Refer to the Reference Manual,
Since VPU is a multiple instance codec, the application requires this kind of
handle. Once the application receives a handle, the application must pass the handle to all subsequent decoder-related
functions.When writing a VPU driver, this handle can be regard as a device-ID or a port-ID of the VPU for each task.
Since the VPU can only perform one picture processing task at a time, the application task should check if VPU is ready
before starting a new picture operation. An application can easily terminate a single task on VPU by calling a function for
closing a certain instance.
for every task, one can refer to the decoding flow or encoding flow in the VPU API reference manual.