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RTP Payload Format for Real-Time Pointers (RFC2862)

IP.com Disclosure Number: IPCOM000003462D
Original Publication Date: 2000-Jun-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 5 page(s) / 11K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

M. Civanlar: AUTHOR [+2]

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.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 25% of the total text.

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.

A much simpler and economical system can be designed by capturing and

transmitting the pointer coordinates separately [2]. The pointer

coordinates with respect to a displayed viewgraph can easily be

obtained in electronic presentation systems. For presentations

prepared for optical systems, such as transparencies for overhead

projectors, an arrangement where the viewgraph is captured in a frame

buffer on a computer can be used to ass...