1f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 2f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * jidctfst.c 3f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 4f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Copyright (C) 1994-1998, Thomas G. Lane. 5f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This file is part of the Independent JPEG Group's software. 6f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * For conditions of distribution and use, see the accompanying README file. 7f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 8f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This file contains a fast, not so accurate integer implementation of the 9f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine 10f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * must also perform dequantization of the input coefficients. 11f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 12f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT 13f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * on each row (or vice versa, but it's more convenient to emit a row at 14f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * a time). Direct algorithms are also available, but they are much more 15f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * complex and seem not to be any faster when reduced to code. 16f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 17f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This implementation is based on Arai, Agui, and Nakajima's algorithm for 18f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in 19f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Japanese, but the algorithm is described in the Pennebaker & Mitchell 20f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * JPEG textbook (see REFERENCES section in file README). The following code 21f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * is based directly on figure 4-8 in P&M. 22f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * While an 8-point DCT cannot be done in less than 11 multiplies, it is 23f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * possible to arrange the computation so that many of the multiplies are 24f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * simple scalings of the final outputs. These multiplies can then be 25f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * folded into the multiplications or divisions by the JPEG quantization 26f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * table entries. The AA&N method leaves only 5 multiplies and 29 adds 27f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * to be done in the DCT itself. 28f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * The primary disadvantage of this method is that with fixed-point math, 29f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * accuracy is lost due to imprecise representation of the scaled 30f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * quantization values. The smaller the quantization table entry, the less 31f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * precise the scaled value, so this implementation does worse with high- 32f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * quality-setting files than with low-quality ones. 33f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 34f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 35f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define JPEG_INTERNALS 36f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#include "jinclude.h" 37f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#include "jpeglib.h" 38f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#include "jdct.h" /* Private declarations for DCT subsystem */ 39f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 40f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef DCT_IFAST_SUPPORTED 41f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 42f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 43f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 44f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This module is specialized to the case DCTSIZE = 8. 45f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 46f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 47f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#if DCTSIZE != 8 48f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ 49f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 50f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 51f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 52f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Scaling decisions are generally the same as in the LL&M algorithm; 53f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * see jidctint.c for more details. However, we choose to descale 54f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * (right shift) multiplication products as soon as they are formed, 55f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * rather than carrying additional fractional bits into subsequent additions. 56f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * This compromises accuracy slightly, but it lets us save a few shifts. 57f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * More importantly, 16-bit arithmetic is then adequate (for 8-bit samples) 58f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * everywhere except in the multiplications proper; this saves a good deal 59f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * of work on 16-bit-int machines. 60f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 61f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * The dequantized coefficients are not integers because the AA&N scaling 62f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * factors have been incorporated. We represent them scaled up by PASS1_BITS, 63f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * so that the first and second IDCT rounds have the same input scaling. 64f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * For 8-bit JSAMPLEs, we choose IFAST_SCALE_BITS = PASS1_BITS so as to 65f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * avoid a descaling shift; this compromises accuracy rather drastically 66f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * for small quantization table entries, but it saves a lot of shifts. 67f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * For 12-bit JSAMPLEs, there's no hope of using 16x16 multiplies anyway, 68f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * so we use a much larger scaling factor to preserve accuracy. 69f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 70f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * A final compromise is to represent the multiplicative constants to only 71f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * 8 fractional bits, rather than 13. This saves some shifting work on some 72f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * machines, and may also reduce the cost of multiplication (since there 73f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * are fewer one-bits in the constants). 74f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 75f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 76f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#if BITS_IN_JSAMPLE == 8 77f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define CONST_BITS 8 78f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define PASS1_BITS 2 79f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 80f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define CONST_BITS 8 81f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ 82f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 83f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 84f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus 85f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * causing a lot of useless floating-point operations at run time. 86f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * To get around this we use the following pre-calculated constants. 87f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * If you change CONST_BITS you may want to add appropriate values. 88f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * (With a reasonable C compiler, you can just rely on the FIX() macro...) 89f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 90f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 91f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#if CONST_BITS == 8 92f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_082392200 ((INT32) 277) /* FIX(1.082392200) */ 93f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_414213562 ((INT32) 362) /* FIX(1.414213562) */ 94f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_847759065 ((INT32) 473) /* FIX(1.847759065) */ 95f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_2_613125930 ((INT32) 669) /* FIX(2.613125930) */ 96f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 97f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_082392200 FIX(1.082392200) 98f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_414213562 FIX(1.414213562) 99f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_1_847759065 FIX(1.847759065) 100f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define FIX_2_613125930 FIX(2.613125930) 101f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 102f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 103f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 104f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* We can gain a little more speed, with a further compromise in accuracy, 105f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * by omitting the addition in a descaling shift. This yields an incorrectly 106f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * rounded result half the time... 107f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 108f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 109f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifndef USE_ACCURATE_ROUNDING 110f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#undef DESCALE 111f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define DESCALE(x,n) RIGHT_SHIFT(x, n) 112f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 113f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 114f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 115f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Multiply a DCTELEM variable by an INT32 constant, and immediately 116f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * descale to yield a DCTELEM result. 117f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 118f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 119f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define MULTIPLY(var,const) ((DCTELEM) DESCALE((var) * (const), CONST_BITS)) 120f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 121f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 122f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Dequantize a coefficient by multiplying it by the multiplier-table 123f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * entry; produce a DCTELEM result. For 8-bit data a 16x16->16 124f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * multiplication will do. For 12-bit data, the multiplier table is 125f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * declared INT32, so a 32-bit multiply will be used. 126f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 127f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 128f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#if BITS_IN_JSAMPLE == 8 129f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define DEQUANTIZE(coef,quantval) (((IFAST_MULT_TYPE) (coef)) * (quantval)) 130f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 131f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define DEQUANTIZE(coef,quantval) \ 132f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org DESCALE((coef)*(quantval), IFAST_SCALE_BITS-PASS1_BITS) 133f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 134f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 135f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 136f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* Like DESCALE, but applies to a DCTELEM and produces an int. 137f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * We assume that int right shift is unsigned if INT32 right shift is. 138f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 139f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 140f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef RIGHT_SHIFT_IS_UNSIGNED 141f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define ISHIFT_TEMPS DCTELEM ishift_temp; 142f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#if BITS_IN_JSAMPLE == 8 143f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define DCTELEMBITS 16 /* DCTELEM may be 16 or 32 bits */ 144f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 145f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define DCTELEMBITS 32 /* DCTELEM must be 32 bits */ 146f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 147f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define IRIGHT_SHIFT(x,shft) \ 148f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ((ishift_temp = (x)) < 0 ? \ 149f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (ishift_temp >> (shft)) | ((~((DCTELEM) 0)) << (DCTELEMBITS-(shft))) : \ 150f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org (ishift_temp >> (shft))) 151f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 152f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define ISHIFT_TEMPS 153f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define IRIGHT_SHIFT(x,shft) ((x) >> (shft)) 154f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 155f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 156f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifdef USE_ACCURATE_ROUNDING 157f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define IDESCALE(x,n) ((int) IRIGHT_SHIFT((x) + (1 << ((n)-1)), n)) 158f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#else 159f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#define IDESCALE(x,n) ((int) IRIGHT_SHIFT(x, n)) 160f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 161f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 162f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 163f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org/* 164f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * Perform dequantization and inverse DCT on one block of coefficients. 165f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 166f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 167f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgGLOBAL(void) 168f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.orgjpeg_idct_ifast (j_decompress_ptr cinfo, jpeg_component_info * compptr, 169f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JCOEFPTR coef_block, 170f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPARRAY output_buf, JDIMENSION output_col) 171f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org{ 172f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; 173f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org DCTELEM tmp10, tmp11, tmp12, tmp13; 174f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org DCTELEM z5, z10, z11, z12, z13; 175f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JCOEFPTR inptr; 176f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org IFAST_MULT_TYPE * quantptr; 177f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int * wsptr; 178f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPROW outptr; 179f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPLE *range_limit = IDCT_range_limit(cinfo); 180f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int ctr; 181f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int workspace[DCTSIZE2]; /* buffers data between passes */ 182f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org SHIFT_TEMPS /* for DESCALE */ 183f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org ISHIFT_TEMPS /* for IDESCALE */ 184f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 185f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Pass 1: process columns from input, store into work array. */ 186f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 187f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr = coef_block; 188f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org quantptr = (IFAST_MULT_TYPE *) compptr->dct_table; 189f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr = workspace; 190f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ctr = DCTSIZE; ctr > 0; ctr--) { 191f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Due to quantization, we will usually find that many of the input 192f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * coefficients are zero, especially the AC terms. We can exploit this 193f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * by short-circuiting the IDCT calculation for any column in which all 194f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * the AC terms are zero. In that case each output is equal to the 195f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * DC coefficient (with scale factor as needed). 196f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * With typical images and quantization tables, half or more of the 197f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * column DCT calculations can be simplified this way. 198f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 199f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 200f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && 201f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && 202f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && 203f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr[DCTSIZE*7] == 0) { 204f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* AC terms all zero */ 205f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org int dcval = (int) DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 206f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 207f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*0] = dcval; 208f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*1] = dcval; 209f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*2] = dcval; 210f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*3] = dcval; 211f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*4] = dcval; 212f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*5] = dcval; 213f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*6] = dcval; 214f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*7] = dcval; 215f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 216f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr++; /* advance pointers to next column */ 217f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org quantptr++; 218f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr++; 219f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org continue; 220f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 221f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 222f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Even part */ 223f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 224f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); 225f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); 226f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); 227f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); 228f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 229f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp10 = tmp0 + tmp2; /* phase 3 */ 230f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp11 = tmp0 - tmp2; 231f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 232f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp13 = tmp1 + tmp3; /* phases 5-3 */ 233f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp12 = MULTIPLY(tmp1 - tmp3, FIX_1_414213562) - tmp13; /* 2*c4 */ 234f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 235f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp0 = tmp10 + tmp13; /* phase 2 */ 236f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp3 = tmp10 - tmp13; 237f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp1 = tmp11 + tmp12; 238f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp2 = tmp11 - tmp12; 239f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 240f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Odd part */ 241f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 242f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); 243f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); 244f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); 245f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); 246f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 247f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z13 = tmp6 + tmp5; /* phase 6 */ 248f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z10 = tmp6 - tmp5; 249f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z11 = tmp4 + tmp7; 250f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z12 = tmp4 - tmp7; 251f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 252f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp7 = z11 + z13; /* phase 5 */ 253f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */ 254f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 255f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */ 256f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */ 257f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */ 258f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 259f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp6 = tmp12 - tmp7; /* phase 2 */ 260f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp5 = tmp11 - tmp6; 261f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp4 = tmp10 + tmp5; 262f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 263f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*0] = (int) (tmp0 + tmp7); 264f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*7] = (int) (tmp0 - tmp7); 265f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*1] = (int) (tmp1 + tmp6); 266f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*6] = (int) (tmp1 - tmp6); 267f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*2] = (int) (tmp2 + tmp5); 268f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*5] = (int) (tmp2 - tmp5); 269f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*4] = (int) (tmp3 + tmp4); 270f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[DCTSIZE*3] = (int) (tmp3 - tmp4); 271f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 272f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org inptr++; /* advance pointers to next column */ 273f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org quantptr++; 274f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr++; 275f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 276f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 277f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Pass 2: process rows from work array, store into output array. */ 278f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Note that we must descale the results by a factor of 8 == 2**3, */ 279f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* and also undo the PASS1_BITS scaling. */ 280f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 281f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr = workspace; 282f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org for (ctr = 0; ctr < DCTSIZE; ctr++) { 283f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr = output_buf[ctr] + output_col; 284f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Rows of zeroes can be exploited in the same way as we did with columns. 285f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * However, the column calculation has created many nonzero AC terms, so 286f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * the simplification applies less often (typically 5% to 10% of the time). 287f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * On machines with very fast multiplication, it's possible that the 288f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * test takes more time than it's worth. In that case this section 289f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org * may be commented out. 290f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org */ 291f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 292f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#ifndef NO_ZERO_ROW_TEST 293f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 && 294f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) { 295f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* AC terms all zero */ 296f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org JSAMPLE dcval = range_limit[IDESCALE(wsptr[0], PASS1_BITS+3) 297f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 298f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 299f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[0] = dcval; 300f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[1] = dcval; 301f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[2] = dcval; 302f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[3] = dcval; 303f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[4] = dcval; 304f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[5] = dcval; 305f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[6] = dcval; 306f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[7] = dcval; 307f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 308f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr += DCTSIZE; /* advance pointer to next row */ 309f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org continue; 310f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 311f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif 312f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 313f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Even part */ 314f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 315f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp10 = ((DCTELEM) wsptr[0] + (DCTELEM) wsptr[4]); 316f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp11 = ((DCTELEM) wsptr[0] - (DCTELEM) wsptr[4]); 317f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 318f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp13 = ((DCTELEM) wsptr[2] + (DCTELEM) wsptr[6]); 319f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp12 = MULTIPLY((DCTELEM) wsptr[2] - (DCTELEM) wsptr[6], FIX_1_414213562) 320f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org - tmp13; 321f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 322f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp0 = tmp10 + tmp13; 323f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp3 = tmp10 - tmp13; 324f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp1 = tmp11 + tmp12; 325f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp2 = tmp11 - tmp12; 326f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 327f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Odd part */ 328f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 329f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z13 = (DCTELEM) wsptr[5] + (DCTELEM) wsptr[3]; 330f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z10 = (DCTELEM) wsptr[5] - (DCTELEM) wsptr[3]; 331f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z11 = (DCTELEM) wsptr[1] + (DCTELEM) wsptr[7]; 332f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z12 = (DCTELEM) wsptr[1] - (DCTELEM) wsptr[7]; 333f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 334f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp7 = z11 + z13; /* phase 5 */ 335f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562); /* 2*c4 */ 336f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 337f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org z5 = MULTIPLY(z10 + z12, FIX_1_847759065); /* 2*c2 */ 338f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5; /* 2*(c2-c6) */ 339f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp12 = MULTIPLY(z10, - FIX_2_613125930) + z5; /* -2*(c2+c6) */ 340f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 341f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp6 = tmp12 - tmp7; /* phase 2 */ 342f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp5 = tmp11 - tmp6; 343f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org tmp4 = tmp10 + tmp5; 344f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 345f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org /* Final output stage: scale down by a factor of 8 and range-limit */ 346f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 347f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[0] = range_limit[IDESCALE(tmp0 + tmp7, PASS1_BITS+3) 348f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 349f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[7] = range_limit[IDESCALE(tmp0 - tmp7, PASS1_BITS+3) 350f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 351f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[1] = range_limit[IDESCALE(tmp1 + tmp6, PASS1_BITS+3) 352f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 353f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[6] = range_limit[IDESCALE(tmp1 - tmp6, PASS1_BITS+3) 354f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 355f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[2] = range_limit[IDESCALE(tmp2 + tmp5, PASS1_BITS+3) 356f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 357f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[5] = range_limit[IDESCALE(tmp2 - tmp5, PASS1_BITS+3) 358f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 359f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[4] = range_limit[IDESCALE(tmp3 + tmp4, PASS1_BITS+3) 360f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 361f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org outptr[3] = range_limit[IDESCALE(tmp3 - tmp4, PASS1_BITS+3) 362f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org & RANGE_MASK]; 363f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 364f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org wsptr += DCTSIZE; /* advance pointer to next row */ 365f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org } 366f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org} 367f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org 368f0c4f33a4aa0760ba0e12a254b69d996442c9c5hbono@chromium.org#endif /* DCT_IFAST_SUPPORTED */ 369