“Networked Digital Video” Moderated by David L. Nelson

  • ©Andrew Lippman, Dan Heist, and Eric M. Hoffert



Entry Number: 16


    Networked Digital Video



Additional Information:

    The analog video era is ending. Digitization and computerization of motion video will qualitatively transform both computer and video-based applications, but video networking presents a special set of challenges.
    Motion video is necessarily a real-time process, and current approaches treat the transmission of digital video as an equivalent real-time problem. This has created an impasse, because personal computers, contention-based LANs, and packet-switched WANs are notoriously poor at delivering real-time data. One solution is to implement spatial and temporal scalability in the video compression technique, allowing for dynamic trade- offs among pixel resolution, frame rate, quality (bits/pixel), and therefore bit rate. End-to-end network protocols can take advantage of scalability to relax the real-time nature of video transmission, which in turn enables development of a new class of video applications using available network technologies.
    In this panel, a taxonomy of current applications such as video mail, video- based training, and desktop video conferencing is presented according to whether the video is delivered in real time, stored and forwarded, or published, and whether the interaction is one-to-one, peer-to-peer, or one-to-many. Enabling technologies for these applications are identified with particular emphasis on the problems associated with networking video over LANs and WANs. The role of standards such as JPEG and MPEG is also considered.

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