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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
- #define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
- GLOBAL void
- jpeg_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr,
- JCOEFPTR coef_block,
- JSAMPARRAY output_buf, JDIMENSION output_col)
- {
- INT32 tmp0, tmp1, tmp2, tmp3;
- INT32 tmp10, tmp11, tmp12, tmp13;
- INT32 z1, z2, z3, z4, z5;
- JCOEFPTR inptr;
- ISLOW_MULT_TYPE * quantptr;
- int * wsptr;
- JSAMPROW outptr;
- JSAMPLE *range_limit = IDCT_range_limit(cinfo);
- int ctr;
- int workspace[DCTSIZE2];
- SHIFT_TEMPS
-
-
-
- inptr = coef_block;
- quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
- wsptr = workspace;
- for (ctr = DCTSIZE; ctr > 0; ctr--) {
-
-
- if ((inptr[DCTSIZE*1] | inptr[DCTSIZE*2] | inptr[DCTSIZE*3] |
- inptr[DCTSIZE*4] | inptr[DCTSIZE*5] | inptr[DCTSIZE*6] |
- inptr[DCTSIZE*7]) == 0) {
-
- int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS;
-
- wsptr[DCTSIZE*0] = dcval;
- wsptr[DCTSIZE*1] = dcval;
- wsptr[DCTSIZE*2] = dcval;
- wsptr[DCTSIZE*3] = dcval;
- wsptr[DCTSIZE*4] = dcval;
- wsptr[DCTSIZE*5] = dcval;
- wsptr[DCTSIZE*6] = dcval;
- wsptr[DCTSIZE*7] = dcval;
-
- inptr++;
- quantptr++;
- wsptr++;
- continue;
- }
-
-
-
-
- z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
- z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
-
- z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
- z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
- tmp0 = (z2 + z3) << CONST_BITS;
- tmp1 = (z2 - z3) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
-
-
- tmp0 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]);
- tmp1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]);
- tmp2 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]);
- tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
-
- z1 = tmp0 + tmp3;
- z2 = tmp1 + tmp2;
- z3 = tmp0 + tmp2;
- z4 = tmp1 + tmp3;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
-
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336);
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869);
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026);
- tmp3 = MULTIPLY(tmp3, 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;
-
- tmp0 += z1 + z3;
- tmp1 += z2 + z4;
- tmp2 += z2 + z3;
- tmp3 += z1 + z4;
-
-
-
- wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*7] = (int) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*1] = (int) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*6] = (int) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*5] = (int) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*3] = (int) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
- wsptr[DCTSIZE*4] = (int) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
-
- inptr++;
- quantptr++;
- wsptr++;
- }
-
-
-
-
- wsptr = workspace;
- for (ctr = 0; ctr < DCTSIZE; ctr++) {
- outptr = output_buf[ctr] + output_col;
-
-
- #ifndef NO_ZERO_ROW_TEST
- if ((wsptr[1] | wsptr[2] | wsptr[3] | wsptr[4] | wsptr[5] | wsptr[6] |
- wsptr[7]) == 0) {
-
- JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
- & RANGE_MASK];
-
- outptr[0] = dcval;
- outptr[1] = dcval;
- outptr[2] = dcval;
- outptr[3] = dcval;
- outptr[4] = dcval;
- outptr[5] = dcval;
- outptr[6] = dcval;
- outptr[7] = dcval;
- wsptr += DCTSIZE;
- continue;
- }
- #endif
-
-
-
-
- z2 = (INT32) wsptr[2];
- z3 = (INT32) wsptr[6];
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
-
- tmp0 = ((INT32) wsptr[0] + (INT32) wsptr[4]) << CONST_BITS;
- tmp1 = ((INT32) wsptr[0] - (INT32) wsptr[4]) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
-
-
- tmp0 = (INT32) wsptr[7];
- tmp1 = (INT32) wsptr[5];
- tmp2 = (INT32) wsptr[3];
- tmp3 = (INT32) wsptr[1];
-
- z1 = tmp0 + tmp3;
- z2 = tmp1 + tmp2;
- z3 = tmp0 + tmp2;
- z4 = tmp1 + tmp3;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
-
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336);
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869);
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026);
- tmp3 = MULTIPLY(tmp3, 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;
-
- tmp0 += z1 + z3;
- tmp1 += z2 + z4;
- tmp2 += z2 + z3;
- tmp3 += z1 + z4;
-
-
-
- outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp3,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[7] = range_limit[(int) DESCALE(tmp10 - tmp3,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[1] = range_limit[(int) DESCALE(tmp11 + tmp2,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[6] = range_limit[(int) DESCALE(tmp11 - tmp2,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[2] = range_limit[(int) DESCALE(tmp12 + tmp1,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[5] = range_limit[(int) DESCALE(tmp12 - tmp1,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[3] = range_limit[(int) DESCALE(tmp13 + tmp0,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
- outptr[4] = range_limit[(int) DESCALE(tmp13 - tmp0,
- CONST_BITS+PASS1_BITS+3)
- & RANGE_MASK];
-
- wsptr += DCTSIZE;
- }
- }
- #endif
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