Video and Image Processing Suite User Guide

ID 683416
Date 2/12/2021

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

3.1.5. Clocked Video and 4:2:0 Chroma Subsampling

Other than the Chroma Resampler II IP core, none of the VIP IP cores offer explicit support for clocked video with 4:2:0 subsampling.

When processing 4:2:0 streams, you need to use chroma resampler to convert to 4:2:2 or 4:4:4 before or after any video processing is performed. The video streams can be converted back to 4:2:0 for transmission from the pipeline with another chroma resampler.

Figure 17. Pipeline with Color Space and Subsampling Adaptive Interfaces Block DiagramThe figure below shows how the chroma resampler handles the conversion.

The connectivity cores (SDI, HDMI and DisplayPort) present data at their interfaces in accordance with their respective standards, not in line with the AV-ST mappings. Before the data is processed, it must be arranged in an Avalon-ST compliant manner. The input and output preparation areas present a gray area in the pipeline where video packets are Avalon-ST video compliant but the arrangement of data within the packet may not match the expectations of the processing blocks.