IPS-VIDEO Altera, IPS-VIDEO Datasheet - Page 128

• Manufacturer Part Number: IPS-VIDEO
• Description: MegaCore Suite W/ 17 DSP Video/image Processing Functions
• Manufacturer: Altera
• Type: -r

Specifications of IPS-VIDEO

• Software Application: IP CORE, SUITES
• Supported Families: Arria GX, Cyclone II, HardCopy II, Stratix II
• Core Architecture: FPGA
• Core Sub-architecture: Arria, Cyclone, Stratix
• Rohs Compliant: NA
• Function: Suite of IP Functions for Video and Image Processing
• License: Initial License
• Lead Free Status / RoHS Status: na
• Lead Free Status / RoHS Status: na

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Video and Image Processing Suite User Guide
When both the input and output sides have finished processing a frame, the buffers
swap roles so that the frame that the output can use the frame that you have just
input. You can overwrite the frame that the function uses to create the output with a
fresh input.
The motion-adaptive algorithm uses four fields to build a progressive output frame
and the output side has to read pixels from two frame buffers rather than one.
Consequently, the motion-adaptive algorithm actually uses three frame buffers in
external RAM when you select double-buffering. When the input and output sides
finish processing a frame, the output side exchanges its buffer containing the oldest
frame, frame n-2, with the frame it receives at the input side, frame n. It keeps frame n-
1 for one extra iteration because it uses it with frame n to produce the next output.
When triple-buffering is in use, external RAM usually uses three frame buffers. The
function uses four frame buffers when you select the motion-adaptive algorithm. At
any time, one buffer is in use by the input and one (two for the motion adaptive case)
is (are) in use by the output in the same way as the double-buffering case. The last
frame buffer is spare.
This configuration allows the input and output sides to swap asynchronously. When
the input finishes, it swaps with the spare frame if the spare frame contains data that
the output frame uses. Otherwise the function drops the frame which you have just
wrote and the function writes a fresh frame over the dropped frame.
When the output finishes, it also swaps with the spare frame and continues if the
spare frame contains fresh data from the input side. Otherwise it does not swap and
just repeats the last frame.
Triple-buffering allows simple frame rate conversion. For example, suppose you
connect the Deinterlacer’s input to a HDTV video stream in 1080i60 format and
connect its output i to a 1080p50 monitor. The input has 60 interlaced fields per
second, but the output tries to pull 50 progressive frames per second.
If you configure the Deinterlacer to output one frame for each input field, it produces
60 frames of output per second. If you enable triple-buffering, on average the function
drops one frame in six so that it produces 50 frames per second. If you chose one
frame output for every pair of fields input, the Deinterlacer produces 30 frames per
second output and triple-buffering leads to the function repeating two out of every
three frames on average.
When you select double or triple-buffering the Deinterlacer has two or more Avalon-
MM master ports. These must be connected to an external memory with enough space
for all of the frame buffers required. The amount of space varies depending on the
type of buffering and algorithm selected. An estimate of the required memory is
shown in the Deinterlacer parameter editor.
If the external memory in your system runs at a different clock rate to the Deinterlacer
MegaCore function, you can turn on an option to use a separate clock for the Avalon-
MM master interfaces and use the memory clock to drive these interfaces.
To prevent memory read and write bursts from being spread across two adjacent
memory rows, you can turn on an option to align the initial address of each read and
write burst to a multiple of the burst target used for the read and write masters (or the
maximum of the read and write burst targets if using different values). Turning on
this option may have a negative impact on memory usage but increases memory
efficiency.
Chapter 5: Functional Descriptions
May 2011 Altera Corporation
Deinterlacer