RTP Payload Format for the Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec
RFC 4352
Network Working Group J. Sjoberg
Request for Comments: 4352 M. Westerlund
Category: Standards Track Ericsson
A. Lakaniemi
S. Wenger
Nokia
January 2006
RTP Payload Format for the
Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec
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 (2006).
Abstract
This document specifies a Real-time Transport Protocol (RTP) payload
format for Extended Adaptive Multi-Rate Wideband (AMR-WB+) encoded
audio signals. The AMR-WB+ codec is an audio extension of the AMR-WB
speech codec. It encompasses the AMR-WB frame types and a number of
new frame types designed to support high-quality music and speech. A
media type registration for AMR-WB+ is included in this
specification.
Sjoberg, et al. Standards Track [Page 1]
RFC 4352 RTP Payload Format for AMR-WB+ January 2006
Table of Contents
1. Introduction ....................................................3
2. Definitions .....................................................4
2.1. Glossary ...................................................4
2.2. Terminology ................................................4
3. Background of AMR-WB+ and Design Principles .....................4
3.1. The AMR-WB+ Audio Codec ....................................4
3.2. Multi-rate Encoding and Rate Adaptation ....................8
3.3. Voice Activity Detection and Discontinuous Transmission ....8
3.4. Support for Multi-Channel Session ..........................8
3.5. Unequal Bit-Error Detection and Protection .................9
3.6. Robustness against Packet Loss .............................9
3.6.1. Use of Forward Error Correction (FEC) ...............9
3.6.2. Use of Frame Interleaving ..........................10
3.7. AMR-WB+ Audio over IP Scenarios ...........................11
3.8. Out-of-Band Signaling .....................................11
4. RTP Payload Format for AMR-WB+ .................................12
4.1. RTP Header Usage ..........................................13
4.2. Payload Structure .........................................14
4.3. Payload Definitions .......................................14
4.3.1. Payload Header .....................................14
4.3.2. The Payload Table of Contents ......................15
4.3.3. Audio Data .........................................20
4.3.4. Methods for Forming the Payload ....................21
4.3.5. Payload Examples ...................................21
4.4. Interleaving Considerations ...............................24
4.5. Implementation Considerations .............................25
4.5.1. ISF Recovery in Case of Packet Loss ................26
4.5.2. Decoding Validation ................................28
5. Congestion Control .............................................28
6. Security Considerations ........................................28
6.1. Confidentiality ...........................................29
6.2. Authentication and Integrity ..............................29
7. Payload Format Parameters ......................................29
7.1. Media Type Registration ...................................30
7.2. Mapping Media Type Parameters into SDP ....................32
7.2.1. Offer-Answer Model Considerations ..................32
7.2.2. Examples ...........................................34
8. IANA Considerations ............................................34
9. Contributors ...................................................34
10. Acknowledgements ..............................................34
11. References ....................................................35
11.1. Normative References .....................................35
11.2. Informative References ...................................35
Sjoberg, et al. Standards Track [Page 2]
Show full document text