Most likely the earliest DCT-based video compression standard. It is an ITU-T standard that assumes CIF or QCIF format and is targeted at ISDN and LAN bandwidths. It has, for the most part, been superceded by the H.263 standard.
ITU-TSS recommendation "Video codec for audiovisual services at p x 64 kbit/s"; Covers the compression and decompression of the video signal in video conference
An early video codec standard which is in heavy use in videoconferencing applications. A precursor to MPEG-1, H.261 is optimized for low data rates and low motion content.
Edit / CCITT standard describing a protocol for digitally encoding and decoding video images to allow videoconferencing terminals from different manufacturers to interoperate. See Also: H.323
This is a video coding standard enacted by the ITU in 1990. H.261 refers to differing video codecs being able to interpret both the encoding and compression of a signal, and to carry out decoding and decompression of that signal. H.261 was designed around ISDN lines, and it supports two resolutions: QCIF and CIF.
ITU standard for video coding for videoconferencing. H.261 is a discrete cosine transform (DCT) based algorithm for video in the 64kb's to 2mb/s range. All H.323 compliant videoconferencing system are required to support this codec.
Analog/digital conversion algorithm standard for videoconferencing.
ITU-T recommendation regarding a video codec for audio-visual services at p x 64 Kbps. Note that motion compensation and field sub-sampling (loop filter) are implementation-optional in the standard. Users considering the H.261 codec at bit rates of 384 Kbps or below should verify that the manufacturer has implemented these optional aspects.
Videophone video compression standard.
A video compression standard developed by the CCITT for use in encoding video to be transferred over an ISDN (Integrated Service Digital Network). In this compression method, data is compressed so that the output bit rate is p x 64 Kbits per second, where can range from 1 to 30 depending on the number of ISDN channels used. This standard was developed primarily to support video phone and videoconferencing applications.
CCITT recommendation regarding a video codec for audiovisual services.
An old codec (see Codec) developed by Apple for video conferencing. Supports video resolutions (sharpness and clarity of an image) of 352 x 288 and 176 x 144 at up to 29.97 frames per second.
The video component of the H.320 video conferencing standard intended for use on communication lines that have multiples of 64-Kbit capacity.
A ITU-TS standard for video compression know as Codes for Audiovisual Services at N x 384Kbit/s. It sets a common algorithm for converting analog video signals to digital, operating at or above 384Kbit/s.
The first encoding algorithm for videoconferencing.
"Video Codec for Audiovisual Services at P x 64 Kbit/s" has been known informally as "P x 64" because it defines video coding based on P 64,000-bit per second channels. (P is typically two or more.).
ITU-T codec Recommendation regarding a video codec for audiovisual services at p x 64 Kbps. Regrettably, motion compensation and field sub-sampling (loop filter) are implementation optional in the standard. Users considering an ITU-T codec for operation at bit rates of 384 Kbps or below should ensure that the manufacturer has implemented these options.
The ITU-T Px64 standard relating to the video compression algorithm.
An ITU-T standard for video coding (or compressing the video signal).
This video compression standard was defined in 1990 by the CCITT (now the ITU-T) and was the first worldwide video compression standard. It was developed specifically to enable Video Conferencing units, manufactured by different companies, to communicate with each other, originally over ISDN or digital leased lines for operation at bit-rates between around 40 kbps and 1.9 Mbps. The application area is primarily interactive communications, and therefore the algorithm has been designed to provide good quality compression with a reasonably low delay.
The ITU-T's Recommendations that allows dissimilar video codecs to interpret how a signal has been encoded and compressed, and to decode and decompress that signal. It also defines two picture formats: CIF and QCIF.
The video standard for audiovisual services at p x 64 Kbps. Part of the H.320 standard.
A standard for coding and decoding video ; part of H.320
A video compression scheme defined by the ITU, originally for use in video telephony and related systems; particularly suited to operation at moderately low rates (e.g.ISDN).
H.261 is an 1990 ITU video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. The data rate of the coding algorithm was designed to be able to operate between 40 kbit/s and 2 Mbit/s. The standard supports CIF and QCIF video frames with luma resolutions of 352x288 and 176x144 respectively (and 4:2:0 sampling with chroma resolutions of 176x144 and 88x72, respectively).