root/jfdctint.c
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DEFINITIONS
This source file includes following definitions.
- jpeg_fdct_islow
- jpeg_fdct_7x7
- jpeg_fdct_6x6
- jpeg_fdct_5x5
- jpeg_fdct_4x4
- jpeg_fdct_3x3
- jpeg_fdct_2x2
- jpeg_fdct_1x1
- jpeg_fdct_9x9
- jpeg_fdct_10x10
- jpeg_fdct_11x11
- jpeg_fdct_12x12
- jpeg_fdct_13x13
- jpeg_fdct_14x14
- jpeg_fdct_15x15
- jpeg_fdct_16x16
- jpeg_fdct_16x8
- jpeg_fdct_14x7
- jpeg_fdct_12x6
- jpeg_fdct_10x5
- jpeg_fdct_8x4
- jpeg_fdct_6x3
- jpeg_fdct_4x2
- jpeg_fdct_2x1
- jpeg_fdct_8x16
- jpeg_fdct_7x14
- jpeg_fdct_6x12
- jpeg_fdct_5x10
- jpeg_fdct_4x8
- jpeg_fdct_3x6
- jpeg_fdct_2x4
- jpeg_fdct_1x2
/*
* jfdctint.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* Modification developed 2003-2009 by Guido Vollbeding.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a slow-but-accurate integer implementation of the
* forward DCT (Discrete Cosine Transform).
*
* A 2-D DCT can be done by 1-D DCT on each row followed by 1-D DCT
* 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.
*
* 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.
*
* We also provide FDCT routines with various input sample block sizes for
* direct resolution reduction or enlargement and for direct resolving the
* common 2x1 and 1x2 subsampling cases without additional resampling: NxN
* (N=1...16), 2NxN, and Nx2N (N=1...8) pixels for one 8x8 output DCT block.
*
* For N<8 we fill the remaining block coefficients with zero.
* For N>8 we apply a partial N-point FDCT on the input samples, computing
* just the lower 8 frequency coefficients and discarding the rest.
*
* We must scale the output coefficients of the N-point FDCT appropriately
* to the standard 8-point FDCT level by 8/N per 1-D pass. This scaling
* is folded into the constant multipliers (pass 2) and/or final/initial
* shifting.
*
* CAUTION: We rely on the FIX() macro except for the N=1,2,4,8 cases
* since there would be too many additional constants to pre-calculate.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jdct.h" /* Private declarations for DCT subsystem */
#ifdef DCT_ISLOW_SUPPORTED
/*
* This module is specialized to the case DCTSIZE = 8.
*/
#if DCTSIZE != 8
Sorry, this code only copes with 8x8 DCT blocks. /* deliberate syntax err */
#endif
/*
* The poop on this scaling stuff is as follows:
*
* Each 1-D DCT step produces outputs which are a factor of sqrt(N)
* larger than the true DCT 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 DCT,
* because the y0 and y4 outputs need not be divided by sqrt(N).
* In the IJG code, this factor of 8 is removed by the quantization step
* (in jcdctmgr.c), NOT in this module.
*
* 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. (For 12-bit sample data, the intermediate
* array is INT32 anyway.)
*
* 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.
*/
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 13
#define PASS1_BITS 2
#else
#define CONST_BITS 13
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
#if CONST_BITS == 13
#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
#define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */
#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */
#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */
#define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */
#define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */
#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */
#define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */
#define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */
#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */
#define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */
#else
#define FIX_0_298631336 FIX(0.298631336)
#define FIX_0_390180644 FIX(0.390180644)
#define FIX_0_541196100 FIX(0.541196100)
#define FIX_0_765366865 FIX(0.765366865)
#define FIX_0_899976223 FIX(0.899976223)
#define FIX_1_175875602 FIX(1.175875602)
#define FIX_1_501321110 FIX(1.501321110)
#define FIX_1_847759065 FIX(1.847759065)
#define FIX_1_961570560 FIX(1.961570560)
#define FIX_2_053119869 FIX(2.053119869)
#define FIX_2_562915447 FIX(2.562915447)
#define FIX_3_072711026 FIX(3.072711026)
#endif
/* 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.
* For 12-bit samples, a full 32-bit multiplication will be needed.
*/
#if BITS_IN_JSAMPLE == 8
#define MULTIPLY(var,const) MULTIPLY16C16(var,const)
#else
#define MULTIPLY(var,const) ((var) * (const))
#endif
/*
* Perform the forward DCT on one block of samples.
*/
void
jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
INT32 tmp10, tmp11, tmp12, tmp13;
INT32 z1;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
dataptr = data;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
tmp10 = tmp0 + tmp3;
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-1);
dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
CONST_BITS-PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-1);
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM)
RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM)
RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM)
RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
/* Add fudge factor here for final descale. */
tmp10 = tmp0 + tmp3 + (ONE << (PASS1_BITS-1));
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
dataptr[DCTSIZE*2] = (DCTELEM)
RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[DCTSIZE*1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM)
RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*7] = (DCTELEM)
RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
#ifdef DCT_SCALING_SUPPORTED
/*
* Perform the forward DCT on a 7x7 sample block.
*/
void
jpeg_fdct_7x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
INT32 tmp10, tmp11, tmp12;
INT32 z1, z2, z3;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* cK represents sqrt(2) * cos(K*pi/14). */
dataptr = data;
for (ctr = 0; ctr < 7; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[6]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[5]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[4]);
tmp3 = GETJSAMPLE(elemptr[3]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[6]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[5]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[4]);
z1 = tmp0 + tmp2;
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((z1 + tmp1 + tmp3 - 7 * CENTERJSAMPLE) << PASS1_BITS);
tmp3 += tmp3;
z1 -= tmp3;
z1 -= tmp3;
z1 = MULTIPLY(z1, FIX(0.353553391)); /* (c2+c6-c4)/2 */
z2 = MULTIPLY(tmp0 - tmp2, FIX(0.920609002)); /* (c2+c4-c6)/2 */
z3 = MULTIPLY(tmp1 - tmp2, FIX(0.314692123)); /* c6 */
dataptr[2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS-PASS1_BITS);
z1 -= z2;
z2 = MULTIPLY(tmp0 - tmp1, FIX(0.881747734)); /* c4 */
dataptr[4] = (DCTELEM)
DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.707106781)), /* c2+c6-c4 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS-PASS1_BITS);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(0.935414347)); /* (c3+c1-c5)/2 */
tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.170262339)); /* (c3+c5-c1)/2 */
tmp0 = tmp1 - tmp2;
tmp1 += tmp2;
tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.378756276)); /* -c1 */
tmp1 += tmp2;
tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.613604268)); /* c5 */
tmp0 += tmp3;
tmp2 += tmp3 + MULTIPLY(tmp12, FIX(1.870828693)); /* c3+c1-c5 */
dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/7)**2 = 64/49, which we fold
* into the constant multipliers:
* cK now represents sqrt(2) * cos(K*pi/14) * 64/49.
*/
dataptr = data;
for (ctr = 0; ctr < 7; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*6];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*5];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*4];
tmp3 = dataptr[DCTSIZE*3];
tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*6];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*5];
tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*4];
z1 = tmp0 + tmp2;
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(z1 + tmp1 + tmp3, FIX(1.306122449)), /* 64/49 */
CONST_BITS+PASS1_BITS);
tmp3 += tmp3;
z1 -= tmp3;
z1 -= tmp3;
z1 = MULTIPLY(z1, FIX(0.461784020)); /* (c2+c6-c4)/2 */
z2 = MULTIPLY(tmp0 - tmp2, FIX(1.202428084)); /* (c2+c4-c6)/2 */
z3 = MULTIPLY(tmp1 - tmp2, FIX(0.411026446)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS+PASS1_BITS);
z1 -= z2;
z2 = MULTIPLY(tmp0 - tmp1, FIX(1.151670509)); /* c4 */
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.923568041)), /* c2+c6-c4 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+PASS1_BITS);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.221765677)); /* (c3+c1-c5)/2 */
tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.222383464)); /* (c3+c5-c1)/2 */
tmp0 = tmp1 - tmp2;
tmp1 += tmp2;
tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.800824523)); /* -c1 */
tmp1 += tmp2;
tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.801442310)); /* c5 */
tmp0 += tmp3;
tmp2 += tmp3 + MULTIPLY(tmp12, FIX(2.443531355)); /* c3+c1-c5 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 6x6 sample block.
*/
void
jpeg_fdct_6x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2;
INT32 tmp10, tmp11, tmp12;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* cK represents sqrt(2) * cos(K*pi/12). */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
CONST_BITS-PASS1_BITS);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
CONST_BITS-PASS1_BITS);
dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << PASS1_BITS));
dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << PASS1_BITS);
dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << PASS1_BITS));
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/6)**2 = 16/9, which we fold
* into the constant multipliers:
* cK now represents sqrt(2) * cos(K*pi/12) * 16/9.
*/
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 5x5 sample block.
*/
void
jpeg_fdct_5x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2;
INT32 tmp10, tmp11;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* cK represents sqrt(2) * cos(K*pi/10). */
dataptr = data;
for (ctr = 0; ctr < 5; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[4]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[3]);
tmp2 = GETJSAMPLE(elemptr[2]);
tmp10 = tmp0 + tmp1;
tmp11 = tmp0 - tmp1;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[4]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[3]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp2 - 5 * CENTERJSAMPLE) << (PASS1_BITS+1));
tmp11 = MULTIPLY(tmp11, FIX(0.790569415)); /* (c2+c4)/2 */
tmp10 -= tmp2 << 2;
tmp10 = MULTIPLY(tmp10, FIX(0.353553391)); /* (c2-c4)/2 */
dataptr[2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS-PASS1_BITS-1);
dataptr[4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS-PASS1_BITS-1);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp1, FIX(0.831253876)); /* c3 */
dataptr[1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.513743148)), /* c1-c3 */
CONST_BITS-PASS1_BITS-1);
dataptr[3] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.176250899)), /* c1+c3 */
CONST_BITS-PASS1_BITS-1);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/5)**2 = 64/25, which we partially
* fold into the constant multipliers (other part was done in pass 1):
* cK now represents sqrt(2) * cos(K*pi/10) * 32/25.
*/
dataptr = data;
for (ctr = 0; ctr < 5; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*4];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*3];
tmp2 = dataptr[DCTSIZE*2];
tmp10 = tmp0 + tmp1;
tmp11 = tmp0 - tmp1;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*4];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*3];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp2, FIX(1.28)), /* 32/25 */
CONST_BITS+PASS1_BITS);
tmp11 = MULTIPLY(tmp11, FIX(1.011928851)); /* (c2+c4)/2 */
tmp10 -= tmp2 << 2;
tmp10 = MULTIPLY(tmp10, FIX(0.452548340)); /* (c2-c4)/2 */
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp1, FIX(1.064004961)); /* c3 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.657591230)), /* c1-c3 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.785601151)), /* c1+c3 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 4x4 sample block.
*/
void
jpeg_fdct_4x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1;
INT32 tmp10, tmp11;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We must also scale the output by (8/4)**2 = 2**2, which we add here. */
/* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+2));
dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+2));
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS-PASS1_BITS-3);
dataptr[1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS-PASS1_BITS-2);
dataptr[3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS-PASS1_BITS-2);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
*/
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
/* Even part */
/* Add fudge factor here for final descale. */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3] + (ONE << (PASS1_BITS-1));
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS+PASS1_BITS-1);
dataptr[DCTSIZE*1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 3x3 sample block.
*/
void
jpeg_fdct_3x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We scale the results further by 2**2 as part of output adaption */
/* scaling for different DCT size. */
/* cK represents sqrt(2) * cos(K*pi/6). */
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[2]);
tmp1 = GETJSAMPLE(elemptr[1]);
tmp2 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[2]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 - 3 * CENTERJSAMPLE) << (PASS1_BITS+2));
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(0.707106781)), /* c2 */
CONST_BITS-PASS1_BITS-2);
/* Odd part */
dataptr[1] = (DCTELEM)
DESCALE(MULTIPLY(tmp2, FIX(1.224744871)), /* c1 */
CONST_BITS-PASS1_BITS-2);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/3)**2 = 64/9, which we partially
* fold into the constant multipliers (other part was done in pass 1):
* cK now represents sqrt(2) * cos(K*pi/6) * 16/9.
*/
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*2];
tmp1 = dataptr[DCTSIZE*1];
tmp2 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*2];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(1.257078722)), /* c2 */
CONST_BITS+PASS1_BITS);
/* Odd part */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(MULTIPLY(tmp2, FIX(2.177324216)), /* c1 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 2x2 sample block.
*/
void
jpeg_fdct_2x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
JSAMPROW elemptr;
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* Row 0 */
elemptr = sample_data[0] + start_col;
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[1]);
tmp1 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[1]);
/* Row 1 */
elemptr = sample_data[1] + start_col;
tmp2 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[1]);
tmp3 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[1]);
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/2)**2 = 2**4.
*/
/* Column 0 */
/* Apply unsigned->signed conversion */
data[DCTSIZE*0] = (DCTELEM) ((tmp0 + tmp2 - 4 * CENTERJSAMPLE) << 4);
data[DCTSIZE*1] = (DCTELEM) ((tmp0 - tmp2) << 4);
/* Column 1 */
data[DCTSIZE*0+1] = (DCTELEM) ((tmp1 + tmp3) << 4);
data[DCTSIZE*1+1] = (DCTELEM) ((tmp1 - tmp3) << 4);
}
/*
* Perform the forward DCT on a 1x1 sample block.
*/
void
jpeg_fdct_1x1 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* We leave the result scaled up by an overall factor of 8. */
/* We must also scale the output by (8/1)**2 = 2**6. */
/* Apply unsigned->signed conversion */
data[0] = (DCTELEM)
((GETJSAMPLE(sample_data[0][start_col]) - CENTERJSAMPLE) << 6);
}
/*
* Perform the forward DCT on a 9x9 sample block.
*/
void
jpeg_fdct_9x9 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
INT32 tmp10, tmp11, tmp12, tmp13;
INT32 z1, z2;
DCTELEM workspace[8];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* we scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* cK represents sqrt(2) * cos(K*pi/18). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[8]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[7]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[6]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[5]);
tmp4 = GETJSAMPLE(elemptr[4]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[8]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[7]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[6]);
tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[5]);
z1 = tmp0 + tmp2 + tmp3;
z2 = tmp1 + tmp4;
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) ((z1 + z2 - 9 * CENTERJSAMPLE) << 1);
dataptr[6] = (DCTELEM)
DESCALE(MULTIPLY(z1 - z2 - z2, FIX(0.707106781)), /* c6 */
CONST_BITS-1);
z1 = MULTIPLY(tmp0 - tmp2, FIX(1.328926049)); /* c2 */
z2 = MULTIPLY(tmp1 - tmp4 - tmp4, FIX(0.707106781)); /* c6 */
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp2 - tmp3, FIX(1.083350441)) /* c4 */
+ z1 + z2, CONST_BITS-1);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp3 - tmp0, FIX(0.245575608)) /* c8 */
+ z1 - z2, CONST_BITS-1);
/* Odd part */
dataptr[3] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12 - tmp13, FIX(1.224744871)), /* c3 */
CONST_BITS-1);
tmp11 = MULTIPLY(tmp11, FIX(1.224744871)); /* c3 */
tmp0 = MULTIPLY(tmp10 + tmp12, FIX(0.909038955)); /* c5 */
tmp1 = MULTIPLY(tmp10 + tmp13, FIX(0.483689525)); /* c7 */
dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp0 + tmp1, CONST_BITS-1);
tmp2 = MULTIPLY(tmp12 - tmp13, FIX(1.392728481)); /* c1 */
dataptr[5] = (DCTELEM) DESCALE(tmp0 - tmp11 - tmp2, CONST_BITS-1);
dataptr[7] = (DCTELEM) DESCALE(tmp1 - tmp11 + tmp2, CONST_BITS-1);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 9)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/9)**2 = 64/81, which we partially
* fold into the constant multipliers and final/initial shifting:
* cK now represents sqrt(2) * cos(K*pi/18) * 128/81.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*0];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*7];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*6];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*5];
tmp4 = dataptr[DCTSIZE*4];
tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*0];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*7];
tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*6];
tmp13 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*5];
z1 = tmp0 + tmp2 + tmp3;
z2 = tmp1 + tmp4;
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(z1 + z2, FIX(1.580246914)), /* 128/81 */
CONST_BITS+2);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(MULTIPLY(z1 - z2 - z2, FIX(1.117403309)), /* c6 */
CONST_BITS+2);
z1 = MULTIPLY(tmp0 - tmp2, FIX(2.100031287)); /* c2 */
z2 = MULTIPLY(tmp1 - tmp4 - tmp4, FIX(1.117403309)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp2 - tmp3, FIX(1.711961190)) /* c4 */
+ z1 + z2, CONST_BITS+2);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp3 - tmp0, FIX(0.388070096)) /* c8 */
+ z1 - z2, CONST_BITS+2);
/* Odd part */
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12 - tmp13, FIX(1.935399303)), /* c3 */
CONST_BITS+2);
tmp11 = MULTIPLY(tmp11, FIX(1.935399303)); /* c3 */
tmp0 = MULTIPLY(tmp10 + tmp12, FIX(1.436506004)); /* c5 */
tmp1 = MULTIPLY(tmp10 + tmp13, FIX(0.764348879)); /* c7 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp11 + tmp0 + tmp1, CONST_BITS+2);
tmp2 = MULTIPLY(tmp12 - tmp13, FIX(2.200854883)); /* c1 */
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp0 - tmp11 - tmp2, CONST_BITS+2);
dataptr[DCTSIZE*7] = (DCTELEM)
DESCALE(tmp1 - tmp11 + tmp2, CONST_BITS+2);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 10x10 sample block.
*/
void
jpeg_fdct_10x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
DCTELEM workspace[8*2];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* we scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* cK represents sqrt(2) * cos(K*pi/20). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[9]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[8]);
tmp12 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[7]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[6]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[5]);
tmp10 = tmp0 + tmp4;
tmp13 = tmp0 - tmp4;
tmp11 = tmp1 + tmp3;
tmp14 = tmp1 - tmp3;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[9]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[8]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[7]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[6]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[5]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 - 10 * CENTERJSAMPLE) << 1);
tmp12 += tmp12;
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.144122806)) - /* c4 */
MULTIPLY(tmp11 - tmp12, FIX(0.437016024)), /* c8 */
CONST_BITS-1);
tmp10 = MULTIPLY(tmp13 + tmp14, FIX(0.831253876)); /* c6 */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.513743148)), /* c2-c6 */
CONST_BITS-1);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.176250899)), /* c2+c6 */
CONST_BITS-1);
/* Odd part */
tmp10 = tmp0 + tmp4;
tmp11 = tmp1 - tmp3;
dataptr[5] = (DCTELEM) ((tmp10 - tmp11 - tmp2) << 1);
tmp2 <<= CONST_BITS;
dataptr[1] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.396802247)) + /* c1 */
MULTIPLY(tmp1, FIX(1.260073511)) + tmp2 + /* c3 */
MULTIPLY(tmp3, FIX(0.642039522)) + /* c7 */
MULTIPLY(tmp4, FIX(0.221231742)), /* c9 */
CONST_BITS-1);
tmp12 = MULTIPLY(tmp0 - tmp4, FIX(0.951056516)) - /* (c3+c7)/2 */
MULTIPLY(tmp1 + tmp3, FIX(0.587785252)); /* (c1-c9)/2 */
tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.309016994)) + /* (c3-c7)/2 */
(tmp11 << (CONST_BITS - 1)) - tmp2;
dataptr[3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS-1);
dataptr[7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS-1);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 10)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/10)**2 = 16/25, which we partially
* fold into the constant multipliers and final/initial shifting:
* cK now represents sqrt(2) * cos(K*pi/20) * 32/25.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*1];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*0];
tmp12 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*7];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*6];
tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
tmp10 = tmp0 + tmp4;
tmp13 = tmp0 - tmp4;
tmp11 = tmp1 + tmp3;
tmp14 = tmp1 - tmp3;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*1];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*0];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*7];
tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*6];
tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(1.28)), /* 32/25 */
CONST_BITS+2);
tmp12 += tmp12;
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.464477191)) - /* c4 */
MULTIPLY(tmp11 - tmp12, FIX(0.559380511)), /* c8 */
CONST_BITS+2);
tmp10 = MULTIPLY(tmp13 + tmp14, FIX(1.064004961)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.657591230)), /* c2-c6 */
CONST_BITS+2);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.785601151)), /* c2+c6 */
CONST_BITS+2);
/* Odd part */
tmp10 = tmp0 + tmp4;
tmp11 = tmp1 - tmp3;
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp2, FIX(1.28)), /* 32/25 */
CONST_BITS+2);
tmp2 = MULTIPLY(tmp2, FIX(1.28)); /* 32/25 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.787906876)) + /* c1 */
MULTIPLY(tmp1, FIX(1.612894094)) + tmp2 + /* c3 */
MULTIPLY(tmp3, FIX(0.821810588)) + /* c7 */
MULTIPLY(tmp4, FIX(0.283176630)), /* c9 */
CONST_BITS+2);
tmp12 = MULTIPLY(tmp0 - tmp4, FIX(1.217352341)) - /* (c3+c7)/2 */
MULTIPLY(tmp1 + tmp3, FIX(0.752365123)); /* (c1-c9)/2 */
tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.395541753)) + /* (c3-c7)/2 */
MULTIPLY(tmp11, FIX(0.64)) - tmp2; /* 16/25 */
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS+2);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS+2);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on an 11x11 sample block.
*/
void
jpeg_fdct_11x11 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
INT32 z1, z2, z3;
DCTELEM workspace[8*3];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* we scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* cK represents sqrt(2) * cos(K*pi/22). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[10]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[9]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[8]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[7]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[6]);
tmp5 = GETJSAMPLE(elemptr[5]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[10]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[9]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[8]);
tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[7]);
tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[6]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 - 11 * CENTERJSAMPLE) << 1);
tmp5 += tmp5;
tmp0 -= tmp5;
tmp1 -= tmp5;
tmp2 -= tmp5;
tmp3 -= tmp5;
tmp4 -= tmp5;
z1 = MULTIPLY(tmp0 + tmp3, FIX(1.356927976)) + /* c2 */
MULTIPLY(tmp2 + tmp4, FIX(0.201263574)); /* c10 */
z2 = MULTIPLY(tmp1 - tmp3, FIX(0.926112931)); /* c6 */
z3 = MULTIPLY(tmp0 - tmp1, FIX(1.189712156)); /* c4 */
dataptr[2] = (DCTELEM)
DESCALE(z1 + z2 - MULTIPLY(tmp3, FIX(1.018300590)) /* c2+c8-c6 */
- MULTIPLY(tmp4, FIX(1.390975730)), /* c4+c10 */
CONST_BITS-1);
dataptr[4] = (DCTELEM)
DESCALE(z2 + z3 + MULTIPLY(tmp1, FIX(0.062335650)) /* c4-c6-c10 */
- MULTIPLY(tmp2, FIX(1.356927976)) /* c2 */
+ MULTIPLY(tmp4, FIX(0.587485545)), /* c8 */
CONST_BITS-1);
dataptr[6] = (DCTELEM)
DESCALE(z1 + z3 - MULTIPLY(tmp0, FIX(1.620527200)) /* c2+c4-c6 */
- MULTIPLY(tmp2, FIX(0.788749120)), /* c8+c10 */
CONST_BITS-1);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.286413905)); /* c3 */
tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.068791298)); /* c5 */
tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.764581576)); /* c7 */
tmp0 = tmp1 + tmp2 + tmp3 - MULTIPLY(tmp10, FIX(1.719967871)) /* c7+c5+c3-c1 */
+ MULTIPLY(tmp14, FIX(0.398430003)); /* c9 */
tmp4 = MULTIPLY(tmp11 + tmp12, - FIX(0.764581576)); /* -c7 */
tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.399818907)); /* -c1 */
tmp1 += tmp4 + tmp5 + MULTIPLY(tmp11, FIX(1.276416582)) /* c9+c7+c1-c3 */
- MULTIPLY(tmp14, FIX(1.068791298)); /* c5 */
tmp10 = MULTIPLY(tmp12 + tmp13, FIX(0.398430003)); /* c9 */
tmp2 += tmp4 + tmp10 - MULTIPLY(tmp12, FIX(1.989053629)) /* c9+c5+c3-c7 */
+ MULTIPLY(tmp14, FIX(1.399818907)); /* c1 */
tmp3 += tmp5 + tmp10 + MULTIPLY(tmp13, FIX(1.305598626)) /* c1+c5-c9-c7 */
- MULTIPLY(tmp14, FIX(1.286413905)); /* c3 */
dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-1);
dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-1);
dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-1);
dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS-1);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 11)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/11)**2 = 64/121, which we partially
* fold into the constant multipliers and final/initial shifting:
* cK now represents sqrt(2) * cos(K*pi/22) * 128/121.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*2];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*1];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*0];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*7];
tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*6];
tmp5 = dataptr[DCTSIZE*5];
tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*2];
tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*1];
tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*0];
tmp13 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*7];
tmp14 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*6];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5,
FIX(1.057851240)), /* 128/121 */
CONST_BITS+2);
tmp5 += tmp5;
tmp0 -= tmp5;
tmp1 -= tmp5;
tmp2 -= tmp5;
tmp3 -= tmp5;
tmp4 -= tmp5;
z1 = MULTIPLY(tmp0 + tmp3, FIX(1.435427942)) + /* c2 */
MULTIPLY(tmp2 + tmp4, FIX(0.212906922)); /* c10 */
z2 = MULTIPLY(tmp1 - tmp3, FIX(0.979689713)); /* c6 */
z3 = MULTIPLY(tmp0 - tmp1, FIX(1.258538479)); /* c4 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(z1 + z2 - MULTIPLY(tmp3, FIX(1.077210542)) /* c2+c8-c6 */
- MULTIPLY(tmp4, FIX(1.471445400)), /* c4+c10 */
CONST_BITS+2);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(z2 + z3 + MULTIPLY(tmp1, FIX(0.065941844)) /* c4-c6-c10 */
- MULTIPLY(tmp2, FIX(1.435427942)) /* c2 */
+ MULTIPLY(tmp4, FIX(0.621472312)), /* c8 */
CONST_BITS+2);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(z1 + z3 - MULTIPLY(tmp0, FIX(1.714276708)) /* c2+c4-c6 */
- MULTIPLY(tmp2, FIX(0.834379234)), /* c8+c10 */
CONST_BITS+2);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.360834544)); /* c3 */
tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.130622199)); /* c5 */
tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.808813568)); /* c7 */
tmp0 = tmp1 + tmp2 + tmp3 - MULTIPLY(tmp10, FIX(1.819470145)) /* c7+c5+c3-c1 */
+ MULTIPLY(tmp14, FIX(0.421479672)); /* c9 */
tmp4 = MULTIPLY(tmp11 + tmp12, - FIX(0.808813568)); /* -c7 */
tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.480800167)); /* -c1 */
tmp1 += tmp4 + tmp5 + MULTIPLY(tmp11, FIX(1.350258864)) /* c9+c7+c1-c3 */
- MULTIPLY(tmp14, FIX(1.130622199)); /* c5 */
tmp10 = MULTIPLY(tmp12 + tmp13, FIX(0.421479672)); /* c9 */
tmp2 += tmp4 + tmp10 - MULTIPLY(tmp12, FIX(2.104122847)) /* c9+c5+c3-c7 */
+ MULTIPLY(tmp14, FIX(1.480800167)); /* c1 */
tmp3 += tmp5 + tmp10 + MULTIPLY(tmp13, FIX(1.381129125)) /* c1+c5-c9-c7 */
- MULTIPLY(tmp14, FIX(1.360834544)); /* c3 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+2);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+2);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+2);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+2);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 12x12 sample block.
*/
void
jpeg_fdct_12x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
DCTELEM workspace[8*4];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* cK represents sqrt(2) * cos(K*pi/24). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[11]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[10]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[9]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[8]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[7]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[6]);
tmp10 = tmp0 + tmp5;
tmp13 = tmp0 - tmp5;
tmp11 = tmp1 + tmp4;
tmp14 = tmp1 - tmp4;
tmp12 = tmp2 + tmp3;
tmp15 = tmp2 - tmp3;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[11]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[10]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[9]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[8]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[7]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[6]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) (tmp10 + tmp11 + tmp12 - 12 * CENTERJSAMPLE);
dataptr[6] = (DCTELEM) (tmp13 - tmp14 - tmp15);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.224744871)), /* c4 */
CONST_BITS);
dataptr[2] = (DCTELEM)
DESCALE(tmp14 - tmp15 + MULTIPLY(tmp13 + tmp15, FIX(1.366025404)), /* c2 */
CONST_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp1 + tmp4, FIX_0_541196100); /* c9 */
tmp14 = tmp10 + MULTIPLY(tmp1, FIX_0_765366865); /* c3-c9 */
tmp15 = tmp10 - MULTIPLY(tmp4, FIX_1_847759065); /* c3+c9 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.121971054)); /* c5 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.860918669)); /* c7 */
tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.580774953)) /* c5+c7-c1 */
+ MULTIPLY(tmp5, FIX(0.184591911)); /* c11 */
tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.184591911)); /* -c11 */
tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.339493912)) /* c1+c5-c11 */
+ MULTIPLY(tmp5, FIX(0.860918669)); /* c7 */
tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.725788011)) /* c1+c11-c7 */
- MULTIPLY(tmp5, FIX(1.121971054)); /* c5 */
tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.306562965)) /* c3 */
- MULTIPLY(tmp2 + tmp5, FIX_0_541196100); /* c9 */
dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 12)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/12)**2 = 4/9, which we partially
* fold into the constant multipliers and final shifting:
* cK now represents sqrt(2) * cos(K*pi/24) * 8/9.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*3];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*2];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*1];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*0];
tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*7];
tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*6];
tmp10 = tmp0 + tmp5;
tmp13 = tmp0 - tmp5;
tmp11 = tmp1 + tmp4;
tmp14 = tmp1 - tmp4;
tmp12 = tmp2 + tmp3;
tmp15 = tmp2 - tmp3;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*3];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*2];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*1];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*0];
tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*7];
tmp5 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*6];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(0.888888889)), /* 8/9 */
CONST_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(MULTIPLY(tmp13 - tmp14 - tmp15, FIX(0.888888889)), /* 8/9 */
CONST_BITS+1);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.088662108)), /* c4 */
CONST_BITS+1);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp14 - tmp15, FIX(0.888888889)) + /* 8/9 */
MULTIPLY(tmp13 + tmp15, FIX(1.214244803)), /* c2 */
CONST_BITS+1);
/* Odd part */
tmp10 = MULTIPLY(tmp1 + tmp4, FIX(0.481063200)); /* c9 */
tmp14 = tmp10 + MULTIPLY(tmp1, FIX(0.680326102)); /* c3-c9 */
tmp15 = tmp10 - MULTIPLY(tmp4, FIX(1.642452502)); /* c3+c9 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(0.997307603)); /* c5 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.765261039)); /* c7 */
tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.516244403)) /* c5+c7-c1 */
+ MULTIPLY(tmp5, FIX(0.164081699)); /* c11 */
tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.164081699)); /* -c11 */
tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.079550144)) /* c1+c5-c11 */
+ MULTIPLY(tmp5, FIX(0.765261039)); /* c7 */
tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.645144899)) /* c1+c11-c7 */
- MULTIPLY(tmp5, FIX(0.997307603)); /* c5 */
tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.161389302)) /* c3 */
- MULTIPLY(tmp2 + tmp5, FIX(0.481063200)); /* c9 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+1);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+1);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 13x13 sample block.
*/
void
jpeg_fdct_13x13 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
INT32 z1, z2;
DCTELEM workspace[8*5];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* cK represents sqrt(2) * cos(K*pi/26). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[12]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[11]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[10]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[9]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[8]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[7]);
tmp6 = GETJSAMPLE(elemptr[6]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[12]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[11]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[10]);
tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[9]);
tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[8]);
tmp15 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[7]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
(tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 + tmp6 - 13 * CENTERJSAMPLE);
tmp6 += tmp6;
tmp0 -= tmp6;
tmp1 -= tmp6;
tmp2 -= tmp6;
tmp3 -= tmp6;
tmp4 -= tmp6;
tmp5 -= tmp6;
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.373119086)) + /* c2 */
MULTIPLY(tmp1, FIX(1.058554052)) + /* c6 */
MULTIPLY(tmp2, FIX(0.501487041)) - /* c10 */
MULTIPLY(tmp3, FIX(0.170464608)) - /* c12 */
MULTIPLY(tmp4, FIX(0.803364869)) - /* c8 */
MULTIPLY(tmp5, FIX(1.252223920)), /* c4 */
CONST_BITS);
z1 = MULTIPLY(tmp0 - tmp2, FIX(1.155388986)) - /* (c4+c6)/2 */
MULTIPLY(tmp3 - tmp4, FIX(0.435816023)) - /* (c2-c10)/2 */
MULTIPLY(tmp1 - tmp5, FIX(0.316450131)); /* (c8-c12)/2 */
z2 = MULTIPLY(tmp0 + tmp2, FIX(0.096834934)) - /* (c4-c6)/2 */
MULTIPLY(tmp3 + tmp4, FIX(0.937303064)) + /* (c2+c10)/2 */
MULTIPLY(tmp1 + tmp5, FIX(0.486914739)); /* (c8+c12)/2 */
dataptr[4] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS);
dataptr[6] = (DCTELEM) DESCALE(z1 - z2, CONST_BITS);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.322312651)); /* c3 */
tmp2 = MULTIPLY(tmp10 + tmp12, FIX(1.163874945)); /* c5 */
tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.937797057)) + /* c7 */
MULTIPLY(tmp14 + tmp15, FIX(0.338443458)); /* c11 */
tmp0 = tmp1 + tmp2 + tmp3 -
MULTIPLY(tmp10, FIX(2.020082300)) + /* c3+c5+c7-c1 */
MULTIPLY(tmp14, FIX(0.318774355)); /* c9-c11 */
tmp4 = MULTIPLY(tmp14 - tmp15, FIX(0.937797057)) - /* c7 */
MULTIPLY(tmp11 + tmp12, FIX(0.338443458)); /* c11 */
tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(1.163874945)); /* -c5 */
tmp1 += tmp4 + tmp5 +
MULTIPLY(tmp11, FIX(0.837223564)) - /* c5+c9+c11-c3 */
MULTIPLY(tmp14, FIX(2.341699410)); /* c1+c7 */
tmp6 = MULTIPLY(tmp12 + tmp13, - FIX(0.657217813)); /* -c9 */
tmp2 += tmp4 + tmp6 -
MULTIPLY(tmp12, FIX(1.572116027)) + /* c1+c5-c9-c11 */
MULTIPLY(tmp15, FIX(2.260109708)); /* c3+c7 */
tmp3 += tmp5 + tmp6 +
MULTIPLY(tmp13, FIX(2.205608352)) - /* c3+c5+c9-c7 */
MULTIPLY(tmp15, FIX(1.742345811)); /* c1+c11 */
dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 13)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/13)**2 = 64/169, which we partially
* fold into the constant multipliers and final shifting:
* cK now represents sqrt(2) * cos(K*pi/26) * 128/169.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*4];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*3];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*2];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*1];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*0];
tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*7];
tmp6 = dataptr[DCTSIZE*6];
tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*4];
tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*3];
tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*2];
tmp13 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*1];
tmp14 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*0];
tmp15 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*7];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 + tmp1 + tmp2 + tmp3 + tmp4 + tmp5 + tmp6,
FIX(0.757396450)), /* 128/169 */
CONST_BITS+1);
tmp6 += tmp6;
tmp0 -= tmp6;
tmp1 -= tmp6;
tmp2 -= tmp6;
tmp3 -= tmp6;
tmp4 -= tmp6;
tmp5 -= tmp6;
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.039995521)) + /* c2 */
MULTIPLY(tmp1, FIX(0.801745081)) + /* c6 */
MULTIPLY(tmp2, FIX(0.379824504)) - /* c10 */
MULTIPLY(tmp3, FIX(0.129109289)) - /* c12 */
MULTIPLY(tmp4, FIX(0.608465700)) - /* c8 */
MULTIPLY(tmp5, FIX(0.948429952)), /* c4 */
CONST_BITS+1);
z1 = MULTIPLY(tmp0 - tmp2, FIX(0.875087516)) - /* (c4+c6)/2 */
MULTIPLY(tmp3 - tmp4, FIX(0.330085509)) - /* (c2-c10)/2 */
MULTIPLY(tmp1 - tmp5, FIX(0.239678205)); /* (c8-c12)/2 */
z2 = MULTIPLY(tmp0 + tmp2, FIX(0.073342435)) - /* (c4-c6)/2 */
MULTIPLY(tmp3 + tmp4, FIX(0.709910013)) + /* (c2+c10)/2 */
MULTIPLY(tmp1 + tmp5, FIX(0.368787494)); /* (c8+c12)/2 */
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 - z2, CONST_BITS+1);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.001514908)); /* c3 */
tmp2 = MULTIPLY(tmp10 + tmp12, FIX(0.881514751)); /* c5 */
tmp3 = MULTIPLY(tmp10 + tmp13, FIX(0.710284161)) + /* c7 */
MULTIPLY(tmp14 + tmp15, FIX(0.256335874)); /* c11 */
tmp0 = tmp1 + tmp2 + tmp3 -
MULTIPLY(tmp10, FIX(1.530003162)) + /* c3+c5+c7-c1 */
MULTIPLY(tmp14, FIX(0.241438564)); /* c9-c11 */
tmp4 = MULTIPLY(tmp14 - tmp15, FIX(0.710284161)) - /* c7 */
MULTIPLY(tmp11 + tmp12, FIX(0.256335874)); /* c11 */
tmp5 = MULTIPLY(tmp11 + tmp13, - FIX(0.881514751)); /* -c5 */
tmp1 += tmp4 + tmp5 +
MULTIPLY(tmp11, FIX(0.634110155)) - /* c5+c9+c11-c3 */
MULTIPLY(tmp14, FIX(1.773594819)); /* c1+c7 */
tmp6 = MULTIPLY(tmp12 + tmp13, - FIX(0.497774438)); /* -c9 */
tmp2 += tmp4 + tmp6 -
MULTIPLY(tmp12, FIX(1.190715098)) + /* c1+c5-c9-c11 */
MULTIPLY(tmp15, FIX(1.711799069)); /* c3+c7 */
tmp3 += tmp5 + tmp6 +
MULTIPLY(tmp13, FIX(1.670519935)) - /* c3+c5+c9-c7 */
MULTIPLY(tmp15, FIX(1.319646532)); /* c1+c11 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+1);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+1);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 14x14 sample block.
*/
void
jpeg_fdct_14x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
DCTELEM workspace[8*6];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* cK represents sqrt(2) * cos(K*pi/28). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[13]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[12]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[11]);
tmp13 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[10]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[9]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[8]);
tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[7]);
tmp10 = tmp0 + tmp6;
tmp14 = tmp0 - tmp6;
tmp11 = tmp1 + tmp5;
tmp15 = tmp1 - tmp5;
tmp12 = tmp2 + tmp4;
tmp16 = tmp2 - tmp4;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[13]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[12]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[11]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[10]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[9]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[8]);
tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[7]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
(tmp10 + tmp11 + tmp12 + tmp13 - 14 * CENTERJSAMPLE);
tmp13 += tmp13;
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.274162392)) + /* c4 */
MULTIPLY(tmp11 - tmp13, FIX(0.314692123)) - /* c12 */
MULTIPLY(tmp12 - tmp13, FIX(0.881747734)), /* c8 */
CONST_BITS);
tmp10 = MULTIPLY(tmp14 + tmp15, FIX(1.105676686)); /* c6 */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.273079590)) /* c2-c6 */
+ MULTIPLY(tmp16, FIX(0.613604268)), /* c10 */
CONST_BITS);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.719280954)) /* c6+c10 */
- MULTIPLY(tmp16, FIX(1.378756276)), /* c2 */
CONST_BITS);
/* Odd part */
tmp10 = tmp1 + tmp2;
tmp11 = tmp5 - tmp4;
dataptr[7] = (DCTELEM) (tmp0 - tmp10 + tmp3 - tmp11 - tmp6);
tmp3 <<= CONST_BITS;
tmp10 = MULTIPLY(tmp10, - FIX(0.158341681)); /* -c13 */
tmp11 = MULTIPLY(tmp11, FIX(1.405321284)); /* c1 */
tmp10 += tmp11 - tmp3;
tmp11 = MULTIPLY(tmp0 + tmp2, FIX(1.197448846)) + /* c5 */
MULTIPLY(tmp4 + tmp6, FIX(0.752406978)); /* c9 */
dataptr[5] = (DCTELEM)
DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(2.373959773)) /* c3+c5-c13 */
+ MULTIPLY(tmp4, FIX(1.119999435)), /* c1+c11-c9 */
CONST_BITS);
tmp12 = MULTIPLY(tmp0 + tmp1, FIX(1.334852607)) + /* c3 */
MULTIPLY(tmp5 - tmp6, FIX(0.467085129)); /* c11 */
dataptr[3] = (DCTELEM)
DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.424103948)) /* c3-c9-c13 */
- MULTIPLY(tmp5, FIX(3.069855259)), /* c1+c5+c11 */
CONST_BITS);
dataptr[1] = (DCTELEM)
DESCALE(tmp11 + tmp12 + tmp3 + tmp6 -
MULTIPLY(tmp0 + tmp6, FIX(1.126980169)), /* c3+c5-c1 */
CONST_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 14)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/14)**2 = 16/49, which we partially
* fold into the constant multipliers and final shifting:
* cK now represents sqrt(2) * cos(K*pi/28) * 32/49.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*3];
tmp13 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*2];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*1];
tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*0];
tmp6 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
tmp10 = tmp0 + tmp6;
tmp14 = tmp0 - tmp6;
tmp11 = tmp1 + tmp5;
tmp15 = tmp1 - tmp5;
tmp12 = tmp2 + tmp4;
tmp16 = tmp2 - tmp4;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*3];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*2];
tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*1];
tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*0];
tmp6 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12 + tmp13,
FIX(0.653061224)), /* 32/49 */
CONST_BITS+1);
tmp13 += tmp13;
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(0.832106052)) + /* c4 */
MULTIPLY(tmp11 - tmp13, FIX(0.205513223)) - /* c12 */
MULTIPLY(tmp12 - tmp13, FIX(0.575835255)), /* c8 */
CONST_BITS+1);
tmp10 = MULTIPLY(tmp14 + tmp15, FIX(0.722074570)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.178337691)) /* c2-c6 */
+ MULTIPLY(tmp16, FIX(0.400721155)), /* c10 */
CONST_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.122795725)) /* c6+c10 */
- MULTIPLY(tmp16, FIX(0.900412262)), /* c2 */
CONST_BITS+1);
/* Odd part */
tmp10 = tmp1 + tmp2;
tmp11 = tmp5 - tmp4;
dataptr[DCTSIZE*7] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp10 + tmp3 - tmp11 - tmp6,
FIX(0.653061224)), /* 32/49 */
CONST_BITS+1);
tmp3 = MULTIPLY(tmp3 , FIX(0.653061224)); /* 32/49 */
tmp10 = MULTIPLY(tmp10, - FIX(0.103406812)); /* -c13 */
tmp11 = MULTIPLY(tmp11, FIX(0.917760839)); /* c1 */
tmp10 += tmp11 - tmp3;
tmp11 = MULTIPLY(tmp0 + tmp2, FIX(0.782007410)) + /* c5 */
MULTIPLY(tmp4 + tmp6, FIX(0.491367823)); /* c9 */
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(1.550341076)) /* c3+c5-c13 */
+ MULTIPLY(tmp4, FIX(0.731428202)), /* c1+c11-c9 */
CONST_BITS+1);
tmp12 = MULTIPLY(tmp0 + tmp1, FIX(0.871740478)) + /* c3 */
MULTIPLY(tmp5 - tmp6, FIX(0.305035186)); /* c11 */
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.276965844)) /* c3-c9-c13 */
- MULTIPLY(tmp5, FIX(2.004803435)), /* c1+c5+c11 */
CONST_BITS+1);
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp11 + tmp12 + tmp3
- MULTIPLY(tmp0, FIX(0.735987049)) /* c3+c5-c1 */
- MULTIPLY(tmp6, FIX(0.082925825)), /* c9-c11-c13 */
CONST_BITS+1);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 15x15 sample block.
*/
void
jpeg_fdct_15x15 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
INT32 z1, z2, z3;
DCTELEM workspace[8*7];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* cK represents sqrt(2) * cos(K*pi/30). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[14]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[13]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[12]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[11]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[10]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[9]);
tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[8]);
tmp7 = GETJSAMPLE(elemptr[7]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[14]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[13]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[12]);
tmp13 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[11]);
tmp14 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[10]);
tmp15 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[9]);
tmp16 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[8]);
z1 = tmp0 + tmp4 + tmp5;
z2 = tmp1 + tmp3 + tmp6;
z3 = tmp2 + tmp7;
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) (z1 + z2 + z3 - 15 * CENTERJSAMPLE);
z3 += z3;
dataptr[6] = (DCTELEM)
DESCALE(MULTIPLY(z1 - z3, FIX(1.144122806)) - /* c6 */
MULTIPLY(z2 - z3, FIX(0.437016024)), /* c12 */
CONST_BITS);
tmp2 += ((tmp1 + tmp4) >> 1) - tmp7 - tmp7;
z1 = MULTIPLY(tmp3 - tmp2, FIX(1.531135173)) - /* c2+c14 */
MULTIPLY(tmp6 - tmp2, FIX(2.238241955)); /* c4+c8 */
z2 = MULTIPLY(tmp5 - tmp2, FIX(0.798468008)) - /* c8-c14 */
MULTIPLY(tmp0 - tmp2, FIX(0.091361227)); /* c2-c4 */
z3 = MULTIPLY(tmp0 - tmp3, FIX(1.383309603)) + /* c2 */
MULTIPLY(tmp6 - tmp5, FIX(0.946293579)) + /* c8 */
MULTIPLY(tmp1 - tmp4, FIX(0.790569415)); /* (c6+c12)/2 */
dataptr[2] = (DCTELEM) DESCALE(z1 + z3, CONST_BITS);
dataptr[4] = (DCTELEM) DESCALE(z2 + z3, CONST_BITS);
/* Odd part */
tmp2 = MULTIPLY(tmp10 - tmp12 - tmp13 + tmp15 + tmp16,
FIX(1.224744871)); /* c5 */
tmp1 = MULTIPLY(tmp10 - tmp14 - tmp15, FIX(1.344997024)) + /* c3 */
MULTIPLY(tmp11 - tmp13 - tmp16, FIX(0.831253876)); /* c9 */
tmp12 = MULTIPLY(tmp12, FIX(1.224744871)); /* c5 */
tmp4 = MULTIPLY(tmp10 - tmp16, FIX(1.406466353)) + /* c1 */
MULTIPLY(tmp11 + tmp14, FIX(1.344997024)) + /* c3 */
MULTIPLY(tmp13 + tmp15, FIX(0.575212477)); /* c11 */
tmp0 = MULTIPLY(tmp13, FIX(0.475753014)) - /* c7-c11 */
MULTIPLY(tmp14, FIX(0.513743148)) + /* c3-c9 */
MULTIPLY(tmp16, FIX(1.700497885)) + tmp4 + tmp12; /* c1+c13 */
tmp3 = MULTIPLY(tmp10, - FIX(0.355500862)) - /* -(c1-c7) */
MULTIPLY(tmp11, FIX(2.176250899)) - /* c3+c9 */
MULTIPLY(tmp15, FIX(0.869244010)) + tmp4 - tmp12; /* c11+c13 */
dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 15)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/15)**2 = 64/225, which we partially
* fold into the constant multipliers and final shifting:
* cK now represents sqrt(2) * cos(K*pi/30) * 256/225.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*6];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*5];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*4];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*3];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*2];
tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*1];
tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*0];
tmp7 = dataptr[DCTSIZE*7];
tmp10 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*6];
tmp11 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*5];
tmp12 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*4];
tmp13 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*3];
tmp14 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*2];
tmp15 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*1];
tmp16 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*0];
z1 = tmp0 + tmp4 + tmp5;
z2 = tmp1 + tmp3 + tmp6;
z3 = tmp2 + tmp7;
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(z1 + z2 + z3, FIX(1.137777778)), /* 256/225 */
CONST_BITS+2);
z3 += z3;
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(MULTIPLY(z1 - z3, FIX(1.301757503)) - /* c6 */
MULTIPLY(z2 - z3, FIX(0.497227121)), /* c12 */
CONST_BITS+2);
tmp2 += ((tmp1 + tmp4) >> 1) - tmp7 - tmp7;
z1 = MULTIPLY(tmp3 - tmp2, FIX(1.742091575)) - /* c2+c14 */
MULTIPLY(tmp6 - tmp2, FIX(2.546621957)); /* c4+c8 */
z2 = MULTIPLY(tmp5 - tmp2, FIX(0.908479156)) - /* c8-c14 */
MULTIPLY(tmp0 - tmp2, FIX(0.103948774)); /* c2-c4 */
z3 = MULTIPLY(tmp0 - tmp3, FIX(1.573898926)) + /* c2 */
MULTIPLY(tmp6 - tmp5, FIX(1.076671805)) + /* c8 */
MULTIPLY(tmp1 - tmp4, FIX(0.899492312)); /* (c6+c12)/2 */
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z3, CONST_BITS+2);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(z2 + z3, CONST_BITS+2);
/* Odd part */
tmp2 = MULTIPLY(tmp10 - tmp12 - tmp13 + tmp15 + tmp16,
FIX(1.393487498)); /* c5 */
tmp1 = MULTIPLY(tmp10 - tmp14 - tmp15, FIX(1.530307725)) + /* c3 */
MULTIPLY(tmp11 - tmp13 - tmp16, FIX(0.945782187)); /* c9 */
tmp12 = MULTIPLY(tmp12, FIX(1.393487498)); /* c5 */
tmp4 = MULTIPLY(tmp10 - tmp16, FIX(1.600246161)) + /* c1 */
MULTIPLY(tmp11 + tmp14, FIX(1.530307725)) + /* c3 */
MULTIPLY(tmp13 + tmp15, FIX(0.654463974)); /* c11 */
tmp0 = MULTIPLY(tmp13, FIX(0.541301207)) - /* c7-c11 */
MULTIPLY(tmp14, FIX(0.584525538)) + /* c3-c9 */
MULTIPLY(tmp16, FIX(1.934788705)) + tmp4 + tmp12; /* c1+c13 */
tmp3 = MULTIPLY(tmp10, - FIX(0.404480980)) - /* -(c1-c7) */
MULTIPLY(tmp11, FIX(2.476089912)) - /* c3+c9 */
MULTIPLY(tmp15, FIX(0.989006518)) + tmp4 - tmp12; /* c11+c13 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+2);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+2);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+2);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+2);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 16x16 sample block.
*/
void
jpeg_fdct_16x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
DCTELEM workspace[DCTSIZE2];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* cK represents sqrt(2) * cos(K*pi/32). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[15]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[14]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[13]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[12]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[11]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[10]);
tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[9]);
tmp7 = GETJSAMPLE(elemptr[7]) + GETJSAMPLE(elemptr[8]);
tmp10 = tmp0 + tmp7;
tmp14 = tmp0 - tmp7;
tmp11 = tmp1 + tmp6;
tmp15 = tmp1 - tmp6;
tmp12 = tmp2 + tmp5;
tmp16 = tmp2 - tmp5;
tmp13 = tmp3 + tmp4;
tmp17 = tmp3 - tmp4;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[15]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[14]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[13]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[12]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[11]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[10]);
tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[9]);
tmp7 = GETJSAMPLE(elemptr[7]) - GETJSAMPLE(elemptr[8]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 + tmp13 - 16 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
CONST_BITS-PASS1_BITS);
tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
+ MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
- MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
tmp10 = tmp11 + tmp12 + tmp13 -
MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
- MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
+ MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
+ MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == DCTSIZE * 2)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/16)**2 = 1/2**2.
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*3];
tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*2];
tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*1];
tmp7 = dataptr[DCTSIZE*7] + wsptr[DCTSIZE*0];
tmp10 = tmp0 + tmp7;
tmp14 = tmp0 - tmp7;
tmp11 = tmp1 + tmp6;
tmp15 = tmp1 - tmp6;
tmp12 = tmp2 + tmp5;
tmp16 = tmp2 - tmp5;
tmp13 = tmp3 + tmp4;
tmp17 = tmp3 - tmp4;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*3];
tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*2];
tmp6 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*1];
tmp7 = dataptr[DCTSIZE*7] - wsptr[DCTSIZE*0];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(tmp10 + tmp11 + tmp12 + tmp13, PASS1_BITS+2);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
CONST_BITS+PASS1_BITS+2);
tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
+ MULTIPLY(tmp16, FIX(2.172734804)), /* c2+10 */
CONST_BITS+PASS1_BITS+2);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
- MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
CONST_BITS+PASS1_BITS+2);
/* Odd part */
tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
tmp10 = tmp11 + tmp12 + tmp13 -
MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
- MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
+ MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
+ MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS+2);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS+2);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS+2);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS+2);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 16x8 sample block.
*
* 16-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
*/
void
jpeg_fdct_16x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
INT32 z1;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32). */
dataptr = data;
ctr = 0;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[15]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[14]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[13]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[12]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[11]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[10]);
tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[9]);
tmp7 = GETJSAMPLE(elemptr[7]) + GETJSAMPLE(elemptr[8]);
tmp10 = tmp0 + tmp7;
tmp14 = tmp0 - tmp7;
tmp11 = tmp1 + tmp6;
tmp15 = tmp1 - tmp6;
tmp12 = tmp2 + tmp5;
tmp16 = tmp2 - tmp5;
tmp13 = tmp3 + tmp4;
tmp17 = tmp3 - tmp4;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[15]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[14]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[13]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[12]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[11]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[10]);
tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[9]);
tmp7 = GETJSAMPLE(elemptr[7]) - GETJSAMPLE(elemptr[8]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 + tmp13 - 16 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
CONST_BITS-PASS1_BITS);
tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
+ MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
- MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
tmp10 = tmp11 + tmp12 + tmp13 -
MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
- MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
+ MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
+ MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by 8/16 = 1/2.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
tmp10 = tmp0 + tmp3;
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS+1);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS+1);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
CONST_BITS+PASS1_BITS+1);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12,
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13,
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12,
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13,
CONST_BITS+PASS1_BITS+1);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 14x7 sample block.
*
* 14-point FDCT in pass 1 (rows), 7-point in pass 2 (columns).
*/
void
jpeg_fdct_14x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
INT32 z1, z2, z3;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Zero bottom row of output coefficient block. */
MEMZERO(&data[DCTSIZE*7], SIZEOF(DCTELEM) * DCTSIZE);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28). */
dataptr = data;
for (ctr = 0; ctr < 7; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[13]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[12]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[11]);
tmp13 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[10]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[9]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[8]);
tmp6 = GETJSAMPLE(elemptr[6]) + GETJSAMPLE(elemptr[7]);
tmp10 = tmp0 + tmp6;
tmp14 = tmp0 - tmp6;
tmp11 = tmp1 + tmp5;
tmp15 = tmp1 - tmp5;
tmp12 = tmp2 + tmp4;
tmp16 = tmp2 - tmp4;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[13]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[12]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[11]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[10]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[9]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[8]);
tmp6 = GETJSAMPLE(elemptr[6]) - GETJSAMPLE(elemptr[7]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 + tmp13 - 14 * CENTERJSAMPLE) << PASS1_BITS);
tmp13 += tmp13;
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.274162392)) + /* c4 */
MULTIPLY(tmp11 - tmp13, FIX(0.314692123)) - /* c12 */
MULTIPLY(tmp12 - tmp13, FIX(0.881747734)), /* c8 */
CONST_BITS-PASS1_BITS);
tmp10 = MULTIPLY(tmp14 + tmp15, FIX(1.105676686)); /* c6 */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.273079590)) /* c2-c6 */
+ MULTIPLY(tmp16, FIX(0.613604268)), /* c10 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.719280954)) /* c6+c10 */
- MULTIPLY(tmp16, FIX(1.378756276)), /* c2 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = tmp1 + tmp2;
tmp11 = tmp5 - tmp4;
dataptr[7] = (DCTELEM) ((tmp0 - tmp10 + tmp3 - tmp11 - tmp6) << PASS1_BITS);
tmp3 <<= CONST_BITS;
tmp10 = MULTIPLY(tmp10, - FIX(0.158341681)); /* -c13 */
tmp11 = MULTIPLY(tmp11, FIX(1.405321284)); /* c1 */
tmp10 += tmp11 - tmp3;
tmp11 = MULTIPLY(tmp0 + tmp2, FIX(1.197448846)) + /* c5 */
MULTIPLY(tmp4 + tmp6, FIX(0.752406978)); /* c9 */
dataptr[5] = (DCTELEM)
DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(2.373959773)) /* c3+c5-c13 */
+ MULTIPLY(tmp4, FIX(1.119999435)), /* c1+c11-c9 */
CONST_BITS-PASS1_BITS);
tmp12 = MULTIPLY(tmp0 + tmp1, FIX(1.334852607)) + /* c3 */
MULTIPLY(tmp5 - tmp6, FIX(0.467085129)); /* c11 */
dataptr[3] = (DCTELEM)
DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.424103948)) /* c3-c9-c13 */
- MULTIPLY(tmp5, FIX(3.069855259)), /* c1+c5+c11 */
CONST_BITS-PASS1_BITS);
dataptr[1] = (DCTELEM)
DESCALE(tmp11 + tmp12 + tmp3 + tmp6 -
MULTIPLY(tmp0 + tmp6, FIX(1.126980169)), /* c3+c5-c1 */
CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/14)*(8/7) = 32/49, which we
* partially fold into the constant multipliers and final shifting:
* 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14) * 64/49.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*6];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*5];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*4];
tmp3 = dataptr[DCTSIZE*3];
tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*6];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*5];
tmp12 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*4];
z1 = tmp0 + tmp2;
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(z1 + tmp1 + tmp3, FIX(1.306122449)), /* 64/49 */
CONST_BITS+PASS1_BITS+1);
tmp3 += tmp3;
z1 -= tmp3;
z1 -= tmp3;
z1 = MULTIPLY(z1, FIX(0.461784020)); /* (c2+c6-c4)/2 */
z2 = MULTIPLY(tmp0 - tmp2, FIX(1.202428084)); /* (c2+c4-c6)/2 */
z3 = MULTIPLY(tmp1 - tmp2, FIX(0.411026446)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS+PASS1_BITS+1);
z1 -= z2;
z2 = MULTIPLY(tmp0 - tmp1, FIX(1.151670509)); /* c4 */
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.923568041)), /* c2+c6-c4 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS+PASS1_BITS+1);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(1.221765677)); /* (c3+c1-c5)/2 */
tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.222383464)); /* (c3+c5-c1)/2 */
tmp0 = tmp1 - tmp2;
tmp1 += tmp2;
tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.800824523)); /* -c1 */
tmp1 += tmp2;
tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.801442310)); /* c5 */
tmp0 += tmp3;
tmp2 += tmp3 + MULTIPLY(tmp12, FIX(2.443531355)); /* c3+c1-c5 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+PASS1_BITS+1);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 12x6 sample block.
*
* 12-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
*/
void
jpeg_fdct_12x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Zero 2 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*6], SIZEOF(DCTELEM) * DCTSIZE * 2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24). */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[11]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[10]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[9]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[8]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[7]);
tmp5 = GETJSAMPLE(elemptr[5]) + GETJSAMPLE(elemptr[6]);
tmp10 = tmp0 + tmp5;
tmp13 = tmp0 - tmp5;
tmp11 = tmp1 + tmp4;
tmp14 = tmp1 - tmp4;
tmp12 = tmp2 + tmp3;
tmp15 = tmp2 - tmp3;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[11]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[10]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[9]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[8]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[7]);
tmp5 = GETJSAMPLE(elemptr[5]) - GETJSAMPLE(elemptr[6]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 - 12 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[6] = (DCTELEM) ((tmp13 - tmp14 - tmp15) << PASS1_BITS);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.224744871)), /* c4 */
CONST_BITS-PASS1_BITS);
dataptr[2] = (DCTELEM)
DESCALE(tmp14 - tmp15 + MULTIPLY(tmp13 + tmp15, FIX(1.366025404)), /* c2 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp1 + tmp4, FIX_0_541196100); /* c9 */
tmp14 = tmp10 + MULTIPLY(tmp1, FIX_0_765366865); /* c3-c9 */
tmp15 = tmp10 - MULTIPLY(tmp4, FIX_1_847759065); /* c3+c9 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.121971054)); /* c5 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.860918669)); /* c7 */
tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.580774953)) /* c5+c7-c1 */
+ MULTIPLY(tmp5, FIX(0.184591911)); /* c11 */
tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.184591911)); /* -c11 */
tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.339493912)) /* c1+c5-c11 */
+ MULTIPLY(tmp5, FIX(0.860918669)); /* c7 */
tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.725788011)) /* c1+c11-c7 */
- MULTIPLY(tmp5, FIX(1.121971054)); /* c5 */
tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.306562965)) /* c3 */
- MULTIPLY(tmp2 + tmp5, FIX_0_541196100); /* c9 */
dataptr[1] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/12)*(8/6) = 8/9, which we
* partially fold into the constant multipliers and final shifting:
* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
CONST_BITS+PASS1_BITS+1);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS+1);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 10x5 sample block.
*
* 10-point FDCT in pass 1 (rows), 5-point in pass 2 (columns).
*/
void
jpeg_fdct_10x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Zero 3 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*5], SIZEOF(DCTELEM) * DCTSIZE * 3);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20). */
dataptr = data;
for (ctr = 0; ctr < 5; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[9]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[8]);
tmp12 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[7]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[6]);
tmp4 = GETJSAMPLE(elemptr[4]) + GETJSAMPLE(elemptr[5]);
tmp10 = tmp0 + tmp4;
tmp13 = tmp0 - tmp4;
tmp11 = tmp1 + tmp3;
tmp14 = tmp1 - tmp3;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[9]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[8]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[7]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[6]);
tmp4 = GETJSAMPLE(elemptr[4]) - GETJSAMPLE(elemptr[5]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 + tmp12 - 10 * CENTERJSAMPLE) << PASS1_BITS);
tmp12 += tmp12;
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.144122806)) - /* c4 */
MULTIPLY(tmp11 - tmp12, FIX(0.437016024)), /* c8 */
CONST_BITS-PASS1_BITS);
tmp10 = MULTIPLY(tmp13 + tmp14, FIX(0.831253876)); /* c6 */
dataptr[2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.513743148)), /* c2-c6 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.176250899)), /* c2+c6 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = tmp0 + tmp4;
tmp11 = tmp1 - tmp3;
dataptr[5] = (DCTELEM) ((tmp10 - tmp11 - tmp2) << PASS1_BITS);
tmp2 <<= CONST_BITS;
dataptr[1] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.396802247)) + /* c1 */
MULTIPLY(tmp1, FIX(1.260073511)) + tmp2 + /* c3 */
MULTIPLY(tmp3, FIX(0.642039522)) + /* c7 */
MULTIPLY(tmp4, FIX(0.221231742)), /* c9 */
CONST_BITS-PASS1_BITS);
tmp12 = MULTIPLY(tmp0 - tmp4, FIX(0.951056516)) - /* (c3+c7)/2 */
MULTIPLY(tmp1 + tmp3, FIX(0.587785252)); /* (c1-c9)/2 */
tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.309016994)) + /* (c3-c7)/2 */
(tmp11 << (CONST_BITS - 1)) - tmp2;
dataptr[3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/10)*(8/5) = 32/25, which we
* fold into the constant multipliers:
* 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10) * 32/25.
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*4];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*3];
tmp2 = dataptr[DCTSIZE*2];
tmp10 = tmp0 + tmp1;
tmp11 = tmp0 - tmp1;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*4];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*3];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp2, FIX(1.28)), /* 32/25 */
CONST_BITS+PASS1_BITS);
tmp11 = MULTIPLY(tmp11, FIX(1.011928851)); /* (c2+c4)/2 */
tmp10 -= tmp2 << 2;
tmp10 = MULTIPLY(tmp10, FIX(0.452548340)); /* (c2-c4)/2 */
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp1, FIX(1.064004961)); /* c3 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.657591230)), /* c1-c3 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.785601151)), /* c1+c3 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on an 8x4 sample block.
*
* 8-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
*/
void
jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
INT32 tmp10, tmp11, tmp12, tmp13;
INT32 z1;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Zero 4 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*4], SIZEOF(DCTELEM) * DCTSIZE * 4);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We must also scale the output by 8/4 = 2, which we add here. */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
tmp10 = tmp0 + tmp3;
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << (PASS1_BITS+1));
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << (PASS1_BITS+1));
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-2);
dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
CONST_BITS-PASS1_BITS-1);
dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
CONST_BITS-PASS1_BITS-1);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-2);
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS-1);
dataptr[3] = (DCTELEM)
RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS-1);
dataptr[5] = (DCTELEM)
RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS-1);
dataptr[7] = (DCTELEM)
RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS-1);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
/* Add fudge factor here for final descale. */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3] + (ONE << (PASS1_BITS-1));
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS+PASS1_BITS-1);
dataptr[DCTSIZE*1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 6x3 sample block.
*
* 6-point FDCT in pass 1 (rows), 3-point in pass 2 (columns).
*/
void
jpeg_fdct_6x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2;
INT32 tmp10, tmp11, tmp12;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << (PASS1_BITS+1));
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
CONST_BITS-PASS1_BITS-1);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
CONST_BITS-PASS1_BITS-1);
/* Odd part */
tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
CONST_BITS-PASS1_BITS-1);
dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << (PASS1_BITS+1)));
dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << (PASS1_BITS+1));
dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << (PASS1_BITS+1)));
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
* fold into the constant multipliers (other part was done in pass 1):
* 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6) * 16/9.
*/
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*2];
tmp1 = dataptr[DCTSIZE*1];
tmp2 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*2];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(1.257078722)), /* c2 */
CONST_BITS+PASS1_BITS);
/* Odd part */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(MULTIPLY(tmp2, FIX(2.177324216)), /* c1 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 4x2 sample block.
*
* 4-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
*/
void
jpeg_fdct_4x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1;
INT32 tmp10, tmp11;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We must also scale the output by (8/4)*(8/2) = 2**3, which we add here. */
/* 4-point FDCT kernel, */
/* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
dataptr = data;
for (ctr = 0; ctr < 2; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+3));
dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+3));
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS-PASS1_BITS-4);
dataptr[1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS-PASS1_BITS-3);
dataptr[3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS-PASS1_BITS-3);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
*/
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
/* Even part */
/* Add fudge factor here for final descale. */
tmp0 = dataptr[DCTSIZE*0] + (ONE << (PASS1_BITS-1));
tmp1 = dataptr[DCTSIZE*1];
dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp0 + tmp1, PASS1_BITS);
/* Odd part */
dataptr[DCTSIZE*1] = (DCTELEM) RIGHT_SHIFT(tmp0 - tmp1, PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 2x1 sample block.
*
* 2-point FDCT in pass 1 (rows), 1-point in pass 2 (columns).
*/
void
jpeg_fdct_2x1 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1;
JSAMPROW elemptr;
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
elemptr = sample_data[0] + start_col;
tmp0 = GETJSAMPLE(elemptr[0]);
tmp1 = GETJSAMPLE(elemptr[1]);
/* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/2)*(8/1) = 2**5.
*/
/* Even part */
/* Apply unsigned->signed conversion */
data[0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
/* Odd part */
data[1] = (DCTELEM) ((tmp0 - tmp1) << 5);
}
/*
* Perform the forward DCT on an 8x16 sample block.
*
* 8-point FDCT in pass 1 (rows), 16-point in pass 2 (columns).
*/
void
jpeg_fdct_8x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16, tmp17;
INT32 z1;
DCTELEM workspace[DCTSIZE2];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) + GETJSAMPLE(elemptr[4]);
tmp10 = tmp0 + tmp3;
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[7]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[6]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[5]);
tmp3 = GETJSAMPLE(elemptr[3]) - GETJSAMPLE(elemptr[4]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
CONST_BITS-PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
dataptr[7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == DCTSIZE * 2)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by 8/16 = 1/2.
* 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
*/
dataptr = data;
wsptr = workspace;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*3];
tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*2];
tmp6 = dataptr[DCTSIZE*6] + wsptr[DCTSIZE*1];
tmp7 = dataptr[DCTSIZE*7] + wsptr[DCTSIZE*0];
tmp10 = tmp0 + tmp7;
tmp14 = tmp0 - tmp7;
tmp11 = tmp1 + tmp6;
tmp15 = tmp1 - tmp6;
tmp12 = tmp2 + tmp5;
tmp16 = tmp2 - tmp5;
tmp13 = tmp3 + tmp4;
tmp17 = tmp3 - tmp4;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*4];
tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*3];
tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*2];
tmp6 = dataptr[DCTSIZE*6] - wsptr[DCTSIZE*1];
tmp7 = dataptr[DCTSIZE*7] - wsptr[DCTSIZE*0];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(tmp10 + tmp11 + tmp12 + tmp13, PASS1_BITS+1);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(1.306562965)) + /* c4[16] = c2[8] */
MULTIPLY(tmp11 - tmp12, FIX_0_541196100), /* c12[16] = c6[8] */
CONST_BITS+PASS1_BITS+1);
tmp10 = MULTIPLY(tmp17 - tmp15, FIX(0.275899379)) + /* c14[16] = c7[8] */
MULTIPLY(tmp14 - tmp16, FIX(1.387039845)); /* c2[16] = c1[8] */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp15, FIX(1.451774982)) /* c6+c14 */
+ MULTIPLY(tmp16, FIX(2.172734804)), /* c2+c10 */
CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(0.211164243)) /* c2-c6 */
- MULTIPLY(tmp17, FIX(1.061594338)), /* c10+c14 */
CONST_BITS+PASS1_BITS+1);
/* Odd part */
tmp11 = MULTIPLY(tmp0 + tmp1, FIX(1.353318001)) + /* c3 */
MULTIPLY(tmp6 - tmp7, FIX(0.410524528)); /* c13 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(1.247225013)) + /* c5 */
MULTIPLY(tmp5 + tmp7, FIX(0.666655658)); /* c11 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(1.093201867)) + /* c7 */
MULTIPLY(tmp4 - tmp7, FIX(0.897167586)); /* c9 */
tmp14 = MULTIPLY(tmp1 + tmp2, FIX(0.138617169)) + /* c15 */
MULTIPLY(tmp6 - tmp5, FIX(1.407403738)); /* c1 */
tmp15 = MULTIPLY(tmp1 + tmp3, - FIX(0.666655658)) + /* -c11 */
MULTIPLY(tmp4 + tmp6, - FIX(1.247225013)); /* -c5 */
tmp16 = MULTIPLY(tmp2 + tmp3, - FIX(1.353318001)) + /* -c3 */
MULTIPLY(tmp5 - tmp4, FIX(0.410524528)); /* c13 */
tmp10 = tmp11 + tmp12 + tmp13 -
MULTIPLY(tmp0, FIX(2.286341144)) + /* c7+c5+c3-c1 */
MULTIPLY(tmp7, FIX(0.779653625)); /* c15+c13-c11+c9 */
tmp11 += tmp14 + tmp15 + MULTIPLY(tmp1, FIX(0.071888074)) /* c9-c3-c15+c11 */
- MULTIPLY(tmp6, FIX(1.663905119)); /* c7+c13+c1-c5 */
tmp12 += tmp14 + tmp16 - MULTIPLY(tmp2, FIX(1.125726048)) /* c7+c5+c15-c3 */
+ MULTIPLY(tmp5, FIX(1.227391138)); /* c9-c11+c1-c13 */
tmp13 += tmp15 + tmp16 + MULTIPLY(tmp3, FIX(1.065388962)) /* c15+c3+c11-c7 */
+ MULTIPLY(tmp4, FIX(2.167985692)); /* c1+c13+c5-c9 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS+1);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS+1);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 7x14 sample block.
*
* 7-point FDCT in pass 1 (rows), 14-point in pass 2 (columns).
*/
void
jpeg_fdct_7x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15, tmp16;
INT32 z1, z2, z3;
DCTELEM workspace[8*6];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[6]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[5]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[4]);
tmp3 = GETJSAMPLE(elemptr[3]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[6]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[5]);
tmp12 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[4]);
z1 = tmp0 + tmp2;
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((z1 + tmp1 + tmp3 - 7 * CENTERJSAMPLE) << PASS1_BITS);
tmp3 += tmp3;
z1 -= tmp3;
z1 -= tmp3;
z1 = MULTIPLY(z1, FIX(0.353553391)); /* (c2+c6-c4)/2 */
z2 = MULTIPLY(tmp0 - tmp2, FIX(0.920609002)); /* (c2+c4-c6)/2 */
z3 = MULTIPLY(tmp1 - tmp2, FIX(0.314692123)); /* c6 */
dataptr[2] = (DCTELEM) DESCALE(z1 + z2 + z3, CONST_BITS-PASS1_BITS);
z1 -= z2;
z2 = MULTIPLY(tmp0 - tmp1, FIX(0.881747734)); /* c4 */
dataptr[4] = (DCTELEM)
DESCALE(z2 + z3 - MULTIPLY(tmp1 - tmp3, FIX(0.707106781)), /* c2+c6-c4 */
CONST_BITS-PASS1_BITS);
dataptr[6] = (DCTELEM) DESCALE(z1 + z2, CONST_BITS-PASS1_BITS);
/* Odd part */
tmp1 = MULTIPLY(tmp10 + tmp11, FIX(0.935414347)); /* (c3+c1-c5)/2 */
tmp2 = MULTIPLY(tmp10 - tmp11, FIX(0.170262339)); /* (c3+c5-c1)/2 */
tmp0 = tmp1 - tmp2;
tmp1 += tmp2;
tmp2 = MULTIPLY(tmp11 + tmp12, - FIX(1.378756276)); /* -c1 */
tmp1 += tmp2;
tmp3 = MULTIPLY(tmp10 + tmp12, FIX(0.613604268)); /* c5 */
tmp0 += tmp3;
tmp2 += tmp3 + MULTIPLY(tmp12, FIX(1.870828693)); /* c3+c1-c5 */
dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-PASS1_BITS);
dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-PASS1_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 14)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/7)*(8/14) = 32/49, which we
* fold into the constant multipliers:
* 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28) * 32/49.
*/
dataptr = data;
wsptr = workspace;
for (ctr = 0; ctr < 7; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*3];
tmp13 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*2];
tmp4 = dataptr[DCTSIZE*4] + wsptr[DCTSIZE*1];
tmp5 = dataptr[DCTSIZE*5] + wsptr[DCTSIZE*0];
tmp6 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
tmp10 = tmp0 + tmp6;
tmp14 = tmp0 - tmp6;
tmp11 = tmp1 + tmp5;
tmp15 = tmp1 - tmp5;
tmp12 = tmp2 + tmp4;
tmp16 = tmp2 - tmp4;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*3];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*2];
tmp4 = dataptr[DCTSIZE*4] - wsptr[DCTSIZE*1];
tmp5 = dataptr[DCTSIZE*5] - wsptr[DCTSIZE*0];
tmp6 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12 + tmp13,
FIX(0.653061224)), /* 32/49 */
CONST_BITS+PASS1_BITS);
tmp13 += tmp13;
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp13, FIX(0.832106052)) + /* c4 */
MULTIPLY(tmp11 - tmp13, FIX(0.205513223)) - /* c12 */
MULTIPLY(tmp12 - tmp13, FIX(0.575835255)), /* c8 */
CONST_BITS+PASS1_BITS);
tmp10 = MULTIPLY(tmp14 + tmp15, FIX(0.722074570)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp14, FIX(0.178337691)) /* c2-c6 */
+ MULTIPLY(tmp16, FIX(0.400721155)), /* c10 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp15, FIX(1.122795725)) /* c6+c10 */
- MULTIPLY(tmp16, FIX(0.900412262)), /* c2 */
CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = tmp1 + tmp2;
tmp11 = tmp5 - tmp4;
dataptr[DCTSIZE*7] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp10 + tmp3 - tmp11 - tmp6,
FIX(0.653061224)), /* 32/49 */
CONST_BITS+PASS1_BITS);
tmp3 = MULTIPLY(tmp3 , FIX(0.653061224)); /* 32/49 */
tmp10 = MULTIPLY(tmp10, - FIX(0.103406812)); /* -c13 */
tmp11 = MULTIPLY(tmp11, FIX(0.917760839)); /* c1 */
tmp10 += tmp11 - tmp3;
tmp11 = MULTIPLY(tmp0 + tmp2, FIX(0.782007410)) + /* c5 */
MULTIPLY(tmp4 + tmp6, FIX(0.491367823)); /* c9 */
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp10 + tmp11 - MULTIPLY(tmp2, FIX(1.550341076)) /* c3+c5-c13 */
+ MULTIPLY(tmp4, FIX(0.731428202)), /* c1+c11-c9 */
CONST_BITS+PASS1_BITS);
tmp12 = MULTIPLY(tmp0 + tmp1, FIX(0.871740478)) + /* c3 */
MULTIPLY(tmp5 - tmp6, FIX(0.305035186)); /* c11 */
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(tmp10 + tmp12 - MULTIPLY(tmp1, FIX(0.276965844)) /* c3-c9-c13 */
- MULTIPLY(tmp5, FIX(2.004803435)), /* c1+c5+c11 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp11 + tmp12 + tmp3
- MULTIPLY(tmp0, FIX(0.735987049)) /* c3+c5-c1 */
- MULTIPLY(tmp6, FIX(0.082925825)), /* c9-c11-c13 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 6x12 sample block.
*
* 6-point FDCT in pass 1 (rows), 12-point in pass 2 (columns).
*/
void
jpeg_fdct_6x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14, tmp15;
DCTELEM workspace[8*4];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[5]);
tmp11 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) + GETJSAMPLE(elemptr[3]);
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[5]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[4]);
tmp2 = GETJSAMPLE(elemptr[2]) - GETJSAMPLE(elemptr[3]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp11 - 6 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(1.224744871)), /* c2 */
CONST_BITS-PASS1_BITS);
dataptr[4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(0.707106781)), /* c4 */
CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = DESCALE(MULTIPLY(tmp0 + tmp2, FIX(0.366025404)), /* c5 */
CONST_BITS-PASS1_BITS);
dataptr[1] = (DCTELEM) (tmp10 + ((tmp0 + tmp1) << PASS1_BITS));
dataptr[3] = (DCTELEM) ((tmp0 - tmp1 - tmp2) << PASS1_BITS);
dataptr[5] = (DCTELEM) (tmp10 + ((tmp2 - tmp1) << PASS1_BITS));
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 12)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/6)*(8/12) = 8/9, which we
* fold into the constant multipliers:
* 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24) * 8/9.
*/
dataptr = data;
wsptr = workspace;
for (ctr = 0; ctr < 6; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*3];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*2];
tmp2 = dataptr[DCTSIZE*2] + wsptr[DCTSIZE*1];
tmp3 = dataptr[DCTSIZE*3] + wsptr[DCTSIZE*0];
tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*7];
tmp5 = dataptr[DCTSIZE*5] + dataptr[DCTSIZE*6];
tmp10 = tmp0 + tmp5;
tmp13 = tmp0 - tmp5;
tmp11 = tmp1 + tmp4;
tmp14 = tmp1 - tmp4;
tmp12 = tmp2 + tmp3;
tmp15 = tmp2 - tmp3;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*3];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*2];
tmp2 = dataptr[DCTSIZE*2] - wsptr[DCTSIZE*1];
tmp3 = dataptr[DCTSIZE*3] - wsptr[DCTSIZE*0];
tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*7];
tmp5 = dataptr[DCTSIZE*5] - dataptr[DCTSIZE*6];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(0.888888889)), /* 8/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(MULTIPLY(tmp13 - tmp14 - tmp15, FIX(0.888888889)), /* 8/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.088662108)), /* c4 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp14 - tmp15, FIX(0.888888889)) + /* 8/9 */
MULTIPLY(tmp13 + tmp15, FIX(1.214244803)), /* c2 */
CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp1 + tmp4, FIX(0.481063200)); /* c9 */
tmp14 = tmp10 + MULTIPLY(tmp1, FIX(0.680326102)); /* c3-c9 */
tmp15 = tmp10 - MULTIPLY(tmp4, FIX(1.642452502)); /* c3+c9 */
tmp12 = MULTIPLY(tmp0 + tmp2, FIX(0.997307603)); /* c5 */
tmp13 = MULTIPLY(tmp0 + tmp3, FIX(0.765261039)); /* c7 */
tmp10 = tmp12 + tmp13 + tmp14 - MULTIPLY(tmp0, FIX(0.516244403)) /* c5+c7-c1 */
+ MULTIPLY(tmp5, FIX(0.164081699)); /* c11 */
tmp11 = MULTIPLY(tmp2 + tmp3, - FIX(0.164081699)); /* -c11 */
tmp12 += tmp11 - tmp15 - MULTIPLY(tmp2, FIX(2.079550144)) /* c1+c5-c11 */
+ MULTIPLY(tmp5, FIX(0.765261039)); /* c7 */
tmp13 += tmp11 - tmp14 + MULTIPLY(tmp3, FIX(0.645144899)) /* c1+c11-c7 */
- MULTIPLY(tmp5, FIX(0.997307603)); /* c5 */
tmp11 = tmp15 + MULTIPLY(tmp0 - tmp3, FIX(1.161389302)) /* c3 */
- MULTIPLY(tmp2 + tmp5, FIX(0.481063200)); /* c9 */
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp11, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp13, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 5x10 sample block.
*
* 5-point FDCT in pass 1 (rows), 10-point in pass 2 (columns).
*/
void
jpeg_fdct_5x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3, tmp4;
INT32 tmp10, tmp11, tmp12, tmp13, tmp14;
DCTELEM workspace[8*2];
DCTELEM *dataptr;
DCTELEM *wsptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10). */
dataptr = data;
ctr = 0;
for (;;) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[4]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[3]);
tmp2 = GETJSAMPLE(elemptr[2]);
tmp10 = tmp0 + tmp1;
tmp11 = tmp0 - tmp1;
tmp0 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[4]);
tmp1 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[3]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp10 + tmp2 - 5 * CENTERJSAMPLE) << PASS1_BITS);
tmp11 = MULTIPLY(tmp11, FIX(0.790569415)); /* (c2+c4)/2 */
tmp10 -= tmp2 << 2;
tmp10 = MULTIPLY(tmp10, FIX(0.353553391)); /* (c2-c4)/2 */
dataptr[2] = (DCTELEM) DESCALE(tmp11 + tmp10, CONST_BITS-PASS1_BITS);
dataptr[4] = (DCTELEM) DESCALE(tmp11 - tmp10, CONST_BITS-PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp1, FIX(0.831253876)); /* c3 */
dataptr[1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0, FIX(0.513743148)), /* c1-c3 */
CONST_BITS-PASS1_BITS);
dataptr[3] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp1, FIX(2.176250899)), /* c1+c3 */
CONST_BITS-PASS1_BITS);
ctr++;
if (ctr != DCTSIZE) {
if (ctr == 10)
break; /* Done. */
dataptr += DCTSIZE; /* advance pointer to next row */
} else
dataptr = workspace; /* switch pointer to extended workspace */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/5)*(8/10) = 32/25, which we
* fold into the constant multipliers:
* 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20) * 32/25.
*/
dataptr = data;
wsptr = workspace;
for (ctr = 0; ctr < 5; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + wsptr[DCTSIZE*1];
tmp1 = dataptr[DCTSIZE*1] + wsptr[DCTSIZE*0];
tmp12 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*7];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*6];
tmp4 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
tmp10 = tmp0 + tmp4;
tmp13 = tmp0 - tmp4;
tmp11 = tmp1 + tmp3;
tmp14 = tmp1 - tmp3;
tmp0 = dataptr[DCTSIZE*0] - wsptr[DCTSIZE*1];
tmp1 = dataptr[DCTSIZE*1] - wsptr[DCTSIZE*0];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*7];
tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*6];
tmp4 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11 + tmp12, FIX(1.28)), /* 32/25 */
CONST_BITS+PASS1_BITS);
tmp12 += tmp12;
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp12, FIX(1.464477191)) - /* c4 */
MULTIPLY(tmp11 - tmp12, FIX(0.559380511)), /* c8 */
CONST_BITS+PASS1_BITS);
tmp10 = MULTIPLY(tmp13 + tmp14, FIX(1.064004961)); /* c6 */
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp13, FIX(0.657591230)), /* c2-c6 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
DESCALE(tmp10 - MULTIPLY(tmp14, FIX(2.785601151)), /* c2+c6 */
CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = tmp0 + tmp4;
tmp11 = tmp1 - tmp3;
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp2, FIX(1.28)), /* 32/25 */
CONST_BITS+PASS1_BITS);
tmp2 = MULTIPLY(tmp2, FIX(1.28)); /* 32/25 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(MULTIPLY(tmp0, FIX(1.787906876)) + /* c1 */
MULTIPLY(tmp1, FIX(1.612894094)) + tmp2 + /* c3 */
MULTIPLY(tmp3, FIX(0.821810588)) + /* c7 */
MULTIPLY(tmp4, FIX(0.283176630)), /* c9 */
CONST_BITS+PASS1_BITS);
tmp12 = MULTIPLY(tmp0 - tmp4, FIX(1.217352341)) - /* (c3+c7)/2 */
MULTIPLY(tmp1 + tmp3, FIX(0.752365123)); /* (c1-c9)/2 */
tmp13 = MULTIPLY(tmp10 + tmp11, FIX(0.395541753)) + /* (c3-c7)/2 */
MULTIPLY(tmp11, FIX(0.64)) - tmp2; /* 16/25 */
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp12 + tmp13, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp12 - tmp13, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
wsptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 4x8 sample block.
*
* 4-point FDCT in pass 1 (rows), 8-point in pass 2 (columns).
*/
void
jpeg_fdct_4x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2, tmp3;
INT32 tmp10, tmp11, tmp12, tmp13;
INT32 z1;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We must also scale the output by 8/4 = 2, which we add here. */
/* 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16). */
dataptr = data;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[3]);
tmp1 = GETJSAMPLE(elemptr[1]) + GETJSAMPLE(elemptr[2]);
tmp10 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[3]);
tmp11 = GETJSAMPLE(elemptr[1]) - GETJSAMPLE(elemptr[2]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 - 4 * CENTERJSAMPLE) << (PASS1_BITS+1));
dataptr[2] = (DCTELEM) ((tmp0 - tmp1) << (PASS1_BITS+1));
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS-PASS1_BITS-2);
dataptr[1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS-PASS1_BITS-1);
dataptr[3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS-PASS1_BITS-1);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
*/
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
/* Add fudge factor here for final descale. */
tmp10 = tmp0 + tmp3 + (ONE << (PASS1_BITS-1));
tmp12 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp13 = tmp1 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
tmp3 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
dataptr[DCTSIZE*2] = (DCTELEM)
RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
tmp10 = tmp0 + tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
dataptr[DCTSIZE*1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM)
RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*7] = (DCTELEM)
RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 3x6 sample block.
*
* 3-point FDCT in pass 1 (rows), 6-point in pass 2 (columns).
*/
void
jpeg_fdct_3x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1, tmp2;
INT32 tmp10, tmp11, tmp12;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT; */
/* furthermore, we scale the results by 2**PASS1_BITS. */
/* We scale the results further by 2 as part of output adaption */
/* scaling for different DCT size. */
/* 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6). */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[2]);
tmp1 = GETJSAMPLE(elemptr[1]);
tmp2 = GETJSAMPLE(elemptr[0]) - GETJSAMPLE(elemptr[2]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM)
((tmp0 + tmp1 - 3 * CENTERJSAMPLE) << (PASS1_BITS+1));
dataptr[2] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp1, FIX(0.707106781)), /* c2 */
CONST_BITS-PASS1_BITS-1);
/* Odd part */
dataptr[1] = (DCTELEM)
DESCALE(MULTIPLY(tmp2, FIX(1.224744871)), /* c1 */
CONST_BITS-PASS1_BITS-1);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/6)*(8/3) = 32/9, which we partially
* fold into the constant multipliers (other part was done in pass 1):
* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12) * 16/9.
*/
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*5];
tmp11 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
tmp10 = tmp0 + tmp2;
tmp12 = tmp0 - tmp2;
tmp0 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*5];
tmp1 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*4];
tmp2 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
dataptr[DCTSIZE*0] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 + tmp11, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*2] = (DCTELEM)
DESCALE(MULTIPLY(tmp12, FIX(2.177324216)), /* c2 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM)
DESCALE(MULTIPLY(tmp10 - tmp11 - tmp11, FIX(1.257078722)), /* c4 */
CONST_BITS+PASS1_BITS);
/* Odd part */
tmp10 = MULTIPLY(tmp0 + tmp2, FIX(0.650711829)); /* c5 */
dataptr[DCTSIZE*1] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp0 + tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
DESCALE(MULTIPLY(tmp0 - tmp1 - tmp2, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*5] = (DCTELEM)
DESCALE(tmp10 + MULTIPLY(tmp2 - tmp1, FIX(1.777777778)), /* 16/9 */
CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 2x4 sample block.
*
* 2-point FDCT in pass 1 (rows), 4-point in pass 2 (columns).
*/
void
jpeg_fdct_2x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1;
INT32 tmp10, tmp11;
DCTELEM *dataptr;
JSAMPROW elemptr;
int ctr;
SHIFT_TEMPS
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
/* Pass 1: process rows. */
/* Note results are scaled up by sqrt(8) compared to a true DCT. */
/* We must also scale the output by (8/2)*(8/4) = 2**3, which we add here. */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part */
tmp0 = GETJSAMPLE(elemptr[0]);
tmp1 = GETJSAMPLE(elemptr[1]);
/* Apply unsigned->signed conversion */
dataptr[0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 3);
/* Odd part */
dataptr[1] = (DCTELEM) ((tmp0 - tmp1) << 3);
dataptr += DCTSIZE; /* advance pointer to next row */
}
/* Pass 2: process columns.
* We leave the results scaled up by an overall factor of 8.
* 4-point FDCT kernel,
* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
*/
dataptr = data;
for (ctr = 0; ctr < 2; ctr++) {
/* Even part */
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*3];
tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*2];
tmp10 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*3];
tmp11 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*2];
dataptr[DCTSIZE*0] = (DCTELEM) (tmp0 + tmp1);
dataptr[DCTSIZE*2] = (DCTELEM) (tmp0 - tmp1);
/* Odd part */
tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS-1);
dataptr[DCTSIZE*1] = (DCTELEM)
RIGHT_SHIFT(tmp0 + MULTIPLY(tmp10, FIX_0_765366865), /* c2-c6 */
CONST_BITS);
dataptr[DCTSIZE*3] = (DCTELEM)
RIGHT_SHIFT(tmp0 - MULTIPLY(tmp11, FIX_1_847759065), /* c2+c6 */
CONST_BITS);
dataptr++; /* advance pointer to next column */
}
}
/*
* Perform the forward DCT on a 1x2 sample block.
*
* 1-point FDCT in pass 1 (rows), 2-point in pass 2 (columns).
*/
void
jpeg_fdct_1x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col)
{
INT32 tmp0, tmp1;
/* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
tmp0 = GETJSAMPLE(sample_data[0][start_col]);
tmp1 = GETJSAMPLE(sample_data[1][start_col]);
/* We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/1)*(8/2) = 2**5.
*/
/* Even part */
/* Apply unsigned->signed conversion */
data[DCTSIZE*0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
/* Odd part */
data[DCTSIZE*1] = (DCTELEM) ((tmp0 - tmp1) << 5);
}
#endif /* DCT_SCALING_SUPPORTED */
#endif /* DCT_ISLOW_SUPPORTED */