Connects the video source to the video output device and also controls post-processing and scaling on the video device. The service exposes methods that make the HAL calls to connect source to sink and position output as needed.
Note: Application developers must not use this service directly.
Overview of the API(click to expand)
This service is responsible for connecting the input pipeline to the backend video. The Media Framework is responsible for determining the life cycle of a connection and pipeline policy (which application is in foreground and has focus, resources, and so on). Media Framework uses VideoOutput APIs to achieve connection and video post-processing.
- VideoOutput does NOT have policy.
- It provides API to connect video source (frames from decoder and so on) to video plane.
- It provides the HAL abstraction for the backend (i.e. VideoOutput will work with HAL or KMS/DRM or other hardware abstraction layer)
- It provides the interface for H/W video post-processing and scaling. The post-processing functionality will be implemented with a plugin design to allow various degrees of functionality based on product.
Direct use of videooutputd by application developers is strongly discouraged. Instead, the modules of media framework like UMS, LSM are supposed to use these APIs.