From 1084b1289dc46a6aaf8c204d3ca3257146cab7b7 Mon Sep 17 00:00:00 2001 From: Bernard Aboba Date: Mon, 21 Jan 2019 12:04:34 -0800 Subject: [PATCH] Fix alignment --- webrtc.html | 78 +++++++++++++++++++++++++---------------------------- 1 file changed, 37 insertions(+), 41 deletions(-) diff --git a/webrtc.html b/webrtc.html index 9d161776b..b02108d96 100644 --- a/webrtc.html +++ b/webrtc.html @@ -7510,44 +7510,40 @@

Methods

Simulcast functionality

-

Simulcast functionality is provided via the - addTransceiver method of the RTCPeerConnection object - and the setParameters method of the RTCRtpSender object.

-

The addTransceiver method establishes the simulcast envelope which includes - the maximum number of simulcast streams that can be sent, as well as the ordering of the encodings. - While characteristics of individual simulcast streams can be modified using the setParameters - method, the simulcast envelope cannot be changed. One of the implications of this model is that - the addTrack method cannot provide simulcast functionality since it - does not take sendEncodings as an argument, and therefore cannot configure - an RTCRtpTransceiver to send simulcast.

-

While setParameters cannot modify the simulcast envelope, it is still possible to control the - number of streams that are sent and the characteristics of those streams. - Using setParameters, simulcast streams can be made inactive by setting the active - attribute to false, or can be reactivated by setting the active - attribute to true. Using setParameters, stream characteristics can be changed - by modifying attributes such as maxBitrate and maxFramerate.

-

This specification does not define how to configure createOffer to - receive multiple RTP encodings. However when setRemoteDescription is called with a - corresponding remote description that is able to send - multiple RTP encodings as defined in [[!JSEP]], the - RTCRtpReceiver may receive multiple RTP - encodings and the parameters retrieved via the transceiver's - receiver.getParameters() will reflect the - encodings negotiated.

-

An RTCRtpReceiver can receive multiple RTP streams in a scenario - where a Selective Forwarding Unit (SFU) switches between simulcast streams it receives from user agents. - If the SFU does not rewrite RTP headers so as to arrange the switched streams into a single RTP - stream prior to forwarding, the RTCRtpReceiver will receive packets from - distinct RTP streams, each with their own SSRC and sequence number space. - While the SFU may only forward a single RTP stream at any given time, packets - from multiple RTP streams can become intermingled at the receiver due to reordering. - An RTCRtpReceiver equipped to receive multiple RTP streams will therefore - need to be able to correctly order the received packets, recognize potential loss events and - react to them. Correct operation in this scenario is non-trivial and therefore is optional - for implementations of this specification.

-
-

Encoding Parameter Examples

-
+

Simulcast functionality is provided via the addTransceiver method of the + RTCPeerConnection object and the setParameters method of the + RTCRtpSender object.

+

The addTransceiver method establishes the simulcast envelope which + includes the maximum number of simulcast streams that can be sent, as well as the ordering of the + encodings. While characteristics of individual simulcast streams can be modified using + the setParameters method, the simulcast envelope cannot be changed. One of the + implications of this model is that the addTrack method cannot provide simulcast + functionality since it does not take sendEncodings as an argument, and therefore cannot + configure an RTCRtpTransceiver to send simulcast.

+

While setParameters cannot modify the simulcast envelope, it is still possible + to control the number of streams that are sent and the characteristics of those streams. Using + setParameters, simulcast streams can be made inactive by setting the active + attribute to false, or can be reactivated by setting the active + attribute to true. Using setParameters, stream characteristics can be + changed by modifying attributes such as maxBitrate and maxFramerate.

+

This specification does not define how to configure createOffer to receive multiple + RTP encodings. However when setRemoteDescription is called with a corresponding remote + description that is able to send multiple RTP encodings as defined in [[!JSEP]], the + RTCRtpReceiver may receive multiple RTP encodings and the parameters retrieved + via the transceiver's receiver.getParameters() will reflect the encodings negotiated.

+

An RTCRtpReceiver can receive multiple RTP streams in a scenario + where a Selective Forwarding Unit (SFU) switches between simulcast streams it receives from user agents. + If the SFU does not rewrite RTP headers so as to arrange the switched streams into a single RTP + stream prior to forwarding, the RTCRtpReceiver will receive packets from distinct + RTP streams, each with their own SSRC and sequence number space. While the SFU may only forward a single + RTP stream at any given time, packets from multiple RTP streams can become intermingled at the receiver + due to reordering. An RTCRtpReceiver equipped to receive multiple RTP streams will + therefore need to be able to correctly order the received packets, recognize potential loss events and + react to them. Correct operation in this scenario is non-trivial and therefore is optional for + implementations of this specification.

+
+

Encoding Parameter Examples

+

Examples of simulcast scenarios implemented with encoding parameters:

    
@@ -7564,9 +7560,9 @@ 
Encoding Parameter Examples

   {rid: 'h', active: false, maxFramerate: 30},
   {rid: 'q', active: true, maxFramerate: 15}
 ];
-
-
-
+ +
+

"Hold" functionality