The Filter2DRequest class is used by the filtering request dispatcher class. An object of this class encapsulates a single request to process a single color channel (YUV) for a given image. It essentially allocates and holds handles to OpenCL resources needed for enqueueing 2-D convolution filtering requests. These resources include OpenCL buffers, event lists, and handles to kernel and command queue. The application creates a single command queue that is passed down to enqueue every kernel enqueue command.
After an object of the Filter2DRequest class is created, it can be used to make a call to the Filter2D method. This call will enqueue all the operations, moving input data or filter coefficients, kernel calls, and reading of output data back to the host. The same API call will create a list of dependencies between these transfers and also creates an output event that signals the completion of output data transfer to the host.