Network Working Group S. Casner
Request for Comments: 3555 Packet Design
Category: Standards Track P. Hoschka
W3C/INRIA/MIT
July 2003
Network Working Group S. Casner
Request for Comments: 3555 Packet Design
Category: Standards Track P. Hoschka
W3C/INRIA/MIT
July 2003
MIME Type Registration of RTP Payload Formats
RTP有效负载格式的MIME类型注册
Status of this Memo
本备忘录的状况
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.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (2003). All Rights Reserved.
版权所有（C）互联网协会（2003年）。版权所有。
Abstract
摘要
This document defines the procedure to register RTP Payload Formats as audio, video or other MIME subtype names. This is useful in a text-based format or control protocol to identify the type of an RTP transmission. This document also registers all the RTP payload formats defined in the RTP Profile for Audio and Video Conferences as MIME subtypes. Some of these may also be used for transfer modes other than RTP.
本文档定义了将RTP有效负载格式注册为音频、视频或其他MIME子类型名称的过程。这在基于文本的格式或控制协议中非常有用，可以识别RTP传输的类型。本文档还将音频和视频会议的RTP配置文件中定义的所有RTP有效负载格式注册为MIME子类型。其中一些也可用于RTP以外的传输模式。
Table of Contents
目录
1. Introduction .................................................. 2
1.1. IANA Considerations ...................................... 2
1.2. Terminology .............................................. 3
2. Procedure For Registering MIME Types for RTP Payload Types .... 3
3. Mapping to SDP Parameters ..................................... 5
4. Registrations for "Audio/Video Profile" ....................... 6
4.1. Audio Type Registrations ................................. 6
4.2. Video Type Registrations ................................. 30
5. Security Considerations ....................................... 42
6. Normative References .......................................... 43
7. Authors' Addresses ............................................ 44
8. Full Copyright Statement ...................................... 45
1. Introduction .................................................. 2
1.1. IANA Considerations ...................................... 2
1.2. Terminology .............................................. 3
2. Procedure For Registering MIME Types for RTP Payload Types .... 3
3. Mapping to SDP Parameters ..................................... 5
4. Registrations for "Audio/Video Profile" ....................... 6
4.1. Audio Type Registrations ................................. 6
4.2. Video Type Registrations ................................. 30
5. Security Considerations ....................................... 42
6. Normative References .......................................... 43
7. Authors' Addresses ............................................ 44
8. Full Copyright Statement ...................................... 45
The MIME registration procedure described in RFC 2048 [1] was originally designed for transport of multimedia information via asynchronous Internet mail, but the MIME namespace now provides identification for other transport modes as well. This document defines the procedure to register MIME subtype names for use with the Real-time Transport Protocol (RTP), RFC 3550 [2], to identify RTP payload formats.
RFC 2048[1]中描述的MIME注册过程最初是为通过异步Internet邮件传输多媒体信息而设计的，但MIME名称空间现在也为其他传输模式提供标识。本文档定义了注册MIME子类型名称的过程，以便与实时传输协议（RTP）RFC 3550[2]一起使用，以识别RTP有效负载格式。
This document also registers all the RTP payload formats defined in the RTP Profile for Audio and Video Conferences, RFC 3551 [3], as MIME subtypes under the "audio" and "video" MIME types.
本文档还将音频和视频会议RTP配置文件RFC 3551[3]中定义的所有RTP有效负载格式注册为“音频”和“视频”MIME类型下的MIME子类型。
This document registers the following MIME subtypes:
本文档注册了以下MIME子类型：
audio/DVI4 audio/G722 audio/G723 audio/G726-16 audio/G726-24 audio/G726-32 audio/G726-40 audio/G728 audio/G729 audio/G729D audio/G729E audio/GSM audio/GSM-EFR audio/L8 audio/L16 audio/LPC audio/MPA audio/PCMA audio/PCMU audio/QCELP audio/RED audio/VDVI video/BT656 video/CelB video/JPEG video/H261 video/H263 video/H263-1998 video/H263-2000 video/MPV
音频/DVI4音频/G722音频/G723音频/G726-16音频/G726-24音频/G726-32音频/G726-40音频/G728音频/G729音频/G729D音频/G729E音频/GSM音频/GSM-EFR音频/L8音频/L16音频/LPC音频/MPA音频/PCMA音频/PCMU音频/QCELP音频/RED音频/VDVI视频/BT656视频/CelB视频/JPEG视频/H261视频/H263视频/H263-1998视频/H263-2000视频/MPV
video/MP2T video/MP1S video/MP2P video/BMPEG video/nv
视频/MP2T视频/MP1S视频/MP2P视频/BMPEG视频/nv
MIME subtype audio/L16 has already been registered via RFC 2586 for transports other than RTP. That registration is incorporated here and augmented with additional information for RTP transport.
MIME子类型audio/L16已通过RFC 2586注册用于RTP以外的传输。该注册包含在此处，并添加了RTP传输的附加信息。
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 RFC 2119 [4] and indicate requirement levels for implementations compliant with this specification.
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[4]中的描述进行解释，并表示符合本规范的实施的要求级别。
Registering an RTP payload type as a MIME type follows the same procedures as described in RFC 2048 and uses the registration template shown in Section 2.8 of RFC 2048. Some additional parameters are required to specify how a particular payload format is transported over RTP:
将RTP有效负载类型注册为MIME类型遵循RFC 2048中描述的相同过程，并使用RFC 2048第2.8节中所示的注册模板。需要一些附加参数来指定特定有效负载格式如何通过RTP传输：
Published specification A description of the encoding and a specification of the payload format must be provided, usually by reference to an RTP payload format specification RFC. That RFC may be separate, or the MIME subtype registration may be incorporated into the payload format specification RFC. The payload format specification MUST include the RTP timestamp clock rate (or multiple rates for audio encodings with multiple sampling rates).
发布的规范必须提供编码说明和有效负载格式规范，通常参考RTP有效负载格式规范RFC。该RFC可以是单独的，或者MIME子类型注册可以合并到有效负载格式规范RFC中。有效负载格式规范必须包括RTP时间戳时钟速率（或具有多个采样率的音频编码的多个速率）。
A reference to a further description of the data compression format itself should be provided, if available.
如果可用，应提供对数据压缩格式本身的进一步说明的参考。
Required parameters If the payload format does not have a fixed RTP timestamp clock rate, then a "rate" parameter is required to specify the RTP timestamp clock rate. A particular payload format may have additional required parameters.
所需参数如果有效负载格式没有固定的RTP时间戳时钟速率，则需要“速率”参数来指定RTP时间戳时钟速率。特定有效负载格式可能具有额外的必需参数。
Optional parameters Most audio payload formats can have an optional "channels" parameter to specify the number of audio channels included in the transmission. Any payload format, but most likely audio formats, may also include the optional parameters "ptime", to specify the recommended length of time in milliseconds represented by the media in a packet, and/or "maxptime" to specify the maximum amount of media which can be encapsulated in each packet, expressed as time in milliseconds. The "ptime" and "maxptime" parameters are defined in the Session Description Protocol (SDP) [5].
可选参数大多数音频有效负载格式可以有一个可选的“通道”参数，用于指定传输中包含的音频通道数。任何有效负载格式，但最可能的音频格式，也可以包括可选参数“ptime”，以指定由分组中的媒体表示的推荐时间长度（以毫秒为单位），和/或“maxptime”以指定可封装在每个分组中的媒体的最大量（以毫秒为单位）。“ptime”和“maxptime”参数在会话描述协议（SDP）[5]中定义。
A particular payload format may have additional optional parameters.
特定有效负载格式可能具有附加可选参数。
Encoding considerations The fact that the type can be transferred via RTP MUST be noted.
编码注意事项必须注意类型可以通过RTP传输的事实。
Depending on whether the type has already been registered for transfer with a non-RTP protocol (e.g. MIME mail or http) or not, several different cases can occur:
根据类型是否已注册为使用非RTP协议（例如MIME邮件或http）传输，可能会出现以下几种不同的情况：
a) Not yet registered as a MIME type
a) 尚未注册为MIME类型
A new registration should be constructed using the MIME registration template. The registration may specify transfer via other means in addition to RTP if that is feasible and desired. The encoding considerations must specify how the type is transferred via RTP.
应使用MIME注册模板构造新注册。注册可以指定通过RTP之外的其他方式进行转让，如果这是可行和需要的话。编码注意事项必须指定如何通过RTP传输类型。
Optional parameters may be defined as needed, and it must be clearly stated whether to which mode(s) of transfer the parameters apply.
可根据需要定义可选参数，并且必须明确说明参数是否适用于哪种传输模式。
b) MIME type exists for a non-RTP protocol
b) 存在非RTP协议的MIME类型
The encoding considerations of the existing type should be changed to indicate that the type can also be transferred via RTP.
应更改现有类型的编码注意事项，以表明该类型也可以通过RTP传输。
RTP-specific parameters may be added, and it must be clearly stated that these are only to be used when the media type is transmitted via RTP transport.
可以添加RTP特定参数，并且必须明确说明，这些参数仅在通过RTP传输传输媒体类型时使用。
c) Update an existing MIME type for RTP to be used for a non-RTP protocol
c) 更新RTP的现有MIME类型以用于非RTP协议
The encoding considerations of the existing type should be changed to indicate that the type can also be transferred via a non-RTP protocol (e.g. SMTP, HTTP).
应更改现有类型的编码注意事项，以表明该类型也可以通过非RTP协议（例如SMTP、HTTP）传输。
Non-RTP-specific parameters can be added, and it must be clearly stated that these are only to be used when the media type is transmitted via a non-RTP transport.
可以添加非RTP特定参数，并且必须明确说明，这些参数仅在通过非RTP传输传输介质类型时使用。
The representation of a MIME media type is specified in the syntax of the Content-Type header field in RFC 2045 [6] as follows:
MIME媒体类型的表示在RFC 2045[6]中内容类型标题字段的语法中指定，如下所示：
type "/" subtype *(";" parameter)
type "/" subtype *(";" parameter)
Parameters may be required for a particular type or subtype or they may be optional. For media types which represent RTP payload formats, the parameters "rate", "channels", "ptime", and "maxptime" have general definitions (given above) that may apply across types and subtypes. The format for a parameter is specified in RFC 2045 as
特定类型或子类型可能需要参数，也可能是可选的。对于表示RTP有效负载格式的媒体类型，参数“速率”、“通道”、“ptime”和“maxptime”具有可跨类型和子类型应用的通用定义（如上所述）。参数的格式在RFC 2045中指定为
attribute "=" value
属性“=”值
where attribute is the parameter name and the permissible values are specified for each parameter. The value may need to be a quoted string if it contains any of the special characters listed in RFC 2045.
其中，attribute是参数名称，并且为每个参数指定了允许的值。如果该值包含RFC 2045中列出的任何特殊字符，则该值可能需要为带引号的字符串。
The information carried in the media type string has a specific mapping to fields in the Session Description Protocol (SDP) [5], which is commonly used to describe RTP sessions. The mapping is as follows:
媒体类型字符串中包含的信息与会话描述协议（SDP）[5]中的字段具有特定映射，该协议通常用于描述RTP会话。映射如下：
o The MIME type (e.g., audio) goes in SDP "m=" as the media name.
o MIME类型（例如音频）以SDP“m=”作为媒体名称。
o The MIME subtype (payload format) goes in SDP "a=rtpmap" as the encoding name.
o MIME子类型（有效负载格式）以SDP“a=rtpmap”作为编码名称。
o The general (possibly optional) parameters "rate" and "channels" also go in "a=rtpmap" as clock rate and encoding parameters, respectively.
o 一般（可能可选）参数“速率”和“通道”也分别作为时钟速率和编码参数进入“a=rtpmap”。
o The general (and optional) parameters "ptime" and "maxptime" go in the SDP "a=ptime" and "a=maxptime" attributes, respectively.
o 一般（和可选）参数“optime”和“maxptime”分别进入SDP“a=optime”和“a=maxptime”属性。
o Any payload-format-specific parameters go in the SDP "a=fmtp" attribute. The set of allowed parameters is defined by the RFC that specifies the payload format and MUST NOT be extended by the MIME subtype registration without a corresponding revision of the payload format specification. The format and syntax of these parameters may also be defined by the payload format specification, but it is suggested that the parameters be copied directly from the MIME media type string as a semicolon separated list of parameter=value pairs. For payload formats that specify some other syntax for the fmtp parameters, the registration of that payload format as a MIME subtype must specify what the parameters are in MIME format and how to map them to the SDP "a=fmtp" attribute. See Section 4.1.21 for an example.
o 任何特定于有效负载格式的参数都会进入SDP“a=fmtp”属性。允许的参数集由指定有效负载格式的RFC定义，并且在没有有效负载格式规范的相应修订版的情况下，不得通过MIME子类型注册进行扩展。这些参数的格式和语法也可以由有效负载格式规范定义，但建议直接从MIME媒体类型字符串复制参数，作为以分号分隔的参数=值对列表。对于为fmtp参数指定其他语法的有效负载格式，将该有效负载格式注册为MIME子类型必须指定MIME格式中的参数以及如何将其映射到SDP“a=fmtp”属性。示例见第4.1.21节。
An example mapping is as follows:
映射示例如下所示：
audio/L16; rate=48000; channels=2; ptime=5; emphasis=50-15
audio/L16; rate=48000; channels=2; ptime=5; emphasis=50-15
m=audio 49170 RTP/AVP 97
a=rtpmap:97 L16/48000/2
a=fmtp:97 emphasis=50-15
a=ptime:5
m=audio 49170 RTP/AVP 97
a=rtpmap:97 L16/48000/2
a=fmtp:97 emphasis=50-15
a=ptime:5
Note that the payload format (encoding) names defined in the RTP Profile are commonly shown in upper case. MIME subtypes are commonly shown in lower case. These names are case-insensitive in both places. Similarly, parameter names are case-insensitive both in MIME types and in the default mapping to the SDP a=fmtp attribute.
请注意，RTP配置文件中定义的有效负载格式（编码）名称通常以大写形式显示。MIME子类型通常以小写形式显示。这些名称在两个位置都不区分大小写。类似地，参数名在MIME类型和到SDP a=fmtp属性的默认映射中都不区分大小写。
In the following sections, all RTP payload formats described in the RTP Profile for Audio and Video Conferences, RFC 3551 [3], are registered as MIME subtypes.
在以下章节中，音频和视频会议的RTP配置文件RFC 3551[3]中描述的所有RTP有效负载格式都注册为MIME子类型。
The following sections register all of the RTP audio payload types defined in RFC 3551 as MIME types.
以下各节将RFC 3551中定义的所有RTP音频有效负载类型注册为MIME类型。
For most audio payload formats, the RTP timestamp clock rate is equal to the sampling rate. Some payload formats operate only at one fixed sampling rate, while others are adjustable.
对于大多数音频有效负载格式，RTP时间戳时钟速率等于采样速率。一些有效负载格式仅在一个固定采样率下工作，而其他有效负载格式可调。
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: DVI4
MIME子类型名称：DVI4
Required parameters: rate The RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000, but other rates may be specified.
所需参数：速率RTP时间戳时钟速率，等于采样速率。典型费率为8000，但可能会指定其他费率。
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G722
MIME子类型名称：G722
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G723
MIME子类型名称：G723
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
bitrate: the data rate in kb/s used or preferred for the audio bit stream, with permissible values 5.3 or 6.3. If unspecified, the bitrate may change from frame to frame as indicated inband.
比特率：音频比特流使用或首选的数据速率（kb/s），允许值为5.3或6.3。如果未指定，比特率可能会随着帧的变化而变化，如带内所示。
annexa: indicates that Annex A, voice activity detection, is used or preferred. Permissible values are "yes" and "no" (without the quotes); "yes" is implied if this parameter is omitted.
附录A：表示使用或首选附录A“语音活动检测”。允许值为“是”和“否”（不带引号）；如果省略此参数，则表示“是”。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G726-16
MIME子类型名称：G726-16
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G726-24
MIME子类型名称：G726-24
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations:
编码注意事项：
This type is only defined for transfer via RTP [RFC 3550].
此类型仅定义为通过RTP[RFC 3550]传输。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G726-32
MIME子类型名称：G726-32
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G726-40
MIME子类型名称：G726-40
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G728
MIME子类型名称：G728
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G729
MIME子类型名称：G729
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
annexb: indicates that Annex B, voice activity detection, is used or preferred. Permissible values are "yes" and "no" (without the quotes); "yes" is implied if this parameter is omitted.
附录B：表示使用或首选附录B“语音活动检测”。允许值为“是”和“否”（不带引号）；如果省略此参数，则表示“是”。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G729D
MIME子类型名称：G729D
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
annexb: indicates that Annex B, voice activity detection, is used or preferred. Permissible values are "yes" and "no" (without the quotes); "yes" is implied if this parameter is omitted.
附录B：表示使用或首选附录B“语音活动检测”。允许值为“是”和“否”（不带引号）；如果省略此参数，则表示“是”。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: G729E
MIME子类型名称：G729E
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
annexb: indicates that Annex B, voice activity detection, is used or preferred. Permissible values are "yes" and "no" (without the quotes); "yes" is implied if this parameter is omitted.
附录B：表示使用或首选附录B“语音活动检测”。允许值为“是”和“否”（不带引号）；如果省略此参数，则表示“是”。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: GSM
MIME子类型名称：GSM
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: GSM-EFR
MIME子类型名称：GSM-EFR
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: L8
MIME子类型名称：L8
Required parameters: rate, the RTP timestamp clock rate
所需参数：速率、RTP时间戳时钟速率
Optional parameters: channels, ptime, maxptime
可选参数：通道、ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME subtype audio/L16 has already been registered via RFC 2586 for transports other than RTP. That registration is incorporated here and augmented with additional information for RTP transport.
MIME子类型audio/L16已通过RFC 2586注册用于RTP以外的传输。该注册包含在此处，并添加了RTP传输的附加信息。
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: L16
MIME子类型名称：L16
Required parameters rate: number of samples per second -- For non-RTP transport, the permissible values for rate are 8000, 11025, 16000, 22050, 24000, 32000, 44100, and 48000 samples per second. For RTP transport, other values are permissible but the aforementioned values are RECOMMENDED. For RTP, the rate parameter indicates the RTP timestamp clock rate, which is equal to the sample rate.
所需参数速率：每秒样本数——对于非RTP传输，速率的允许值为每秒8000、11025、16000、22050、24000、32000、44100和48000个样本。对于RTP运输，允许使用其他值，但建议使用上述值。对于RTP，rate参数表示RTP时间戳时钟速率，它等于采样速率。
Optional parameters channels: how many audio streams are interleaved -- defaults to 1; stereo would be 2, etc. Interleaving takes place between individual two-byte samples.
可选参数通道：交错的音频流数量——默认为1；立体声将是2，等等。交错发生在单个两字节样本之间。
emphasis: analog preemphasis applied to the signal before quantization. The only emphasis value defined here is emphasis=50-15 to indicate the 50/15 microsecond preemphasis used with Compact Disks. This parameter MUST be omitted if no analog preemphasis was applied.
重点：模拟预相位在量化前应用于信号。此处定义的唯一emphasis值为emphasis=50-15，表示光盘使用了50/15微秒的预相位。如果未应用模拟预相位，则必须忽略此参数。
channel-order: specifies the sample interleaving order for multiple-channel audio streams (see [7] Section 7). Permissible values are DV.LRLsRs, DV.LRCS, DV.LRCWo, DV.LRLsRsC, DV.LRLsRsCS, DV.LmixRmixTWoQ1Q2, DV.LRCWoLsRsLmixRmix, DV.LRCWoLs1Rs1Ls2Rs2, DV.LRCWoLsRsLcRc. For interoperation with DV video systems, only a subset of these channel combinations is specified for use with 20-bit linear encoding in the DV video specification [4]; those are DV.LRLsRs, DV.LRCS, DV.LmixRmixTWoQ1Q2. This parameter MUST be omitted when the AIFF-C channel order convention (see RFC 3551) is in use.
通道顺序：指定多通道音频流的示例交错顺序（请参阅[7]第7节）。允许值为DV.LRLsRs、DV.LRCS、DV.LRCWo、DV.LRLsRsC、DV.LRLsRsCS、DV.LMixrimxtWOQ1Q2、DV.LRCWoLsRsLmixRmix、DV.LRCWoLs1Rs1Ls2Rs2、DV.LRCWoLsRsLcRc。对于与DV视频系统的互操作，在DV视频规范[4]中，仅指定这些信道组合的子集用于20位线性编码；这些是DV.LRLsRs、DV.LRCS、DV.lmixrimxtwoq1q2。当使用AIFF-C信道顺序约定（参见RFC 3551）时，必须忽略此参数。
For RTP, ptime: RECOMMENDED duration of each packet in milliseconds.
对于RTP，ptime：每个数据包的建议持续时间（毫秒）。
For RTP, maxptime: maximum duration of each packet in milliseconds.
对于RTP，maxptime：每个数据包的最大持续时间（毫秒）。
Encoding considerations Audio data is binary data, and must be encoded for non-binary transport; the Base64 encoding is suitable for Email. Note that audio data does not compress easily using lossless compression.
编码注意事项音频数据是二进制数据，并且必须为非二进制传输进行编码；Base64编码适用于电子邮件。请注意，使用无损压缩时，音频数据不容易压缩。
This type is also defined for transfer via RTP [RFC 3550].
此类型也定义为通过RTP[RFC 3550]传输。
Security considerations Audio data is believed to offer no security risks. See Section 5 of RFC 3555.
安全注意事项音频数据被认为没有安全风险。见RFC 3555第5节。
Interoperability considerations This type is compatible with the encoding used in the WAV (Microsoft Windows RIFF) and Apple AIFF union types, and with the public domain "sox" and "rateconv" programs.
互操作性注意事项此类型与WAV（Microsoft Windows RIFF）和Apple AIFF联合类型中使用的编码兼容，并与公共域“sox”和“rateconv”程序兼容。
Published specification RFC 2586 for non-RTP transports, RFC 3551 for RTP
发布的非RTP传输规范RFC 2586，RTP规范RFC 3551
Applications which use this media The public domain "sox" and "rateconv" programs accept this type.
在公共域“sox”和“rateconv”程序中使用此媒体的应用程序接受此类型。
1. Magic number(s) : None 2. File extension(s) : WAV L16 3. Macintosh file type code : AIFF
1. 神奇数字：无2。文件扩展名：WAV L16 3。Macintosh文件类型代码：AIFF
Person to contact for further information 1. Name : James Salsman 2. E-mail : jps-L16@bovik.org
有关更多信息，请联系人员1。姓名：詹姆斯·萨尔斯曼2。电邮：jps-L16@bovik.org
Intended usage Common
预期用途常见
It is expected that many audio and speech applications will use this type. Already the most popular platforms provide this type with the rate=11025 parameter referred to as "radio quality speech."
预计许多音频和语音应用程序将使用这种类型。最流行的平台已经为这种类型提供了rate=11025参数，称为“无线电质量语音”
Author/Change controller James Salsman for non-RTP transports. Stephen Casner for RTP transport.
非RTP传输的作者/变更控制员James Salsman。Stephen Casner负责RTP运输。
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: LPC
MIME子类型名称：LPC
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: MPA (MPEG audio)
MIME子类型名称：MPA（MPEG音频）
Required parameters: None
所需参数：无
Optional parameters: layer: which layer of MPEG audio encoding; permissible values are 1, 2, 3.
可选参数：层：MPEG音频编码的哪一层；允许值为1、2、3。
samplerate: the rate at which audio is sampled. MPEG-1 audio supports sampling rates of 32, 44.1, and 48 kHz; MPEG-2 supports sampling rates of 16, 22.05 and 24 kHz. This parameter is separate from the RTP timestamp clock rate which is always 90000 Hz for MPA.
采样率：音频采样的速率。MPEG-1音频支持32、44.1和48 kHz的采样率；MPEG-2支持16、22.05和24 kHz的采样率。该参数与RTP时间戳时钟频率分开，对于MPA，RTP时间戳时钟频率始终为90000 Hz。
mode: permissible values are "stereo", "joint_stereo", "single_channel", "dual_channel". The "channels" parameter does not apply to MPA. It is undefined to put a number of channels in the SDP rtpmap attribute for MPA.
模式：允许值为“立体声”、“联合立体声”、“单声道”、“双声道”。“通道”参数不适用于兆帕。未定义在MPA的SDP rtpmap属性中放置多个通道。
bitrate: the data rate for the audio bit stream.
比特率：音频比特流的数据速率。
ptime: RECOMMENDED duration of each packet in milliseconds.
ptime：每个数据包的建议持续时间（毫秒）。
maxptime: maximum duration of each packet in milliseconds.
maxptime：每个数据包的最大持续时间（毫秒）。
Parameters which are omitted are left to the encoder to choose based on the session bandwidth, configuration information, or other constraints. The selected layer as well as the sampling rate and mode are indicated in the payload so receivers can process the data without these parameters being specified externally.
省略的参数留给编码器根据会话带宽、配置信息或其他约束进行选择。所选层以及采样率和模式在有效载荷中指示，因此接收器可以处理数据，而无需外部指定这些参数。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: PCMA
MIME子类型名称：PCMA
Required parameters: rate The RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000, but other rates may be specified.
所需参数：速率RTP时间戳时钟速率，等于采样速率。典型费率为8000，但可能会指定其他费率。
Optional parameters: channels, ptime, maxptime
可选参数：通道、ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: PCMU
MIME子类型名称：PCMU
Required parameters: rate The RTP timestamp clock rate, which is equal to the sampling rate. The typical rate is 8000, but other rates may be specified.
所需参数：速率RTP时间戳时钟速率，等于采样速率。典型费率为8000，但可能会指定其他费率。
Optional parameters: channels, ptime, maxptime
可选参数：通道、ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: QCELP
MIME子类型名称：QCELP
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2658
已发布规范：RFC 2658
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: RED
MIME子类型名称：红色
Required parameters: pt: a comma-separated list of RTP payload types. Because comma is a special character, the list must be a quoted-string (enclosed in double quotes). For static payload types, each list element is simply the type number. For dynamic payload types, each list element is a mapping of the dynamic payload type number to an embedded MIME content-type specification for the payload format corresponding to the dynamic payload type. The format of the mapping is:
所需参数：pt：以逗号分隔的RTP有效负载类型列表。因为逗号是特殊字符，所以列表必须是带引号的字符串（用双引号括起来）。对于静态有效负载类型，每个列表元素只是类型编号。对于动态有效负载类型，每个列表元素都是动态有效负载类型编号到对应于动态有效负载类型的有效负载格式的嵌入式MIME内容类型规范的映射。映射的格式为：
dynamic-payload-type "=" content-type
动态有效负载类型“=”内容类型
If the content-type string includes a comma, then the content-type string MUST be a quoted-string. If the content-type string does not include a comma, it MAY still be quoted. Since it is part of the list which must itself be a quoted-string, that means the quotation marks MUST be quoted with backslash quoting as specified in RFC 2045. If the content-type string itself contains a quoted-string, then the requirement for backslash quoting is recursively applied. To specify the audio/RED payload format in SDP, the pt parameter is mapped to an a=fmtp attribute by eliminating the parameter name (pt) and changing the commas to slashes. For example, 'pt="0,5"' maps to 'a=fmtp:99 0/5'. A more complicated example, with a dynamic payload type, is:
如果内容类型字符串包含逗号，则内容类型字符串必须是带引号的字符串。如果内容类型字符串不包含逗号，则仍可将其引用。由于它是列表的一部分，而列表本身必须是带引号的字符串，这意味着必须按照RFC 2045中的规定使用反斜杠引号引用引号。如果内容类型字符串本身包含带引号的字符串，则递归应用反斜杠引号的要求。要在SDP中指定音频/红色有效负载格式，可通过删除参数名称（pt）并将逗号更改为斜杠，将pt参数映射到a=fmtp属性。例如，“pt=“0,5”映射为“a=fmtp:99 0/5”。对于动态有效负载类型，更复杂的示例是：
pt = "0, 103 = \"audio/G729D;annexb=yes\" "
pt = "0, 103 = \"audio/G729D;annexb=yes\" "
m=audio 49170 RTP/AVP 99 0 103
a=rtpmap:99 RED/8000
a=fmtp:99 0/103
a=rtpmap:103 G729D/8000
a=fmtp:103 annexb=yes
m=audio 49170 RTP/AVP 99 0 103
a=rtpmap:99 RED/8000
a=fmtp:99 0/103
a=rtpmap:103 G729D/8000
a=fmtp:103 annexb=yes
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2198
已发布规范：RFC 2198
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: audio
MIME媒体类型名称：音频
MIME subtype name: VDVI
MIME子类型名称：VDVI
Required parameters: None
所需参数：无
Optional parameters: ptime, maxptime
可选参数：ptime、maxptime
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
For all of the video payload formats registered here, the RTP timestamp clock rate is always 90000 Hz, so the "rate" parameter is not applicable. Likewise, the "channel" parameter is not used with video, and while "ptime" and "maxptime" could be used with video, they typically are not.
对于此处注册的所有视频有效负载格式，RTP时间戳时钟速率始终为90000 Hz，因此“速率”参数不适用。同样，“channel”参数不用于视频，虽然“ptime”和“maxptime”可用于视频，但它们通常不用于视频。
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: BT656
MIME子类型名称：BT656
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2431
已发布规范：RFC 2431
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: CelB
MIME子类型名称：CelB
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2029
发布规范：RFC 2029
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: JPEG
MIME子类型名称：JPEG
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2435
已发布规范：RFC 2435
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: H261
MIME子类型名称：H261
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2032
已发布规范：RFC 2032
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: H263
MIME子类型名称：H263
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2190
已发布规范：RFC 2190
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: H263-1998
MIME子类型名称：H263-1998
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2429
已发布规范：RFC 2429
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: H263-2000
MIME子类型名称：H263-2000
Required parameters: None
所需参数：无
Optional parameters: profile: H.263 profile number, in the range 0 through 10, specifying the supported H.263 annexes/subparts.
可选参数：profile:H.263 profile number，范围从0到10，指定支持的H.263附件/子部分。
level: Level of bitstream operation, in the range 0 through 100, specifying the level of computational complexity of the decoding process.
级别：位流操作的级别，范围为0到100，指定解码过程的计算复杂度级别。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2429 The specific values for the profile and level parameters and their meaning are defined in Annex X of ITU-T Recommendation H.263, "Video coding for low bit rate communication". Note that the RTP payload format for H263-2000 is the same as for H263-1998, but additional annexes/subparts are specified along with the profiles and levels.
已发布规范：RFC 2429剖面和电平参数的具体值及其含义在ITU-T建议H.263“低比特率通信的视频编码”的附录X中定义。请注意，H263-2000的RTP有效载荷格式与H263-1998的相同，但附加附件/子部分与概要文件和级别一起指定。
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: MPV MPEG-1 or -2 Elementary Streams
MIME子类型名称：MPV MPEG-1或-2基本流
Required parameters: None
所需参数：无
Optional parameters: type: the type of MPEG video, from the set "mpeg1", "mpeg2-halfd1", or "mpeg2-fulld1". The default is "mpeg1". The mapping to a=fmtp is identity.
可选参数：类型：MPEG视频的类型，来自设置“mpeg1”、“mpeg2-halfd1”或“mpeg2-fulld1”。默认值为“mpeg1”。到a=fmtp的映射是identity。
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2250
已发布规范：RFC 2250
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: MP2T MPEG-2 Transport Streams
MIME子类型名称：MP2T MPEG-2传输流
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2250
已发布规范：RFC 2250
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: MP1S MPEG-1 Systems Streams
MIME子类型名称：MP1S MPEG-1系统流
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2250
已发布规范：RFC 2250
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: MP2P MPEG-2 Program Streams
MIME子类型名称：MP2P MPEG-2节目流
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2250
已发布规范：RFC 2250
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: BMPEG
MIME子类型名称：BMPEG
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 2343
已发布规范：RFC 2343
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
MIME media type name: video
MIME媒体类型名称：视频
MIME subtype name: nv
MIME子类型名称：nv
Required parameters: None
所需参数：无
Optional parameters: None
可选参数：无
Encoding considerations: This type is only defined for transfer via RTP [RFC 3550].
编码注意事项：此类型仅为通过RTP[RFC 3550]传输而定义。
Security considerations: See Section 5 of RFC 3555
安全注意事项：见RFC 3555第5节
Interoperability considerations: none
互操作性注意事项：无
Published specification: RFC 3551
已发布规范：RFC 3551
Applications which use this media type: Audio and video streaming and conferencing tools.
使用此媒体类型的应用程序：音频和视频流和会议工具。
Additional information: none
其他信息：无
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Person & email address to contact for further information:
Stephen Casner <casner@acm.org>
Intended usage: COMMON
预期用途：普通
Author/Change controller: Stephen Casner
作者/变更控制员：斯蒂芬·卡斯纳
The MIME subtype registration procedure specified in this memo does not impose any security considerations on its own. This memo also contains several MIME type registrations. The registrations themselves do not impose security risks, but some may state security considerations specific to the particular registration.
本备忘录中指定的MIME子类型注册过程本身并不强加任何安全考虑。此备忘录还包含多个MIME类型注册。注册本身不会带来安全风险，但有些可能会说明特定注册的安全注意事项。
Several audio and video encodings are perfect for hiding data using steganography.
有几种音频和视频编码非常适合使用隐写术隐藏数据。
The RTP specification, RFC 3550, provides security considerations for the transport of audio and video data over RTP, including the use of encryption where confidentiality is required.
RTP规范RFC 3550为通过RTP传输音频和视频数据提供了安全注意事项，包括在需要保密的情况下使用加密。
[1] Freed, N., Klensin, J. and J. Postel, "Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures", BCP 13, RFC 2048, November 1996.
[1] Freed，N.，Klensin，J.和J.Postel，“多用途互联网邮件扩展（MIME）第四部分：注册程序”，BCP 13，RFC 2048，1996年11月。
[2] Schulzrinne, H., Casner, S., Frederick, R. and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", RFC 3550, July 2003.
[2] Schulzrinne，H.，Casner，S.，Frederick，R.和V.Jacobson，“RTP：实时应用的传输协议”，RFC 35502003年7月。
[3] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and Video Conferences with Minimal Control", RFC 3551, July 2003.
[3] Schulzrinne，H.和S.Casner，“具有最小控制的音频和视频会议的RTP配置文件”，RFC 3551，2003年7月。
[4] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[4] Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[5] Handley, M. and V. Jacobson, "SDP: Session Description Protocol", RFC 2327, April 1998.
[5] Handley，M.和V.Jacobson，“SDP：会话描述协议”，RFC 2327，1998年4月。
[6] Freed, N. and N. Borenstein, "Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies", RFC 2045, November 1996.
[6] Freed，N.和N.Borenstein，“多用途互联网邮件扩展（MIME）第一部分：互联网邮件正文格式”，RFC 20451996年11月。
[7] Kobayashi, K., Ogawa, A., Casner, S. and C. Bormann, "RTP Payload Format for 12-bit DAT Audio and 20- and 24-bit Linear Sampled Audio", RFC 3190, January 2002.
[7] Kobayashi，K.，Ogawa，A.，Casner，S.和C.Bormann，“12位DAT音频和20位和24位线性采样音频的RTP有效载荷格式”，RFC 3190，2002年1月。
Stephen L. Casner Packet Design 3400 Hillview Avenue, Building 3 Palo Alto, CA 94304 United States
Stephen L.Casner Packet Design美国加利福尼亚州帕洛阿尔托市Hillview大道3400号3号楼，邮编94304
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EMail: casner@acm.org
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EMail: casner@acm.org
Philipp Hoschka INRIA Route des Lucioles 2004 06904, Sophia-Antipolis Cedex BP 93, France
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EMail: ph@w3.org
Phone: (+33) 4 92 38 79 84
Fax: (+33) 4 92 38 77 65
EMail: ph@w3.org
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Acknowledgement
确认
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