2.4.1.1 microsoft_latency_management_capability
The microsoft_latency_management_capability parameter specifies whether the Wi-Fi Display Sink is capable of dynamically changing the display latency of the video bit stream. When sent by the Wi-Fi Display Sink, the parameter specifies the desired latency mode.
This parameter is included by the Wi-Fi Display Source in the M3 request to specify support for latency management, by the Wi-Fi Display Sink in the M3 response to specify support for latency management, and by the Wi-Fi Display Source in a SET_PARAMETER request to set the latency mode to a new value.
For the purposes of this section, "latency" is defined as the time from the moment the last RTP packet is received for a video frame, until the time that the Wi-Fi Display Sink renders the frame to the output device.
The ABNF syntax is as follows:
-
microsoft-latency-management-capability = "microsoft_latency_management_capability:" SP ( latency-management-cap / latency-mode ) CRLF latency-management-cap = "supported" / "none" latency-mode = "low" / "normal" / "high"
Possible values for the latency-management-cap parameter are as follows:
|
Value |
Meaning |
|---|---|
|
supported |
Specifies that the Wi-Fi Display Sink is capable of changing the latency mode. |
|
none |
Specifies that the Wi-Fi Display Sink is not capable of changing the latency mode. |
Possible values for the latency-mode parameter are as follows:
|
Value |
Meaning |
|---|---|
|
low |
Specifies that the Wi-Fi Display Sink SHOULD keep latency under 50 milliseconds.<7> |
|
normal |
Specifies that the Wi-Fi Display Sink SHOULD keep latency under 100 milliseconds.<8> |
|
high |
Specifies that the Wi-Fi Display Sink SHOULD buffer additional frames in order to ensure smooth playback, as long as the latency stays under 500 milliseconds. |