H.263 is a video codec designed by the ITU-T as a low-bitrate encoding solution for videoconferencing. It was first designed to be utilized in H.324 based systems (PSTN and other circuit-switched network videoconferencing and videotelephony), but has since found use in H.323 (RTP/IP-based videoconferencing), H.320 (ISDN-based videoconferencing), RTSP (streaming media) and SIP (Internet conferencing) solutions as well. A video codec is a device or software module that enables the use of compression for digital video. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... This article needs to be cleaned up to conform to a higher standard of quality. ... H.324 is an ITU-T recomendation for voice, video and data transmission over regular analog phone lines. ... The public switched telephone network (PSTN) is the concentration of the worlds public circuit-switched telephone networks, in much the same way that the Internet is the concentration of the worlds public IP-based packet-switched networks. ... A circuit switched network is one where a dedicated connection (circuit or channel) must be set up between two nodes before they may communicate. ... H.323 is an umbrella recommendation from the ITU-T, that defines the protocols to provide audio-visual communication sessions on any packet network. ... The Real-time Transport Protocol (or RTP) defines a standardized packet format for delivering audio and video over the Internet. ... H.320 is a umbrella recommendation by the ITU-T for running Multimedia (Audio/Video/Data) over ISDN based networks. ... An ISDN Telephone Integrated Services Digital Network (ISDN) is a type of circuit switched telephone network system, designed to allow digital (as opposed to analog) transmission of voice and data over ordinary telephone copper wires, resulting in better quality and higher speeds, than available with analog systems. ... RTSP is the Real Time Streaming Protocol developed by the IETF and published in 1998 as RFC 2326. ... Streaming media is media that is consumed (read, heard, viewed) while it is being delivered. ... The three letter abbreviation SIP can refer to the following: Computing/electronics: In computing (and specifically Internet telephony), the IETF standard Session Initiation Protocol. ...

H.263 was developed as an evolutionary improvement based on experience from H.261, the previous ITU-T standard for video compression, and the MPEG-1 and MPEG-2 standards. Its first version was completed in 1995 and provided a suitable replacement for H.261 at all bitrates. It was further enhanced in projects known as H.263v2 (a.k.a. H.263+ or H.263 1998) and H.263v3 (a.k.a. H.263++ or H.263 2000). 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. ... MPEG-1 is the designation for a group of audio and video coding standards agreed upon by MPEG (Moving Pictures Experts Group). ... MPEG-2 (1994) is the designation for a group of coding standards for digital audio and video, agreed upon by MPEG (Moving Pictures Experts Group), and published as the ISO/IEC 13818 international standard. ... 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. ... H.263. ...

The next enhanced codec developed by the ITU-T (in partnership with MPEG) after H.263 is the H.264 standard, also known as AVC and MPEG-4 part 10. As H.264 provides a significant improvement in capability beyond H.263, the H.263 standard is now considered primarily a legacy design (although this is a recent development). Most new videoconferencing products now include H.264 as well as H.263 and H.261 capabilities. The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... The Moving Picture Experts Group or MPEG is a working group of ISO/IEC charged with the development of video and audio encoding standards. ... H.264, or MPEG-4 Part 10, is a high compression digital video codec standard written by the ITU-T Video Coding Experts Group (VCEG) together with the ISO/IEC Moving Picture Experts Group (MPEG) as the product of a collective partnership effort known as the Joint Video Team (JVT). ... MPEG-4, introduced in late 1998, is the designation for a group of audio and video coding standards and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG). ...

For more information on H.263, see the following sources:

External link

• IETF AVT Working Group - Group that reviews codec packetizations for RTP
  • RTP Payload Format for H.263 Video Streams (RFC 2190)
  • RTP Payload Format for the 1998 Version of ITU-T Rec. H.263 Video (H.263+) (RFC 2429)
• Find H.263 specification on ITU website
• Intel's H.263 codec installer for Windows
• I263 video codec
• H.263 Specifications
• H.263 implementation in vic (source code available)
• Video Demystified - Book which includes info about H.263
• List of H.261-H.263 resources