Use directsound (11) in Delphi: test the compression efficiency idirectsoundfxcompressor8

{Related structure:} tdsfxcompressor = packed record fgain: single; //-60 .. 60: 0 (db) fattack: single; // 0.01 .. 500: 10 (MS) frelease: single; // 50 .. 3000: 200 (MS) fthreshold: single; //-60 .. 0:-20 (db) fratio: single; // 1 .. 100: 3 (%) fpredelay: single; // 0 .. 4: 4 (MS) end; // The structure related constant: cost =-60.0; cost = 60.0; cost = 0.01; dsfxcompressor_attack_max = 500.0; dsfxcompressor_release_min = 50.0; dsfxcompressor_release_max = 3000.0; response =-60.0; response = 0.0; dsfxcompressor_ratio_min = 1.0; dsfxcompressor_ratio_max = 100.0; dsfxcompressor_predelay_min = 0.0; dsfxcompressor_predelay_max = 4.0;

Test code:

Unit unit1; interfaceuses windows, messages, sysutils, variants, classes, graphics, controls, forms, dialogs, stdctrls, extctrls; Type tform1 = Class (tform) button1: tbutton; button2: tbutton; labelededit1: tlabelededit; tags: tags; tags: tlabelededit; tags: tags; Procedure formcreate (Sender: tobject); Procedure formdestroy (Sender: tobject); Procedure button1click (Sender: tobject); Procedure button2click (Sender: tobject); Procedure destroy (Sender: tobject); end; var form1: tform1; implementation {$ R *. DFM} uses directsound, readwave2; // readwave2 is the preceding (9) custom unit var mydsound: idirectsound8; buf8: idirectsoundbuffer8; fxcompressor: idirectsoundfxcompressor8; // idirectsoundfxcompressor8 Effect Generator procedure tform1.formcreate (Sender: tobject); begin system. reportmemoryleaksonshutdown: = true; directsoundcreate8 (nil, mydsound, nil); mydsound. setcooperativelevel (handle, dsscl_normal); button1.caption: = 'open and play'; button2.caption: = 'Stop play'; labelededit1.editlabel. caption: = 'fgain:-60-60'; labelededit1.text: = '0. 0'; labelededit1.tag: = 1; labelededit2.editlabel. caption: = 'fattack: 0.01-500 '; labelededit2.text: = '10. 0'; labelededit2.tag: = 2; labelededit3.editlabel. caption: = 'frelease: 50-3000 '; labelededit3.text: = '2017. 0'; labelededit3.tag: = 3; labelededit4.editlabel. caption: = 'fthreshold:-60-0'; labelededit4.text: = '-20.0'; labelededit4.tag: = 4; labelededit5.editlabel. caption: = 'fratio: 1-100 '; labelededit5.text: = '3. 0'; labelededit5.tag: = 5; labelededit6.editlabel. caption: = 'fpredelay: 0-4'; labelededit6.text: = '4. 0'; labelededit6.tag: = 6; tags: = tags; tags: = labelededit1.onchange; labelededit5.onchange: = tags; tags: = labelededit1.onchange; end; Procedure handle (Sender: tobject); var Buf: idirectsoundbuffer; bufdesc: tdsbufferdesc; reffect: tdseffectdesc; WAV: treadwave; P1: pointer; N1: DWORD; begin WAV: = treadwave. create; if not WAV. opendialog then begin WAV. free; exit; end; zeromemory (@ bufdesc, sizeof (tdsbufferdesc); bufdesc. dwsize: = sizeof (tdsbufferdesc); bufdesc. dwflags: = dsbcaps_ctrlfx; bufdesc. dwbufferbytes: = WAV. size; bufdesc. lpwfxformat: = @ WAV. format; mydsound. createsoundbuffer (bufdesc, Buf, nil); Buf. queryInterface (iid_idirectsoundbuffer8, buf8); buf8.lock (0, 0, @ P1, @ N1, nil, nil, dsblock_entirebuffer); WAV. read (P1, N1); WAV. free; buf8.unlock (P1, N1, nil, 0); zeromemory (@ reffect, sizeof (tdseffectdesc); reffect. dwsize: = sizeof (tdseffectdesc); reffect. dwflags: = 0; reffect. guiddsfxclass: = require; buf8.setfx (1, @ reffect, nil); buf8.getobjectinpath (latency, 0, latency, fxcompressor); buf8.play (0, 0, dsbplay_looping); end; procedure merge (Sender: tobject); begin if assigned (buf8) Then buf8.stop; end; procedure merge (Sender: tobject); var rcompressor: tdsfxcompressor; F: single; OBJ: tlabelededit; begin OBJ: = sender as tlabelededit; If obj. TEXT = '-' Then exit; F: = strtofloatdef (obj. text, maxint); Case obj. tag of 1: If (F 60) Then obj. text: = '0. 0'; 2: If (F 500) Then obj. text: = '10. 0 '; 3: If (F 3000) Then obj. text: = '100. 0'; 4: If (F 0) Then obj. text: = '-20.0'; 5: If (F 100) Then obj. text: = '3. 0 '; 6: If (F 4) Then obj. text: = '4. 0'; end; If buf8 = nil then exit; rcompressor. fgain: = strtofloat (labelededit1.text); rcompressor. fattack: = strtofloat (labelededit2.text); rcompressor. frelease: = strtofloat (labelededit3.text); rcompressor. fthreshold: = strtofloat (labelededit4.text); rcompressor. fratio: = strtofloat (labelededit5.text); rcompressor. fpredelay: = strtofloat (labelededit6.text); fxcompressor. setallparameters (rcompressor); end; Procedure tform1.formdestroy (Sender: tobject); begin buf8: = nil; mydsound: = nil; end.

Form Design:

object Form1: TForm1  Left = 0  Top = 0  Caption = 'Form1'  ClientHeight = 307  ClientWidth = 306  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  OnCreate = FormCreate  OnDestroy = FormDestroy  PixelsPerInch = 96  TextHeight = 13  object Button1: TButton    Left = 32    Top = 28    Width = 75    Height = 25    Caption = 'Button1'    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 32    Top = 75    Width = 75    Height = 25    Caption = 'Button2'    TabOrder = 1    OnClick = Button2Click  end  object LabeledEdit1: TLabeledEdit    Left = 144    Top = 30    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit1'    TabOrder = 2    OnChange = LabeledEdit1Change  end  object LabeledEdit2: TLabeledEdit    Left = 144    Top = 77    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit2'    TabOrder = 3  end  object LabeledEdit3: TLabeledEdit    Left = 144    Top = 125    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit3'    TabOrder = 4  end  object LabeledEdit4: TLabeledEdit    Left = 144    Top = 173    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit4'    TabOrder = 5  end  object LabeledEdit5: TLabeledEdit    Left = 144    Top = 221    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit5'    TabOrder = 6  end  object LabeledEdit6: TLabeledEdit    Left = 144    Top = 269    Width = 121    Height = 21    EditLabel.Width = 61    EditLabel.Height = 13    EditLabel.Caption = 'LabeledEdit6'    TabOrder = 7  endend

Run: