IPSR-VIDEO Altera, IPSR-VIDEO Datasheet - Page 84

• Manufacturer Part Number: IPSR-VIDEO
• Description: RENEWAL Of IPS-VIDEO
• Manufacturer: Altera
• Series: IP Suitesr

Specifications of IPSR-VIDEO

• Software Application: IP CORE, SUITES
• Supported Families: Arria GX, Cyclone II, HardCopy II, Stratix II
• Features: Common Avalon Streaming (Avalon-St) Interface And Avalon-St Video Protocol
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Lead Free Status / RoHS Status: na

5–4
Video and Image Processing Suite User Guide
Alpha Blending
Non-image data packets of each active foreground layer, displayed or consumed, are
processed in a sequential order, layer 1 first. Non-image data packets from the
background layer are integrally transmitted whereas non-image data packets from the
foreground layers are treated differently depending on their type. Control packets, of
type 15, are processed by the core to extract the width and height of each layer and are
discarded on the fly. Other packets, of type 1 to type 14, are propagated unchanged.
The second step corresponds to the usual behavior of other Video and Image
Processing MegaCore functions that have an Avalon-MM slave interface.
After the non-image data packets from the background layer and the foreground
layers have been processed and/or propagated, the MegaCore function waits for the
Go bit to be set to 1 before reading the top left position of each layer.
Consequently, the behavior of the Alpha Blending Mixer differs slightly from the
other Video and Image Processing MegaCore functions.
This behavior is illustrated by the following pseudo-code:
For information about using Avalon-MM Slave interfaces for run-time control, refer to
“Avalon-MM Slave Interfaces” on page
refer to
signals, refer to
When Alpha blending is on, the Avalon-ST input ports for the alpha channels expect
a video stream compliant with the Avalon-ST Video protocol. Alpha frames contain a
single color plane and are transmitted in video data packets. The first value in each
packet, transmitted while the startofpacket signal is high, contains the packet type
identifier 0. This condition holds true even when the width of the alpha channels data
ports is less than 4 bits wide. The last alpha value for the bottom-right pixel is
transmitted while the endofpacket signal is high.
go = 0;
while (true)
{
}
status = 0;
read_non_image_data_packet_from background_layer();
read_control_first_pass(); // Check layer status
for_each_layer layer_id
{
}
while (go != 1)
status = 1;
read_control_second_pass(); // Copies top-left coordinates to
send_image_data_header();
process_frame();
Table 7–2 on page
// process non-image data packets for displayed or consumed
if (layer_id is not disabled)
{
handle_non_image_packet_from_foreground_layer(layer_id);
}
wait;
Table 6–3 on page
7–2. For information about the Avalon-MM interface
6–2.
4–17. For details of the control register maps,
(disable/displayed/consumed)
Chapter 5: Functional Descriptions
internal registers
January 2011 Altera Corporation
layers
Alpha Blending Mixer