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RTP Payload Format for Enhanced Variable Rate Codecs (EVRC) and Selectable Mode Vocoders (SMV) (RFC3558)

IP.com Disclosure Number: IPCOM000013146D
Original Publication Date: 2003-Jul-01
Included in the Prior Art Database: 2003-Jul-29
Document File: 24 page(s) / 50K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

A. Li: AUTHOR

Abstract

This document describes the RTP payload format for Enhanced Variable Rate Codec (EVRC) Speech and Selectable Mode Vocoder (SMV) Speech. Two sub-formats are specified for different application scenarios. A bundled/interleaved format is included to reduce the effect of packet loss on speech quality and amortize the overhead of the RTP header over more than one speech frame. A non-bundled format is also supported for conversational applications.

This text was extracted from an ASCII text file.
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Network Working Group� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � A. Li

Request for Comments: 3558� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � UCLA

Category: Standards Track� � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � July 2003

� � � � � RTP Payload Format for Enhanced Variable Rate Codecs (EVRC)

� � � � � � � � � � � � � � � � � � and Selectable Mode Vocoders (SMV)

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 (2003).� All Rights Reserved.

Abstract

� � This document describes the RTP payload format for Enhanced Variable

� � Rate Codec (EVRC) Speech and Selectable Mode Vocoder (SMV) Speech.

� � Two sub-formats are specified for different application scenarios.� A

� � bundled/interleaved format is included to reduce the effect of packet

� � loss on speech quality and amortize the overhead of the RTP header

� � over more than one speech frame.� A non-bundled format is also

� � supported for conversational applications.

Table of Contents

� � 1. Introduction ................................................... 2

� � 2. Background ..................................................... 2

� � 3. The Codecs Supported ........................................... 3

� � � � � 3.1. EVRC ...................................................... 3

� � � � � 3.2. SMV ....................................................... 3

� � � � � 3.3. Other Frame-Based Vocoders ................................ 4

� � 4. RTP/Vocoder Packet Format ...................................... 4

� � � � � 4.1. Interleaved/Bundled Packet Format ......................... 5

� � � � � 4.2. Header-Free Packet Format ................................. 6

� � � � � 4.3. Determining the Format of Packets ......................... 7

� � 5. Packet Table of Contents Entries and Codec Data Frame Format ... 7

� � � � � 5.1. Packet Table of Contents entries .......................... 7

� � � � � 5.2. Codec Data Frames ......................................... 8

� � 6. Interleaving Codec Data Frames ................................. 9

� � 7. Bundling Codec Data Frames .................................... 12

� � 8. Handling Missing Codec Data Frames ............................ 12

Li� � � � � � � � � � � � � � � � � � � � � � � � � Standards Track� � � � � � � � � � � � � � � � � � � � [Page 1]

RFC 3558� � � � � � � � � RTP Payload Format for EVRC and SMV� � � � � � � � � July 2003

� � 9. Implementation Issues ......................................... 12

� � � � � 9.1. Interleaving Length .............................