Developer Guide and Reference

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Example 5

Example 5 converts a 2D image from the RGB format to the YUV format. It demonstrates how storing both images in 2D SoA
n_container
s can improve performance.
#include <iostream> #include <sdlt/sdlt.h> using namespace sdlt; #define WIDTH 1024 #define HEIGHT 1024 struct RGBs { float r; float g; float b; }; struct YUVs { float y; float u; float v; YUVs(){ }; YUVs& operator=(const RGBs &tmp){ y = 0.229f * tmp.r + 0.587f * tmp.g + 0.114f * tmp.b; u = -0.147f * tmp.r - 0.289f * tmp.g + 0.436f * tmp.b; v = 0.615 * tmp.r - 0.515f * tmp.g - 0.100 * tmp.b; return *this; } YUVs(const RGBs &tmp){ y = 0.229f * tmp.r + 0.587f * tmp.g + 0.114f * tmp.b; u = -0.147f * tmp.r - 0.289f * tmp.g + 0.436f * tmp.b; v = 0.615 * tmp.r - 0.515f * tmp.g - 0.100 * tmp.b; } }; SDLT_PRIMITIVE(RGBs, r, g, b) SDLT_PRIMITIVE(YUVs, y, u, v) int main(){ typedef layout::soa<> LayoutT; n_extent_t<int, int> extents(HEIGHT, WIDTH); /* Creating a typedef for SoA N-dimensional container. RGBTy and YUVTy are user defined structures whose collection needs to be stored in SoA format in memory. Layout in memory specified as layout::soa. In the below case N-dimensional SoA container is used in 2-D context */ typedef sdlt::n_container< RGBs, LayoutT, decltype(extents) > ContainerRGB; typedef sdlt::n_container< YUVs, LayoutT, decltype(extents) > ContainerYUV; //Instantiate Input and Output Containers ContainerRGB inputRGB(extents); ContainerYUV outputYUV(extents); auto input = inputRGB.const_access(); //Get Constant Accessor object for inputRGB auto output = outputYUV.access(); //Get Accessor object for outputYUV //Select the iteration range in each dimension const auto iRGB1 = bounds_d<1>(input); //bound_d<1>(input); const auto iRGB0 = bounds_d<0>(input); //bound_d<0>(input); for(int y = iRGB0.lower(); y < iRGB0.upper(); y++) { #pragma simd for (int x = iRGB1.lower(); x < iRGB1.upper(); x++){ const RGBs temp1 = input[y][x]; YUVs temp2 = temp1; output[y][x] = temp2; } } return 0; }

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

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