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Content Duration MIME Header Definition (RFC2424)

IP.com Disclosure Number: IPCOM000003001D
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 5 page(s) / 7K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

G. Vaudreuil: AUTHOR [+2]

Abstract

This document describes the MIME header Content-Duration that is intended for use with any time varying media content (typically audio/* or video/*). The length of time is represented in seconds without any units indication.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 45% of the total text.

Network Working Group G. Vaudreuil

Request for Comments: 2424 Lucent Technologies

Category: Standards Track G. Parsons

Northern Telecom

September 1998

Content Duration

MIME Header Definition

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 (1998). All Rights Reserved.

Overview

This document describes the MIME header Content-Duration that is

intended for use with any timed media content (typically audio/* or

video/*).

1. Abstract

This document describes the MIME header Content-Duration that is

intended for use with any time varying media content (typically

audio/* or video/*). The length of time is represented in seconds

without any units indication.

2. Content-Duration Header Field

Time varying media contents, for example, a spoken voice message or a

video clip, have an inherent time duration. Many audio and video

encodings may include their duration as header information or may

allow accurate calculation based on the byte length of the data.

However, it may be useful to present the time duration of the content

in a MIME header to allow its simple determination without dealing

with the actual content.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this

document are to be interpreted as described in [REQ].

2.1 Syntax

The Content-Duration field's value is a single number specifying the

time duration in seconds of the content. Formally:

duration := "Content-Duration" ":" 1*10DIGIT

Note that practically (though highly unlikely in MIME media), the

upper bound on the numerical value of the time duration is (2^^31 -

1) or 2147483647.

2.2 Semantics

This field represents the time duration of the associated time

varying media content. The time duration is noted in seconds with no

units tag. The time value should be exact, however the exact value

of the time duration cannot be known without opening the content and

playing it. If an exact value must be known, then the latter method

should be used. This mechanism simply allows placing a sender

determined time duration value in the header for easy access.

Though there are several ways to present this duration to the

recipient (e.g. with the inbox headers, when audio attachment

opened), the actual use of this field on reception ...