Video and Image Processing Suite User Guide

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

25.1. Avalon-ST Video Protocol

The Avalon-ST Video protocol uses an implicit model for ideal use conditions.

In the implicit model ideal use conditions, the data stream contains repeating sequences of these set of packets:

N user packets (N ≥ 0) > 1 valid control packet > 1 frame/field packet (matching the dimensions specified in the control packet)

However, the Avalon-ST Video protocol allows for different sequences of input packets without any errors in the data processing. For example:

  • Every frame or field packets could receive multiple control packets.
  • Some or all of the user packets could arrive between the control and frame or field packet.
  • The video need not send a control packet with every frame or field packet if the input resolution and interlace field remains constant for each frame packet.
The Avalon-ST Video protocol also allows for a wide range of error cases that may disrupt the data processing and produce corrupted output video. These error cases include:
  • Control packets have insufficient number of beats of data to be decoded
  • Length of frame or field packet does not match the resolution specified by the preceding control packet.