Video and Image Processing Suite User Guide

ID 683416
Date 2/12/2021
Public

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2. Avalon Streaming Video

The Video and Image Processing IPs conform to the Avalon streaming video standard of data transmission.
This standard is a configurable protocol layer that sits on top of the Intel Avalon streaming standard. The standard comprises video packets, control packets, and/or user packets.
Note: Before you start using the VIP IPs, you must fully understand this protocol layer. The IPs transmit and receive all video data in this format.

The individual video formats supported (i.e. NTSC, 1080p, UHD 4K) depend primarily on the configuration of the Avalon streaming video standard and the clock frequency. The IPs may transmit pixel information either in sequence or in parallel, in RGB or YCbCr color spaces, and under a variety of different chroma samplings and bit depths, depending on which is the most suitable for the end application. The Avalon streaming video protocol adheres to the Avalon streaming standard packet data transfers, with backpressure and a ready latency of 1.

Figure 1. Avalon Streaming Video SignalsThe figure shows two VIP IPs and the Avalon streaming video signals used for data transfer. The Avalon streaming optional channel signal is always unused.
Figure 2. Avalon Streaming Video Packet Transmission (Symbols in Parallel)The figure shows an example transmission of twelve “symbols” using the Avalon streaming video configuration of the Avalon streaming specification.

A “ready latency” of 1 is used for Avalon streaming video. The example shows the receiving video sink drops its ready signal in cycle 3, to indicate that it is not ready to receive any data in cycles 4 or 5. The video source responds by extending its valid, endofpacket and data signals into cycle 6. As the ready signal returns high in cycle 5, the video source data in cycle 6 is safely registered by the sink.

The symbols D0, D1… can be pixel color plane data from an Avalon streaming video image packet or data from a control packet or a user packet. The type of packet is determined by the lowest 4 bits of the first symbol transmitted.

Table 6.  Avalon Streaming Packet Type Identifiers

Type Identifier D0[3:0]

Description
0x0 (0) Video data packet
0x1–0x8 (1–8) User data packet
0x9–0xC (9–12) Reserved
0xD (13) Clocked Video data ancillary user packet
0xE (14) Reserved
0xF (15) Control packet