IPS-VIDEO Altera, IPS-VIDEO Datasheet - Page 125

• 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

Chapter 5: Functional Descriptions
Deinterlacer
May 2011 Altera Corporation
1
The Deinterlacer does not support interlaced streams where F0 fields are one line
higher than F1 fields in most of its parameterizations. (Bob with one output frame for
each input frame is the only exception.) Altera recommends using the Clipper
MegaCore function to feed the Deinterlacer with an interlaced video stream that it can
support.
Bob with Scanline Duplication
The bob with scanline duplication algorithm is the simplest and cheapest in terms of
logic. Output frames are produced by simply repeating every line in the current field
twice. The function uses only the current field, therefore if the output frame rate is the
same as the input frame rate, the function discards half of the input fields.
Bob with Scanline Interpolation
The bob with scanline interpolation algorithm has a slightly higher logic cost than bob
with scanline duplication but offers significantly better quality.
Output frames are produced by filling in the missing lines from the current field with
the linear interpolation of the lines above and below them. At the top of an F1 field or
the bottom of an F0 field there is only one line available so it is just duplicated. The
function only uses the current field, therefore if the output frame rate is the same as
the input frame rate, the function discards half of the input fields.
Weave
Weave deinterlacing creates an output frame by filling all of the missing lines in the
current field with lines from the previous field. This option gives good results for still
parts of an image but unpleasant artefacts in moving parts.
The weave algorithm requires external memory, so either double or triple-buffering
must be selected. This makes it significantly more expensive in logic elements and
external RAM bandwidth than either of the bob algorithms, if external buffering is not
otherwise required.
The results of the weave algorithm can sometimes be perfect, in the instance where
pairs of interlaced fields have been created from original progressive frames. Weave
simply stitches the frames back together and the results are the same as the original,
as long as output frame rate equal to input frame rate is selected and the correct pairs
of fields are put together. Usually progressive sources split each frame into a pair
consisting of an F0 field followed by an F1 field, so selecting F1 to be the current field
often yields the best results.
Motion-Adaptive
The Deinterlacer MegaCore function provides a simple motion-adaptive algorithm.
This is the most sophisticated of the algorithms provided but also the most expensive,
both in terms of logic area and external memory bandwidth requirement.
This algorithm avoids the weaknesses of bob and weave algorithms by using a form
of bob deinterlacing for moving areas of the image and weave style deinterlacing for
still areas.
Video and Image Processing Suite User Guide
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