DV (from Digital Video) is a family of codecs and tape formats used for storing digital video, launched in 1995 by a consortium of video camera manufacturers led by Sony and Panasonic. It includes the recording or cassette formats DV, MiniDV, DVCAM, Digital8, HDV, DVCPro, DVCPro50 and DVCProHD. DV has been used primarily for video recording with camcorders in the amateur and professional sectors.
DV was designed to be a standard for home video using digital data instead of analog.[1] Compared to the analog Video8/Hi8, VHS-C and VHS formats, DV features a higher video resolution (on par with professional-grade Digital Betacam) and also records audio digitally at 16-bit like CD.[2] The most popular tape format using a DV codec was MiniDV; these cassettes measured just 6.35 mm/¼ inch, making it ideal for video cameras and rendering older analog formats obsolete.[2] In the late 1990s and early 2000s, DV was strongly associated with the transition from analog to digital desktop video production, and also with several enduring "prosumer" camera designs such as the Sony VX-1000.[3]
In 2003, DV was joined by a successor format called HDV, which used the same tapes but with an updated video codec with high-definition video; HDV cameras could typically switch between DV and HDV recording modes.[4] In the 2010s, DV rapidly grew obsolete as cameras using memory cards and solid-state drives became the norm, recording at higher bitrates and resolutions that were impractical for mechanical tape formats. Additionally, as manufacturers switched from interlaced to superior progressive recording methods, they broke the interoperability that had previously been maintained across multiple generations of DV and HDV equipment.
Development
DV was developed by the HD Digital VCR Association: in April 1994, 55 companies worldwide took part, which developed the standards and specifications of the format.[5]
The original DV specification, known as Blue Book, was standardized within the IEC61834 family of standards. These standards define common features such as physical videocassettes, recording modulation method, magnetization, and basic system data in part 1. Part 2 describes the specifics of video systems supporting 525-60 for NTSC and 625-50 for PAL.[6] The IEC standards are available as publications sold by IEC and ANSI.
Closely following the ITU-RRec. 601 standard, DV video employs interlaced scanning with the luminance sampling frequency of 13.5MHz. This results in 480 scanlines per complete frame for the 60Hz system, and 576 scanlines per complete frame for the 50Hz system. In both systems the active area contains 720 pixels per scanline, with 704 pixels used for content and 16 pixels on the sides left for digital blanking. The same frame size is used for 4:3 and 16:9 frame aspect ratios, resulting in different pixel aspect ratios for fullscreen and widescreen video.[8][9]
Prior to the DCT compression stage, chroma subsampling is applied to the source video in order to reduce the amount of data to be compressed. Baseline DV uses 4:1:1 subsampling in its 60Hz variant and 4:2:0 subsampling in the 50Hz variant. Low chroma resolution of DV (compared to higher-end digital video formats) is a reason this format is sometimes avoided in chroma keying applications, though advances in chroma keying techniques and software have made producing quality keys from DV material possible.[10]
Audio can be stored in either of two forms: 16-bit Linear PCMstereo at 48kHz sampling rate (768kbit/s per channel, 1.5Mbit/s stereo), or four nonlinear 12-bit PCM channels at 32kHz sampling rate (384kbit/s per channel, 1.5Mbit/s for four channels). In addition, the DV specification also supports 16-bit audio at 44.1kHz (706kbit/s per channel, 1.4Mbit/s stereo), the same sampling rate used for CD audio.[11] In practice, the 48kHz stereo mode is used almost exclusively.
Digital Interface Format
The audio, video, and metadata are packaged into 80-byte Digital Interface Format (DIF) blocks which are multiplexed into a 150-block sequence. DIF blocks are the basic units of DV streams and can be stored as computer files in raw form or wrapped in such file formats as Audio Video Interleave (AVI), QuickTime (QT) and Material Exchange Format (MXF).[12][13] One video frame is formed from either 10 or 12 such sequences, depending on scanning rate, which results in a data rate of about 25Mbit/s for video, and an additional 1.5Mbit/s for audio. When written to tape, each sequence corresponds to one complete track.[8]
Baseline DV employs unlocked audio. This means that the sound may be +/- ⅓ frame out of sync with the video. However, this is the maximum drift of the audio/video synchronization; it is not compounded throughout the recording.
Variants
Sony and Panasonic created their proprietary versions of DV aimed toward professional & broadcast users, which use the same compression scheme, but improve on robustness, linear editing capabilities, color rendition and raster size.
All DV variants except for DVCPRO Progressive are recorded to tape within interlaced video stream. Film-like frame rates are possible by using pulldown. DVCPROHD supports native progressive format when recorded to P2 memory cards.
DVCPRO
DVCPRO compatibility mark
Diagram of DVCPRO tape track layout
DVCPRO, also known as DVCPRO25 and D-7, is a variation of DV developed by Panasonic and introduced in 1995, originally intended for use in electronic news gathering (ENG) equipment.
Unlike baseline DV, DVCPRO uses locked audio, meaning the audio sample clock runs in sync with the video sample clock.[14] Audio is available in 16-bit/48kHz precision.
When recorded to tape, DVCPRO uses wider track pitch—18 μm vs. 10 μm of baseline DV[15]—which reduces the chance of dropout errors during recording. Two extra longitudinal tracks provide support for audio cue and for timecode control. Tape is transported 80% faster compared to baseline DV, resulting in shorter recording time. Long Play mode is not available.
DVCPRO50
DVCPRO50 compatibility mark
Panasonic AJ-D950 DVCPRO50 VCR
DVCPRO50 was introduced by Panasonic in 1997 and is often described as two DV codecs working in parallel.
The DVCPRO50 doubles the coded video data rate to 50Mbit/s. This has the effect of cutting total record time of any given storage medium in half. Chroma resolution is improved by using 4:2:2 chroma subsampling.
A similar format, D-9 (or Digital-S), offered by JVC, uses videocassettes with the same form-factor as VHS.
Comparable high quality standard definition digital tape formats include Sony's Digital Betacam, introduced in 1993, and MPEGIMX, introduced in 2000.
DVCPRO Progressive
DVCPRO Progressive compatibility mark
DVCPRO Progressive was introduced by Panasonic alongside DVCPRO50. It offered 480 or 576 lines of progressive scan recording with 4:2:0 chroma subsampling and four 16-bit 48kHz PCM audio channels. Like HDV-SD, it was meant as an intermediate format during the transition time from standard definition to high definition video.[16][17]
The format offered six modes for recording and playback: 16:9 progressive (50Mbit/s), 4:3 progressive (50Mbit/s), 16:9 interlaced (50Mbit/s), 4:3 interlaced (50Mbit/s), 16:9 interlaced (25Mbit/s), 4:3 interlaced (25Mbit/s).[18]
The format was superseded by DVCPROHD.
DVCPRO HD
DVCPRO HD compatibility mark
Panasonic AJ-HDX900 DVCPRO camcorder pictured in 2018
DVCPRO HD, also known as DVCPRO100 and D-12, is a high-definition video format that can be thought of as four DV codecs that work in parallel. Video data rate depends on frame rate and can be as low as 40Mbit/s for 24 frame/s mode and as high as 100Mbit/s for 50/60 frame/s modes. Like DVCPRO50, DVCPRO HD employs 4:2:2 color sampling. It was introduced in 2000.[19]
DVCPRO HD uses smaller raster size than broadcast high definition television: 960x720 pixels for 720p, 1280x1080 for 1080/59.94i and 1440x1080 for 1080/50i. Similar horizontal downsampling (using rectangular pixels) is used in many other magnetic tape-based HD formats such as HDCAM. To maintain compatibility with HD-SDI, DVCPRO100 equipment upsamples video during playback.
Variable framerates (from 4 to 60 frame/s) are available on Varicam camcorders. DVCPRO HD equipment offers backward compatibility with older DV/DVCPRO formats.
When recorded to tape in standard-play mode, DVCPROHD uses the same 18 μm track pitch as other DVCPRO flavors. A long play variant, DVCPROHD-LP, doubles the recording density by using 9 μm track pitch.
DVCPROHD is codified as SMPTE 370M; the DVCPROHD tape format is SMPTE 371M, and the MXF Op-Atom format used for DVCPROHD on P2 cards is SMPTE 390M.
While technically DVCPRO HD is a direct descendant of DV, it is used almost exclusively by professionals. Tape-based DVCPROHD cameras exist only in shoulder mount variant.
A similar format, Digital-S (D-9 HD), was offered by JVC and used videocassettes with the same form-factor as VHS.
The main competitor to DVCPRO HD was HDCAM, offered by Sony. It uses a similar compression scheme but at higher bitrate.
DVCAM
DVCAM compatibility mark
In 1996, Sony responded with its own professional version of DV called DVCAM.[20]
Like DVCPRO, DVCAM uses locked audio, which prevents audio synchronization drift that may happen on DV if several generations of copies are made.[21]
When recorded to tape, DVCAM uses 15 μm track pitch, which is 50% wider compared to baseline.[15] Accordingly, tape is transported 50% faster, which reduces recording time by one third compared to regular DV. Because of the wider track and track pitch, DVCAM has the ability to do a frame-accurate insert edit, while regular DV may vary by a few frames on each edit compared to the preview.
Digital8 is a combination of the tape transport originally designed for analog Video8 and Hi8 formats with the DV codec. Digital8 equipment records in DV format only, but usually can play back Video8 and Hi8 tapes as well.
The table below show the physical DV cassette formats at a glance:
Cassette formats
DV
DVCPRO
DVCAM
Small S-size / "MiniDV"
Only made MiniDV adapters
Medium M-size
-
-
Large L-size
Extra Large XL-size
-
-
DV was originally designed for recording onto magnetic tape. Tape is enclosed into videocassette of four different sizes: small, medium, large and extra-large. All DV cassettes use 1⁄4 inch (6.4mm) wide tape. DV on magnetic tape uses helical scan, which wraps the tape around a tilted, rotating head drum with video heads mounted to it. As the drum rotates, the heads read the tape diagonally. DV, DVCAM and DVCPRO use a 21.7mm diameter head drum at 9000rpm. The diagonal video tracks read by the heads are 10 microns wide in DV tapes.[15][24]
Technically, any DV cassette can record any variant of DV video. Nevertheless, manufacturers often label cassettes with DV, DVCAM, DVCPRO, DVCPRO50 or DVCPRO HD and indicate recording time with regards to the label posted. Cassettes labeled as DV indicate recording time of baseline DV; another number can indicate recording time of Long Play DV. Cassettes labeled as DVCPRO have a yellow tape door and indicate recording time when DVCPRO25 is used; with DVCPRO50 the recording time is half, with DVCPRO HD it is a quarter. Cassettes labeled as DVCPRO50 have a blue tape door and indicate recording time when DVCPRO50 is used. Cassettes labeled as DVCPRO HD have a red tape door and indicate recording time when DVCPRO HD-LP format is used; a second number may be used for DVCPRO HD recording, which will be half as long.
Panasonic stipulated use of a particular magnetic-tape formulation—metal particle (MP)—as an inherent part of its DVCPRO family of formats. Regular DV tape uses Metal Evaporate (ME) formulation (which, as the name suggests, uses physical vapor deposition to deposit metal onto the tape[25]), which was pioneered for use in Hi8 camcorders. Early Hi8 ME tapes were plagued with excessive dropouts, which forced many shooters to switch to more expensive MP tapes. After the technology improved, the dropout rate was greatly reduced, nevertheless Panasonic deemed ME formulation not robust enough for professional use. Tape-based professional Panasonic DVCPRO camcorders and decks only record onto DVCPRO-branded cassettes, effectively preventing use of ME tape.
Small size (MiniDV)
MiniDV markA MiniDV tape (centre) size comparison against a Video8 tape (left) and VHS tape (right)
Small cassettes (66 x 48 x 12.2mm),[26] also known as S-size or MiniDV cassettes, had been intended for amateur use, but have become accepted in professional productions as well. MiniDV cassettes are used for recording baseline DV, DVCAM, and HDV. These cassettes come in lengths up to about 14~20.8GB for 63 or 90 minutes of DV or HDV video.[27] When recording in DVCAM, these cassettes hold up to 41 minutes of video. There are some 83-minute versions but these use thinner tape than the 63-minute ones and Panasonic advised against playing these cassettes in DVCPRO decks.
Medium size
Adapter to place a MiniDV cassette to use with DVCPRO
Medium or M-size cassettes (97.5 × 64.5 × 14.6mm),[26] which are about the size of eight-millimeter cassettes, are used in professional Panasonic equipment and are often called DVCPRO tapes. Panasonic video recorders that accept medium cassette can play back from and record to medium cassette in different flavors of DVCPRO format; they will also play small cassettes containing DV or DVCAM recording via an adapter. These cassettes come in lengths up to 66 minutes for DVCPRO, 33 minutes for DVCPRO50 and DVCPRO HD-LP, and 16.5 minutes for the original DVCPRO HD.
Large size
DVCAM cassettes in both miniDV and large sizeA 126-minute L-size Maxell DVCPRO cassette
Large or L-size cassettes (125.1 x 78 x 14.6mm)[26] are close in size to small MII cassettes and are accepted by most standalone DV tape recorders and are used in many shoulder-mount camcorders. The L-size cassette can be used in both Sony and Panasonic equipment; nevertheless, they are often called DVCAM tapes. Older Sony decks would not play large cassettes with DVCPRO recordings, but newer models can play these and M-size DVCPRO cassettes. These cassettes come in lengths up to 276 minutes of DV or HDV video (or 184 minutes for DVCAM). Unlike the VHS and Digital8 formats that use thinner tape for their longest-length variants, the 276-minute DV cassette employs the same tape as its shorter-length variants. On the DVCPRO side, these cassettes have nearly double the tape capacity of their M-size counterparts, with duration up to 126 minutes for DVCPRO, 63 minutes for DVCPRO50 and DVCPRO HD-LP, and 31.5 minutes for the original DVCPRO HD.[discuss] A thin-tape 184/92/46-minute version was also released.[citation needed]
Extra-large size
Extra-large cassettes or XL-size (172 x 102 x 14.6mm)[26] are close in size to VHS cassettes and have been designed for use in Panasonic equipment and are sometimes called DVCPROXL. These cassettes are not widespread, only a few models of Panasonic tape recorders can accept them. Each XL-size cassette holds nearly double the amount of tape as the full-length L-size cassettes with a capacity of 252 minutes of DVCPRO video or 126 minutes of DVCPRO50 or DVCPRO HD-LP video.
A disassembled MiniDV cassetteMini-DV tape mechanism inside an early 2000s Panasonic Palmcorder. Quarter for scale.
Panasonic DVCPROHD and AVC-Intra camcorders can record DV (as well as DVCPRO) onto P2 cards.
Some Panasonic AVCHD camcorders (AG-HMC80, AG-AC130, AG-AC160) record DV video onto Secure Digital memory cards.
JVC GY-HM750 can be set to standard definition mode and in this case will record '.AVI or .MOV SD legacy format' video onto SDHC cards. For clarity - and contrary to what has previously been written, the camera does not natively support SxS memory cards, has no slots for them and requires an optional add-on recorder (or 'adapter' as JVC call it) to achieve this - basically this camera is an 'XDCAM EX' High definition unit and the add-on SxS recorder was only made available to achieve better compatibility in facilities which were Sony based.
Most DV and HDV camcorders can feed live DV stream over IEEE 1394 interface to an external file-based recorder.
Video is stored either as native DIF bitstream or wrapped into an audio/video container such as AVI, QuickTime or MXF.
DV-DIF is the raw form of DV video. The files usually have extensions *.dv or *.dif.
DV-AVI is Microsoft's implementation of DV video file, which is wrapped into an AVI container. Two variants of wrapping are available: with Type 1 the multiplexed audio and video is saved into the video section of a single AVI file, with Type 2 video and audio are saved as separate streams in an AVI file (one video stream and one to four audio streams). This container is used primarily on Windows-based computers, though Sony offers two tapeless recorders, the HDD-based HVR-DR60[28] and the CompactFlash-based HVR-MRC1K,[29] for use with DV/HDV camcorders that can record in DV-AVI format either making a file-based copy of the tape or bypassing tape recording altogether. Panasonic AVCHD camcorders use Type 2 DV-AVI for recording DV video onto Secure Digital memory card.[30]
QuickTime-DV is DV video wrapped into QuickTime container. This container is used primarily on Apple computers.
MXF-DV wraps DV video into MXF container, which is presently used on P2-based camcorders (Panasonic) and on XDCAM/XDCAM EX camcorders (Sony).
Connectivity
Panasonic AJ-D455 VCR for professional video use with IEEE 1394 port and DV capability
Nearly all DV camcorders and decks have IEEE 1394 (FireWire, i.LINK) ports for digital video transfer. This is usually a two-way port, so that DV video data can be output to a computer (DV-out), or input from either a computer or another camcorder (DV-in). The DV-in capability makes it possible to copy edited DV video from a computer back onto tape, or make a lossless copy between two mutually connected DV camcorders. However, models made for sale in the European Union usually had the DV-in capability disabled in the firmware by the manufacturer because the camcorder would be classified by the EU as a video recorder and would therefore attract higher duty;[31] a model which only had DV-out could be sold at a lower price in the EU.
When video is captured onto a computer it is stored in a container file, which can be either raw DV stream, AVI, WMV or QuickTime. Whichever container is used, the video itself is not re-encoded and represents a complete digital copy of what has been recorded onto tape. If needed, the video can be recorded back to tape to create a full and lossless copy of the original footage.
Some camcorders also feature a USB 2.0 port for computer connection. This port is usually used for transferring still images, but not for video transfer. Camcorders that offer video transfer over USB usually do not deliver full DV quality; usually it is 320x240 video, except for the Sony DCR-PC1000 camcorder and some Panasonic camcorders that provide transfer of a full-quality DV stream via USB by using the UVC protocol. Full-quality DV can also be captured via USB or Thunderbolt by using separate hardware that receives DV data from the camcorder over a FireWire cable and forwards it without any transcoding to the computer via a USB cable[32] or a Firewire to Thunderbolt adapter[33] - this can be particularly useful for capturing on modern laptop computers which usually do not have a FireWire port or expansion slot but always have USB or Thunderbolt ports.
High end cameras and VTRs may have additional professional outputs such as SDI, SDTI or analog component video. All DV variants have a time code, but some older or consumer computer applications fail to take advantage of it.
Usage
A consumer-grade Sony Handycam MiniDV camcorderA Panasonic DV videorecorder (VCR)
The high quality of DV images, especially when compared to Video8 and Hi8 which were vulnerable to an unacceptable number 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.[citation needed]
My First Kiss and the People Involved (Luigi Campi & Giacomo Belletti—2016)
Application software support
Most DV players, editors and encoders only support the basic DV format, but not its professional versions. The exception to this being that most (not all) consumer Sony miniDV equipment will play mini-DVCAM tapes. 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 container files (ex: Microsoft AVI, Apple MOV). The DV meta-information is preserved in both file types being Sub-timecode and Start/Stop date times which can be muxed to Quicktime SMPTE standard timecode.
Most Windows video software only supports DV in AVI containers, as they use Microsoft's avifile.dll, which only supports reading avi files. Mac OS X video software support both AVI and MOV containers.
Tape formulation compatibility
There was considerable controversy solely based on hearsay over whether or not using tapes from different manufacturers could lead to dropouts.[35] Initially this was suggested around the conception of mostly MiniDV tapes in the mid to late 90s as the only two manufacturers of MiniDV tapes (Sony, who produce their tapes solely under the Sony brand; and Panasonic, who produce their own tapes under their Panasonic brand and outsources for TDK, Canon, etc.) used two different lubrication types for their cameras.
A research undertaken by Sony claimed that there was no hard evidence of the above statement. The only evidence claimed was that using ME tapes in equipment designed for MP tapes can cause tape damage and hence dropouts.[36][unreliable source?] Sony has done a significant amount of internal testing to simulate head clogs as a result of mixing tape lubricants, and has been unable to recreate the problem.[dubious–discuss] Sony recommends using cleaning cassettes once every 50 hours of recording or playback. For those who are still skeptical, Sony recommends cleaning video heads with a cleaning cassette before trying another brand of tape.
In 1999, Steve Epstein, technical editor of Broadcast Engineering magazine, received the following response from a Sony representative regarding tape stock compatibility:
Sony developed DVCAM based on the DV consumer format. The DV format was designed for use with metal evaporated tape, which offers approximately 5dB better carrier-to-noise figures than metal particle tape. Customers have requested VTRs that can play additional DV-based 6mm formats such as the consumer DV LP and DVCPRO. Sony will be offering new VTRs that can play back both of these additional formats without headclog and tape path issues.
It was realized early on that the VTR transport needed to be optimized to play various tape formulations and thicknesses. In addition, there is no need to dub DV LP or DVCPRO footage to another format for use as source material. This new VTR is the DSR 2000 DVCAM Studio recorder, and it is expected to be available later this year.
Robert Ott, Vice President for storage products and marketing, Sony Electronics, Park Ridge, New Jersey[37]
Digital video is an electronic representation of moving visual images (video) in the form of encoded digital data. This is in contrast to analog video, which represents moving visual images in the form of analog signals. Digital video comprises a series of digital images displayed in rapid succession, usually at 24, 25, 30, or 60 frames per second. Digital video has many advantages such as easy copying, multicasting, sharing and storage.
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magnetic tape can with relative ease record and play back audio, visual, and binary computer data.
Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassette recorders (VCRs) and camcorders. Videotapes have also been used for storing scientific or medical data, such as the data produced by an electrocardiogram.
Digital8 is a consumer digital recording videocassette for camcorders developed by Sony, and introduced in 1999. It is technically identical to DV cassettes, but uses physical Hi8 tapes instead.
A camcorder is a self-contained portable electronic device with video and recording as its primary function. It is typically equipped with an articulating screen mounted on the left side, a belt to facilitate holding on the right side, hot-swappable battery facing towards the user, hot-swappable recording media, and an internally contained quiet optical zoom lens.
Betacam is a family of half-inch professional videocassette products developed by Sony in 1982. In colloquial use, Betacam singly is often used to refer to a Betacam camcorder, a Betacam tape, a Betacam video recorder or the format itself.
A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were used in television studios, serving as a replacement for motion picture film stock and making recording for television applications cheaper and quicker. Beginning in 1963, videotape machines made instant replay during televised sporting events possible. Improved formats, in which the tape was contained inside a videocassette, were introduced around 1969; the machines which play them are called videocassette recorders.
The 8mm video format refers informally to three related videocassette formats. These are the original Video8 format and its improved successor Hi8, as well as a more recent digital recording format known as Digital8. Their user base consisted mainly of amateur camcorder users, although they also saw important use in the professional television production field.
D-5 is a professional digital video format introduced by Panasonic at 18th International Television Symposium in Montreux in 1993 and released a year later in 1994. Like Sony's D-1 (8-bit), it is an uncompressed digital component system (10-bit), but uses the same half-inch tapes as Panasonic's digital composite D-3 format. A 120 min. D-3 tape will record 60 min. in D-5/D-5 HD mode. D-5 standard definition (SD) decks can be retrofitted to record high definition with the use of an external HD input/output box/decoder. There were native D5 HD decks as well that didn't need an external processor and could record in both SD and HD. High definition conversion on D5 HD decks does not allow for any error correction that exists on standard definition recordings, as the full bandwidth of the tape is required for high definition recording.
HDV is a format for recording of high-definition video on DV videocassette tape. The format was originally developed by JVC and supported by Sony, Canon, and Sharp. The four companies formed the HDV Consortium in September 2003.
D-VHS is a digital video recording format developed by JVC, in collaboration with Hitachi, Matsushita, and Philips. The "D" in D-VHS originally stood for "Data", but JVC renamed the format as "Digital VHS". Released in December 1997, it uses the same physical cassette format and recording mechanism as S-VHS, but requires higher-quality and more expensive tapes and is capable of recording and displaying both standard-definition and high-definition content. The content data format is in MPEG transport stream, the same data format used for most digital television applications. It used MPEG-2 encoding and was standarized as IEC 60774-5.
XDCAM is a series of products for digital recording using random access solid-state memory media, introduced by Sony in 2003. Four different product lines – the XDCAM SD, XDCAM HD, XDCAM EX and XDCAM HD422 – differ in types of encoder used, frame size, container type and in recording media.
HDCAM is a high-definition video digital recording videocassette version of Digital Betacam introduced in 1997 that uses an 8-bit discrete cosine transform (DCT) compressed 3:1:1 recording, in 1080i-compatible down-sampled resolution of 1440×1080, and adding 24p and 23.976 progressive segmented frame (PsF) modes to later models. The HDCAM codec uses rectangular pixels and as such the recorded 1440×1080 content is upsampled to 1920×1080 on playback. The recorded video bit rate is 144 Mbit/s. Audio is also similar, with four channels of AES3 20-bit, 48 kHz digital audio. Like Betacam, HDCAM tapes were produced in small and large cassette sizes; the small cassette uses the same form factor as the original Betamax. The main competitor to HDCAM was the DVCPRO HD format offered by Panasonic, which uses a similar compression scheme and bit rates ranging from 40 Mbit/s to 100 Mbit/s depending on frame rate.
AVCHD is a file-based format for the digital recording and playback of high-definition video. It is H.264 and Dolby AC-3 packaged into the MPEG transport stream, with a set of constraints designed around camcorders.
D-9 or Digital-S as it was originally known, is a professional digital video videocassette format created by JVC in 1995.
Sony Corporation produces professional, consumer, and prosumer camcorders such as studio and broadcast, digital cinema cameras, camcorders, pan-tilt-zoom and remote cameras.
The Apple Intermediate Codec is a high-quality 8-bit 4:2:0 video codec used mainly as a less processor-intensive way of working with long-GOP MPEG-2 footage such as HDV. It is recommended for use with all HD workflows in Final Cut Express, iMovie, and until Final Cut Pro version 5. The Apple Intermediate Codec abbreviated AIC is designed by Apple Inc. to be an intermediate format in an HDV and AVCHD workflow. It features high performance and quality, being less processor intensive to work with than other editing formats. Unlike native MPEG-2 based HDV - and similar to the standard-definition DV codec - the Apple Intermediate Codec does not use temporal compression, enabling every frame to be decoded immediately without decoding other frames. As a result of this, the Apple Intermediate Codec takes three to four times more space than HDV.
Ingex is an open-source (GPL) suite of software for the digital capture of audio and video data, without the need for traditional audio or video tape or cassettes. Serial digital interface (SDI) capture is supported, as well as real-time transcoding. Portions of the software suite also act as a network file server for media files, as well as archiving to LTO-3 data tape. Audio and video media files can also be stored on USB hard drives or Network Attached Storage. The software is heavily used by the BBC, and was developed by the BBC Research Laboratory.
↑ S.B. Luitjens, S.E. Stupp, J.C. Lodder, Metal evaporated tape: state of the art and prospects, Journal of Magnetism and Magnetic Materials, Volume 155, Issues 1–3, 1996, Pages 261–265, ISSN 0304-8853, doi:10.1016/0304-8853(95)00727-X
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