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Diffstat (limited to 'mpeglib/lib/mpegplay/jrevdct.cpp')
| -rw-r--r-- | mpeglib/lib/mpegplay/jrevdct.cpp | 1690 |
1 files changed, 1690 insertions, 0 deletions
diff --git a/mpeglib/lib/mpegplay/jrevdct.cpp b/mpeglib/lib/mpegplay/jrevdct.cpp new file mode 100644 index 00000000..4ffe48ab --- /dev/null +++ b/mpeglib/lib/mpegplay/jrevdct.cpp @@ -0,0 +1,1690 @@ +/* + * jrevdct.c + * + * This file is part of the Independent JPEG Group's software. + * The IJG code is distributed under the terms reproduced here: + * + * LEGAL ISSUES + * ============ + * + * In plain English: + * + * 1. We don't promise that this software works. (But if you find any bugs, + * please let us know!) + * 2. You can use this software for whatever you want. You don't have to + * pay us. + * 3. You may not pretend that you wrote this software. If you use it in a + * program, you must acknowledge somewhere in your documentation that + * you've used the IJG code. + * + * In legalese: + * + * The authors make NO WARRANTY or representation, either express or implied, + * with respect to this software, its quality, accuracy, merchantability, or + * fitness for a particular purpose. This software is provided "AS IS", and + * you, its user, assume the entire risk as to its quality and accuracy. + * + * This software is copyright (C) 1991, 1992, Thomas G. Lane. + * All Rights Reserved except as specified below. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * software (or portions thereof) for any purpose, without fee, subject to + * these conditions: + * (1) If any part of the source code for this software is distributed, then + * this copyright and no-warranty notice must be included unaltered; and any + * additions, deletions, or changes to the original files must be clearly + * indicated in accompanying documentation. + * (2) If only executable code is distributed, then the accompanying + * documentation must state that "this software is based in part on the + * work of the Independent JPEG Group". + * (3) Permission for use of this software is granted only if the user + * accepts full responsibility for any undesirable consequences; the authors + * accept NO LIABILITY for damages of any kind. + * + * These conditions apply to any software derived from or based on the IJG + * code, not just to the unmodified library. If you use our work, you ought + * to acknowledge us. + * + * Permission is NOT granted for the use of any IJG author's name or company + * name in advertising or publicity relating to this software or products + * derived from it. This software may be referred to only as + * "the Independent JPEG Group's software". + * + * We specifically permit and encourage the use of this software as the + * basis of commercial products, provided that all warranty or liability + * claims are assumed by the product vendor. + * + * + * ARCHIVE LOCATIONS + * ================= + * + * The "official" archive site for this software is ftp.uu.net (Internet + * address 192.48.96.9). The most recent released version can always be + * found there in directory graphics/jpeg. This particular version will + * be archived as graphics/jpeg/jpegsrc.v6a.tar.gz. If you are on the + * Internet, you can retrieve files from ftp.uu.net by standard anonymous + * FTP. If you don't have FTP access, UUNET's archives are also available + * via UUCP; contact help@uunet.uu.net for information on retrieving files + * that way. + * + * Numerous Internet sites maintain copies of the UUNET files. However, + * only ftp.uu.net is guaranteed to have the latest official version. + * + * You can also obtain this software in DOS-compatible "zip" archive + * format from the SimTel archives (ftp.coast.net:/SimTel/msdos/graphics/), + * or on CompuServe in the Graphics Support forum (GO CIS:GRAPHSUP), + * library 12 "JPEG Tools". Again, these versions may sometimes lag behind + * the ftp.uu.net release. + * + * The JPEG FAQ (Frequently Asked Questions) article is a useful source of + * general information about JPEG. It is updated constantly and therefore + * is not included in this distribution. The FAQ is posted every two weeks + * to Usenet newsgroups comp.graphics.misc, news.answers, and other groups. + * You can always obtain the latest version from the news.answers archive + * at rtfm.mit.edu. By FTP, fetch /pub/usenet/news.answers/jpeg-faq/part1 + * and .../part2. If you don't have FTP, send e-mail to + * mail-server@rtfm.mit.edu with body + * send usenet/news.answers/jpeg-faq/part1 + * send usenet/news.answers/jpeg-faq/part2 + * + * ============== + * + * + * This file contains the basic inverse-DCT transformation subroutine. + * + * This implementation is based on an algorithm described in + * C. Loeffler, A. Ligtenberg and G. Moschytz, "Practical Fast 1-D DCT + * Algorithms with 11 Multiplications", Proc. Int'l. Conf. on Acoustics, + * Speech, and Signal Processing 1989 (ICASSP '89), pp. 988-991. + * The primary algorithm described there uses 11 multiplies and 29 adds. + * We use their alternate method with 12 multiplies and 32 adds. + * The advantage of this method is that no data path contains more than one + * multiplication; this allows a very simple and accurate implementation in + * scaled fixed-point arithmetic, with a minimal number of shifts. + * + * + * CHANGES FOR BERKELEY MPEG + * ========================= + * + * This file has been altered to use the Berkeley MPEG header files, + * to add the capability to handle sparse DCT matrices efficiently, + * and to relabel the inverse DCT function as well as the file + * (formerly jidctint.c). + * + * I've made lots of modifications to attempt to take advantage of the + * sparse nature of the DCT matrices we're getting. Although the logic + * is cumbersome, it's straightforward and the resulting code is much + * faster. + * + * A better way to do this would be to pass in the DCT block as a sparse + * matrix, perhaps with the difference cases encoded. + */ + +#include "jrevdct.h" + + + + +/* We assume that right shift corresponds to signed division by 2 with + * rounding towards minus infinity. This is correct for typical "arithmetic + * shift" instructions that shift in copies of the sign bit. But some + * C compilers implement >> with an unsigned shift. For these machines you + * must define RIGHT_SHIFT_IS_UNSIGNED. + * RIGHT_SHIFT provides a proper signed right shift of an INT32 quantity. + * It is only applied with constant shift counts. SHIFT_TEMPS must be + * included in the variables of any routine using RIGHT_SHIFT. + */ + +#ifdef RIGHT_SHIFT_IS_UNSIGNED +#define SHIFT_TEMPS INT32 shift_temp; +#define RIGHT_SHIFT(x,shft) \ + ((shift_temp = (x)) < 0 ? \ + (shift_temp >> (shft)) | ((~((INT32) 0)) << (32-(shft))) : \ + (shift_temp >> (shft))) +#else +#define SHIFT_TEMPS +#define RIGHT_SHIFT(x,shft) ((x) >> (shft)) +#endif + +/* + * This routine is specialized to the case DCTSIZE = 8. + */ + +#if DCTSIZE != 8 + Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ +#endif + + +/* + * A 2-D IDCT can be done by 1-D IDCT on each row followed by 1-D IDCT + * on each column. Direct algorithms are also available, but they are + * much more complex and seem not to be any faster when reduced to code. + * + * The poop on this scaling stuff is as follows: + * + * Each 1-D IDCT step produces outputs which are a factor of sqrt(N) + * larger than the true IDCT outputs. The final outputs are therefore + * a factor of N larger than desired; since N=8 this can be cured by + * a simple right shift at the end of the algorithm. The advantage of + * this arrangement is that we save two multiplications per 1-D IDCT, + * because the y0 and y4 inputs need not be divided by sqrt(N). + * + * We have to do addition and subtraction of the integer inputs, which + * is no problem, and multiplication by fractional constants, which is + * a problem to do in integer arithmetic. We multiply all the constants + * by CONST_SCALE and convert them to integer constants (thus retaining + * CONST_BITS bits of precision in the constants). After doing a + * multiplication we have to divide the product by CONST_SCALE, with proper + * rounding, to produce the correct output. This division can be done + * cheaply as a right shift of CONST_BITS bits. We postpone shifting + * as long as possible so that partial sums can be added together with + * full fractional precision. + * + * The outputs of the first pass are scaled up by PASS1_BITS bits so that + * they are represented to better-than-integral precision. These outputs + * require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word + * with the recommended scaling. (To scale up 12-bit sample data further, an + * intermediate INT32 array would be needed.) + * + * To avoid overflow of the 32-bit intermediate results in pass 2, we must + * have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis + * shows that the values given below are the most effective. + */ + +#ifdef EIGHT_BIT_SAMPLES +#define PASS1_BITS 2 +#else +#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ +#endif + +#define ONE ((INT32) 1) + +#define CONST_SCALE (ONE << CONST_BITS) + +/* Convert a positive real constant to an integer scaled by CONST_SCALE. + * IMPORTANT: if your compiler doesn't do this arithmetic at compile time, + * you will pay a significant penalty in run time. In that case, figure + * the correct integer constant values and insert them by hand. + */ + +#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5)) + +/* When adding two opposite-signed fixes, the 0.5 cancels */ +#define FIX2(x) ((INT32) ((x) * CONST_SCALE)) + +/* Descale and correctly round an INT32 value that's scaled by N bits. + * We assume RIGHT_SHIFT rounds towards minus infinity, so adding + * the fudge factor is correct for either sign of X. + */ + +#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n) + +/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result. + * For 8-bit samples with the recommended scaling, all the variable + * and constant values involved are no more than 16 bits wide, so a + * 16x16->32 bit multiply can be used instead of a full 32x32 multiply; + * this provides a useful speedup on many machines. + * There is no way to specify a 16x16->32 multiply in portable C, but + * some C compilers will do the right thing if you provide the correct + * combination of casts. + * NB: for 12-bit samples, a full 32-bit multiplication will be needed. + */ + +#ifdef EIGHT_BIT_SAMPLES +#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */ +#define MULTIPLY(var,const) (((INT16) (var)) * ((INT16) (const))) +#endif +#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */ +#define MULTIPLY(var,const) (((INT16) (var)) * ((INT32) (const))) +#endif +#endif + +#ifndef MULTIPLY /* default definition */ +#define MULTIPLY(var,const) ((var) * (const)) +#endif + +#ifndef NO_SPARSE_DCT +#define SPARSE_SCALE_FACTOR 8 +#endif + +/* Precomputed idct value arrays. */ + +static DCTELEM PreIDCT[64][64]; + + +/* + *-------------------------------------------------------------- + * + * init_pre_idct -- + * + * Pre-computes singleton coefficient IDCT values. + * + * Results: + * None. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +void init_pre_idct() { + int i; + + for (i=0; i<64; i++) { + memset((char *) PreIDCT[i], 0, 64*sizeof(DCTELEM)); + PreIDCT[i][i] = 1 << SPARSE_SCALE_FACTOR; + j_rev_dct(PreIDCT[i]); + } + + int pos; + int rr; + DCTELEM *ndataptr; + + for(pos=0;pos<64;pos++) { + ndataptr = PreIDCT[pos]; + + for(rr=0; rr<4; rr++) { + for(i=0;i<16;i++) { + ndataptr[i] = ndataptr[i]/256; + } + ndataptr += 16; + + } + } + + + + + + +} + +#ifndef NO_SPARSE_DCT + + +/* + *-------------------------------------------------------------- + * + * j_rev_dct_sparse -- + * + * Performs the inverse DCT on one block of coefficients. + * + * Results: + * None. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ + +void j_rev_dct_sparse (DCTBLOCK data, int pos) { + short int val; + register int *dp; + register int v; + int quant; + + // cout << "j_rev_dct_sparse"<<endl; + + /* If DC Coefficient. */ + + if (pos == 0) { + dp = (int *)data; + v = *data; + quant = 8; + + /* Compute 32 bit value to assign. This speeds things up a bit */ + if (v < 0) { + val = -v; + val += (quant / 2); + val /= quant; + val = -val; + } + else { + val = (v + (quant / 2)) / quant; + } + + v = ((val & 0xffff) | (val << 16)); + + dp[0] = v; dp[1] = v; dp[2] = v; dp[3] = v; + dp[4] = v; dp[5] = v; dp[6] = v; dp[7] = v; + dp[8] = v; dp[9] = v; dp[10] = v; dp[11] = v; + dp[12] = v; dp[13] = v; dp[14] = v; dp[15] = v; + dp[16] = v; dp[17] = v; dp[18] = v; dp[19] = v; + dp[20] = v; dp[21] = v; dp[22] = v; dp[23] = v; + dp[24] = v; dp[25] = v; dp[26] = v; dp[27] = v; + dp[28] = v; dp[29] = v; dp[30] = v; dp[31] = v; + + return; + } + //printf("sparse is: %d val:%8x\n",pos,data[pos]); + + /* + j_rev_dct(data); + return; + */ + + /* Some other coefficient. */ + + DCTELEM *dataptr; + DCTELEM *ndataptr; + int coeff, rr; + + + + dataptr = (DCTELEM *)data; + coeff = dataptr[pos]; + ndataptr = PreIDCT[pos]; + + //printf ("COEFFICIENT = %3d, POSITION = %2d\n", coeff, pos); + coeff=coeff/256; + + for (rr=0; rr<4; rr++) { + + dataptr[0] = (ndataptr[0] * coeff); + dataptr[1] = (ndataptr[1] * coeff); + dataptr[2] = (ndataptr[2] * coeff); + dataptr[3] = (ndataptr[3] * coeff); + dataptr[4] = (ndataptr[4] * coeff); + dataptr[5] = (ndataptr[5] * coeff); + dataptr[6] = (ndataptr[6] * coeff); + dataptr[7] = (ndataptr[7] * coeff); + dataptr[8] = (ndataptr[8] * coeff); + dataptr[9] = (ndataptr[9] * coeff); + dataptr[10] = (ndataptr[10] * coeff); + dataptr[11] = (ndataptr[11] * coeff); + dataptr[12] = (ndataptr[12] * coeff); + dataptr[13] = (ndataptr[13] * coeff); + dataptr[14] = (ndataptr[14] * coeff); + dataptr[15] = (ndataptr[15] * coeff); + + + dataptr += 16; + ndataptr += 16; + } + + dataptr = (DCTELEM *) data; + + + + return; + +} + +#else + +/* + *-------------------------------------------------------------- + * + * j_rev_dct_sparse -- + * + * Performs the original inverse DCT on one block of + * coefficients. + * + * Results: + * None. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +void j_rev_dct_sparse (DCTBLOCK data,int pos) { + j_rev_dct(data); +} +#endif /* SPARSE_DCT */ + + +#ifndef FIVE_DCT + +#ifndef ORIG_DCT + + +/* + *-------------------------------------------------------------- + * + * j_rev_dct -- + * + * The inverse DCT function. + * + * Results: + * None. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +void j_rev_dct (DCTBLOCK data) { + + + INT32 tmp0, tmp1, tmp2, tmp3; + INT32 tmp10, tmp11, tmp12, tmp13; + INT32 z1, z2, z3, z4, z5; + INT32 d0, d1, d2, d3, d4, d5, d6, d7; + register DCTELEM *dataptr; + int rowctr; + SHIFT_TEMPS + + + /* Pass 1: process rows. */ + /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ + /* furthermore, we scale the results by 2**PASS1_BITS. */ + + dataptr = data; + + for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) { + /* Due to quantization, we will usually find that many of the input + * coefficients are zero, especially the AC terms. We can exploit this + * by short-circuiting the IDCT calculation for any row in which all + * the AC terms are zero. In that case each output is equal to the + * DC coefficient (with scale factor as needed). + * With typical images and quantization tables, half or more of the + * row DCT calculations can be simplified this way. + */ + + register int *idataptr = (int*)dataptr; + d0 = dataptr[0]; + d1 = dataptr[1]; + if ((d1 == 0) && (idataptr[1] + idataptr[2] + idataptr[3]) == 0) { + /* AC terms all zero */ + if (d0) { + /* Compute a 32 bit value to assign. */ + DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS); + register int v = (dcval & 0xffff) + (dcval << 16); + + idataptr[0] = v; + idataptr[1] = v; + idataptr[2] = v; + idataptr[3] = v; + } + + dataptr += DCTSIZE; /* advance pointer to next row */ + continue; + } + d2 = dataptr[2]; + d3 = dataptr[3]; + d4 = dataptr[4]; + d5 = dataptr[5]; + d6 = dataptr[6]; + d7 = dataptr[7]; + + /* Even part: reverse the even part of the forward DCT. */ + /* The rotator is sqrt(2)*c(-6). */ + if (d6) { + if (d4) { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } + } else { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } + } + } else { + if (d4) { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */ + tmp10 = tmp13 = (d0 + d4) << CONST_BITS; + tmp11 = tmp12 = (d0 - d4) << CONST_BITS; + } else { + /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */ + tmp10 = tmp13 = d4 << CONST_BITS; + tmp11 = tmp12 = -tmp10; + } + } + } else { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */ + tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS; + } else { + /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */ + tmp10 = tmp13 = tmp11 = tmp12 = 0; + } + } + } + } + + + /* Odd part per figure 8; the matrix is unitary and hence its + * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. + */ + + if (d7) { + if (d5) { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */ + z1 = d7 + d1; + z2 = d5 + d3; + z3 = d7 + d3; + z4 = d5 + d1; + z5 = MULTIPLY(z3 + z4, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, 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; + } else { + /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */ + z2 = d5 + d3; + z3 = d7 + d3; + z5 = MULTIPLY(z3 + d5, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + z2 = MULTIPLY(z2, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX(1.961570560)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 += z2 + z4; + tmp2 += z2 + z3; + tmp3 = z1 + z4; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */ + z1 = d7 + d1; + z4 = d5 + d1; + z5 = MULTIPLY(d7 + z4, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(z1, - FIX(0.899976223)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z3 = MULTIPLY(d7, - 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; + } else { + /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */ + z5 = MULTIPLY(d7 + d5, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(0.601344887)); + tmp1 = MULTIPLY(d5, - FIX2(0.509795578)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + z3 = MULTIPLY(d7, - FIX(1.961570560)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z3; + tmp1 += z4; + tmp2 = z2 + z3; + tmp3 = z1 + z4; + } + } + } else { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */ + z1 = d7 + d1; + z3 = d7 + d3; + z5 = MULTIPLY(z3 + d1, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(z1, - FIX(0.899976223)); + z2 = MULTIPLY(d3, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX(1.961570560)); + z4 = MULTIPLY(d1, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 = z2 + z4; + tmp2 += z2 + z3; + tmp3 += z1 + z4; + } else { + /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */ + z3 = d7 + d3; + z5 = MULTIPLY(z3, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(0.601344887)); + tmp2 = MULTIPLY(d3, FIX(0.509795579)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + z2 = MULTIPLY(d3, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX2(0.785694958)); + + tmp0 += z3; + tmp1 = z2 + z5; + tmp2 += z3; + tmp3 = z1 + z5; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */ + z1 = d7 + d1; + z5 = MULTIPLY(z1, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(1.662939224)); + tmp3 = MULTIPLY(d1, FIX2(1.111140466)); + z1 = MULTIPLY(z1, FIX2(0.275899379)); + z3 = MULTIPLY(d7, - FIX(1.961570560)); + z4 = MULTIPLY(d1, - FIX(0.390180644)); + + tmp0 += z1; + tmp1 = z4 + z5; + tmp2 = z3 + z5; + tmp3 += z1; + } else { + /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */ + tmp0 = MULTIPLY(d7, - FIX2(1.387039845)); + tmp1 = MULTIPLY(d7, FIX(1.175875602)); + tmp2 = MULTIPLY(d7, - FIX2(0.785694958)); + tmp3 = MULTIPLY(d7, FIX2(0.275899379)); + } + } + } + } else { + if (d5) { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */ + z2 = d5 + d3; + z4 = d5 + d1; + z5 = MULTIPLY(d3 + z4, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(d1, - FIX(0.899976223)); + z2 = MULTIPLY(z2, - FIX(2.562915447)); + z3 = MULTIPLY(d3, - 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; + } else { + /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */ + z2 = d5 + d3; + z5 = MULTIPLY(z2, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, FIX2(1.662939225)); + tmp2 = MULTIPLY(d3, FIX2(1.111140466)); + z2 = MULTIPLY(z2, - FIX2(1.387039845)); + z3 = MULTIPLY(d3, - FIX(1.961570560)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + tmp0 = z3 + z5; + tmp1 += z2; + tmp2 += z2; + tmp3 = z4 + z5; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */ + z4 = d5 + d1; + z5 = MULTIPLY(z4, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, - FIX2(0.509795578)); + tmp3 = MULTIPLY(d1, FIX2(0.601344887)); + z1 = MULTIPLY(d1, - FIX(0.899976223)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z4 = MULTIPLY(z4, FIX2(0.785694958)); + + tmp0 = z1 + z5; + tmp2 = z2 + z5; + tmp1 += z4; + tmp3 += z4; + } else { + /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */ + tmp0 = MULTIPLY(d5, FIX(1.175875602)); + tmp1 = MULTIPLY(d5, FIX2(0.275899380)); + tmp2 = MULTIPLY(d5, - FIX2(1.387039845)); + tmp3 = MULTIPLY(d5, FIX2(0.785694958)); + } + } + } else { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */ + z5 = d3 + d1; + + tmp2 = MULTIPLY(d3, - FIX(1.451774981)); + tmp3 = MULTIPLY(d1, (FIX(0.211164243) - 1)); + z1 = MULTIPLY(d1, FIX(1.061594337)); + z2 = MULTIPLY(d3, - FIX(2.172734803)); + z4 = MULTIPLY(z5, FIX(0.785694958)); + z5 = MULTIPLY(z5, FIX(1.175875602)); + + tmp0 = z1 - z4; + tmp1 = z2 + z4; + tmp2 += z5; + tmp3 += z5; + } else { + /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */ + tmp0 = MULTIPLY(d3, - FIX2(0.785694958)); + tmp1 = MULTIPLY(d3, - FIX2(1.387039845)); + tmp2 = MULTIPLY(d3, - FIX2(0.275899379)); + tmp3 = MULTIPLY(d3, FIX(1.175875602)); + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */ + tmp0 = MULTIPLY(d1, FIX2(0.275899379)); + tmp1 = MULTIPLY(d1, FIX2(0.785694958)); + tmp2 = MULTIPLY(d1, FIX(1.175875602)); + tmp3 = MULTIPLY(d1, FIX2(1.387039845)); + } else { + /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */ + tmp0 = tmp1 = tmp2 = tmp3 = 0; + } + } + } + } + + /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ + + dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS); + dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS); + dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS); + dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS); + dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS); + dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS); + dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS); + dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS); + + dataptr += DCTSIZE; /* advance pointer to next row */ + } + + /* Pass 2: process columns. */ + /* Note that we must descale the results by a factor of 8 == 2**3, */ + /* and also undo the PASS1_BITS scaling. */ + + dataptr = data; + for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) { + /* Columns of zeroes can be exploited in the same way as we did with rows. + * However, the row calculation has created many nonzero AC terms, so the + * simplification applies less often (typically 5% to 10% of the time). + * On machines with very fast multiplication, it's possible that the + * test takes more time than it's worth. In that case this section + * may be commented out. + */ + + d0 = dataptr[DCTSIZE*0]; + d1 = dataptr[DCTSIZE*1]; + d2 = dataptr[DCTSIZE*2]; + d3 = dataptr[DCTSIZE*3]; + d4 = dataptr[DCTSIZE*4]; + d5 = dataptr[DCTSIZE*5]; + d6 = dataptr[DCTSIZE*6]; + d7 = dataptr[DCTSIZE*7]; + + /* Even part: reverse the even part of the forward DCT. */ + /* The rotator is sqrt(2)*c(-6). */ + if (d6) { + if (d4) { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, -FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } + } else { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */ + z1 = MULTIPLY(d2 + d6, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865)); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */ + tmp2 = MULTIPLY(d6, - FIX2(1.306562965)); + tmp3 = MULTIPLY(d6, FIX(0.541196100)); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } + } + } else { + if (d4) { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = (d0 + d4) << CONST_BITS; + tmp1 = (d0 - d4) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = d4 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp2 - tmp0; + tmp12 = -(tmp0 + tmp2); + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */ + tmp10 = tmp13 = (d0 + d4) << CONST_BITS; + tmp11 = tmp12 = (d0 - d4) << CONST_BITS; + } else { + /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */ + tmp10 = tmp13 = d4 << CONST_BITS; + tmp11 = tmp12 = -tmp10; + } + } + } else { + if (d2) { + if (d0) { + /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp0 = d0 << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp0 + tmp2; + tmp12 = tmp0 - tmp2; + } else { + /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */ + tmp2 = MULTIPLY(d2, FIX(0.541196100)); + tmp3 = (INT32) (MULTIPLY(d2, (FIX(1.306562965) + .5))); + + tmp10 = tmp3; + tmp13 = -tmp3; + tmp11 = tmp2; + tmp12 = -tmp2; + } + } else { + if (d0) { + /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */ + tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS; + } else { + /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */ + tmp10 = tmp13 = tmp11 = tmp12 = 0; + } + } + } + } + + /* Odd part per figure 8; the matrix is unitary and hence its + * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. + */ + if (d7) { + if (d5) { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */ + z1 = d7 + d1; + z2 = d5 + d3; + z3 = d7 + d3; + z4 = d5 + d1; + z5 = MULTIPLY(z3 + z4, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, 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; + } else { + /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */ + z2 = d5 + d3; + z3 = d7 + d3; + z5 = MULTIPLY(z3 + d5, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + z2 = MULTIPLY(z2, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX(1.961570560)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 += z2 + z4; + tmp2 += z2 + z3; + tmp3 = z1 + z4; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */ + z1 = d7 + d1; + z4 = d5 + d1; + z5 = MULTIPLY(d7 + z4, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(z1, - FIX(0.899976223)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z3 = MULTIPLY(d7, - 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; + } else { + /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */ + z5 = MULTIPLY(d5 + d7, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(0.601344887)); + tmp1 = MULTIPLY(d5, - FIX2(0.509795578)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + z3 = MULTIPLY(d7, - FIX(1.961570560)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z3; + tmp1 += z4; + tmp2 = z2 + z3; + tmp3 = z1 + z4; + } + } + } else { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */ + z1 = d7 + d1; + z3 = d7 + d3; + z5 = MULTIPLY(z3 + d1, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, FIX(0.298631336)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(z1, - FIX(0.899976223)); + z2 = MULTIPLY(d3, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX(1.961570560)); + z4 = MULTIPLY(d1, - FIX(0.390180644)); + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 = z2 + z4; + tmp2 += z2 + z3; + tmp3 += z1 + z4; + } else { + /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */ + z3 = d7 + d3; + z5 = MULTIPLY(z3, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(0.601344887)); + z1 = MULTIPLY(d7, - FIX(0.899976223)); + tmp2 = MULTIPLY(d3, FIX(0.509795579)); + z2 = MULTIPLY(d3, - FIX(2.562915447)); + z3 = MULTIPLY(z3, - FIX2(0.785694958)); + + tmp0 += z3; + tmp1 = z2 + z5; + tmp2 += z3; + tmp3 = z1 + z5; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */ + z1 = d7 + d1; + z5 = MULTIPLY(z1, FIX(1.175875602)); + + tmp0 = MULTIPLY(d7, - FIX2(1.662939224)); + tmp3 = MULTIPLY(d1, FIX2(1.111140466)); + z1 = MULTIPLY(z1, FIX2(0.275899379)); + z3 = MULTIPLY(d7, - FIX(1.961570560)); + z4 = MULTIPLY(d1, - FIX(0.390180644)); + + tmp0 += z1; + tmp1 = z4 + z5; + tmp2 = z3 + z5; + tmp3 += z1; + } else { + /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */ + tmp0 = MULTIPLY(d7, - FIX2(1.387039845)); + tmp1 = MULTIPLY(d7, FIX(1.175875602)); + tmp2 = MULTIPLY(d7, - FIX2(0.785694958)); + tmp3 = MULTIPLY(d7, FIX2(0.275899379)); + } + } + } + } else { + if (d5) { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */ + z2 = d5 + d3; + z4 = d5 + d1; + z5 = MULTIPLY(d3 + z4, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, FIX(2.053119869)); + tmp2 = MULTIPLY(d3, FIX(3.072711026)); + tmp3 = MULTIPLY(d1, FIX(1.501321110)); + z1 = MULTIPLY(d1, - FIX(0.899976223)); + z2 = MULTIPLY(z2, - FIX(2.562915447)); + z3 = MULTIPLY(d3, - 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; + } else { + /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */ + z2 = d5 + d3; + z5 = MULTIPLY(z2, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, FIX2(1.662939225)); + tmp2 = MULTIPLY(d3, FIX2(1.111140466)); + z2 = MULTIPLY(z2, - FIX2(1.387039845)); + z3 = MULTIPLY(d3, - FIX(1.961570560)); + z4 = MULTIPLY(d5, - FIX(0.390180644)); + + tmp0 = z3 + z5; + tmp1 += z2; + tmp2 += z2; + tmp3 = z4 + z5; + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */ + z4 = d5 + d1; + z5 = MULTIPLY(z4, FIX(1.175875602)); + + tmp1 = MULTIPLY(d5, - FIX2(0.509795578)); + tmp3 = MULTIPLY(d1, FIX2(0.601344887)); + z1 = MULTIPLY(d1, - FIX(0.899976223)); + z2 = MULTIPLY(d5, - FIX(2.562915447)); + z4 = MULTIPLY(z4, FIX2(0.785694958)); + + tmp0 = z1 + z5; + tmp1 += z4; + tmp2 = z2 + z5; + tmp3 += z4; + } else { + /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */ + tmp0 = MULTIPLY(d5, FIX(1.175875602)); + tmp1 = MULTIPLY(d5, FIX2(0.275899380)); + tmp2 = MULTIPLY(d5, - FIX2(1.387039845)); + tmp3 = MULTIPLY(d5, FIX2(0.785694958)); + } + } + } else { + if (d3) { + if (d1) { + /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */ + z5 = d3 + d1; + + tmp2 = MULTIPLY(d3, - FIX(1.451774981)); + tmp3 = MULTIPLY(d1, (FIX(0.211164243) - 1)); + z1 = MULTIPLY(d1, FIX(1.061594337)); + z2 = MULTIPLY(d3, - FIX(2.172734803)); + z4 = MULTIPLY(z5, FIX(0.785694958)); + z5 = MULTIPLY(z5, FIX(1.175875602)); + + tmp0 = z1 - z4; + tmp1 = z2 + z4; + tmp2 += z5; + tmp3 += z5; + } else { + /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */ + tmp0 = MULTIPLY(d3, - FIX2(0.785694958)); + tmp1 = MULTIPLY(d3, - FIX2(1.387039845)); + tmp2 = MULTIPLY(d3, - FIX2(0.275899379)); + tmp3 = MULTIPLY(d3, FIX(1.175875602)); + } + } else { + if (d1) { + /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */ + tmp0 = MULTIPLY(d1, FIX2(0.275899379)); + tmp1 = MULTIPLY(d1, FIX2(0.785694958)); + tmp2 = MULTIPLY(d1, FIX(1.175875602)); + tmp3 = MULTIPLY(d1, FIX2(1.387039845)); + } else { + /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */ + tmp0 = tmp1 = tmp2 = tmp3 = 0; + } + } + } + } + + /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ + + dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0, + CONST_BITS+PASS1_BITS+3); + + dataptr++; /* advance pointer to next column */ + } +} + +#else + + + +/* + *-------------------------------------------------------------- + * + * j_rev_dct -- + * + * The original inverse DCT function. + * + * Results: + * None. + * + * Side effects: + * None. + * + *-------------------------------------------------------------- + */ +void j_rev_dct (DCTBLOCK data) +{ + INT32 tmp0, tmp1, tmp2, tmp3; + INT32 tmp10, tmp11, tmp12, tmp13; + INT32 z1, z2, z3, z4, z5; + register DCTELEM *dataptr; + int rowctr; + SHIFT_TEMPS + + /* Pass 1: process rows. */ + /* Note results are scaled up by sqrt(8) compared to a true IDCT; */ + /* furthermore, we scale the results by 2**PASS1_BITS. */ + + dataptr = data; + for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) { + /* Due to quantization, we will usually find that many of the input + * coefficients are zero, especially the AC terms. We can exploit this + * by short-circuiting the IDCT calculation for any row in which all + * the AC terms are zero. In that case each output is equal to the + * DC coefficient (with scale factor as needed). + * With typical images and quantization tables, half or more of the + * row DCT calculations can be simplified this way. + */ + + if ((dataptr[1] | dataptr[2] | dataptr[3] | dataptr[4] | + dataptr[5] | dataptr[6] | dataptr[7]) == 0) { + /* AC terms all zero */ + DCTELEM dcval = (DCTELEM) (dataptr[0] << PASS1_BITS); + + dataptr[0] = dcval; + dataptr[1] = dcval; + dataptr[2] = dcval; + dataptr[3] = dcval; + dataptr[4] = dcval; + dataptr[5] = dcval; + dataptr[6] = dcval; + dataptr[7] = dcval; + + dataptr += DCTSIZE; /* advance pointer to next row */ + continue; + } + + /* Even part: reverse the even part of the forward DCT. */ + /* The rotator is sqrt(2)*c(-6). */ + + z2 = (INT32) dataptr[2]; + z3 = (INT32) dataptr[6]; + + z1 = MULTIPLY(z2 + z3, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(z3, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(z2, FIX(0.765366865)); + + tmp0 = ((INT32) dataptr[0] + (INT32) dataptr[4]) << CONST_BITS; + tmp1 = ((INT32) dataptr[0] - (INT32) dataptr[4]) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + + /* Odd part per figure 8; the matrix is unitary and hence its + * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. + */ + + tmp0 = (INT32) dataptr[7]; + tmp1 = (INT32) dataptr[5]; + tmp2 = (INT32) dataptr[3]; + tmp3 = (INT32) dataptr[1]; + + z1 = tmp0 + tmp3; + z2 = tmp1 + tmp2; + z3 = tmp0 + tmp2; + z4 = tmp1 + tmp3; + z5 = MULTIPLY(z3 + z4, FIX(1.175875602)); /* sqrt(2) * c3 */ + + tmp0 = MULTIPLY(tmp0, FIX(0.298631336)); /* sqrt(2) * (-c1+c3+c5-c7) */ + tmp1 = MULTIPLY(tmp1, FIX(2.053119869)); /* sqrt(2) * ( c1+c3-c5+c7) */ + tmp2 = MULTIPLY(tmp2, FIX(3.072711026)); /* sqrt(2) * ( c1+c3+c5-c7) */ + tmp3 = MULTIPLY(tmp3, FIX(1.501321110)); /* sqrt(2) * ( c1+c3-c5-c7) */ + z1 = MULTIPLY(z1, - FIX(0.899976223)); /* sqrt(2) * (c7-c3) */ + z2 = MULTIPLY(z2, - FIX(2.562915447)); /* sqrt(2) * (-c1-c3) */ + z3 = MULTIPLY(z3, - FIX(1.961570560)); /* sqrt(2) * (-c3-c5) */ + z4 = MULTIPLY(z4, - FIX(0.390180644)); /* sqrt(2) * (c5-c3) */ + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 += z2 + z4; + tmp2 += z2 + z3; + tmp3 += z1 + z4; + + /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ + + dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS); + dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS); + dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS); + dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS); + dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS); + dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS); + dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS); + dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS); + + dataptr += DCTSIZE; /* advance pointer to next row */ + } + + /* Pass 2: process columns. */ + /* Note that we must descale the results by a factor of 8 == 2**3, */ + /* and also undo the PASS1_BITS scaling. */ + + dataptr = data; + for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) { + /* Columns of zeroes can be exploited in the same way as we did with rows. + * However, the row calculation has created many nonzero AC terms, so the + * simplification applies less often (typically 5% to 10% of the time). + * On machines with very fast multiplication, it's possible that the + * test takes more time than it's worth. In that case this section + * may be commented out. + */ + +#ifndef NO_ZERO_COLUMN_TEST + if ((dataptr[DCTSIZE*1] | dataptr[DCTSIZE*2] | dataptr[DCTSIZE*3] | + dataptr[DCTSIZE*4] | dataptr[DCTSIZE*5] | dataptr[DCTSIZE*6] | + dataptr[DCTSIZE*7]) == 0) { + /* AC terms all zero */ + DCTELEM dcval = (DCTELEM) DESCALE((INT32) dataptr[0], PASS1_BITS+3); + + dataptr[DCTSIZE*0] = dcval; + dataptr[DCTSIZE*1] = dcval; + dataptr[DCTSIZE*2] = dcval; + dataptr[DCTSIZE*3] = dcval; + dataptr[DCTSIZE*4] = dcval; + dataptr[DCTSIZE*5] = dcval; + dataptr[DCTSIZE*6] = dcval; + dataptr[DCTSIZE*7] = dcval; + + dataptr++; /* advance pointer to next column */ + continue; + } +#endif + + /* Even part: reverse the even part of the forward DCT. */ + /* The rotator is sqrt(2)*c(-6). */ + + z2 = (INT32) dataptr[DCTSIZE*2]; + z3 = (INT32) dataptr[DCTSIZE*6]; + + z1 = MULTIPLY(z2 + z3, FIX(0.541196100)); + tmp2 = z1 + MULTIPLY(z3, - FIX(1.847759065)); + tmp3 = z1 + MULTIPLY(z2, FIX(0.765366865)); + + tmp0 = ((INT32) dataptr[DCTSIZE*0] + (INT32) dataptr[DCTSIZE*4]) << CONST_BITS; + tmp1 = ((INT32) dataptr[DCTSIZE*0] - (INT32) dataptr[DCTSIZE*4]) << CONST_BITS; + + tmp10 = tmp0 + tmp3; + tmp13 = tmp0 - tmp3; + tmp11 = tmp1 + tmp2; + tmp12 = tmp1 - tmp2; + + /* Odd part per figure 8; the matrix is unitary and hence its + * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. + */ + + tmp0 = (INT32) dataptr[DCTSIZE*7]; + tmp1 = (INT32) dataptr[DCTSIZE*5]; + tmp2 = (INT32) dataptr[DCTSIZE*3]; + tmp3 = (INT32) dataptr[DCTSIZE*1]; + + z1 = tmp0 + tmp3; + z2 = tmp1 + tmp2; + z3 = tmp0 + tmp2; + z4 = tmp1 + tmp3; + z5 = MULTIPLY(z3 + z4, FIX(1.175875602)); /* sqrt(2) * c3 */ + + tmp0 = MULTIPLY(tmp0, FIX(0.298631336)); /* sqrt(2) * (-c1+c3+c5-c7) */ + tmp1 = MULTIPLY(tmp1, FIX(2.053119869)); /* sqrt(2) * ( c1+c3-c5+c7) */ + tmp2 = MULTIPLY(tmp2, FIX(3.072711026)); /* sqrt(2) * ( c1+c3+c5-c7) */ + tmp3 = MULTIPLY(tmp3, FIX(1.501321110)); /* sqrt(2) * ( c1+c3-c5-c7) */ + z1 = MULTIPLY(z1, - FIX(0.899976223)); /* sqrt(2) * (c7-c3) */ + z2 = MULTIPLY(z2, - FIX(2.562915447)); /* sqrt(2) * (-c1-c3) */ + z3 = MULTIPLY(z3, - FIX(1.961570560)); /* sqrt(2) * (-c3-c5) */ + z4 = MULTIPLY(z4, - FIX(0.390180644)); /* sqrt(2) * (c5-c3) */ + + z3 += z5; + z4 += z5; + + tmp0 += z1 + z3; + tmp1 += z2 + z4; + tmp2 += z2 + z3; + tmp3 += z1 + z4; + + /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ + + dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0, + CONST_BITS+PASS1_BITS+3); + dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0, + CONST_BITS+PASS1_BITS+3); + + dataptr++; /* advance pointer to next column */ + } +} + + +#endif /* ORIG_DCT */ +#endif /* FIVE_DCT */ + |