IPSR-VIDEO Altera, IPSR-VIDEO Datasheet - Page 114

• 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

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Video and Image Processing Suite User Guide
Constant Precision
Calculation Precision
Result of Output Data Type Conversion
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The values are assigned in the order indicated by the conversion name. For example,
if you select Computer B’G’R’ to CbCrY’: SDTV, din_0 = B’, din_1 = G’, din_2 = R’,
dout_0 = Cb’, dout_1 = Cr, and dout_2 = Y’.
If the channels are in sequence, din_0 is first, then din_1, and din_2. If the channels are
in parallel, din_0 occupies the least significant bits of the word, din_1 the middle bits
and din_2 the most significant bits. For example, if there are 8 bits per sample and one
of the predefined conversions inputs B’G’R’, din_0 carries B’ in bits 0–7, din_1 carries
G’ in bits 8–15, and din_2 carries R’ in bits 16–23.
Predefined conversions only support unsigned input and output data. If signed input
or output data is selected, the predefined conversion produces incorrect results. When
using a predefined conversion, the precision of the constants must still be defined.
Predefined conversions are based on the input bits per pixel per color plane. If using
different input and output bits per pixel per color plane, the results should be scaled
by the correct number of binary places to compensate.
The Color Space Converter MegaCore function requires fixed point types to be
defined for the constant coefficients and constant summands. The user entered
constants (in the white cells of the matrix in the parameter editor) are rounded to fit in
the chosen fixed point type (these are shown in the purple cells of the matrix).
The Color Space Converter MegaCore function does not lose calculation precision
during the conversion. The calculation and result data types are derived from the
range of the input data type, the fixed point types of the constants, and the values of
the constants. If scaling is selected, the result data type is scaled up appropriately such
that precision is not lost.
After the calculation, the fixed point type of the results must be converted to the
integer data type of the output. This conversion is performed in four stages, in the
following order:
Studio B’G’R’ to CbCrY’: SDTV
CbCrY’: SDTV to Studio B’G’R’
Studio B’G’R’ to CbCrY’: HDTV
CbCrY’: HDTV to Studio B’G’R’
IQY' to Computer B'G'R'
Computer B'G'R' to IQY'
UVY' to Computer B'G'R'
Computer B'G'R' to UVY'
Chapter 5: Functional Descriptions
January 2011 Altera Corporation
Color Space Converter