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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 8 x8 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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