The
Real-time Transport Protocol
The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applicati ...
(RTP) specifies a general-purpose data format and
network protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchroniza ...
for transmitting digital media streams on
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
(IP) networks. The details of media encoding, such as signal sampling rate, frame size and timing, are specified in an RTP payload format. The format parameters of the RTP payload are typically communicated between transmission endpoints with the
Session Description Protocol (SDP), but other protocols, such as the
Extensible Messaging and Presence Protocol
Extensible Messaging and Presence Protocol (XMPP, originally named Jabber) is an open communication protocol designed for instant messaging (IM), presence information, and contact list maintenance. Based on XML (Extensible Markup Language), i ...
(XMPP) may be used.
Audio and video payload types
RFC 3551, entitled RTP Profile for Audio and Video (RTP/AVP), specifies the technical parameters of payload formats for audio and video streams.
The standard also describes the process of registering new payload types with IANA; additional payload formats and payload types are defined in the following specifications:
* , Standard 65, ''RTP Profile for Audio and Video Conferences with Minimal Control''
* , ''Media Type Registration of Payload Formats in the RTP Profile for Audio and Video Conferences''
* , ''RTP Payload Format for 12-bit
DAT Audio and 20- and 24-bit Linear Sampled Audio''
* , ''RTP Payload Format for
H.264 Video''
* , ''RTP Payload Format for Transport of MPEG-4 Elementary Streams''
* , ''RTP Payload Format for
MPEG-4
MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related t ...
Audio/Visual Streams''
* , ''RTP Payload Format for
MPEG1/
MPEG2 Video''
* , ''RTP Payload Format for
High Efficiency Video Coding
High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comp ...
(HEVC)''
* , ''RTP Payload Format for JPEG-compressed Video''
* , ''RTP Payload Format for
H.261 Video Streams''
* , ''RTP Payload Format for
PureVoice Audio Video''
* , ''RTP Payload Format for Uncompressed Video''
* , ''RTP Payload Format for the
Opus
''Opus'' (pl. ''opera'') is a Latin word meaning "work". Italian equivalents are ''opera'' (singular) and ''opere'' (pl.).
Opus or OPUS may refer to:
Arts and entertainment Music
* Opus number, (abbr. Op.) specifying order of (usually) publicatio ...
Speech and Audio Codec''
* , ''RTP Payload Format for
JPEG XS''
Payload identifiers 96–127 are used for payloads defined dynamically during a session. It is recommended to dynamically assign port numbers, although port numbers 5004 and 5005 have been registered for use of the profile when a dynamically assigned port is not required.
Applications should always support PCMU (payload type 0); previously, DVI4 (payload type 5) was also recommended, but this was removed in 2013 by RFC 7007.
Text messaging payload
* , ''RTP Payload Format for Text Conversation''
MIDI payload
* , ''
RTP Payload Format for MIDI''
* , ''An Implementation Guide for RTP MIDI''
See also
*
Session Initiation Protocol
The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications. SIP is used in Internet telephony, in private IP telepho ...
*
H.323
H.323 is a recommendation from the ITU Telecommunication Standardization Sector (ITU-T) that defines the protocols to provide audio-visual communication sessions on any packet network. The H.323 standard addresses call signaling and control, mu ...
*
Comparison of audio coding formats
The following tables compare general and technical information for a variety of audio coding formats.
For listening tests comparing the perceived audio quality of audio formats and codecs, see the article Codec listening test.
General informati ...
References
{{reflist
External links
IANA assignments of Real-Time Transport Protocol (RTP) Parameters
VoIP protocols