV
  • DVD

References

External links

• DVworkshops.com Free DV Video Handbook. Cameras, Lights and Interview techniques
• Adam Wilt's DV page with in-depth technical information
• Tips and training for working with DVCPROHD, HDV and DV.
• Digital Video Information Network messageboards
• Technical Documentation on the storage of DV data in AVI files: short and in detail

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