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CentrED/Imaging/JpegLib/imjidctasm.pas

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⬆️ Update Vampyre Imaging lib
2022-05-08 10:47:53 +02:00
unit imjidctasm;
{ This file contains a slow-but-accurate integer implementation of the
inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
must also perform dequantization of the input coefficients.
A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT
on each row (or vice versa, but it's more convenient to emit a row at
a time). 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. }
{ Original : jidctint.c ; Copyright (C) 1991-1996, Thomas G. Lane. }
{ ;-------------------------------------------------------------------------
; JIDCTINT.ASM
; 80386 protected mode assembly translation of JIDCTINT.C
; **** Optimized to all hell by Jason M. Felice (jasonf@apk.net) ****
; **** E-mail welcome ****
;
; ** This code does not make O/S calls -- use it for OS/2, Win95, WinNT,
; ** DOS prot. mode., Linux, whatever... have fun.
;
; ** Note, this code is dependant on the structure member order in the .h
; ** files for the following structures:
; -- amazingly NOT j_decompress_struct... cool.
; -- jpeg_component_info (dependant on position of dct_table element)
;
; Originally created with the /Fa option of MSVC 4.0 (why work when you
; don't have to?)
;
; (this code, when compiled is 1K bytes smaller than the optimized MSVC
; release build, not to mention 120-130 ms faster in my profile test with 1
; small color and and 1 medium black-and-white jpeg: stats using TASM 4.0
; and MSVC 4.0 to create a non-console app; jpeg_idct_islow accumulated
; 5,760 hits on all trials)
;
; TASM -t -ml -os jidctint.asm, jidctint.obj
;-------------------------------------------------------------------------
Converted to Delphi 2.0 BASM for PasJPEG
by Jacques NOMSSI NZALI <nomssi@physik.tu-chemnitz.de>
October 13th 1996
* assumes Delphi "register" calling convention
first 3 parameter are in EAX,EDX,ECX
* register allocation revised
}
interface
{$I imjconfig.inc}
uses
imjmorecfg,
imjinclude,
imjpeglib,
imjdct; { Private declarations for DCT subsystem }
{ Perform dequantization and inverse DCT on one block of coefficients. }
{GLOBAL}
procedure jpeg_idct_islow (cinfo : j_decompress_ptr;
compptr : jpeg_component_info_ptr;
coef_block : JCOEFPTR;
output_buf : JSAMPARRAY;
output_col : JDIMENSION);
implementation
{ This module is specialized to the case DCTSIZE = 8. }
{$ifndef DCTSIZE_IS_8}
Sorry, this code only copes with 8x8 DCTs. { deliberate syntax err }
{$endif}
{ The poop on this scaling stuff is as follows:
Each 1-D IDCT step produces outputs which are a factor of sqrt(N)
larger than the true IDCT outputs. The final outputs are therefore
a factor of N larger than desired; since N=8 this can be cured by
a simple right shift at the end of the algorithm. The advantage of
this arrangement is that we save two multiplications per 1-D IDCT,
because the y0 and y4 inputs need not be divided by sqrt(N).
We have to do addition and subtraction of the integer inputs, which
is no problem, and multiplication by fractional constants, which is
a problem to do in integer arithmetic. We multiply all the constants
by CONST_SCALE and convert them to integer constants (thus retaining
CONST_BITS bits of precision in the constants). After doing a
multiplication we have to divide the product by CONST_SCALE, with proper
rounding, to produce the correct output. This division can be done
cheaply as a right shift of CONST_BITS bits. We postpone shifting
as long as possible so that partial sums can be added together with
full fractional precision.
The outputs of the first pass are scaled up by PASS1_BITS bits so that
they are represented to better-than-integral precision. These outputs
require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word
with the recommended scaling. (To scale up 12-bit sample data further, an
intermediate INT32 array would be needed.)
To avoid overflow of the 32-bit intermediate results in pass 2, we must
have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
shows that the values given below are the most effective. }
const
CONST_BITS = 13;
{$ifdef BITS_IN_JSAMPLE_IS_8}
const
PASS1_BITS = 2;
{$else}
const
PASS1_BITS = 1; { lose a little precision to avoid overflow }
{$endif}
const
CONST_SCALE = (INT32(1) shl CONST_BITS);
const
FIX_0_298631336 = INT32(Round(CONST_SCALE * 0.298631336)); {2446}
FIX_0_390180644 = INT32(Round(CONST_SCALE * 0.390180644)); {3196}
FIX_0_541196100 = INT32(Round(CONST_SCALE * 0.541196100)); {4433}
FIX_0_765366865 = INT32(Round(CONST_SCALE * 0.765366865)); {6270}
FIX_0_899976223 = INT32(Round(CONST_SCALE * 0.899976223)); {7373}
FIX_1_175875602 = INT32(Round(CONST_SCALE * 1.175875602)); {9633}
FIX_1_501321110 = INT32(Round(CONST_SCALE * 1.501321110)); {12299}
FIX_1_847759065 = INT32(Round(CONST_SCALE * 1.847759065)); {15137}
FIX_1_961570560 = INT32(Round(CONST_SCALE * 1.961570560)); {16069}
FIX_2_053119869 = INT32(Round(CONST_SCALE * 2.053119869)); {16819}
FIX_2_562915447 = INT32(Round(CONST_SCALE * 2.562915447)); {20995}
FIX_3_072711026 = INT32(Round(CONST_SCALE * 3.072711026)); {25172}
{ for DESCALE }
const
ROUND_CONST = (INT32(1) shl (CONST_BITS-PASS1_BITS-1));
const
ROUND_CONST_2 = (INT32(1) shl (CONST_BITS+PASS1_BITS+3-1));
{ Perform dequantization and inverse DCT on one block of coefficients. }
{GLOBAL}
procedure jpeg_idct_islow (cinfo : j_decompress_ptr;
compptr : jpeg_component_info_ptr;
coef_block : JCOEFPTR;
output_buf : JSAMPARRAY;
output_col : JDIMENSION);
type
PWorkspace = ^TWorkspace;
TWorkspace = coef_bits_field; { buffers data between passes }
const
coefDCTSIZE = DCTSIZE*SizeOf(JCOEF);
wrkDCTSIZE = DCTSIZE*SizeOf(int);
var
tmp0, tmp1, tmp2, tmp3 : INT32;
tmp10, tmp11, tmp12, tmp13 : INT32;
z1, z2, z3, z4, z5 : INT32;
var
inptr : JCOEFPTR;
quantptr : ISLOW_MULT_TYPE_FIELD_PTR;
wsptr : PWorkspace;
outptr : JSAMPROW;
var
range_limit : JSAMPROW;
ctr : int;
workspace : TWorkspace;
var
dcval : int;
var
dcval_ : JSAMPLE;
asm
push edi
push esi
push ebx
cld { The only direction we use, might as well set it now, as opposed }
{ to inside 2 loops. }
{ Each IDCT routine is responsible for range-limiting its results and
converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
be quite far out of range if the input data is corrupt, so a bulletproof
range-limiting step is required. We use a mask-and-table-lookup method
to do the combined operations quickly. See the comments with
prepare_range_limit_table (in jdmaster.c) for more info. }
{range_limit := JSAMPROW(@(cinfo^.sample_range_limit^[CENTERJSAMPLE]));}
mov eax, [eax].jpeg_decompress_struct.sample_range_limit {eax=cinfo}
add eax, (MAXJSAMPLE+1 + CENTERJSAMPLE)*(Type JSAMPLE)
mov range_limit, eax
{ Pass 1: process columns from input, store into work array. }
{ Note results are scaled up by sqrt(8) compared to a true IDCT; }
{ furthermore, we scale the results by 2**PASS1_BITS. }
{inptr := coef_block;}
mov esi, ecx { ecx=coef_block }
{quantptr := ISLOW_MULT_TYPE_FIELD_PTR (compptr^.dct_table);}
mov edi, [edx].jpeg_component_info.dct_table { edx=compptr }
{wsptr := PWorkspace(@workspace);}
lea ecx, workspace
{for ctr := pred(DCTSIZE) downto 0 do
begin}
mov ctr, DCTSIZE
@loop518:
{ Due to quantization, we will usually find that many of the input
coefficients are zero, especially the AC terms. We can exploit this
by short-circuiting the IDCT calculation for any column in which all
the AC terms are zero. In that case each output is equal to the
DC coefficient (with scale factor as needed).
With typical images and quantization tables, half or more of the
column DCT calculations can be simplified this way. }
{if ((inptr^[DCTSIZE*1]) or (inptr^[DCTSIZE*2]) or (inptr^[DCTSIZE*3]) or
(inptr^[DCTSIZE*4]) or (inptr^[DCTSIZE*5]) or (inptr^[DCTSIZE*6]) or
(inptr^[DCTSIZE*7]) = 0) then
begin}
mov eax, DWORD PTR [esi+coefDCTSIZE*1]
or eax, DWORD PTR [esi+coefDCTSIZE*2]
or eax, DWORD PTR [esi+coefDCTSIZE*3]
mov edx, DWORD PTR [esi+coefDCTSIZE*4]
or eax, edx
or eax, DWORD PTR [esi+coefDCTSIZE*5]
or eax, DWORD PTR [esi+coefDCTSIZE*6]
or eax, DWORD PTR [esi+coefDCTSIZE*7]
jne @loop520
{ AC terms all zero }
{dcval := ISLOW_MULT_TYPE(inptr^[DCTSIZE*0]) *
(quantptr^[DCTSIZE*0]) shl PASS1_BITS;}
mov eax, DWORD PTR [esi+coefDCTSIZE*0]
imul eax, DWORD PTR [edi+wrkDCTSIZE*0]
shl eax, PASS1_BITS
{wsptr^[DCTSIZE*0] := dcval;
wsptr^[DCTSIZE*1] := dcval;
wsptr^[DCTSIZE*2] := dcval;
wsptr^[DCTSIZE*3] := dcval;
wsptr^[DCTSIZE*4] := dcval;
wsptr^[DCTSIZE*5] := dcval;
wsptr^[DCTSIZE*6] := dcval;
wsptr^[DCTSIZE*7] := dcval;}
mov DWORD PTR [ecx+ wrkDCTSIZE*0], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*1], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*2], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*3], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*4], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*5], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*6], eax
mov DWORD PTR [ecx+ wrkDCTSIZE*7], eax
{Inc(JCOEF_PTR(inptr)); { advance pointers to next column }
{Inc(ISLOW_MULT_TYPE_PTR(quantptr));
Inc(int_ptr(wsptr));
continue;}
dec ctr
je @loop519
add esi, Type JCOEF
add edi, Type ISLOW_MULT_TYPE
add ecx, Type int { int_ptr }
jmp @loop518
@loop520:
{end;}
{ Even part: reverse the even part of the forward DCT. }
{ The rotator is sqrt(2)*c(-6). }
{z2 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*2]) * quantptr^[DCTSIZE*2];
z3 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*6]) * quantptr^[DCTSIZE*6];
z1 := (z2 + z3) * INT32(FIX_0_541196100);
tmp2 := z1 + INT32(z3) * INT32(- FIX_1_847759065);
tmp3 := z1 + INT32(z2) * INT32(FIX_0_765366865);}
mov edx, DWORD PTR [esi+coefDCTSIZE*2]
imul edx, DWORD PTR [edi+wrkDCTSIZE*2] {z2}
mov eax, DWORD PTR [esi+coefDCTSIZE*6]
imul eax, DWORD PTR [edi+wrkDCTSIZE*6] {z3}
lea ebx, [eax+edx]
imul ebx, FIX_0_541196100 {z1}
imul eax, (-FIX_1_847759065)
add eax, ebx
mov tmp2, eax
imul edx, FIX_0_765366865
add edx, ebx
mov tmp3, edx
{z2 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*0]) * quantptr^[DCTSIZE*0];
z3 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*4]) * quantptr^[DCTSIZE*4];}
mov edx, DWORD PTR [esi+coefDCTSIZE*4]
imul edx, DWORD PTR [edi+wrkDCTSIZE*4] { z3 = edx }
mov eax, DWORD PTR [esi+coefDCTSIZE*0]
imul eax, DWORD PTR [edi+wrkDCTSIZE*0] { z2 = eax }
{tmp0 := (z2 + z3) shl CONST_BITS;
tmp1 := (z2 - z3) shl CONST_BITS;}
lea ebx,[eax+edx]
sub eax, edx
shl ebx, CONST_BITS { tmp0 = ebx }
shl eax, CONST_BITS { tmp1 = eax }
{tmp10 := tmp0 + tmp3;
tmp13 := tmp0 - tmp3;}
mov edx, tmp3
sub ebx, edx
mov tmp13, ebx
add edx, edx
add ebx, edx
mov tmp10, ebx
{tmp11 := tmp1 + tmp2;
tmp12 := tmp1 - tmp2;}
mov ebx, tmp2
sub eax, ebx
mov tmp12, eax
add ebx, ebx
add eax, ebx
mov tmp11, eax
{ Odd part per figure 8; the matrix is unitary and hence its
transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. }
{tmp0 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*7]) * quantptr^[DCTSIZE*7];}
mov eax, DWORD PTR [esi+coefDCTSIZE*7]
imul eax, DWORD PTR [edi+wrkDCTSIZE*7]
mov edx, eax { edx = tmp0 }
{tmp0 := (tmp0) * INT32(FIX_0_298631336); { sqrt(2) * (-c1+c3+c5-c7) }
imul eax, FIX_0_298631336
mov tmp0, eax
{tmp3 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*1]) * quantptr^[DCTSIZE*1];}
mov eax, DWORD PTR [esi+coefDCTSIZE*1]
imul eax, DWORD PTR [edi+wrkDCTSIZE*1]
mov tmp3, eax
{z1 := tmp0 + tmp3;}
{z1 := (z1) * INT32(- FIX_0_899976223); { sqrt(2) * (c7-c3) }
add eax, edx
imul eax, (-FIX_0_899976223)
mov z1, eax
{tmp1 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*5]) * quantptr^[DCTSIZE*5];}
mov eax, DWORD PTR [esi+coefDCTSIZE*5]
imul eax, DWORD PTR [edi+wrkDCTSIZE*5]
mov ebx, eax { ebx = tmp1 }
{tmp1 := (tmp1) * INT32(FIX_2_053119869); { sqrt(2) * ( c1+c3-c5+c7) }
imul eax, FIX_2_053119869
mov tmp1, eax
{tmp2 := ISLOW_MULT_TYPE(inptr^[DCTSIZE*3]) * quantptr^[DCTSIZE*3];}
mov eax, DWORD PTR [esi+coefDCTSIZE*3]
imul eax, DWORD PTR [edi+wrkDCTSIZE*3]
mov tmp2, eax
{z3 := tmp0 + tmp2;}
add edx, eax { edx = z3 }
{z2 := tmp1 + tmp2;}
{z2 := (z2) * INT32(- FIX_2_562915447); { sqrt(2) * (-c1-c3) }
add eax, ebx
imul eax, (-FIX_2_562915447)
mov z2, eax
{z4 := tmp1 + tmp3;}
add ebx, tmp3 { ebx = z4 }
{z5 := INT32(z3 + z4) * INT32(FIX_1_175875602); { sqrt(2) * c3 }
lea eax, [edx+ebx]
imul eax, FIX_1_175875602 { eax = z5 }
{z4 := (z4) * INT32(- FIX_0_390180644); { sqrt(2) * (c5-c3) }
{Inc(z4, z5);}
imul ebx, (-FIX_0_390180644)
add ebx, eax
mov z4, ebx
{z3 := (z3) * INT32(- FIX_1_961570560); { sqrt(2) * (-c3-c5) }
{Inc(z3, z5);}
imul edx, (-FIX_1_961570560)
add eax, edx { z3 = eax }
{Inc(tmp0, z1 + z3);}
mov ebx, z1
add ebx, eax
add tmp0, ebx
{tmp2 := (tmp2) * INT32(FIX_3_072711026); { sqrt(2) * ( c1+c3+c5-c7) }
{Inc(tmp2, z2 + z3);}
mov ebx, tmp2
imul ebx, FIX_3_072711026
mov edx, z2 { z2 = edx }
add ebx, edx
add eax, ebx
mov tmp2, eax
{Inc(tmp1, z2 + z4);}
mov eax, z4 { z4 = eax }
add edx, eax
add tmp1, edx
{tmp3 := (tmp3) * INT32(FIX_1_501321110); { sqrt(2) * ( c1+c3-c5-c7) }
{Inc(tmp3, z1 + z4);}
mov edx, tmp3
imul edx, FIX_1_501321110
add edx, eax
add edx, z1 { tmp3 = edx }
{ Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 }
{wsptr^[DCTSIZE*0] := int (DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS));}
{wsptr^[DCTSIZE*7] := int (DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS));}
mov eax, tmp10
add eax, ROUND_CONST
lea ebx, [eax+edx]
sar ebx, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*0], ebx
sub eax, edx
sar eax, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*7], eax
{wsptr^[DCTSIZE*1] := int (DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS));}
{wsptr^[DCTSIZE*6] := int (DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS));}
mov eax, tmp11
add eax, ROUND_CONST
mov edx, tmp2
lea ebx, [eax+edx]
sar ebx, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*1], ebx
sub eax, edx
sar eax, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*6], eax
{wsptr^[DCTSIZE*2] := int (DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS));}
{wsptr^[DCTSIZE*5] := int (DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS));}
mov eax, tmp12
add eax, ROUND_CONST
mov edx, tmp1
lea ebx, [eax+edx]
sar ebx, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*2], ebx
sub eax, edx
sar eax, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*5], eax
{wsptr^[DCTSIZE*3] := int (DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS));}
{wsptr^[DCTSIZE*4] := int (DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS));}
mov eax, tmp13
add eax, ROUND_CONST
mov edx, tmp0
lea ebx, [eax+edx]
sar ebx, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*3], ebx
sub eax, edx
sar eax, CONST_BITS-PASS1_BITS
mov DWORD PTR [ecx+wrkDCTSIZE*4], eax
{Inc(JCOEF_PTR(inptr)); { advance pointers to next column }
{Inc(ISLOW_MULT_TYPE_PTR(quantptr));
Inc(int_ptr(wsptr));}
dec ctr
je @loop519
add esi, Type JCOEF
add edi, Type ISLOW_MULT_TYPE
add ecx, Type int { int_ptr }
{end;}
jmp @loop518
@loop519:
{ Save to memory what we've registerized for the preceding loop. }
{ Pass 2: process rows from work array, store into output array. }
{ Note that we must descale the results by a factor of 8 == 2**3, }
{ and also undo the PASS1_BITS scaling. }
{wsptr := @workspace;}
lea esi, workspace
{for ctr := 0 to pred(DCTSIZE) do
begin}
mov ctr, 0
@loop523:
{outptr := output_buf^[ctr];}
mov eax, ctr
mov ebx, output_buf
mov edi, DWORD PTR [ebx+eax*4] { 4 = SizeOf(pointer) }
{Inc(JSAMPLE_PTR(outptr), output_col);}
add edi, uInt(output_col)
{ Rows of zeroes can be exploited in the same way as we did with columns.
However, the column calculation has created many nonzero AC terms, so
the simplification applies less often (typically 5% to 10% of the time).
On machines with very fast multiplication, it's possible that the
test takes more time than it's worth. In that case this section
may be commented out. }
{$ifndef NO_ZERO_ROW_TEST}
{if ((wsptr^[1]) or (wsptr^[2]) or (wsptr^[3]) or (wsptr^[4]) or
(wsptr^[5]) or (wsptr^[6]) or (wsptr^[7]) = 0) then
begin}
mov eax, DWORD PTR [esi+4*1]
or eax, DWORD PTR [esi+4*2]
or eax, DWORD PTR [esi+4*3]
jne @loop525 { Nomssi: early exit path may help }
or eax, DWORD PTR [esi+4*4]
or eax, DWORD PTR [esi+4*5]
or eax, DWORD PTR [esi+4*6]
or eax, DWORD PTR [esi+4*7]
jne @loop525
{ AC terms all zero }
{JSAMPLE(dcval_) := range_limit^[int(DESCALE(INT32(wsptr^[0]),
PASS1_BITS+3)) and RANGE_MASK];}
mov eax, DWORD PTR [esi+4*0]
add eax, (INT32(1) shl (PASS1_BITS+3-1))
sar eax, PASS1_BITS+3
and eax, RANGE_MASK
mov ebx, range_limit
mov al, BYTE PTR [ebx+eax]
mov ah, al
{outptr^[0] := dcval_;
outptr^[1] := dcval_;
outptr^[2] := dcval_;
outptr^[3] := dcval_;
outptr^[4] := dcval_;
outptr^[5] := dcval_;
outptr^[6] := dcval_;
outptr^[7] := dcval_;}
stosw
stosw
stosw
stosw
{Inc(int_ptr(wsptr), DCTSIZE); { advance pointer to next row }
{continue;}
add esi, wrkDCTSIZE
inc ctr
cmp ctr, DCTSIZE
jl @loop523
jmp @loop524
{end;}
@loop525:
{$endif}
{ Even part: reverse the even part of the forward DCT. }
{ The rotator is sqrt(2)*c(-6). }
{z2 := INT32 (wsptr^[2]);}
mov edx, DWORD PTR [esi+4*2] { z2 = edx }
{z3 := INT32 (wsptr^[6]);}
mov ecx, DWORD PTR [esi+4*6] { z3 = ecx }
{z1 := (z2 + z3) * INT32(FIX_0_541196100);}
lea eax, [edx+ecx]
imul eax, FIX_0_541196100
mov ebx, eax { z1 = ebx }
{tmp2 := z1 + (z3) * INT32(- FIX_1_847759065);}
imul ecx, (-FIX_1_847759065)
add ecx, ebx { tmp2 = ecx }
{tmp3 := z1 + (z2) * INT32(FIX_0_765366865);}
imul edx, FIX_0_765366865
add ebx, edx { tmp3 = ebx }
{tmp0 := (INT32(wsptr^[0]) + INT32(wsptr^[4])) shl CONST_BITS;}
{tmp1 := (INT32(wsptr^[0]) - INT32(wsptr^[4])) shl CONST_BITS;}
mov edx, DWORD PTR [esi+4*4]
mov eax, DWORD PTR [esi+4*0]
sub eax, edx
add edx, edx
add edx, eax
shl edx, CONST_BITS { tmp0 = edx }
shl eax, CONST_BITS { tmp1 = eax }
{tmp10 := tmp0 + tmp3;}
{tmp13 := tmp0 - tmp3;}
sub edx, ebx
mov tmp13, edx
add ebx, ebx
add edx, ebx
mov tmp10, edx
{tmp11 := tmp1 + tmp2;}
{tmp12 := tmp1 - tmp2;}
lea ebx, [ecx+eax]
mov tmp11, ebx
sub eax, ecx
mov tmp12, eax
{ Odd part per figure 8; the matrix is unitary and hence its
transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. }
{ The following lines no longer produce code, since wsptr has been
optimized to esi, it is more efficient to access these values
directly.
tmp0 := INT32(wsptr^[7]);
tmp1 := INT32(wsptr^[5]);
tmp2 := INT32(wsptr^[3]);
tmp3 := INT32(wsptr^[1]); }
{z2 := tmp1 + tmp2;}
{z2 := (z2) * INT32(- FIX_2_562915447); { sqrt(2) * (-c1-c3) }
mov ebx, DWORD PTR [esi+4*3] { tmp2 }
mov ecx, DWORD PTR [esi+4*5] { tmp1 }
lea eax, [ebx+ecx]
imul eax, (-FIX_2_562915447)
mov z2, eax
{z3 := tmp0 + tmp2;}
mov edx, DWORD PTR [esi+4*7] { tmp0 }
add ebx, edx { old z3 = ebx }
mov eax, ebx
{z3 := (z3) * INT32(- FIX_1_961570560); { sqrt(2) * (-c3-c5) }
imul eax, (-FIX_1_961570560)
mov z3, eax
{z1 := tmp0 + tmp3;}
{z1 := (z1) * INT32(- FIX_0_899976223); { sqrt(2) * (c7-c3) }
mov eax, DWORD PTR [esi+4*1] { tmp3 }
add edx, eax
imul edx, (-FIX_0_899976223) { z1 = edx }
{z4 := tmp1 + tmp3;}
add eax, ecx { +tmp1 }
add ebx, eax { z3 + z4 = ebx }
{z4 := (z4) * INT32(- FIX_0_390180644); { sqrt(2) * (c5-c3) }
imul eax, (-FIX_0_390180644) { z4 = eax }
{z5 := (z3 + z4) * INT32(FIX_1_175875602); { sqrt(2) * c3 }
{Inc(z3, z5);}
imul ebx, FIX_1_175875602
mov ecx, z3
add ecx, ebx { ecx = z3 }
{Inc(z4, z5);}
add ebx, eax { z4 = ebx }
{tmp0 := (tmp0) * INT32(FIX_0_298631336); { sqrt(2) * (-c1+c3+c5-c7) }
{Inc(tmp0, z1 + z3);}
mov eax, DWORD PTR [esi+4*7]
imul eax, FIX_0_298631336
add eax, edx
add eax, ecx
mov tmp0, eax
{tmp1 := (tmp1) * INT32(FIX_2_053119869); { sqrt(2) * ( c1+c3-c5+c7) }
{Inc(tmp1, z2 + z4);}
mov eax, DWORD PTR [esi+4*5]
imul eax, FIX_2_053119869
add eax, z2
add eax, ebx
mov tmp1, eax
{tmp2 := (tmp2) * INT32(FIX_3_072711026); { sqrt(2) * ( c1+c3+c5-c7) }
{Inc(tmp2, z2 + z3);}
mov eax, DWORD PTR [esi+4*3]
imul eax, FIX_3_072711026
add eax, z2
add ecx, eax { ecx = tmp2 }
{tmp3 := (tmp3) * INT32(FIX_1_501321110); { sqrt(2) * ( c1+c3-c5-c7) }
{Inc(tmp3, z1 + z4);}
mov eax, DWORD PTR [esi+4*1]
imul eax, FIX_1_501321110
add eax, edx
add ebx, eax { ebx = tmp3 }
{ Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 }
{outptr^[0] := range_limit^[ int(DESCALE(tmp10 + tmp3,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK]; }
{outptr^[7] := range_limit^[ int(DESCALE(tmp10 - tmp3,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
mov edx, tmp10
add edx, ROUND_CONST_2
lea eax, [ebx+edx]
sub edx, ebx
shr eax, CONST_BITS+PASS1_BITS+3
and eax, RANGE_MASK
mov ebx, range_limit { once for all }
mov al, BYTE PTR [ebx+eax]
mov [edi+0], al
shr edx, CONST_BITS+PASS1_BITS+3
and edx, RANGE_MASK
mov al, BYTE PTR [ebx+edx]
mov [edi+7], al
{outptr^[1] := range_limit^[ int(DESCALE(tmp11 + tmp2,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
mov eax, tmp11
add eax, ROUND_CONST_2
lea edx, [eax+ecx]
shr edx, CONST_BITS+PASS1_BITS+3
and edx, RANGE_MASK
mov dl, BYTE PTR [ebx+edx]
mov [edi+1], dl
{outptr^[6] := range_limit^[ int(DESCALE(tmp11 - tmp2,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
sub eax, ecx
shr eax, CONST_BITS+PASS1_BITS+3
and eax, RANGE_MASK
mov al, BYTE PTR [ebx+eax]
mov [edi+6], al
{outptr^[2] := range_limit^[ int(DESCALE(tmp12 + tmp1,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
mov eax, tmp12
add eax, ROUND_CONST_2
mov ecx, tmp1
lea edx, [eax+ecx]
shr edx, CONST_BITS+PASS1_BITS+3
and edx, RANGE_MASK
mov dl, BYTE PTR [ebx+edx]
mov [edi+2], dl
{outptr^[5] := range_limit^[ int(DESCALE(tmp12 - tmp1,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
sub eax, ecx
shr eax, CONST_BITS+PASS1_BITS+3
and eax, RANGE_MASK
mov al, BYTE PTR [ebx+eax]
mov [edi+5], al
{outptr^[3] := range_limit^[ int(DESCALE(tmp13 + tmp0,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
mov eax, tmp13
add eax, ROUND_CONST_2
mov ecx, tmp0
lea edx, [eax+ecx]
shr edx, CONST_BITS+PASS1_BITS+3
and edx, RANGE_MASK
mov dl, BYTE PTR [ebx+edx]
mov [edi+3], dl
{outptr^[4] := range_limit^[ int(DESCALE(tmp13 - tmp0,
CONST_BITS+PASS1_BITS+3)) and RANGE_MASK];}
sub eax, ecx
shr eax, CONST_BITS+PASS1_BITS+3
and eax, RANGE_MASK
mov al, BYTE PTR [ebx+eax]
mov [edi+4], al
{Inc(int_ptr(wsptr), DCTSIZE); { advance pointer to next row }
add esi, wrkDCTSIZE
add edi, DCTSIZE
{end;}
inc ctr
cmp ctr, DCTSIZE
jl @loop523
@loop524:
@loop496:
pop ebx
pop esi
pop edi
end;
end.