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• 特性
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

An instance of the WebRTC API's RTCRtpEncodingParameters dictionary describes a single configuration of a codec 对于 RTCRtpSender . It's used in the RTCRtpSendParameters describing the configuration of an RTP sender's encodings ; RTCRtpDecodingParameters is used to describe the configuration of an RTP receiver's encodings .

特性

active

若 true , the described encoding is currently actively being used. That is, for RTP senders, the encoding is currently being used to send data, while for receivers, the encoding is being used to decode received data. The default value is true .

codecPayloadType

When describing a codec for an RTCRtpSender , codecPayloadType is a single 8-bit byte (or octet) specifying the codec to use for sending the stream; the value matches one from the owning RTCRtpParameters 对象的 codecs parameter. This value can only be set when creating the transceiver; after that, this value is read only.

dtx

Only used for an RTCRtpSender whose kind is audio , this property indicates whether or not to use discontinuous transmission (a feature by which a phone is turned off or the microphone muted automatically in the absence of voice activity). The value is taken from the enumerated string type RTCDtxStatus .

maxBitrate

An unsigned long integer indicating the maximum number of bits per second to allow for this encoding. Other parameters may further constrain the bit rate, such as the value of maxFramerate or transport or physical network limitations.

maxFramerate

A double-precision floating-point value specifying the maximum number of frames per second to allow for this encoding.

ptime

An unsigned long integer value indicating the preferred duration of a media packet in milliseconds. This is typically only relevant for audio encodings. The user agent will try to match this as well as it can, but there is no guarantee.

rid

DOMString which, if set, specifies an RTP stream ID ( RID ) to be sent using the RID header extension. This parameter cannot be modified using setParameters() . Its value can only be set when the transceiver is first created.

scaleResolutionDownBy

Only used for senders whose track's kind is 视频 , this is a double-precision floating-point value specifying a factor by which to scale down the video during encoding. The default value, 1.0, means that the sent video's size will be the same as the original. A value of 2.0 scales the video frames down by a factor of 2 in each dimension, resulting in a video 1/4 the size of the original. The value must not be less than 1.0 (you can't use this to scale the video up).

规范

规范	状态	注释
WebRTC 1.0: Real-time Communication Between Browsers The definition of 'RTCRtpEncodingParameters' in that specification.	候选推荐	初始定义。

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
RTCRtpEncodingParameters	Chrome 67	Edge ≤79	Firefox 46	IE No	Opera ?	Safari ?	WebView Android 67	Chrome Android 67	Firefox Android 46	Opera Android ?	Safari iOS ?	Samsung Internet Android 9.0
active	Chrome 67	Edge ≤79	Firefox 46	IE No	Opera ?	Safari ?	WebView Android 67	Chrome Android 67	Firefox Android 46	Opera Android ?	Safari iOS ?	Samsung Internet Android 9.0
codecPayloadType	Chrome No	Edge No	Firefox No	IE No	Opera ?	Safari ?	WebView Android No	Chrome Android No	Firefox Android No	Opera Android ?	Safari iOS ?	Samsung Internet Android No
dtx	Chrome No	Edge No	Firefox No	IE No	Opera ?	Safari ?	WebView Android No	Chrome Android No	Firefox Android No	Opera Android ?	Safari iOS ?	Samsung Internet Android No
fec 非标	Chrome No	Edge No	Firefox 46 46 This non-standard property should not be used in production code.	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 46 46 This non-standard property should not be used in production code.	Opera Android No	Safari iOS No	Samsung Internet Android No
maxBitrate	Chrome 67	Edge ≤79	Firefox 46	IE No	Opera ?	Safari ?	WebView Android 67	Chrome Android 67	Firefox Android 46	Opera Android ?	Safari iOS ?	Samsung Internet Android 9.0
maxFramerate	Chrome No	Edge No	Firefox No	IE No	Opera ?	Safari ?	WebView Android No	Chrome Android No	Firefox Android No	Opera Android ?	Safari iOS ?	Samsung Internet Android No
priority 弃用 非标	Chrome 67 67 The standard version of this property is RTCRtpSendParameters.priority .	Edge ≤79 ≤79 The standard version of this property is RTCRtpSendParameters.priority .	Firefox 46 46 The standard version of this property is RTCRtpSendParameters.priority .	IE No	Opera ?	Safari ?	WebView Android 67 67 The standard version of this property is RTCRtpSendParameters.priority .	Chrome Android 67 67 The standard version of this property is RTCRtpSendParameters.priority .	Firefox Android 46 46 The standard version of this property is RTCRtpSendParameters.priority .	Opera Android ?	Safari iOS ?	Samsung Internet Android 9.0 9.0 The standard version of this property is RTCRtpSendParameters.priority .
ptime	Chrome No	Edge No	Firefox No	IE No	Opera ?	Safari ?	WebView Android No	Chrome Android No	Firefox Android No	Opera Android ?	Safari iOS ?	Samsung Internet Android No
rid 非标	Chrome No	Edge No	Firefox 46 46 The standard version of this property is RTCRtpCodecParameters.rid .	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 46 46 The standard version of this property is RTCRtpCodecParameters.rid .	Opera Android No	Safari iOS No	Samsung Internet Android No
rtx 非标	Chrome No	Edge No	Firefox 46 46 This non-standard property should not be used in production code.	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 46 46 This non-standard property should not be used in production code.	Opera Android No	Safari iOS No	Samsung Internet Android No
scaleResolutionDownBy	Chrome 74	Edge No	Firefox 46	IE No	Opera ?	Safari ?	WebView Android 74	Chrome Android 74	Firefox Android 46	Opera Android ?	Safari iOS ?	Samsung Internet Android 11.0
ssrc 非标	Chrome No	Edge No	Firefox 46 46 This non-standard property should not be used in production code.	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 46 46 This non-standard property should not be used in production code.	Opera Android No	Safari iOS No	Samsung Internet Android No

图例

完整支持

完整支持

不支持

不支持

兼容性未知 ?

兼容性未知

非标。预期跨浏览器支持较差。

非标。预期跨浏览器支持较差。

弃用。不要用于新网站。

弃用。不要用于新网站。

见实现注意事项。

另请参阅

• Introduction to the Real-time Transport Protocol (RTP)
• RTCRtpSender , RTCRtpReceiver ，和 RTCRtpTransceiver

元数据

• 最后修改： Jul 2, 2019

相关话题

1. WebRTC API
2. RTCRtpEncodingParameters
3. 特性

   1. maxBitrate
4. Related pages for WebRTC

   1. MediaDevices.getUserMedia()
   2. Navigator.mediaDevices
   3. RTCCertificate
   4. RTCDTMFSender
   5. RTCDTMFToneChangeEvent
   6. RTCDataChannel
   7. RTCDataChannelEvent
   8. RTCDtlsTransport
   9. RTCErrorEvent
   10. RTCIceCandidate
   11. RTCIceTransport
   12. RTCPeerConnection
   13. RTCPeerConnectionIceErrorEvent
   14. RTCPeerConnectionIceEvent
   15. RTCRtpReceiver
   16. RTCRtpSender
   17. RTCRtpTransceiver
   18. RTCSctpTransport
   19. RTCSessionDescription
   20. RTCStatsEvent
   21. RTCStatsReport
   22. RTCTrackEvent