【webrtc】rtp扩展：绝对发送时间、绝对采集时间、时间戳插值

• WebRTC RTP 标头扩展审查
• 绝对发送时间和绝对采集时间，二者是不同的
• 当没有打开绝对采集时间戳的扩展时，webrtc依旧会使用AbsoluteCaptureTimeInterpolator 在接收测估算 绝对采集时间戳。

Absolute Send Time 带宽估计算法用

The Absolute Send Time extension is used to stamp RTP packets with a timestamp showing the departure time from the system that put this packet on the wire (or as close to this as we can manage). Contact [email protected] for more info.

Name: “Absolute Sender Time” ; “RTP Header Extension for Absolute Sender Time”

• Formal name: http://www.webrtc.org/experiments/rtp-hdrext/abs-send-t