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lanttu |
%IDCT
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%IDCT constant coefficient generator for odd and even terms.
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%Timo Alho, timo.a.alho@tut.fi
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%10.6.2004
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coeff_width=15;
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%all coefficients are scaled by 1/sqrt(2)
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mult=2^(coeff_width-1) /sqrt(2);
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N=8;
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A=zeros(N, N);
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j=[0:1:N-1];
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A(1, :) = sqrt(1/N) * cos(0);
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for i = 1:N-1
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A(i+1, :) = sqrt(2/N) * cos((2.*j+1)*i*pi/(2*N));
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end
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A=A'; %transpose DCT -> IDCT
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Aodd=A(1:4, 1:2:8);
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Aeven=A(1:4, 2:2:8);
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fout=fopen('ROM_IDCT_ODD', 'w');
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fprintf(fout, 'TYPE Rom16x4x%i IS ARRAY (0 TO 15) OF signed(%i*4-1 downto 0);\n' , coeff_width, (coeff_width));
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fprintf(fout, 'CONSTANT ROM_IDCT_ODD : Rom16x4x%i := (\n', coeff_width);
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for a3=0:1
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for a2=0:1
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for a1=0:1
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for a0=0:1
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Y0 = Aodd(1,1)*a0 + Aodd(1,2)*a1 + Aodd(1,3)*a2 + Aodd(1,4)*a3;
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Y1 = Aodd(2,1)*a0 + Aodd(2,2)*a1 + Aodd(2,3)*a2 + Aodd(2,4)*a3;
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Y2 = Aodd(3,1)*a0 + Aodd(3,2)*a1 + Aodd(3,3)*a2 + Aodd(3,4)*a3;
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Y3 = Aodd(4,1)*a0 + Aodd(4,2)*a1 + Aodd(4,3)*a2 + Aodd(4,4)*a3;
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Y0=round(mult*Y0);
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Y1=round(mult*Y1);
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Y2=round(mult*Y2);
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Y3=round(mult*Y3);
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fprintf(fout, 'conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i),\n', Y0, coeff_width, Y1, coeff_width, Y2, coeff_width, Y3, coeff_width);
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end
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end
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end
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end
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fprintf(fout, 'REMOVE THIS, AND LAST dot\n);\n');
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fclose(fout);
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fout=fopen('ROM_IDCT_EVEN', 'w');
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fprintf(fout, 'TYPE Rom16x4x%i IS ARRAY (0 TO 15) OF signed(%i*4-1 downto 0);\n' , coeff_width, (coeff_width));
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fprintf(fout, 'CONSTANT ROM_IDCT_EVEN : Rom16x4x%i := (\n', coeff_width);
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for a3=0:1
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for a2=0:1
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for a1=0:1
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for a0=0:1
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Y0 = Aeven(1,1)*a0 + Aeven(1,2)*a1 + Aeven(1,3)*a2 + Aeven(1,4)*a3;
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Y1 = Aeven(2,1)*a0 + Aeven(2,2)*a1 + Aeven(2,3)*a2 + Aeven(2,4)*a3;
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Y2 = Aeven(3,1)*a0 + Aeven(3,2)*a1 + Aeven(3,3)*a2 + Aeven(3,4)*a3;
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Y3 = Aeven(4,1)*a0 + Aeven(4,2)*a1 + Aeven(4,3)*a2 + Aeven(4,4)*a3;
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Y0=round(mult*Y0);
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Y1=round(mult*Y1);
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Y2=round(mult*Y2);
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Y3=round(mult*Y3);
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fprintf(fout, 'conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i),\n', Y0, coeff_width, Y1, coeff_width, Y2, coeff_width, Y3, coeff_width);
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end
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end
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end
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end
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fprintf(fout, 'REMOVE THIS, AND LAST dot\n);\n');
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fclose(fout);
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