#include "stdafx.h"
#pragma hdrstop
/***************************************************************************
*
* INTEL Corporation Proprietary Information
*
*
* Copyright (c) 1996 Intel Corporation.
* All rights reserved.
*
***************************************************************************
*/
/*
* jfdctint.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
* 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.
*/
#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 DCTs. /* 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 2446 /* FIX(0.298631336) */
#define FIX_0_390180644 3196 /* FIX(0.390180644) */
#define FIX_0_541196100 4433 /* FIX(0.541196100) */
#define FIX_0_765366865 6270 /* FIX(0.765366865) */
#define FIX_0_899976223 7373 /* FIX(0.899976223) */
#define FIX_1_175875602 9633 /* FIX(1.175875602) */
#define FIX_1_501321110 12299 /* FIX(1.501321110) */
#define FIX_1_847759065 15137 /* FIX(1.847759065) */
#define FIX_1_961570560 16069 /* FIX(1.961570560) */
#define FIX_2_053119869 16819 /* FIX(2.053119869) */
#define FIX_2_562915447 20995 /* FIX(2.562915447) */
#define FIX_3_072711026 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
#define DATASIZE 4
#define DCTWIDTH 32
#if _MSC_FULL_VER >= 13008827 && defined(_M_IX86)
#pragma warning(push)
#pragma warning(disable:4731) // EBP modified with inline asm
#endif
/*
* Perform the forward DCT on one block of samples.
*/
GLOBAL(void)
pfdct8x8llm (DCTELEM * data)
{
INT32 tmp4, tmp5, tmp6, tmp7;
int counter;
__asm{
/* 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;
mov esi, [data]
mov counter, 8
// for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
// tmp0 = dataptr[0] + dataptr[7];
// tmp7 = dataptr[0] - dataptr[7];
// tmp1 = dataptr[1] + dataptr[6];
// tmp6 = dataptr[1] - dataptr[6];
// tmp2 = dataptr[2] + dataptr[5];
// tmp5 = dataptr[2] - dataptr[5];
// tmp3 = dataptr[3] + dataptr[4];
// tmp4 = dataptr[3] - dataptr[4];
StartRow:
mov eax, [esi][DATASIZE*0]
mov ebx, [esi][DATASIZE*7]
mov edx, eax
add eax, ebx ; eax = tmp0
sub edx, ebx ; edx = tmp7
mov ebx, [esi][DATASIZE*3]
mov ecx, [esi][DATASIZE*4]
mov edi, ebx
add ebx, ecx ; ebx = tmp3
sub edi, ecx ; edi = tmp4
mov tmp4, edi
mov tmp7, edx
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
// tmp10 = tmp0 + tmp3;
// tmp13 = tmp0 - tmp3;
// tmp11 = tmp1 + tmp2;
// tmp12 = tmp1 - tmp2;
mov ecx, eax
add eax, ebx ; eax = tmp10
sub ecx, ebx ; ecx = tmp13
mov edx, [esi][DATASIZE*1]
mov edi, [esi][DATASIZE*6]
mov ebx, edx
add edx, edi ; edx = tmp1
sub ebx, edi ; ebx = tmp6
mov tmp6, ebx
push ebp
mov edi, [esi][DATASIZE*2]
mov ebp, [esi][DATASIZE*5]
mov ebx, edi
add edi, ebp ; edi = tmp2
sub ebx, ebp ; ebx = tmp5
mov ebp, edx
add edx, edi ; edx = tmp11
sub ebp, edi ; ebp = tmp12
// dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS);
// dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
mov edi, eax
add eax, edx ; eax = tmp10 + tmp11
shl eax, 2
sub edi, edx ; edi = tmp10 - tmp11
shl edi, 2
mov [esi][DATASIZE*0], eax
mov [esi][DATASIZE*4], edi
mov eax, ebp ; eax = tmp12
// z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
add ebp, ecx ; eax = tmp12 + tmp13
add esi, 32
imul ebp, FIX_0_541196100 ; ebp = z1
// dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
// CONST_BITS-PASS1_BITS);
imul ecx, FIX_0_765366865
// dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
// CONST_BITS-PASS1_BITS);
imul eax, FIX_1_847759065
add ecx, ebp ; add z1
xor eax, 0xFFFFFFFF
add ecx, 1024 ; rounding adj
inc eax ; negate the result
add eax, ebp ; add z1
pop ebp
sar ecx, 11
add eax, 1024
mov [esi][DATASIZE*2-32], ecx
mov edi, tmp4
sar eax, 11
mov ecx, tmp6
mov [esi][DATASIZE*6-32], eax
push esi
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents cos(K*pi/16).
* i0..i3 in the paper are tmp4..tmp7 here.
*/
// z1 = tmp4 + tmp7;
// z2 = tmp5 + tmp6;
// z3 = tmp4 + tmp6;
// z4 = tmp5 + tmp7;
mov edx, tmp7
mov eax, edi ; edi = eax = tmp4
mov esi, edi ; esi = tmp4
add edi, edx ; edi = z1
add eax, ecx ; eax = z3
add ecx, ebx ; ecx = z2
// z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
// z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
imul edi, FIX_0_899976223
imul ecx, FIX_2_562915447
xor ecx, 0xFFFFFFFF
add edx, ebx ; edx = z4
// tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
// tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
imul esi, FIX_0_298631336
imul ebx, FIX_2_053119869
xor edi, 0xFFFFFFFF
inc ecx ; ecx = z2
inc edi ; edi = z1
add ebx, ecx ; ebx = z2 + tmp5
add esi, edi ; esi = z1 + tmp4
mov tmp5, ebx
// z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
mov ebx, eax ; ebx = z3
add eax, edx ; eax = z3 + z4
imul eax, FIX_1_175875602
// z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
// z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
imul ebx, FIX_1_961570560
imul edx, FIX_0_390180644
xor ebx, 0xFFFFFFFF
xor edx, 0xFFFFFFFF
inc ebx ; ebx = z3
inc edx ; edx = z4
// z3 += z5;
// z4 += z5;
add ebx, eax ; ebx = z3
add edx, eax ; edx = z4
// tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
// tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
mov eax, tmp6
add ecx, ebx ; ecx = z2 + z3
imul eax, FIX_3_072711026
add ecx, eax ; ecx = tmp6 + z2 + z3
mov eax, tmp7
imul eax, FIX_1_501321110
// dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS);
// dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS);
// dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS);
// dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS);
add edi, edx ; edi = z1 + z4
add ecx, 1024
add edi, eax ; edi = tmp7 + z1 + z4
mov eax, tmp5 ; eax = tmp5 + z2
add ebx, esi ; ebx = tmp4 + z1 + z3
add edx, eax ; edx = tmp5 + z2 + z4
sar ecx, 11
add ebx, 1024
sar ebx, 11
pop esi
add edx, 1024
add edi, 1024
sar edx, 11
mov [esi][DATASIZE*7-32], ebx
sar edi, 11
mov [esi][DATASIZE*3-32], ecx
mov [esi][DATASIZE*5-32], edx
mov ecx, counter
mov [esi][DATASIZE*1-32], edi
dec ecx
mov counter, ecx
jnz StartRow
// 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;
mov esi, [data]
mov counter, 8
//for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
// tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
// tmp7 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*7];
// tmp1 = dataptr[DCTSIZE*1] + dataptr[DCTSIZE*6];
// tmp6 = dataptr[DCTSIZE*1] - dataptr[DCTSIZE*6];
// tmp2 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*5];
// tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5];
// tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4];
// tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4];
StartCol:
mov eax, [esi][DCTWIDTH*0]
mov ebx, [esi][DCTWIDTH*7]
mov edx, eax
add eax, ebx ; eax = tmp0
sub edx, ebx ; edx = tmp7
mov ebx, [esi][DCTWIDTH*3]
mov ecx, [esi][DCTWIDTH*4]
mov edi, ebx
add ebx, ecx ; ebx = tmp3
sub edi, ecx ; edi = tmp4
mov tmp4, edi
mov tmp7, edx
/* Even part per LL&M figure 1 --- note that published figure is faulty;
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
*/
// tmp10 = tmp0 + tmp3;
// tmp13 = tmp0 - tmp3;
// tmp11 = tmp1 + tmp2;
// tmp12 = tmp1 - tmp2;
mov ecx, eax ; ecx = tmp0
add eax, ebx ; eax = tmp10
sub ecx, ebx ; ecx = tmp13
mov edx, [esi][DCTWIDTH*1]
mov edi, [esi][DCTWIDTH*6]
mov ebx, edx
add edx, edi ; edx = tmp1
sub ebx, edi ; ebx = tmp6
mov tmp6, ebx
push ebp
mov edi, [esi][DCTWIDTH*2]
mov ebp, [esi][DCTWIDTH*5]
mov ebx, edi
add edi, ebp ; edi = tmp2
sub ebx, ebp ; ebx = tmp5
mov ebp, edx ; ebp = tmp1
add edx, edi ; edx = tmp11
sub ebp, edi ; ebx = tmp12
// dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
// dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
add eax, 2 ; adj for rounding
mov edi, eax
add eax, edx ; eax = tmp10 + tmp11
sar eax, 2
sub edi, edx ; edi = tmp10 - tmp11
sar edi, 2
mov [esi][DCTWIDTH*0], eax
mov [esi][DCTWIDTH*4], edi
mov eax, ebp ; eax = tmp12
// z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
add ebp, ecx ; eax = tmp12 + tmp13
add esi, 4
imul ebp, FIX_0_541196100 ; ebp = z1
// dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
// CONST_BITS+PASS1_BITS);
imul ecx, FIX_0_765366865
// dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
// CONST_BITS+PASS1_BITS);
imul eax, FIX_1_847759065
add ecx, ebp ; add z1
xor eax, 0xFFFFFFFF
add ecx, 16384 ; rounding adj
inc eax ; negate the result
add eax, ebp ; add z1
pop ebp
sar ecx, 15
add eax, 16384
mov [esi][DCTWIDTH*2-4], ecx
mov edi, tmp4
sar eax, 15
mov ecx, tmp6
mov [esi][DCTWIDTH*6-4], eax
push esi
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
* cK represents cos(K*pi/16).
* i0..i3 in the paper are tmp4..tmp7 here.
*/
// z1 = tmp4 + tmp7;
// z2 = tmp5 + tmp6;
// z3 = tmp4 + tmp6;
// z4 = tmp5 + tmp7;
mov edx, tmp7
mov eax, edi ; edi = eax = tmp4
mov esi, edi ; esi = tmp4
add edi, edx ; edi = z1
add eax, ecx ; eax = z3
add ecx, ebx ; ecx = z2
// z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
// z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
imul edi, FIX_0_899976223
imul ecx, FIX_2_562915447
xor ecx, 0xFFFFFFFF
add edx, ebx ; edx = z4
// tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
// tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
imul esi, FIX_0_298631336
imul ebx, FIX_2_053119869
xor edi, 0xFFFFFFFF
inc ecx ; ecx = z2
inc edi ; edi = z1
add ebx, ecx ; ebx = z2 + tmp5
add esi, edi ; esi = z1 + tmp4
mov tmp5, ebx
// z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
mov ebx, eax ; ebx = z3
add eax, edx ; eax = z3 + z4
imul eax, FIX_1_175875602
// z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
// z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
imul ebx, FIX_1_961570560
imul edx, FIX_0_390180644
xor ebx, 0xFFFFFFFF
xor edx, 0xFFFFFFFF
inc ebx ; ebx = z3
inc edx ; edx = z4
// z3 += z5;
// z4 += z5;
add ebx, eax ; ebx = z3
add edx, eax ; edx = z4
// tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
// tmp7 = MULTIPLY(tmp7, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
mov eax, tmp6
add ecx, ebx ; ecx = z2 + z3
imul eax, FIX_3_072711026
add ecx, eax ; ecx = tmp6 + z2 + z3
mov eax, tmp7
imul eax, FIX_1_501321110
// dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3,
// CONST_BITS+PASS1_BITS);
// dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4,
// CONST_BITS+PASS1_BITS);
// dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3,
// CONST_BITS+PASS1_BITS);
// dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4,
// CONST_BITS+PASS1_BITS);
add edi, edx ; edi = z1 + z4
add ecx, 16384
add edi, eax ; edi = tmp7 + z1 + z4
mov eax, tmp5 ; eax = tmp5 + z2
add ebx, esi ; ebx = tmp4 + z1 + z3
add edx, eax ; edx = tmp5 + z2 + z4
sar ecx, 15
add ebx, 16384
sar ebx, 15
pop esi
add edx, 16384
add edi, 16384
sar edx, 15
mov [esi][DCTWIDTH*7-4], ebx
sar edi, 15
mov [esi][DCTWIDTH*3-4], ecx
mov [esi][DCTWIDTH*5-4], edx
mov ecx, counter
mov [esi][DCTWIDTH*1-4], edi
dec ecx
mov counter, ecx
jnz StartCol
} //end asm
// dataptr++; /* advance pointer to next column */
// }
}
#if _MSC_FULL_VER >= 13008827
#pragma warning(pop)
#endif
#endif /* DCT_ISLOW_SUPPORTED */