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- #define JPEG_INTERNALS
- #include "jinclude.h"
- #include "jpeglib.h"
- #include "jdct.h"
- #ifdef DCT_ISLOW_SUPPORTED
- #if DCTSIZE != 8
- Sorry, this code only copes with 8x8 DCTs.
- #endif
- #if BITS_IN_JSAMPLE == 8
- #define CONST_BITS 13
- #define PASS1_BITS 2
- #else
- #define CONST_BITS 13
- #define PASS1_BITS 1
- #endif
- #if CONST_BITS == 13
- #define FIX_0_298631336 ((INT32) 2446)
- #define FIX_0_390180644 ((INT32) 3196)
- #define FIX_0_541196100 ((INT32) 4433)
- #define FIX_0_765366865 ((INT32) 6270)
- #define FIX_0_899976223 ((INT32) 7373)
- #define FIX_1_175875602 ((INT32) 9633)
- #define FIX_1_501321110 ((INT32) 12299)
- #define FIX_1_847759065 ((INT32) 15137)
- #define FIX_1_961570560 ((INT32) 16069)
- #define FIX_2_053119869 ((INT32) 16819)
- #define FIX_2_562915447 ((INT32) 20995)
- #define FIX_3_072711026 ((INT32) 25172)
- #else
- #define FIX_0_298631336 FIX(0.298631336)
- #define FIX_0_390180644 FIX(0.390180644)
- #define FIX_0_541196100 FIX(0.541196100)
- #define FIX_0_765366865 FIX(0.765366865)
- #define FIX_0_899976223 FIX(0.899976223)
- #define FIX_1_175875602 FIX(1.175875602)
- #define FIX_1_501321110 FIX(1.501321110)
- #define FIX_1_847759065 FIX(1.847759065)
- #define FIX_1_961570560 FIX(1.961570560)
- #define FIX_2_053119869 FIX(2.053119869)
- #define FIX_2_562915447 FIX(2.562915447)
- #define FIX_3_072711026 FIX(3.072711026)
- #endif
- #if BITS_IN_JSAMPLE == 8
- #define MULTIPLY(var,const) MULTIPLY16C16(var,const)
- #else
- #define MULTIPLY(var,const) ((var) * (const))
- #endif
- GLOBAL void
- jpeg_fdct_islow (DCTELEM * data)
- {
- INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
- INT32 tmp10, tmp11, tmp12, tmp13;
- INT32 z1, z2, z3, z4, z5;
- DCTELEM *dataptr;
- int ctr;
- SHIFT_TEMPS
-
-
-
- dataptr = data;
- for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
- tmp0 = dataptr[0] + dataptr[7];
- tmp7 = dataptr[0] - dataptr[7];
- tmp1 = dataptr[1] + dataptr[6];
- tmp6 = dataptr[1] - dataptr[6];
- tmp2 = dataptr[2] + dataptr[5];
- tmp5 = dataptr[2] - dataptr[5];
- tmp3 = dataptr[3] + dataptr[4];
- tmp4 = dataptr[3] - dataptr[4];
-
-
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
- dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
- dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
-
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
- dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
- CONST_BITS-PASS1_BITS);
- dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
- CONST_BITS-PASS1_BITS);
-
-
-
- z1 = tmp4 + tmp7;
- z2 = tmp5 + tmp6;
- z3 = tmp4 + tmp6;
- z4 = tmp5 + tmp7;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
-
- tmp4 = MULTIPLY(tmp4, FIX_0_298631336);
- tmp5 = MULTIPLY(tmp5, FIX_2_053119869);
- tmp6 = MULTIPLY(tmp6, FIX_3_072711026);
- tmp7 = MULTIPLY(tmp7, FIX_1_501321110);
- z1 = MULTIPLY(z1, - FIX_0_899976223);
- z2 = MULTIPLY(z2, - FIX_2_562915447);
- z3 = MULTIPLY(z3, - FIX_1_961570560);
- z4 = MULTIPLY(z4, - FIX_0_390180644);
-
- z3 += z5;
- z4 += z5;
-
- dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
- dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
- dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
- dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
-
- dataptr += DCTSIZE;
- }
-
- dataptr = data;
- for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
- tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
- tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
- tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
- tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
- tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
- tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
- tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
- tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
-
-
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
- dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
- dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
-
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
- dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
- CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
- CONST_BITS+PASS1_BITS);
-
-
-
- z1 = tmp4 + tmp7;
- z2 = tmp5 + tmp6;
- z3 = tmp4 + tmp6;
- z4 = tmp5 + tmp7;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
-
- tmp4 = MULTIPLY(tmp4, FIX_0_298631336);
- tmp5 = MULTIPLY(tmp5, FIX_2_053119869);
- tmp6 = MULTIPLY(tmp6, FIX_3_072711026);
- tmp7 = MULTIPLY(tmp7, FIX_1_501321110);
- z1 = MULTIPLY(z1, - FIX_0_899976223);
- z2 = MULTIPLY(z2, - FIX_2_562915447);
- z3 = MULTIPLY(z3, - FIX_1_961570560);
- z4 = MULTIPLY(z4, - FIX_0_390180644);
-
- z3 += z5;
- z4 += z5;
-
- dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3,
- CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4,
- CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3,
- CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4,
- CONST_BITS+PASS1_BITS);
-
- dataptr++;
- }
- }
- #endif
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