RFC 2862 (rfc2862) - Page 1 of 7

RTP Payload Format for Real-Time Pointers

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Network Working Group                                        M. Civanlar
Request for Comments: 2862                                       G. Cash
Category: Standards Track                                           AT&T
                                                               June 2000


               RTP Payload Format for Real-Time Pointers

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2000).  All Rights Reserved.

Abstract

   This document describes an RTP [1] payload format for transporting
   the coordinates of a dynamic pointer that may be used during a
   presentation. Although a mouse can be used as the pointer, this
   payload format is not intended and may not have all functionalities
   needed to implement a general mouse event transmission mechanism.

1. Introduction

   In most presentations, significant information is conveyed through
   the use of viewgraphs and a pointer. This makes accurate transmission
   of them vital in remote conferencing applications. Using regular
   video of a presenter's display for this purpose is problematic
   because, while the viewgraphs require a high spatial resolution, the
   pointer movements need to be sampled and transmitted at a high
   temporal resolution so that the presenter's pointing actions can be
   displayed synchronously with the corresponding audio and video
   signals. In many instances, this synchronization carries vital
   information.  As an example, consider a speaker pointing at two
   alternatives on a viewgraph in sequence and saying "this one is
   better than this".  To satisfy both high spatial and high temporal
   resolution requirements, at least S-VHS quality video may need to be
   used. Codecs that can compress S-VHS video effectively in real-time
   are expensive for this purpose, and transmitting such video
   uncompressed requires very high bandwidths.





Civanlar & Cash             Standards Track
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