RTP Payload Format for ITU-T Recommendation G.722.1
RFC 5577
Document | Type |
RFC - Proposed Standard
(July 2009; Errata)
Obsoletes RFC 3047
|
|
---|---|---|---|
Authors | Patrick Luthi , Roni Even | ||
Last updated | 2015-10-14 | ||
Replaces | draft-even-avt-rfc3047-bis | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5577 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Cullen Jennings | ||
Send notices to | (None) |
Network Working Group P. Luthi Request for Comments: 5577 Tandberg Obsoletes: 3047 R. Even Category: Standards Track Gesher Erove Ltd July 2009 RTP Payload Format for ITU-T Recommendation G.722.1 Abstract International Telecommunication Union (ITU-T) Recommendation G.722.1 is a wide-band audio codec. This document describes the payload format for including G.722.1-generated bit streams within an RTP packet. The document also describes the syntax and semantics of the Session Description Protocol (SDP) parameters needed to support G.722.1 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) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Luthi & Even Standards Track [Page 1] RFC 5577 G7221 July 2009 Table of Contents 1. Introduction ....................................................2 2. Terminology .....................................................3 3. RTP Usage for G.722.1 ...........................................3 3.1. RTP G.722.1 Header Fields ..................................3 3.2. RTP Payload Format for G.722.1 .............................3 3.3. Multiple G.722.1 Frames in an RTP Packet ...................5 3.4. Computing the Number of G.722.1 Frames .....................6 4. IANA Considerations .............................................6 4.1. Media Type Registration ....................................6 4.1.1. Registration of Media Type audio/G7221 ..............6 5. SDP Parameters ..................................................8 5.1. Usage with the SDP Offer/Answer Model ......................8 6. Security Considerations .........................................8 7. Changes from RFC 3047 ...........................................9 8. Acknowledgments .................................................9 9. References ......................................................9 9.1. Normative References .......................................9 9.2. Informative References ....................................10 1. Introduction ITU-T G.722.1 [ITU.G7221] is a low-complexity coder; it compresses 50 Hz - 14 kHz audio signals into one of the following bit rates: 24 kbit/s, 32 kbit/s, or 48 kbit/s. The coder may be used for speech, music, and other types of audio. Some of the applications for which this coder is suitable are: o Real-time communications such as videoconferencing and telephony o Streaming audio o Archival and messaging ITU-T G.722.1 [ITU.G7221] uses 20-ms frames and a sampling rate clock of 16 kHz or 32kHz. The encoding and decoding algorithm can change the bit rate at any 20-ms frame boundary, but no bit rate change notification is provided in-band with the bit stream. For any given bit rate, the number of bits in a frame is a constant. Within this fixed frame, G.722.1 uses variable-length coding (e.g., Huffman coding) to represent most of the encoded parameters. All variable-length codes are transmitted in order from the leftmost bit (most significant bit -- MSB) to the rightmost bit (least significant bit -- LSB), see [ITU.G7221] for more details. Luthi & Even Standards Track [Page 2]Show full document text