dspchengxu.rar_dsp 实验箱

#include "typedef.h" #include "Dct.h" //void fdct_8x8( void Dct( Word16 *dct_data , // 输入原始数据 Word16 *Dct_Coef // DCT系数 ) { /* -------------------------------------------------------- */ /* Set up the cosine coefficients c0..c7. */ /* -------------------------------------------------------- */ const unsigned short c1 = 0x2C62, c3 = 0x25A0; const unsigned short c5 = 0x1924, c7 = 0x08D4; const unsigned short c0 = 0xB505, c2 = 0x29CF; const unsigned short c6 = 0x1151; /* -------------------------------------------------------- */ /* Intermediate calculations. */ /* -------------------------------------------------------- */ Word16 f0, f1, f2, f3, f4, f5, f6, f7; /* Spatial domain samples. */ Word32 g0, g1, h0, h1, p0, p1; /* Even-half intermediate. */ Word16 r0, r1; /* Even-half intermediate. */ Word32 P0, P1, R0, R1; /* Even-half intermediate. */ Word16 g2, g3, h2, h3; /* Odd-half intermediate. */ Word16 q0a,s0a,q0, q1, s0, s1; /* Odd-half intermediate. */ Word16 Q0, Q1, S0, S1; /* Odd-half intermediate. */ Word32 F0, F1, F2, F3, F4, F5, F6, F7; /* Freq. domain results. */ Word32 F0r,F1r,F2r,F3r, F4r,F5r,F6r,F7r; /* Rounded, truncated results. */ /* -------------------------------------------------------- */ /* Input and output pointers, loop control. */ /* -------------------------------------------------------- */ Word32 i; /* -------------------------------------------------------- */ /* Outer vertical loop. */ /* -------------------------------------------------------- */ /* -------------------------------------------------------- */ /* Perform Vert 1-D FDCT on columns. */ /* -------------------------------------------------------- */ for (i = 0; i < 8; i++) { /* ---------------------------------------------------- */ /* Load the spatial-domain samples. */ /* ---------------------------------------------------- */ f0 = dct_data[i+ 0]; f1 = dct_data[i+ 8]; f2 = dct_data[i+16]; f3 = dct_data[i+24]; f4 = dct_data[i+32]; f5 = dct_data[i+40]; f6 = dct_data[i+48]; f7 = dct_data[i+56]; /* ---------------------------------------------------- */ /* Stage 1: Separate into even and odd halves. */ /* ---------------------------------------------------- */ g0 = f0 + f7; h2 = f0 - f7; g1 = f1 + f6; h3 = f1 - f6; h1 = f2 + f5; g3 = f2 - f5; h0 = f3 + f4; g2 = f3 - f4; /* ---------------------------------------------------- */ /* Stage 2 */ /* ---------------------------------------------------- */ p0 = g0 + h0; r0 = g0 - h0; p1 = g1 + h1; r1 = g1 - h1; q1 = g2; s1 = h2; s0a= h3 + g3; q0a= h3 - g3; s0 = ((Word32)s0a * c0 + 0x7FFF) >> 16; q0 = ((Word32)q0a * c0 + 0x7FFF) >> 16; /* ---------------------------------------------------- */ /* Stage 3 */ /* ---------------------------------------------------- */ P0 = p0 + p1; P1 = p0 - p1; R1 = (Word32)c6 * r1 + (Word32)c2 * r0; R0 = (Word32)c6 * r0 - (Word32)c2 * r1; Q1 = q1 + q0; Q0 = q1 - q0; S1 = s1 + s0; S0 = s1 - s0; /* ---------------------------------------------------- */ /* Stage 4 */ /* ---------------------------------------------------- */ F0 = P0; F4 = P1; F2 = R1; F6 = R0; F1 = (Word32)c7 * Q1 + (Word32)c1 * S1; F7 = (Word32)c7 * S1 - (Word32)c1 * Q1; F5 = (Word32)c3 * Q0 + (Word32)c5 * S0; F3 = (Word32)c3 * S0 - (Word32)c5 * Q0; /* ---------------------------------------------------- */ /* Store the frequency domain results. */ /* ---------------------------------------------------- */ Dct_Coef[i+ 0] = F0; Dct_Coef[i+ 8] = F1 >> 13; Dct_Coef[i+16] = F2 >> 13; Dct_Coef[i+24] = F3 >> 13; Dct_Coef[i+32] = F4; Dct_Coef[i+40] = F5 >> 13; Dct_Coef[i+48] = F6 >> 13; Dct_Coef[i+56] = F7 >> 13; } /* -------------------------------------------------------- */ /* Perform Horizontal 1-D FDCT on each 8x8 block. */ /* -------------------------------------------------------- */ for (i = 0; i < 8; i++) { /* ---------------------------------------------------- */ /* Load the spatial-domain samples. */ /* ---------------------------------------------------- */ f0 = Dct_Coef[8*i+0]; f1 = Dct_Coef[8*i+1]; f2 = Dct_Coef[8*i+2]; f3 = Dct_Coef[8*i+3]; f4 = Dct_Coef[8*i+4]; f5 = Dct_Coef[8*i+5]; f6 = Dct_Coef[8*i+6]; f7 = Dct_Coef[8*i+7]; /* ---------------------------------------------------- */ /* Stage 1: Separate into even and odd halves. */ /* ---------------------------------------------------- */ g0 = f0 + f7; h2 = f0 - f7; g1 = f1 + f6; h3 = f1 - f6; h1 = f2 + f5; g3 = f2 - f5; h0 = f3 + f4; g2 = f3 - f4; /* ---------------------------------------------------- */ /* Stage 2 */ /* ---------------------------------------------------- */ p0 = g0 + h0; r0 = g0 - h0; p1 = g1 + h1; r1 = g1 - h1; q1 = g2; s1 = h2; s0a= h3 + g3; q0a= h3 - g3; s0 = ((Word32)s0a * c0 + 0x7FFF) >> 16; q0 = ((Word32)q0a * c0 + 0x7FFF) >> 16; /* ---------------------------------------------------- */ /* Stage 3 */ /* ---------------------------------------------------- */ P0 = p0 + p1; P1 = p0 - p1; R1 = (Word32)c6 * r1 + (Word32)c2 * r0; R0 = (Word32)c6 * r0 - (Word32)c2 * r1; Q1 = q1 + q0; Q0 = q1 - q0; S1 = s1 + s0; S0 = s1 - s0; /* ---------------------------------------------------- */ /* Stage 4 */ /* ---------------------------------------------------- */ F0 = P0; F4 = P1; F2 = R1; F6 = R0; F1 = (Word32)c7 * Q1 + (Word32)c1 * S1; F7 = (Word32)c7 * S1 - (Word32)c1 * Q1; F5 = (Word32)c3 * Q0 + (Word32)c5 * S0; F3 = (Word32)c3 * S0 - (Word32)c5 * Q0; /* ---------------------------------------------------- */ /* Round and truncate values. */ /* */ /* Note: F0 and F4 have different rounding since no */ /* MPYs have been applied to either term. Also, F0's */ /* rounding is slightly different to offset the */ /* truncation effects from the horizontal pass (which */ /* does not round). */ /* ---------------------------------------------------- */ F0r = (F0 + 0x0006) >> 3; F1r = (F1 + 0x7FFF) >> 16; F2r = (F2 + 0x7FFF) >> 16; F3r = (F3 + 0x7FFF) >> 16; F4r = (F4 + 0x0004) >