Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
This section describes modification done to core AOSP frameworks. No change in framework does not mean there will be none in the future. When we move to the next phase, we will be enhancing the platform functionality and API to meet service providers requirements and customers’ expectations.
Display Manager
Video collaboration devices need to support two HDMI (2.0 or newer) ports for output to external displays. When two external displays are connected over the two HDMI ports, one of the displays must be marked as primary (AOSP Default Display). The other display is marked as secondary and is available to use via presentation API.
Android always needs a primary display. In case there is no physical display connected, then a virtual (fake) display will be indicated. Hot plug detection should take care of adapting whenever physical display is connected. For other pluggable displays, whenever a physical display is disconnected, logical instance is destroyed and created on Hot plug detection. Surface Flinger will just work on display ID for primary, external, and virtual based on information provided from HWC.
While from hardware point from view, HDMI_PRIMARY port may be fixed per HW design, but logical display swapping is made possible with RIDA (Runtime I/O Device Association) where in touch enabled display can be switched and visualized as HDMI primary for applications.
| HDMI 1 - has touch? | HDMI 2 - has touch? | Display clasification |
|---|---|---|
| Yes | Yes | HDMI 1 - primary, HDMI 2 - secondary |
| No | Yes | HDMI 1 - secondary, HDMI 2 - primary |
| Yes | No | HDMI 1 - primary, HDMI 2 - secondary |
| No | No | HDMI 1 - primary, HDMI 2 - secondary |
If RIDA is not used, OEMs can implement their own detection algorithm that classifies the HDMI display as primary or secondary based on support for touch and, algorithm changes the primary display and “routing of views” to the primary display without disruptions in Teams Experience.