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SynthFilter.pas
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SynthFilter.pas
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(*
* File: $RCSfile: SynthFilter.pas,v $
* Revision: $Revision: 1.1.1.1 $
* Version : $Id: SynthFilter.pas,v 1.1.1.1 2002/04/21 12:57:23 fobmagog Exp $
* Author: $Author: fobmagog $
* Homepage: http://delphimpeg.sourceforge.net/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*)
unit SynthFilter;
{$mode delphi}
interface
uses
SysUtils, Shared;
const
ScaleFactor: Single = 32768.0; // the scalefactor scales the calculated float pcm samples to short values
type
// A class for the synthesis filter bank:
// (raw pcm samples are in [-1.0, 1.0], if no violations occur)
{ TSynthesisFilter }
TSynthesisFilter = class
private
FV1: array[0..511] of Single;
FV2: array[0..511] of Single;
FActualV: PSingleArray; // v1 or v2
FActualWritePos: Cardinal; // 0-15
FSamples: array[0..31] of Single; // 32 new subband samples
procedure ComputeNewV;
procedure ComputePCMSample(outbuffer: PInt16);
public
constructor Create();
procedure InputSample(Sample: Single; SubBandNumber: Cardinal);
// calculate 32 PCM samples
procedure CalculatePCMSamples(outbuffer: PInt16);
end;
implementation
const
MY_PI = 3.14159265358979323846;
cos1_64 : single = 1.0 / (2.0 * cos(MY_PI / 64.0));
cos3_64 : single = 1.0 / (2.0 * cos(MY_PI * 3.0 / 64.0));
cos5_64 : single = 1.0 / (2.0 * cos(MY_PI * 5.0 / 64.0));
cos7_64 : single = 1.0 / (2.0 * cos(MY_PI * 7.0 / 64.0));
cos9_64 : single = 1.0 / (2.0 * cos(MY_PI * 9.0 / 64.0));
cos11_64 : single = 1.0 / (2.0 * cos(MY_PI * 11.0 / 64.0));
cos13_64 : single = 1.0 / (2.0 * cos(MY_PI * 13.0 / 64.0));
cos15_64 : single = 1.0 / (2.0 * cos(MY_PI * 15.0 / 64.0));
cos17_64 : single = 1.0 / (2.0 * cos(MY_PI * 17.0 / 64.0));
cos19_64 : single = 1.0 / (2.0 * cos(MY_PI * 19.0 / 64.0));
cos21_64 : single = 1.0 / (2.0 * cos(MY_PI * 21.0 / 64.0));
cos23_64 : single = 1.0 / (2.0 * cos(MY_PI * 23.0 / 64.0));
cos25_64 : single = 1.0 / (2.0 * cos(MY_PI * 25.0 / 64.0));
cos27_64 : single = 1.0 / (2.0 * cos(MY_PI * 27.0 / 64.0));
cos29_64 : single = 1.0 / (2.0 * cos(MY_PI * 29.0 / 64.0));
cos31_64 : single = 1.0 / (2.0 * cos(MY_PI * 31.0 / 64.0));
cos1_32 : single = 1.0 / (2.0 * cos(MY_PI / 32.0));
cos3_32 : single = 1.0 / (2.0 * cos(MY_PI * 3.0 / 32.0));
cos5_32 : single = 1.0 / (2.0 * cos(MY_PI * 5.0 / 32.0));
cos7_32 : single = 1.0 / (2.0 * cos(MY_PI * 7.0 / 32.0));
cos9_32 : single = 1.0 / (2.0 * cos(MY_PI * 9.0 / 32.0));
cos11_32 : single = 1.0 / (2.0 * cos(MY_PI * 11.0 / 32.0));
cos13_32 : single = 1.0 / (2.0 * cos(MY_PI * 13.0 / 32.0));
cos15_32 : single = 1.0 / (2.0 * cos(MY_PI * 15.0 / 32.0));
cos1_16 : single = 1.0 / (2.0 * cos(MY_PI / 16.0));
cos3_16 : single = 1.0 / (2.0 * cos(MY_PI * 3.0 / 16.0));
cos5_16 : single = 1.0 / (2.0 * cos(MY_PI * 5.0 / 16.0));
cos7_16 : single = 1.0 / (2.0 * cos(MY_PI * 7.0 / 16.0));
cos1_8 : single = 1.0 / (2.0 * cos(MY_PI / 8.0));
cos3_8 : single = 1.0 / (2.0 * cos(MY_PI * 3.0 / 8.0));
cos1_4 : single = 1.0 / (2.0 * cos(MY_PI / 4.0));
const
//values are transposed
window: array[0..511] of Single = (
0.000000000, -0.000442505, 0.003250122, -0.007003784,
0.031082153, -0.078628540, 0.100311279, -0.572036743,
1.144989014, 0.572036743, 0.100311279, 0.078628540,
0.031082153, 0.007003784, 0.003250122, 0.000442505,
-0.000015259, -0.000473022, 0.003326416, -0.007919312,
0.030517578, -0.084182739, 0.090927124, -0.600219727,
1.144287109, 0.543823242, 0.108856201, 0.073059082,
0.031478882, 0.006118774, 0.003173828, 0.000396729,
-0.000015259, -0.000534058, 0.003387451, -0.008865356,
0.029785156, -0.089706421, 0.080688477, -0.628295898,
1.142211914, 0.515609741, 0.116577148, 0.067520142,
0.031738281, 0.005294800, 0.003082275, 0.000366211,
-0.000015259, -0.000579834, 0.003433228, -0.009841919,
0.028884888, -0.095169067, 0.069595337, -0.656219482,
1.138763428, 0.487472534, 0.123474121, 0.061996460,
0.031845093, 0.004486084, 0.002990723, 0.000320435,
-0.000015259, -0.000625610, 0.003463745, -0.010848999,
0.027801514, -0.100540161, 0.057617188, -0.683914185,
1.133926392, 0.459472656, 0.129577637, 0.056533813,
0.031814575, 0.003723145, 0.002899170, 0.000289917,
-0.000015259, -0.000686646, 0.003479004, -0.011886597,
0.026535034, -0.105819702, 0.044784546, -0.711318970,
1.127746582, 0.431655884, 0.134887695, 0.051132202,
0.031661987, 0.003005981, 0.002792358, 0.000259399,
-0.000015259, -0.000747681, 0.003479004, -0.012939453,
0.025085449, -0.110946655, 0.031082153, -0.738372803,
1.120223999, 0.404083252, 0.139450073, 0.045837402,
0.031387329, 0.002334595, 0.002685547, 0.000244141,
-0.000030518, -0.000808716, 0.003463745, -0.014022827,
0.023422241, -0.115921021, 0.016510010, -0.765029907,
1.111373901, 0.376800537, 0.143264771, 0.040634155,
0.031005859, 0.001693726, 0.002578735, 0.000213623,
-0.000030518, -0.000885010, 0.003417969, -0.015121460,
0.021575928, -0.120697021, 0.001068115, -0.791213989,
1.101211548, 0.349868774, 0.146362305, 0.035552979,
0.030532837, 0.001098633, 0.002456665, 0.000198364,
-0.000030518, -0.000961304, 0.003372192, -0.016235352,
0.019531250, -0.125259399, -0.015228271, -0.816864014,
1.089782715, 0.323318481, 0.148773193, 0.030609131,
0.029937744, 0.000549316, 0.002349854, 0.000167847,
-0.000030518, -0.001037598, 0.003280640, -0.017349243,
0.017257690, -0.129562378, -0.032379150, -0.841949463,
1.077117920, 0.297210693, 0.150497437, 0.025817871,
0.029281616, 0.000030518, 0.002243042, 0.000152588,
-0.000045776, -0.001113892, 0.003173828, -0.018463135,
0.014801025, -0.133590698, -0.050354004, -0.866363525,
1.063217163, 0.271591187, 0.151596069, 0.021179199,
0.028533936, -0.000442505, 0.002120972, 0.000137329,
-0.000045776, -0.001205444, 0.003051758, -0.019577026,
0.012115479, -0.137298584, -0.069168091, -0.890090942,
1.048156738, 0.246505737, 0.152069092, 0.016708374,
0.027725220, -0.000869751, 0.002014160, 0.000122070,
-0.000061035, -0.001296997, 0.002883911, -0.020690918,
0.009231567, -0.140670776, -0.088775635, -0.913055420,
1.031936646, 0.221984863, 0.151962280, 0.012420654,
0.026840210, -0.001266479, 0.001907349, 0.000106812,
-0.000061035, -0.001388550, 0.002700806, -0.021789551,
0.006134033, -0.143676758, -0.109161377, -0.935195923,
1.014617920, 0.198059082, 0.151306152, 0.008316040,
0.025909424, -0.001617432, 0.001785278, 0.000106812,
-0.000076294, -0.001480103, 0.002487183, -0.022857666,
0.002822876, -0.146255493, -0.130310059, -0.956481934,
0.996246338, 0.174789429, 0.150115967, 0.004394531,
0.024932861, -0.001937866, 0.001693726, 0.000091553,
-0.000076294, -0.001586914, 0.002227783, -0.023910522,
-0.000686646, -0.148422241, -0.152206421, -0.976852417,
0.976852417, 0.152206421, 0.148422241, 0.000686646,
0.023910522, -0.002227783, 0.001586914, 0.000076294,
-0.000091553, -0.001693726, 0.001937866, -0.024932861,
-0.004394531, -0.150115967, -0.174789429, -0.996246338,
0.956481934, 0.130310059, 0.146255493, -0.002822876,
0.022857666, -0.002487183, 0.001480103, 0.000076294,
-0.000106812, -0.001785278, 0.001617432, -0.025909424,
-0.008316040, -0.151306152, -0.198059082, -1.014617920,
0.935195923, 0.109161377, 0.143676758, -0.006134033,
0.021789551, -0.002700806, 0.001388550, 0.000061035,
-0.000106812, -0.001907349, 0.001266479, -0.026840210,
-0.012420654, -0.151962280, -0.221984863, -1.031936646,
0.913055420, 0.088775635, 0.140670776, -0.009231567,
0.020690918, -0.002883911, 0.001296997, 0.000061035,
-0.000122070, -0.002014160, 0.000869751, -0.027725220,
-0.016708374, -0.152069092, -0.246505737, -1.048156738,
0.890090942, 0.069168091, 0.137298584, -0.012115479,
0.019577026, -0.003051758, 0.001205444, 0.000045776,
-0.000137329, -0.002120972, 0.000442505, -0.028533936,
-0.021179199, -0.151596069, -0.271591187, -1.063217163,
0.866363525, 0.050354004, 0.133590698, -0.014801025,
0.018463135, -0.003173828, 0.001113892, 0.000045776,
-0.000152588, -0.002243042, -0.000030518, -0.029281616,
-0.025817871, -0.150497437, -0.297210693, -1.077117920,
0.841949463, 0.032379150, 0.129562378, -0.017257690,
0.017349243, -0.003280640, 0.001037598, 0.000030518,
-0.000167847, -0.002349854, -0.000549316, -0.029937744,
-0.030609131, -0.148773193, -0.323318481, -1.089782715,
0.816864014, 0.015228271, 0.125259399, -0.019531250,
0.016235352, -0.003372192, 0.000961304, 0.000030518,
-0.000198364, -0.002456665, -0.001098633, -0.030532837,
-0.035552979, -0.146362305, -0.349868774, -1.101211548,
0.791213989, -0.001068115, 0.120697021, -0.021575928,
0.015121460, -0.003417969, 0.000885010, 0.000030518,
-0.000213623, -0.002578735, -0.001693726, -0.031005859,
-0.040634155, -0.143264771, -0.376800537, -1.111373901,
0.765029907, -0.016510010, 0.115921021, -0.023422241,
0.014022827, -0.003463745, 0.000808716, 0.000030518,
-0.000244141, -0.002685547, -0.002334595, -0.031387329,
-0.045837402, -0.139450073, -0.404083252, -1.120223999,
0.738372803, -0.031082153, 0.110946655, -0.025085449,
0.012939453, -0.003479004, 0.000747681, 0.000015259,
-0.000259399, -0.002792358, -0.003005981, -0.031661987,
-0.051132202, -0.134887695, -0.431655884, -1.127746582,
0.711318970, -0.044784546, 0.105819702, -0.026535034,
0.011886597, -0.003479004, 0.000686646, 0.000015259,
-0.000289917, -0.002899170, -0.003723145, -0.031814575,
-0.056533813, -0.129577637, -0.459472656, -1.133926392,
0.683914185, -0.057617188, 0.100540161, -0.027801514,
0.010848999, -0.003463745, 0.000625610, 0.000015259,
-0.000320435, -0.002990723, -0.004486084, -0.031845093,
-0.061996460, -0.123474121, -0.487472534, -1.138763428,
0.656219482, -0.069595337, 0.095169067, -0.028884888,
0.009841919, -0.003433228, 0.000579834, 0.000015259,
-0.000366211, -0.003082275, -0.005294800, -0.031738281,
-0.067520142, -0.116577148, -0.515609741, -1.142211914,
0.628295898, -0.080688477, 0.089706421, -0.029785156,
0.008865356, -0.003387451, 0.000534058, 0.000015259,
-0.000396729, -0.003173828, -0.006118774, -0.031478882,
-0.073059082, -0.108856201, -0.543823242, -1.144287109,
0.600219727, -0.090927124, 0.084182739, -0.030517578,
0.007919312, -0.003326416, 0.000473022, 0.000015259);
{ TSynthesisFilter }
constructor TSynthesisFilter.Create();
begin
FillChar(FV1, sizeof(FV1), 0);
FillChar(FV2, sizeof(FV2), 0);
FillChar(FSamples, sizeof(FSamples), 0);
FActualV := @FV1;
FActualWritePos := 15;
end;
procedure TSynthesisFilter.InputSample(Sample: Single; SubBandNumber: Cardinal);
begin
FSamples[subbandnumber] := sample;
end;
procedure TSynthesisFilter.CalculatePCMSamples(outbuffer: PInt16);
begin
ComputeNewV;
ComputePCMSample(outbuffer);
FActualWritePos := (FActualWritePos + 1) and $f;
if (FActualV = @FV1) then
FActualV := @FV2
else
FActualV := @FV1;
FillChar(FSamples, Sizeof(FSamples), 0);
end;
function ClipInt16(Sample: Single): SmallInt;
var
v: Integer;
begin
v := Round(Sample);
if (v > 32767) then
Result := 32767
else if (v < -32768) then
Result := -32768
else
Result := v;
end;
procedure TSynthesisFilter.ComputeNewV;
var new_v: array[0..31] of Single; // new V[0-15] and V[33-48] of Figure 3-A.2 in ISO DIS 11172-3
p: array[0..15] of Single;
pp: array[0..15] of Single;
x1, x2: PSingleArray;
tmp1, tmp2: Single;
begin
// compute new values via a fast cosine transform:
x1 := @FSamples;
p[0] := x1[0] + x1[31];
p[1] := x1[1] + x1[30];
p[2] := x1[2] + x1[29];
p[3] := x1[3] + x1[28];
p[4] := x1[4] + x1[27];
p[5] := x1[5] + x1[26];
p[6] := x1[6] + x1[25];
p[7] := x1[7] + x1[24];
p[8] := x1[8] + x1[23];
p[9] := x1[9] + x1[22];
p[10] := x1[10] + x1[21];
p[11] := x1[11] + x1[20];
p[12] := x1[12] + x1[19];
p[13] := x1[13] + x1[18];
p[14] := x1[14] + x1[17];
p[15] := x1[15] + x1[16];
pp[0] := p[0] + p[15];
pp[1] := p[1] + p[14];
pp[2] := p[2] + p[13];
pp[3] := p[3] + p[12];
pp[4] := p[4] + p[11];
pp[5] := p[5] + p[10];
pp[6] := p[6] + p[9];
pp[7] := p[7] + p[8];
pp[8] := (p[0] - p[15]) * cos1_32;
pp[9] := (p[1] - p[14]) * cos3_32;
pp[10] := (p[2] - p[13]) * cos5_32;
pp[11] := (p[3] - p[12]) * cos7_32;
pp[12] := (p[4] - p[11]) * cos9_32;
pp[13] := (p[5] - p[10]) * cos11_32;
pp[14] := (p[6] - p[9]) * cos13_32;
pp[15] := (p[7] - p[8]) * cos15_32;
p[0] := pp[0] + pp[7];
p[1] := pp[1] + pp[6];
p[2] := pp[2] + pp[5];
p[3] := pp[3] + pp[4];
p[4] := (pp[0] - pp[7]) * cos1_16;
p[5] := (pp[1] - pp[6]) * cos3_16;
p[6] := (pp[2] - pp[5]) * cos5_16;
p[7] := (pp[3] - pp[4]) * cos7_16;
p[8] := pp[8] + pp[15];
p[9] := pp[9] + pp[14];
p[10] := pp[10] + pp[13];
p[11] := pp[11] + pp[12];
p[12] := (pp[8] - pp[15]) * cos1_16;
p[13] := (pp[9] - pp[14]) * cos3_16;
p[14] := (pp[10] - pp[13]) * cos5_16;
p[15] := (pp[11] - pp[12]) * cos7_16;
pp[0] := p[0] + p[3];
pp[1] := p[1] + p[2];
pp[2] := (p[0] - p[3]) * cos1_8;
pp[3] := (p[1] - p[2]) * cos3_8;
pp[4] := p[4] + p[7];
pp[5] := p[5] + p[6];
pp[6] := (p[4] - p[7]) * cos1_8;
pp[7] := (p[5] - p[6]) * cos3_8;
pp[8] := p[8] + p[11];
pp[9] := p[9] + p[10];
pp[10] := (p[8] - p[11]) * cos1_8;
pp[11] := (p[9] - p[10]) * cos3_8;
pp[12] := p[12] + p[15];
pp[13] := p[13] + p[14];
pp[14] := (p[12] - p[15]) * cos1_8;
pp[15] := (p[13] - p[14]) * cos3_8;
p[0] := pp[0] + pp[1];
p[1] := (pp[0] - pp[1]) * cos1_4;
p[2] := pp[2] + pp[3];
p[3] := (pp[2] - pp[3]) * cos1_4;
p[4] := pp[4] + pp[5];
p[5] := (pp[4] - pp[5]) * cos1_4;
p[6] := pp[6] + pp[7];
p[7] := (pp[6] - pp[7]) * cos1_4;
p[8] := pp[8] + pp[9];
p[9] := (pp[8] - pp[9]) * cos1_4;
p[10] := pp[10] + pp[11];
p[11] := (pp[10] - pp[11]) * cos1_4;
p[12] := pp[12] + pp[13];
p[13] := (pp[12] - pp[13]) * cos1_4;
p[14] := pp[14] + pp[15];
p[15] := (pp[14] - pp[15]) * cos1_4;
new_v[12] := p[7];
new_v[4] := new_v[12] + p[5];
new_v[36-17] := -new_v[4] - p[6];
new_v[44-17] := -p[6] - p[7] - p[4];
new_v[14] := p[15];
new_v[10] := new_v[14] + p[11];
new_v[6] := new_v[10] + p[13];
new_v[2] := p[15] + p[13] + p[9];
new_v[34-17] := -new_v[2] - p[14];
tmp1 := -p[14] - p[15] - p[10] - p[11];
new_v[38-17] := tmp1 - p[13];
new_v[46-17] := -p[14] - p[15] - p[12] - p[8];
new_v[42-17] := tmp1 - p[12];
new_v[48-17] := -p[0];
new_v[0] := p[1];
new_v[8] := p[3];
new_v[40-17] := -new_v[8] - p[2];
p[0] := (x1[0] - x1[31]) * cos1_64;
p[1] := (x1[1] - x1[30]) * cos3_64;
p[2] := (x1[2] - x1[29]) * cos5_64;
p[3] := (x1[3] - x1[28]) * cos7_64;
p[4] := (x1[4] - x1[27]) * cos9_64;
p[5] := (x1[5] - x1[26]) * cos11_64;
p[6] := (x1[6] - x1[25]) * cos13_64;
p[7] := (x1[7] - x1[24]) * cos15_64;
p[8] := (x1[8] - x1[23]) * cos17_64;
p[9] := (x1[9] - x1[22]) * cos19_64;
p[10] := (x1[10] - x1[21]) * cos21_64;
p[11] := (x1[11] - x1[20]) * cos23_64;
p[12] := (x1[12] - x1[19]) * cos25_64;
p[13] := (x1[13] - x1[18]) * cos27_64;
p[14] := (x1[14] - x1[17]) * cos29_64;
p[15] := (x1[15] - x1[16]) * cos31_64;
pp[0] := p[0] + p[15];
pp[1] := p[1] + p[14];
pp[2] := p[2] + p[13];
pp[3] := p[3] + p[12];
pp[4] := p[4] + p[11];
pp[5] := p[5] + p[10];
pp[6] := p[6] + p[9];
pp[7] := p[7] + p[8];
pp[8] := (p[0] - p[15]) * cos1_32;
pp[9] := (p[1] - p[14]) * cos3_32;
pp[10] := (p[2] - p[13]) * cos5_32;
pp[11] := (p[3] - p[12]) * cos7_32;
pp[12] := (p[4] - p[11]) * cos9_32;
pp[13] := (p[5] - p[10]) * cos11_32;
pp[14] := (p[6] - p[9]) * cos13_32;
pp[15] := (p[7] - p[8]) * cos15_32;
p[0] := pp[0] + pp[7];
p[1] := pp[1] + pp[6];
p[2] := pp[2] + pp[5];
p[3] := pp[3] + pp[4];
p[4] := (pp[0] - pp[7]) * cos1_16;
p[5] := (pp[1] - pp[6]) * cos3_16;
p[6] := (pp[2] - pp[5]) * cos5_16;
p[7] := (pp[3] - pp[4]) * cos7_16;
p[8] := pp[8] + pp[15];
p[9] := pp[9] + pp[14];
p[10] := pp[10] + pp[13];
p[11] := pp[11] + pp[12];
p[12] := (pp[8] - pp[15]) * cos1_16;
p[13] := (pp[9] - pp[14]) * cos3_16;
p[14] := (pp[10] - pp[13]) * cos5_16;
p[15] := (pp[11] - pp[12]) * cos7_16;
pp[0] := p[0] + p[3];
pp[1] := p[1] + p[2];
pp[2] := (p[0] - p[3]) * cos1_8;
pp[3] := (p[1] - p[2]) * cos3_8;
pp[4] := p[4] + p[7];
pp[5] := p[5] + p[6];
pp[6] := (p[4] - p[7]) * cos1_8;
pp[7] := (p[5] - p[6]) * cos3_8;
pp[8] := p[8] + p[11];
pp[9] := p[9] + p[10];
pp[10] := (p[8] - p[11]) * cos1_8;
pp[11] := (p[9] - p[10]) * cos3_8;
pp[12] := p[12] + p[15];
pp[13] := p[13] + p[14];
pp[14] := (p[12] - p[15]) * cos1_8;
pp[15] := (p[13] - p[14]) * cos3_8;
p[0] := pp[0] + pp[1];
p[1] := (pp[0] - pp[1]) * cos1_4;
p[2] := pp[2] + pp[3];
p[3] := (pp[2] - pp[3]) * cos1_4;
p[4] := pp[4] + pp[5];
p[5] := (pp[4] - pp[5]) * cos1_4;
p[6] := pp[6] + pp[7];
p[7] := (pp[6] - pp[7]) * cos1_4;
p[8] := pp[8] + pp[9];
p[9] := (pp[8] - pp[9]) * cos1_4;
p[10] := pp[10] + pp[11];
p[11] := (pp[10] - pp[11]) * cos1_4;
p[12] := pp[12] + pp[13];
p[13] := (pp[12] - pp[13]) * cos1_4;
p[14] := pp[14] + pp[15];
p[15] := (pp[14] - pp[15]) * cos1_4;
new_v[15] := p[15];
new_v[13] := new_v[15] + p[7];
new_v[11] := new_v[13] + p[11];
new_v[5] := new_v[11] + p[5] + p[13];
new_v[9] := p[15] + p[11] + p[3];
new_v[7] := new_v[9] + p[13];
tmp1 := p[13] + p[15] + p[9];
new_v[1] := tmp1 + p[1];
new_v[33-17] := -new_v[1]- p[14];
new_v[3] := tmp1 + p[5] + p[7];
new_v[35-17] := -new_v[3] - p[6] - p[14];
tmp1 := -p[10] - p[11] - p[14] - p[15];
new_v[39-17] := tmp1 - p[13] - p[2] - p[3];
new_v[37-17] := tmp1 - p[13] - p[5] - p[6] - p[7];
new_v[41-17] := tmp1 - p[12] - p[2] - p[3];
tmp2 := p[4] + p[6] + p[7];
new_v[43-17] := tmp1 - p[12] - tmp2;
tmp1 := -p[8] - p[12] - p[14] - p[15];
new_v[47-17] := tmp1 - p[0];
new_v[45-17] := tmp1 - tmp2;
// insert V[0-15] (== new_v[0-15]) into actual v:
x1 := @new_v;
x2 := @FActualV[FActualWritePos];
x2[0] := x1[0];
x2[16] := x1[1];
x2[32] := x1[2];
x2[48] := x1[3];
x2[64] := x1[4];
x2[80] := x1[5];
x2[96] := x1[6];
x2[112] := x1[7];
x2[128] := x1[8];
x2[144] := x1[9];
x2[160] := x1[10];
x2[176] := x1[11];
x2[192] := x1[12];
x2[208] := x1[13];
x2[224] := x1[14];
x2[240] := x1[15];
// V[16] is always 0.0:
x2[256] := 0.0;
// insert V[17-31] (== -new_v[15-1]) into actual v:
x2[272] := -x1[15];
x2[288] := -x1[14];
x2[304] := -x1[13];
x2[320] := -x1[12];
x2[336] := -x1[11];
x2[352] := -x1[10];
x2[368] := -x1[9];
x2[384] := -x1[8];
x2[400] := -x1[7];
x2[416] := -x1[6];
x2[432] := -x1[5];
x2[448] := -x1[4];
x2[464] := -x1[3];
x2[480] := -x1[2];
x2[496] := -x1[1];
// insert V[32] (== -new_v[0]) into other v:
if (FActualV = @FV1) then
x2 := @FV2[FActualWritePos]
else
x2 := @FV1[FActualWritePos];
x2[0] := -x1[0];
// insert V[33-48] (== new_v[16-31]) into other v:
x2[16] := x1[16];
x2[32] := x1[17];
x2[48] := x1[18];
x2[64] := x1[19];
x2[80] := x1[20];
x2[96] := x1[21];
x2[112] := x1[22];
x2[128] := x1[23];
x2[144] := x1[24];
x2[160] := x1[25];
x2[176] := x1[26];
x2[192] := x1[27];
x2[208] := x1[28];
x2[224] := x1[29];
x2[240] := x1[30];
x2[256] := x1[31];
// insert V[49-63] (==new_v[30-16]) into other v:
x2[272] := x1[30];
x2[288] := x1[29];
x2[304] := x1[28];
x2[320] := x1[27];
x2[336] := x1[26];
x2[352] := x1[25];
x2[368] := x1[24];
x2[384] := x1[23];
x2[400] := x1[22];
x2[416] := x1[21];
x2[432] := x1[20];
x2[448] := x1[19];
x2[464] := x1[18];
x2[480] := x1[17];
x2[496] := x1[16];
end;
//create 32 output samples
procedure TSynthesisFilter.ComputePCMSample(outbuffer: PInt16);
var
dp: PSingle;
pcm_sample: Single;
pcm_sample_index, i: integer;
pcm_sample_buffer: array[0..32-1] of single;
vp_buff: array[0..31] of single;
vp, vp_src: PSingle;
pcm_sample_clip: int16;
begin
pcm_sample_index := 0;
vp_src := @FActualV[0];
dp := @window[0];
//Offset the sample buffer depending on writepos. Works by inserting the samples twice
vp := @vp_buff[FActualWritePos + 1];
for i := 0 to 31 do begin
move(vp_src^, vp_buff[ 0], 16*4);
move(vp_src^, vp_buff[16], 16*4);
pcm_sample := ((
(vp[15] * dp[0]) +
(vp[14] * dp[1]) +
(vp[13] * dp[2]) +
(vp[12] * dp[3]) +
(vp[11] * dp[4]) +
(vp[10] * dp[5]) +
(vp[9] * dp[6]) +
(vp[8] * dp[7]) +
(vp[7] * dp[8]) +
(vp[6] * dp[9]) +
(vp[5] * dp[10]) +
(vp[4] * dp[11]) +
(vp[3] * dp[12]) +
(vp[2] * dp[13]) +
(vp[1] * dp[14]) +
(vp[0] * dp[15])
) * ScaleFactor);
dp += 16;
vp_src += 16;
pcm_sample_buffer[pcm_sample_index] := pcm_sample;
pcm_sample_index += 1;
end;
//pcm samples from both channels are interleaved in outbuffer, so skip every 2nd position
for i := 0 to 31 do begin
pcm_sample_clip := ClipInt16(pcm_sample_buffer[i]);
outbuffer[i * 2] := pcm_sample_clip;
end;
end;
end.