Creating Display Surfaces
An application must set certain additional flags when it creates NvMedia images and video surfaces and feeds them to the NvMedia API:
• NvMediaIDPFlip (display)
• NvMediaVideoOutputFlip (display)
These flags enable surface allocation out of appropriate physically contiguous memory reserves, which is a requirement for the display hardware engines. They need not be set if the application is not feeding created surfaces to any of the two API functions listed above.
Additional Flag for NvMediaIDPFlip
Image capture surfaces that are fed to the NvMediaIDPFlip() function must be created by calling NvMediaImageCreate() with the additional attribute flag NVMEDIA_IMAGE_ATTRIBUTE_DISPLAY.
If this flag is not set when a surface is created, the result may be a warning message like this:
WARNING: Using blit fallback. Performance will be affected
Additional Flag for NvMediaVideoOutputFlip
Image capture surfaces that are fed to the NvMediaVideoOutputFlip() function must be created by calling NvMediaImageCreate() with the additional attribute flag NVMEDIA_SURFACE_CREATE_ATTRIBUTE_DISPLAY.
If this flag is not set when a surface is created, the result may be a warning message like:
WARNING: Using blit fallback. Performance will be affected
Where Surfaces with Additional Flags Are Created
Surfaces created for capture using the NVMEDIA_IMAGE_ATTRIBUTE_CAPTURE flag are created in carveout memory, which is a physically contiguous memory visible only to the current partition.
Surfaces created for display using the NVMEDIA_IMAGE_ATTRIBUTE_DISPLAY or NVMEDIA_SURFACE_CREATE_ATTRIBUTE_DISPLAY flag are created in the following locations:
• If the display hardware/server is owned by the same partition as the application that creates the surfaces, in carveout memory.
• If the display hardware/server is owned by another partition, in a shared memory pool reserve (a different reserve than carveout). This shared memory pool is accessible to the partition that owns the display hardware/server in addition to being physically contiguous.
Surfaces that have a “display” flag set are created according to the rules that apply to surfaces created for display.