用多媒體庫 Bass.dll 播放 mp3 [5] – 設定與擷取音量、相位

本例:

代碼檔案:

unit Unit1;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, StdCtrls, ExtCtrls, ComCtrls;type  TForm1 = class(TForm)    OpenDialog1: TOpenDialog;    Button1: TButton;    Button2: TButton;    Button3: TButton;    TrackBar1: TTrackBar;    TrackBar2: TTrackBar;    Label1: TLabel;    Label2: TLabel;    procedure FormCreate(Sender: TObject);    procedure Button1Click(Sender: TObject);    procedure Button2Click(Sender: TObject);    procedure Button3Click(Sender: TObject);    procedure TrackBar1Change(Sender: TObject);    procedure TrackBar2Change(Sender: TObject);    procedure FormDestroy(Sender: TObject);  end;var  Form1: TForm1;implementation{$R *.dfm}uses Bass;var  hs: HSTREAM;  {流控制代碼}procedure TForm1.FormCreate(Sender: TObject);begin  TrackBar1.ShowSelRange := False;  TrackBar1.Min := 0;  TrackBar1.Max := 40;  TrackBar1.Position := TrackBar1.Max;  TrackBar2.ShowSelRange := False;  TrackBar2.Min := -20;  TrackBar2.Max := 20;  TrackBar2.Position := 0;  if HiWord(BASS_GetVersion)  BASSVERSION then    MessageBox(0, '"Bass.dll" 檔案版本不合適! ', nil, MB_ICONERROR);  if not BASS_Init(-1, 44100, 0, 0, nil) then    ShowMessage('初始化錯誤');end;{開啟}procedure TForm1.Button1Click(Sender: TObject);var  Mp3Path: AnsiString;begin  BASS_StreamFree(hs);  OpenDialog1.Filter := 'Mp3 檔案(*.mp3)|*.mp3|Wav 檔案(*.wav)|*wav';  if OpenDialog1.Execute then    Mp3Path := AnsiString(OpenDialog1.FileName);  hs := BASS_StreamCreateFile(False, PAnsiChar(Mp3Path), 0, 0, 0);  if hs 

表單檔案:

object Form1: TForm1  Left = 205  Top = 107  Caption = 'Form1'  ClientHeight = 157  ClientWidth = 286  Color = clBtnFace  Font.Charset = DEFAULT_CHARSET  Font.Color = clWindowText  Font.Height = -11  Font.Name = 'Tahoma'  Font.Style = []  OldCreateOrder = False  Position = poDesigned  OnCreate = FormCreate  OnDestroy = FormDestroy  PixelsPerInch = 96  TextHeight = 13  object Label1: TLabel    Left = 32    Top = 59    Width = 31    Height = 13    Caption = 'Label1'  end  object Label2: TLabel    Left = 32    Top = 109    Width = 31    Height = 13    Caption = 'Label2'  end  object Button1: TButton    Left = 24    Top = 17    Width = 75    Height = 25    Caption = #25171#24320    TabOrder = 0    OnClick = Button1Click  end  object Button2: TButton    Left = 105    Top = 17    Width = 75    Height = 25    Caption = #25773#25918    TabOrder = 1    OnClick = Button2Click  end  object Button3: TButton    Left = 186    Top = 17    Width = 75    Height = 25    Caption = #26242#20572    TabOrder = 2    OnClick = Button3Click  end  object TrackBar1: TTrackBar    Left = 24    Top = 74    Width = 237    Height = 32    TabOrder = 3    OnChange = TrackBar1Change  end  object TrackBar2: TTrackBar    Left = 24    Top = 123    Width = 237    Height = 28    TabOrder = 4    OnChange = TrackBar2Change  end  object OpenDialog1: TOpenDialog    Left = 248    Top = 32  endend