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Toll Quality Voice - 32 kbit/s ADPCM MIME Sub-type Registration (RFC2422)

IP.com Disclosure Number: IPCOM000002999D
Original Publication Date: 1998-Sep-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 5 page(s) / 9K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

G. Vaudreuil: AUTHOR [+2]

Abstract

This document describes the registration of the MIME sub-type audio/32KADPCM for toll quality audio. This audio encoding is defined by the ITU-T in Recommendation G.726. This document refines an earlier sub-type registration in RFC 1911.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 29% of the total text.

Network Working Group G. Vaudreuil

Request for Comments: 2422 Lucent Technologies

Obsoletes: 1911 G. Parsons

Category: Standards Track Northern Telecom

September 1998

Toll Quality Voice - 32 kbit/s ADPCM

MIME Sub-type Registration

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 registration of the MIME sub-type

audio/32KADPCM for toll quality audio. This audio encoding is

defined by the ITU-T in Recommendation G.726.

1. Abstract

This document describes the registration of the MIME sub-type

audio/32KADPCM for toll quality audio. This audio encoding is

defined by the ITU-T in Recommendation G.726. This document refines

an earlier sub-type registration in RFC 1911.

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. ITU-T Definition

Recommendation G.726 [G726] defines the characteristics that are

recommended for the conversion of a 64 kbit/s A-law or m-law pulse

code modulation (PCM) channel at 8000 samples/second to and from a

40, 32, 24 or 16 kbit/s channel. The conversion is applied to the PCM

bit stream using an adaptive differential pulse code modulation

(ADPCM) transcoding technique. This Recommendation obsoletes G.721

which only defined the 32 kbit/s characteristics.

Recommendation G.726 was prepared by Study Group 15 of the

Telecommunications Standardization Sector of the International

Telecommunication Union (ITU-T) and was approved under the ITU's

Resolution No. 2 procedure on the 14 of December 1990.

3. MIME Definition

3.1 audio/32KADPCM

CCITT Recommendation G.726 [G726] describes the algorithm recommended

for conversion of a 64 kbit/s A-law or u-law PCM channel to and from

a 32 kbit/s channel (this is the same algorithm as described in the

deprecated G.721). The conversion is applied to the PCM stream using

an Adaptive Different...