1ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if !defined(_FX_JPEG_TURBO_) 2ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 3ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * jidctred.c 4ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 5ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Copyright (C) 1994-1998, Thomas G. Lane. 6ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This file is part of the Independent JPEG Group's software. 7ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * For conditions of distribution and use, see the accompanying README file. 8ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 9ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This file contains inverse-DCT routines that produce reduced-size output: 10ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * either 4x4, 2x2, or 1x1 pixels from an 8x8 DCT block. 11ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 12ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * The implementation is based on the Loeffler, Ligtenberg and Moschytz (LL&M) 13ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * algorithm used in jidctint.c. We simply replace each 8-to-8 1-D IDCT step 14ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * with an 8-to-4 step that produces the four averages of two adjacent outputs 15ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * (or an 8-to-2 step producing two averages of four outputs, for 2x2 output). 16ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * These steps were derived by computing the corresponding values at the end 17ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * of the normal LL&M code, then simplifying as much as possible. 18ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 19ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 1x1 is trivial: just take the DC coefficient divided by 8. 20ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 21ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * See jidctint.c for additional comments. 22ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 23ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 24ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define JPEG_INTERNALS 25ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#include "jinclude.h" 26ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#include "jpeglib.h" 27ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#include "jdct.h" /* Private declarations for DCT subsystem */ 28ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 29ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifdef IDCT_SCALING_SUPPORTED 30ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 31ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 32ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 33ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * This module is specialized to the case DCTSIZE = 8. 34ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 35ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 36ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if DCTSIZE != 8 37ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ 38ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 39ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 40ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 41ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Scaling is the same as in jidctint.c. */ 42ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 43ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if BITS_IN_JSAMPLE == 8 44ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define CONST_BITS 13 45ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define PASS1_BITS 2 46ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#else 47ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define CONST_BITS 13 48ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ 49ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 50ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 51ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus 52ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * causing a lot of useless floating-point operations at run time. 53ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * To get around this we use the following pre-calculated constants. 54ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * If you change CONST_BITS you may want to add appropriate values. 55ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * (With a reasonable C compiler, you can just rely on the FIX() macro...) 56ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 57ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 58ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if CONST_BITS == 13 59ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_211164243 ((INT32) 1730) /* FIX(0.211164243) */ 60ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_509795579 ((INT32) 4176) /* FIX(0.509795579) */ 61ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_601344887 ((INT32) 4926) /* FIX(0.601344887) */ 62ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_720959822 ((INT32) 5906) /* FIX(0.720959822) */ 63ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */ 64ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_850430095 ((INT32) 6967) /* FIX(0.850430095) */ 65ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */ 66ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_061594337 ((INT32) 8697) /* FIX(1.061594337) */ 67ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_272758580 ((INT32) 10426) /* FIX(1.272758580) */ 68ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_451774981 ((INT32) 11893) /* FIX(1.451774981) */ 69ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */ 70ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_2_172734803 ((INT32) 17799) /* FIX(2.172734803) */ 71ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */ 72ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_3_624509785 ((INT32) 29692) /* FIX(3.624509785) */ 73ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#else 74ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_211164243 FIX(0.211164243) 75ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_509795579 FIX(0.509795579) 76ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_601344887 FIX(0.601344887) 77ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_720959822 FIX(0.720959822) 78ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_765366865 FIX(0.765366865) 79ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_850430095 FIX(0.850430095) 80ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_0_899976223 FIX(0.899976223) 81ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_061594337 FIX(1.061594337) 82ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_272758580 FIX(1.272758580) 83ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_451774981 FIX(1.451774981) 84ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_1_847759065 FIX(1.847759065) 85ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_2_172734803 FIX(2.172734803) 86ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_2_562915447 FIX(2.562915447) 87ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define FIX_3_624509785 FIX(3.624509785) 88ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 89ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 90ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 91ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result. 92ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * For 8-bit samples with the recommended scaling, all the variable 93ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * and constant values involved are no more than 16 bits wide, so a 94ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * 16x16->32 bit multiply can be used instead of a full 32x32 multiply. 95ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * For 12-bit samples, a full 32-bit multiplication will be needed. 96ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 97ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 98ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#if BITS_IN_JSAMPLE == 8 99ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define MULTIPLY(var,const) MULTIPLY16C16(var,const) 100ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#else 101ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define MULTIPLY(var,const) ((var) * (const)) 102ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 103ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 104ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 105ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* Dequantize a coefficient by multiplying it by the multiplier-table 106ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * entry; produce an int result. In this module, both inputs and result 107ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * are 16 bits or less, so either int or short multiply will work. 108ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 109ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 110ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval)) 111ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 112ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 113ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 114ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Perform dequantization and inverse DCT on one block of coefficients, 115ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * producing a reduced-size 4x4 output block. 116ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 117ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 118ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovGLOBAL(void) 119ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovjpeg_idct_4x4 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 120ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JCOEFPTR coef_block, 121ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY output_buf, JDIMENSION output_col) 122ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 123ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 tmp0, tmp2, tmp10, tmp12; 124ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 z1, z2, z3, z4; 125ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JCOEFPTR inptr; 126ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ISLOW_MULT_TYPE * quantptr; 127ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int * wsptr; 128ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPROW outptr; 129ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPLE *range_limit = IDCT_range_limit(cinfo); 130ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int ctr; 131ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int workspace[DCTSIZE*4]; /* buffers data between passes */ 132ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov SHIFT_TEMPS 133ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 134ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Pass 1: process columns from input, store into work array. */ 135ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 136ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr = coef_block; 137ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 138ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr = workspace; 139ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) { 140ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Don't bother to process column 4, because second pass won't use it */ 141ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (ctr == DCTSIZE-4) 142ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 143ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && 144ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*5] == 0 && 145ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr[DCTSIZE*6] == 0 && inptr[DCTSIZE*7] == 0) { 146ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* AC terms all zero; we need not examine term 4 for 4x4 output */ 147ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; 148ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 149ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*0] = dcval; 150ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*1] = dcval; 151ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*2] = dcval; 152ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*3] = dcval; 153ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 154ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 155ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 156ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 157ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Even part */ 158ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 159ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 160ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 <<= (CONST_BITS+1); 161ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 162ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 163ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 164ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 165ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp2 = MULTIPLY(z2, FIX_1_847759065) + MULTIPLY(z3, - FIX_0_765366865); 166ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 167ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp10 = tmp0 + tmp2; 168ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp12 = tmp0 - tmp2; 169ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 170ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Odd part */ 171ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 172ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 173ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z2 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 174ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z3 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 175ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 176ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 177ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */ 178ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */ 179ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */ 180ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */ 181ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 182ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */ 183ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */ 184ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */ 185ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */ 186ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 187ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Final output stage */ 188ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 189ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp2, CONST_BITS-PASS1_BITS+1); 190ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*3] = (int) DESCALE(tmp10 - tmp2, CONST_BITS-PASS1_BITS+1); 191ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*1] = (int) DESCALE(tmp12 + tmp0, CONST_BITS-PASS1_BITS+1); 192ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*2] = (int) DESCALE(tmp12 - tmp0, CONST_BITS-PASS1_BITS+1); 193ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 194ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 195ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Pass 2: process 4 rows from work array, store into output array. */ 196ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 197ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr = workspace; 198ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ctr = 0; ctr < 4; ctr++) { 199ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_buf[ctr] + output_col; 200ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* It's not clear whether a zero row test is worthwhile here ... */ 201ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 202ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifndef NO_ZERO_ROW_TEST 203ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && 204ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) { 205ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* AC terms all zero */ 206ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3) 207ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 208ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 209ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[0] = dcval; 210ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[1] = dcval; 211ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[2] = dcval; 212ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[3] = dcval; 213ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 214ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr += DCTSIZE; /* advance pointer to next row */ 215ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 216ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 217ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 218ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 219ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Even part */ 220ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 221ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = ((INT32) wsptr[0]) << (CONST_BITS+1); 222ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 223ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp2 = MULTIPLY((INT32) wsptr[2], FIX_1_847759065) 224ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY((INT32) wsptr[6], - FIX_0_765366865); 225ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 226ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp10 = tmp0 + tmp2; 227ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp12 = tmp0 - tmp2; 228ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 229ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Odd part */ 230ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 231ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = (INT32) wsptr[7]; 232ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z2 = (INT32) wsptr[5]; 233ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z3 = (INT32) wsptr[3]; 234ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z4 = (INT32) wsptr[1]; 235ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 236ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = MULTIPLY(z1, - FIX_0_211164243) /* sqrt(2) * (c3-c1) */ 237ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z2, FIX_1_451774981) /* sqrt(2) * (c3+c7) */ 238ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z3, - FIX_2_172734803) /* sqrt(2) * (-c1-c5) */ 239ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z4, FIX_1_061594337); /* sqrt(2) * (c5+c7) */ 240ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 241ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp2 = MULTIPLY(z1, - FIX_0_509795579) /* sqrt(2) * (c7-c5) */ 242ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z2, - FIX_0_601344887) /* sqrt(2) * (c5-c1) */ 243ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z3, FIX_0_899976223) /* sqrt(2) * (c3-c7) */ 244ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY(z4, FIX_2_562915447); /* sqrt(2) * (c1+c3) */ 245ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 246ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Final output stage */ 247ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 248ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp2, 249ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+1) 250ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 251ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[3] = range_limit[(int) DESCALE(tmp10 - tmp2, 252ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+1) 253ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 254ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[1] = range_limit[(int) DESCALE(tmp12 + tmp0, 255ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+1) 256ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 257ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[2] = range_limit[(int) DESCALE(tmp12 - tmp0, 258ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+1) 259ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 260ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 261ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr += DCTSIZE; /* advance pointer to next row */ 262ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 263ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 264ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 265ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 266ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 267ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Perform dequantization and inverse DCT on one block of coefficients, 268ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * producing a reduced-size 2x2 output block. 269ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 270ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 271ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovGLOBAL(void) 272ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovjpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 273ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JCOEFPTR coef_block, 274ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY output_buf, JDIMENSION output_col) 275ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 276ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov INT32 tmp0, tmp10, z1; 277ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JCOEFPTR inptr; 278ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ISLOW_MULT_TYPE * quantptr; 279ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int * wsptr; 280ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPROW outptr; 281ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPLE *range_limit = IDCT_range_limit(cinfo); 282ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int ctr; 283ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int workspace[DCTSIZE*2]; /* buffers data between passes */ 284ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov SHIFT_TEMPS 285ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 286ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Pass 1: process columns from input, store into work array. */ 287ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 288ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr = coef_block; 289ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 290ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr = workspace; 291ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ctr = DCTSIZE; ctr > 0; inptr++, quantptr++, wsptr++, ctr--) { 292ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Don't bother to process columns 2,4,6 */ 293ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (ctr == DCTSIZE-2 || ctr == DCTSIZE-4 || ctr == DCTSIZE-6) 294ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 295ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*3] == 0 && 296ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*7] == 0) { 297ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* AC terms all zero; we need not examine terms 2,4,6 for 2x2 output */ 298ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]) << PASS1_BITS; 299ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 300ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*0] = dcval; 301ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*1] = dcval; 302ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 303ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 304ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 305ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 306ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Even part */ 307ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 308ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 309ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp10 = z1 << (CONST_BITS+2); 310ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 311ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Odd part */ 312ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 313ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 314ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = MULTIPLY(z1, - FIX_0_720959822); /* sqrt(2) * (c7-c5+c3-c1) */ 315ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 316ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 += MULTIPLY(z1, FIX_0_850430095); /* sqrt(2) * (-c1+c3+c5+c7) */ 317ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 318ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 += MULTIPLY(z1, - FIX_1_272758580); /* sqrt(2) * (-c1+c3-c5-c7) */ 319ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov z1 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 320ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 += MULTIPLY(z1, FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */ 321ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 322ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Final output stage */ 323ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 324ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*0] = (int) DESCALE(tmp10 + tmp0, CONST_BITS-PASS1_BITS+2); 325ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr[DCTSIZE*1] = (int) DESCALE(tmp10 - tmp0, CONST_BITS-PASS1_BITS+2); 326ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 327ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 328ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Pass 2: process 2 rows from work array, store into output array. */ 329ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 330ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr = workspace; 331ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov for (ctr = 0; ctr < 2; ctr++) { 332ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr = output_buf[ctr] + output_col; 333ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* It's not clear whether a zero row test is worthwhile here ... */ 334ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 335ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#ifndef NO_ZERO_ROW_TEST 336ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov if (wsptr[1] == 0 && wsptr[3] == 0 && wsptr[5] == 0 && wsptr[7] == 0) { 337ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* AC terms all zero */ 338ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3) 339ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 340ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 341ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[0] = dcval; 342ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[1] = dcval; 343ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 344ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr += DCTSIZE; /* advance pointer to next row */ 345ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov continue; 346ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 347ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif 348ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 349ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Even part */ 350ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 351ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp10 = ((INT32) wsptr[0]) << (CONST_BITS+2); 352ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 353ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Odd part */ 354ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 355ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov tmp0 = MULTIPLY((INT32) wsptr[7], - FIX_0_720959822) /* sqrt(2) * (c7-c5+c3-c1) */ 356ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY((INT32) wsptr[5], FIX_0_850430095) /* sqrt(2) * (-c1+c3+c5+c7) */ 357ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY((INT32) wsptr[3], - FIX_1_272758580) /* sqrt(2) * (-c1+c3-c5-c7) */ 358ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov + MULTIPLY((INT32) wsptr[1], FIX_3_624509785); /* sqrt(2) * (c1+c3+c5+c7) */ 359ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 360ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* Final output stage */ 361ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 362ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[0] = range_limit[(int) DESCALE(tmp10 + tmp0, 363ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+2) 364ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 365ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov outptr[1] = range_limit[(int) DESCALE(tmp10 - tmp0, 366ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov CONST_BITS+PASS1_BITS+3+2) 367ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov & RANGE_MASK]; 368ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 369ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov wsptr += DCTSIZE; /* advance pointer to next row */ 370ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov } 371ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 372ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 373ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 374ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov/* 375ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * Perform dequantization and inverse DCT on one block of coefficients, 376ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * producing a reduced-size 1x1 output block. 377ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 378ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 379ee451cb395940862dad63c85adfe8f2fd55e864cSvet GanovGLOBAL(void) 380ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganovjpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr, 381ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JCOEFPTR coef_block, 382ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPARRAY output_buf, JDIMENSION output_col) 383ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov{ 384ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov int dcval; 385ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov ISLOW_MULT_TYPE * quantptr; 386ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov JSAMPLE *range_limit = IDCT_range_limit(cinfo); 387ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov SHIFT_TEMPS 388ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 389ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov /* We hardly need an inverse DCT routine for this: just take the 390ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov * average pixel value, which is one-eighth of the DC coefficient. 391ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov */ 392ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table; 393ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov dcval = DEQUANTIZE(coef_block[0], quantptr[0]); 394ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov dcval = (int) DESCALE((INT32) dcval, 3); 395ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 396ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov output_buf[0][output_col] = range_limit[dcval & RANGE_MASK]; 397ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov} 398ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 399ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif /* IDCT_SCALING_SUPPORTED */ 400ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov 401ee451cb395940862dad63c85adfe8f2fd55e864cSvet Ganov#endif //_FX_JPEG_TURBO_ 402