| /* |
| * jrevdct.c |
| * |
| * This file is part of the Independent JPEG Group's software. |
| * |
| * 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 README file must be included, with this copyright and no-warranty |
| * notice 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. |
| * |
| * 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. |
| * |
| * 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. |
| */ |
| |
| /** |
| * @file libavcodec/jrevdct.c |
| * Independent JPEG Group's LLM idct. |
| */ |
| |
| #include "libavutil/common.h" |
| #include "dsputil.h" |
| |
| #define EIGHT_BIT_SAMPLES |
| |
| #define DCTSIZE 8 |
| #define DCTSIZE2 64 |
| |
| #define GLOBAL |
| |
| #define RIGHT_SHIFT(x, n) ((x) >> (n)) |
| |
| typedef DCTELEM DCTBLOCK[DCTSIZE2]; |
| |
| #define CONST_BITS 13 |
| |
| /* |
| * 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_t) 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. |
| */ |
| |
| /* Actually FIX is no longer used, we precomputed them all */ |
| #define FIX(x) ((int32_t) ((x) * CONST_SCALE + 0.5)) |
| |
| /* Descale and correctly round an int32_t 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_t variable by an int32_t constant to yield an int32_t 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_t) (var)) * ((int16_t) (const))) |
| #endif |
| #ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */ |
| #define MULTIPLY(var,const) (((int16_t) (var)) * ((int32_t) (const))) |
| #endif |
| #endif |
| |
| #ifndef MULTIPLY /* default definition */ |
| #define MULTIPLY(var,const) ((var) * (const)) |
| #endif |
| |
| |
| /* |
| Unlike our decoder where we approximate the FIXes, we need to use exact |
| ones here or successive P-frames will drift too much with Reference frame coding |
| */ |
| #define FIX_0_211164243 1730 |
| #define FIX_0_275899380 2260 |
| #define FIX_0_298631336 2446 |
| #define FIX_0_390180644 3196 |
| #define FIX_0_509795579 4176 |
| #define FIX_0_541196100 4433 |
| #define FIX_0_601344887 4926 |
| #define FIX_0_765366865 6270 |
| #define FIX_0_785694958 6436 |
| #define FIX_0_899976223 7373 |
| #define FIX_1_061594337 8697 |
| #define FIX_1_111140466 9102 |
| #define FIX_1_175875602 9633 |
| #define FIX_1_306562965 10703 |
| #define FIX_1_387039845 11363 |
| #define FIX_1_451774981 11893 |
| #define FIX_1_501321110 12299 |
| #define FIX_1_662939225 13623 |
| #define FIX_1_847759065 15137 |
| #define FIX_1_961570560 16069 |
| #define FIX_2_053119869 16819 |
| #define FIX_2_172734803 17799 |
| #define FIX_2_562915447 20995 |
| #define FIX_3_072711026 25172 |
| |
| /* |
| * Perform the inverse DCT on one block of coefficients. |
| */ |
| |
| void j_rev_dct(DCTBLOCK data) |
| { |
| int32_t tmp0, tmp1, tmp2, tmp3; |
| int32_t tmp10, tmp11, tmp12, tmp13; |
| int32_t z1, z2, z3, z4, z5; |
| int32_t d0, d1, d2, d3, d4, d5, d6, d7; |
| register DCTELEM *dataptr; |
| int rowctr; |
| |
| /* 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; |
| |
| /* WARNING: we do the same permutation as MMX idct to simplify the |
| video core */ |
| d0 = dataptr[0]; |
| d2 = dataptr[1]; |
| d4 = dataptr[2]; |
| d6 = dataptr[3]; |
| d1 = dataptr[4]; |
| d3 = dataptr[5]; |
| d5 = dataptr[6]; |
| d7 = dataptr[7]; |
| |
| if ((d1 | d2 | d3 | d4 | d5 | d6 | d7) == 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) & 0xffff0000); |
| |
| idataptr[0] = v; |
| idataptr[1] = v; |
| idataptr[2] = v; |
| idataptr[3] = v; |
| } |
| |
| 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). */ |
| { |
| if (d6) { |
| if (d2) { |
| /* 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 */ |
| tmp2 = MULTIPLY(-d6, FIX_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 { |
| if (d2) { |
| /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ |
| tmp2 = MULTIPLY(d2, FIX_0_541196100); |
| tmp3 = MULTIPLY(d2, FIX_1_306562965); |
| |
| 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 */ |
| tmp10 = tmp13 = (d0 + d4) << CONST_BITS; |
| tmp11 = tmp12 = (d0 - d4) << CONST_BITS; |
| } |
| } |
| |
| /* 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 */ |
| tmp0 = MULTIPLY(-d7, FIX_0_601344887); |
| z1 = MULTIPLY(-d7, FIX_0_899976223); |
| z3 = MULTIPLY(-d7, FIX_1_961570560); |
| tmp1 = MULTIPLY(-d5, FIX_0_509795579); |
| z2 = MULTIPLY(-d5, FIX_2_562915447); |
| z4 = MULTIPLY(-d5, FIX_0_390180644); |
| z5 = MULTIPLY(d5 + d7, FIX_1_175875602); |
| |
| 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; |
| |
| tmp0 = MULTIPLY(-d7, FIX_0_601344887); |
| z1 = MULTIPLY(-d7, FIX_0_899976223); |
| tmp2 = MULTIPLY(d3, FIX_0_509795579); |
| z2 = MULTIPLY(-d3, FIX_2_562915447); |
| z5 = MULTIPLY(z3, FIX_1_175875602); |
| z3 = MULTIPLY(-z3, FIX_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); |
| |
| z1 = MULTIPLY(z1, FIX_0_275899380); |
| z3 = MULTIPLY(-d7, FIX_1_961570560); |
| tmp0 = MULTIPLY(-d7, FIX_1_662939225); |
| z4 = MULTIPLY(-d1, FIX_0_390180644); |
| tmp3 = MULTIPLY(d1, FIX_1_111140466); |
| |
| tmp0 += z1; |
| tmp1 = z4 + z5; |
| tmp2 = z3 + z5; |
| tmp3 += z1; |
| } else { |
| /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */ |
| tmp0 = MULTIPLY(-d7, FIX_1_387039845); |
| tmp1 = MULTIPLY(d7, FIX_1_175875602); |
| tmp2 = MULTIPLY(-d7, FIX_0_785694958); |
| tmp3 = MULTIPLY(d7, FIX_0_275899380); |
| } |
| } |
| } |
| } 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, FIX_1_662939225); |
| z4 = MULTIPLY(-d5, FIX_0_390180644); |
| z2 = MULTIPLY(-z2, FIX_1_387039845); |
| tmp2 = MULTIPLY(d3, FIX_1_111140466); |
| z3 = MULTIPLY(-d3, FIX_1_961570560); |
| |
| 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); |
| z1 = MULTIPLY(-d1, FIX_0_899976223); |
| tmp3 = MULTIPLY(d1, FIX_0_601344887); |
| tmp1 = MULTIPLY(-d5, FIX_0_509795579); |
| z2 = MULTIPLY(-d5, FIX_2_562915447); |
| z4 = MULTIPLY(z4, FIX_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, FIX_0_275899380); |
| tmp2 = MULTIPLY(-d5, FIX_1_387039845); |
| tmp3 = MULTIPLY(d5, FIX_0_785694958); |
| } |
| } |
| } else { |
| if (d3) { |
| if (d1) { |
| /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */ |
| z5 = d1 + d3; |
| tmp3 = MULTIPLY(d1, FIX_0_211164243); |
| tmp2 = MULTIPLY(-d3, FIX_1_451774981); |
| 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, FIX_0_785694958); |
| tmp1 = MULTIPLY(-d3, FIX_1_387039845); |
| tmp2 = MULTIPLY(-d3, FIX_0_275899380); |
| tmp3 = MULTIPLY(d3, FIX_1_175875602); |
| } |
| } else { |
| if (d1) { |
| /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */ |
| tmp0 = MULTIPLY(d1, FIX_0_275899380); |
| tmp1 = MULTIPLY(d1, FIX_0_785694958); |
| tmp2 = MULTIPLY(d1, FIX_1_175875602); |
| tmp3 = MULTIPLY(d1, FIX_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 (d2) { |
| /* 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 */ |
| tmp2 = MULTIPLY(-d6, FIX_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 { |
| if (d2) { |
| /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ |
| tmp2 = MULTIPLY(d2, FIX_0_541196100); |
| tmp3 = MULTIPLY(d2, FIX_1_306562965); |
| |
| 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 */ |
| tmp10 = tmp13 = (d0 + d4) << CONST_BITS; |
| tmp11 = tmp12 = (d0 - d4) << CONST_BITS; |
| } |
| } |
| |
| /* 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 */ |
| z1 = d7; |
| 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; |
| z2 = d5; |
| z3 = d7; |
| z4 = d5 + d1; |
| z5 = MULTIPLY(z3 + 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 */ |
| tmp0 = MULTIPLY(-d7, FIX_0_601344887); |
| z1 = MULTIPLY(-d7, FIX_0_899976223); |
| z3 = MULTIPLY(-d7, FIX_1_961570560); |
| tmp1 = MULTIPLY(-d5, FIX_0_509795579); |
| z2 = MULTIPLY(-d5, FIX_2_562915447); |
| z4 = MULTIPLY(-d5, FIX_0_390180644); |
| z5 = MULTIPLY(d5 + d7, FIX_1_175875602); |
| |
| 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; |
| |
| tmp0 = MULTIPLY(-d7, FIX_0_601344887); |
| z1 = MULTIPLY(-d7, FIX_0_899976223); |
| tmp2 = MULTIPLY(d3, FIX_0_509795579); |
| z2 = MULTIPLY(-d3, FIX_2_562915447); |
| z5 = MULTIPLY(z3, FIX_1_175875602); |
| z3 = MULTIPLY(-z3, FIX_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); |
| |
| z1 = MULTIPLY(z1, FIX_0_275899380); |
| z3 = MULTIPLY(-d7, FIX_1_961570560); |
| tmp0 = MULTIPLY(-d7, FIX_1_662939225); |
| z4 = MULTIPLY(-d1, FIX_0_390180644); |
| tmp3 = MULTIPLY(d1, FIX_1_111140466); |
| |
| tmp0 += z1; |
| tmp1 = z4 + z5; |
| tmp2 = z3 + z5; |
| tmp3 += z1; |
| } else { |
| /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */ |
| tmp0 = MULTIPLY(-d7, FIX_1_387039845); |
| tmp1 = MULTIPLY(d7, FIX_1_175875602); |
| tmp2 = MULTIPLY(-d7, FIX_0_785694958); |
| tmp3 = MULTIPLY(d7, FIX_0_275899380); |
| } |
| } |
| } |
| } 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, FIX_1_662939225); |
| z4 = MULTIPLY(-d5, FIX_0_390180644); |
| z2 = MULTIPLY(-z2, FIX_1_387039845); |
| tmp2 = MULTIPLY(d3, FIX_1_111140466); |
| z3 = MULTIPLY(-d3, FIX_1_961570560); |
| |
| 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); |
| z1 = MULTIPLY(-d1, FIX_0_899976223); |
| tmp3 = MULTIPLY(d1, FIX_0_601344887); |
| tmp1 = MULTIPLY(-d5, FIX_0_509795579); |
| z2 = MULTIPLY(-d5, FIX_2_562915447); |
| z4 = MULTIPLY(z4, FIX_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, FIX_0_275899380); |
| tmp2 = MULTIPLY(-d5, FIX_1_387039845); |
| tmp3 = MULTIPLY(d5, FIX_0_785694958); |
| } |
| } |
| } else { |
| if (d3) { |
| if (d1) { |
| /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */ |
| z5 = d1 + d3; |
| tmp3 = MULTIPLY(d1, FIX_0_211164243); |
| tmp2 = MULTIPLY(-d3, FIX_1_451774981); |
| 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, FIX_0_785694958); |
| tmp1 = MULTIPLY(-d3, FIX_1_387039845); |
| tmp2 = MULTIPLY(-d3, FIX_0_275899380); |
| tmp3 = MULTIPLY(d3, FIX_1_175875602); |
| } |
| } else { |
| if (d1) { |
| /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */ |
| tmp0 = MULTIPLY(d1, FIX_0_275899380); |
| tmp1 = MULTIPLY(d1, FIX_0_785694958); |
| tmp2 = MULTIPLY(d1, FIX_1_175875602); |
| tmp3 = MULTIPLY(d1, FIX_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 */ |
| } |
| } |
| |
| #undef DCTSIZE |
| #define DCTSIZE 4 |
| #define DCTSTRIDE 8 |
| |
| void j_rev_dct4(DCTBLOCK data) |
| { |
| int32_t tmp0, tmp1, tmp2, tmp3; |
| int32_t tmp10, tmp11, tmp12, tmp13; |
| int32_t z1; |
| int32_t d0, d2, d4, d6; |
| register DCTELEM *dataptr; |
| int rowctr; |
| |
| /* 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. */ |
| |
| data[0] += 4; |
| |
| 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]; |
| d2 = dataptr[1]; |
| d4 = dataptr[2]; |
| d6 = dataptr[3]; |
| |
| if ((d2 | d4 | d6) == 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) & 0xffff0000); |
| |
| idataptr[0] = v; |
| idataptr[1] = v; |
| } |
| |
| dataptr += DCTSTRIDE; /* advance pointer to next row */ |
| continue; |
| } |
| |
| /* Even part: reverse the even part of the forward DCT. */ |
| /* The rotator is sqrt(2)*c(-6). */ |
| if (d6) { |
| if (d2) { |
| /* 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 */ |
| tmp2 = MULTIPLY(-d6, FIX_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 { |
| if (d2) { |
| /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ |
| tmp2 = MULTIPLY(d2, FIX_0_541196100); |
| tmp3 = MULTIPLY(d2, FIX_1_306562965); |
| |
| 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 */ |
| tmp10 = tmp13 = (d0 + d4) << CONST_BITS; |
| tmp11 = tmp12 = (d0 - d4) << CONST_BITS; |
| } |
| } |
| |
| /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ |
| |
| dataptr[0] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS); |
| dataptr[1] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS); |
| dataptr[2] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS); |
| dataptr[3] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS); |
| |
| dataptr += DCTSTRIDE; /* 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[DCTSTRIDE*0]; |
| d2 = dataptr[DCTSTRIDE*1]; |
| d4 = dataptr[DCTSTRIDE*2]; |
| d6 = dataptr[DCTSTRIDE*3]; |
| |
| /* Even part: reverse the even part of the forward DCT. */ |
| /* The rotator is sqrt(2)*c(-6). */ |
| if (d6) { |
| if (d2) { |
| /* 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 */ |
| tmp2 = MULTIPLY(-d6, FIX_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 { |
| if (d2) { |
| /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */ |
| tmp2 = MULTIPLY(d2, FIX_0_541196100); |
| tmp3 = MULTIPLY(d2, FIX_1_306562965); |
| |
| 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 */ |
| tmp10 = tmp13 = (d0 + d4) << CONST_BITS; |
| tmp11 = tmp12 = (d0 - d4) << CONST_BITS; |
| } |
| } |
| |
| /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */ |
| |
| dataptr[DCTSTRIDE*0] = tmp10 >> (CONST_BITS+PASS1_BITS+3); |
| dataptr[DCTSTRIDE*1] = tmp11 >> (CONST_BITS+PASS1_BITS+3); |
| dataptr[DCTSTRIDE*2] = tmp12 >> (CONST_BITS+PASS1_BITS+3); |
| dataptr[DCTSTRIDE*3] = tmp13 >> (CONST_BITS+PASS1_BITS+3); |
| |
| dataptr++; /* advance pointer to next column */ |
| } |
| } |
| |
| void j_rev_dct2(DCTBLOCK data){ |
| int d00, d01, d10, d11; |
| |
| data[0] += 4; |
| d00 = data[0+0*DCTSTRIDE] + data[1+0*DCTSTRIDE]; |
| d01 = data[0+0*DCTSTRIDE] - data[1+0*DCTSTRIDE]; |
| d10 = data[0+1*DCTSTRIDE] + data[1+1*DCTSTRIDE]; |
| d11 = data[0+1*DCTSTRIDE] - data[1+1*DCTSTRIDE]; |
| |
| data[0+0*DCTSTRIDE]= (d00 + d10)>>3; |
| data[1+0*DCTSTRIDE]= (d01 + d11)>>3; |
| data[0+1*DCTSTRIDE]= (d00 - d10)>>3; |
| data[1+1*DCTSTRIDE]= (d01 - d11)>>3; |
| } |
| |
| void j_rev_dct1(DCTBLOCK data){ |
| data[0] = (data[0] + 4)>>3; |
| } |
| |
| #undef FIX |
| #undef CONST_BITS |
