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, 30, or 60 frames per second. Digital video has many advantages such as easy copying, multicasting, sharing and storage.
DV refers to 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. 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. DV is sometimes referred to as MiniDV, which was the most popular tape format using a DV codec during this time.
Digital Audio Tape is a signal recording and playback medium developed by Sony and introduced in 1987. In appearance it is similar to a Compact Cassette, using 3.81 mm / 0.15" magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. The recording is digital rather than analog. DAT can record at sampling rates equal to, as well as higher and lower than a CD at 16 bits quantization. If a comparable digital source is copied without returning to the analogue domain, then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MD MiniDisc, both of which use a lossy data-reduction system.
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.
S-VHS (スーパー・ヴィエイチエス), the common initialism for Super VHS, is an improved version of the VHS standard for consumer-level video recording. Victor Company of Japan introduced S-VHS in Japan in April 1987, with their JVC-branded HR-S7000 VCR, and in certain overseas markets soon afterward. By the end of 1987, the first S-VHS VCR models from other competitors included Hitachi VT-2700A, Mitsubishi HS-423UR, Panasonic PV-S4764, RCA VPT-695HF, and Toshiba SV-950. It has been standardized as IEC 60774-3 and IEC 60774-4.
Digital8 is a consumer digital recording videocassette for camcorders based on the 8 mm video format developed by Sony, and introduced in 1999.
D-1 or 4:2:2 Component Digital is an SMPTE digital recording video standard, introduced in 1986 through efforts by SMPTE engineering committees. It started as a Sony and Bosch - BTS product and was the first major professional digital video format. SMPTE standardized the format within ITU-R 601, also known as Rec. 601, which was derived from SMPTE 125M and EBU 3246-E standards.
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.
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 launched 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.
VHS-C is the compact VHS videocassette format, introduced by Victor Company of Japan (JVC) in 1982, and used primarily for consumer-grade compact analog recording camcorders. The format is based on the same video tape as is used in VHS, and can be played back in a standard VHS VCR with an adapter. Though quite inexpensive, the format is largely obsolete even as a consumer standard and has been replaced in the marketplace by digital video formats, which have smaller form factors.
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 of 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.
P2 is a professional digital recording solid-state memory storage media format introduced by Panasonic in 2004. The P2 card is essentially a RAID of Secure Digital (SD) memory cards with an LSI controller tightly packaged in a die-cast PC Card enclosure. The system includes cameras, decks as drop-in replacements for videotape decks, and a special 5.25-inch computer drive for random-access integration with non-linear editing systems (NLE). The cards can also be used directly where a PC card (PCMCIA) slot is available, as in most older notebook computers, as a normal hard disk drive, although a custom software driver must first be loaded.
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.
D-2 is a professional digital videocassette format created by Ampex and introduced in 1988 at the NAB Show as a composite video alternative to the component video D-1 format. It garnered Ampex a technical Emmy in 1989. Like D-1, D-2 stores uncompressed digital video on a tape cassette; however, it stores a composite video signal, rather than component video as with D-1. While component video is superior for advanced editing, especially when chroma key effects are used, composite video was more compatible with most analog facilities existing at the time.
A PCM adaptor is a device that encodes digital audio as video for recording on a videocassette recorder. The adapter also has the ability to decode a video signal back to digital audio for playback. This digital audio system was used for mastering early compact discs.
