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Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
This ITU-T recommendation is identical to the audio specification of MPEG-2.
Industry:Software
The ITU-T H.261 recommendation embraces video codecs for audio visual services at p x 64 kbit/s data rate, where p is between 1 and 30. Thus, the standard is informally called “p x 64.” It is aimed at low bit rate media, and is used in the H.320 videoconferencing recommendation.
H.261 provides a resolution of 352 x 288 pixels (CIF) or 176 x 144 pixels (QCIF), independent of bit rate. The H.261 recommendation defines both encoding and decoding. However, it defines, more strictly, how to decode than to encode the bit stream, and has room for options in the encoder.
The coding is based on DCT with word-length encoding. H.261 defines both independently coded frames (key frames), and frames that frame by using block-based motion compensation (non-key frames). H.261 also defines error-correction codes, and it allows rate control by varying quantization and by dropping frames and jumping blocks.
Industry:Software
An ITU-T recommendation concerning “video coding for low bit rate communication.” The H.263 is dedicated to video conferencing via H.324 terminals using V.34 modems at 28.8 kbit/s, and to H.323 LANbased videoconferencing . The coding algorithm in H.263 is based on H.261, but has better performance than the H.261, and it may eventually displace H.261.
Industry:Software
An ITU-T recommendation for low bit rate visual communication.
The H.320 is entitled “narrow-band visual telephone systems and terminal equipment” and is widely accepted for ISDN videoconferencing. The H.320 is not a compression algorithm, but is rather a suite of standards for videoconferencing.
H.320 specifies H.261 as the video compression, and defines the use of one of three audio formats: either G.711, G,722, or G.728.
Industry:Software
ITU recommendation H.324 describes terminals for low bit rate multimedia applications, using V.34 modems operating over the general telephone system. H.324 terminals may carry real-time voice, data, and video or any combination, including video telephony. H.324 makes use of the logical channel procedures of recommendation H.245, in which the content of each logical channel is described when the channel is opened.
H.324 terminals may be used in multipoint configurations through MCUs, and may interwork with H.320 terminals on ISDN, as with terminals on wireless networks.
Industry:Software
A compressed recording system developed by Panasonic which uses compression at about 4:1 to record HD material on standard D5 cassettes.
Industry:Software
A set of formats based on the ATSC Table 3, suggested by the DTV Team as the initial stage of the digital television rollout.
ATSC TABLE 3 Formats for DTV Transmission (i = interlaced, p = progressive) Vertical Size Horizontal Size Aspect Ratio Frame Rate Value (active) Value (active) Information and Scan (HD) 1,080 1,920 16:9 (square pixel) 24p, 30p, 30i (HD) 720 1,280 16:9 (square pixel) 24p, 30p, 60p (SD) 480 704 4:3 non-square pixel) 24p, 30p, 30i, 60p (SD) 480 704 16:9 (non-square pixel) 24p, 30p, 30i, 60p (SD) 480 640 4:3 (square pixel) 24p, 30p, 30i, 60p
Industry:Software
A set of formats based on the ATSC Table 3, suggested by the DTV Team as the second stage of the digital television rollout, expected to be formalized in the year 2000.
Industry:Software
A set of formats based on the ATSC Table 3, suggested by the DTV Team as the third stage of the digital television rollout contingent on some extreme advances in video compression over the next five years. The added format is not part of the ATSC Table 3.
Industry:Software
