Video and Image Processing Suite User Guide

ID 683416
Date 4/04/2022
Document Table of Contents

16.1. Double Buffering

For double-buffering, the Frame Buffer II IP core uses two frame buffers in external RAM.

  • The writer uses one buffer to store input pixels.
  • The reader locks the second buffer that reads the output pixels from the memory.
  • When both writer and reader complete processing a frame, the buffers are exchanged.
  • The input frame can then be read back from the memory and sent to the output, while the buffer that has just been used to create the output can be overwritten with fresh input.

This feature is used when:

  • The frame rate is the same both at the input and at the output sides but the pixel rate is highly irregular at one or both sides.
  • A frame has to be received or sent in a short period of time compared with the overall frame rate. For example, after the Clipper IP core or before one of the foreground layers of the Alpha Blending Mixer IP core.