Wave文件(13):waveOutGetVolume、waveOutSetVolume

Unit1;Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, StdCtrls;TForm1 &＃61; (TForm)Button1: TButton;Button2: TButton;Button3: TButton;ScrollBar1: TScrollBar;ScrollBar2: TScrollBar;FormCreate(Sender: TObject);Button1Click(Sender: TObject);Button2Click(Sender: TObject);Button3Click(Sender: TObject);ScrollBar1Change(Sender: TObject);FormDestroy(Sender: TObject);;Form1: TForm1;MMSystem;GetWaveFmtData(path: ; fmt: TWaveFormatEx; buf: TBytes): Boolean;hFile: HMMIO;ckiRIFF,ckiFmt,ckiData: TMMCKInfo;Result :&＃61; False;hFile :&＃61; mmioOpen(PChar(path), , MMIO_READ);hFile &＃61; Exit;ZeroMemory(&＃64;ckiRIFF, SizeOf(TMMCKInfo));ZeroMemory(&＃64;ckiFmt, SizeOf(TMMCKInfo));ZeroMemory(&＃64;ckiData, SizeOf(TMMCKInfo));ckiRIFF.fccType :&＃61; mmioStringToFOURCC(, );ckiFmt.ckid :&＃61; mmioStringToFOURCC(, );ckiData.ckid :&＃61; mmioStringToFOURCC(, );ZeroMemory(&＃64;fmt, SizeOf(TWaveFormatEx));mmioDescend(hFile, &＃64;ckiRIFF, , MMIO_FINDRIFF);(ckiRIFF.ckid &＃61; FOURCC_RIFF) (ckiRIFF.fccType &＃61; mmioStringToFOURCC(,)) (mmioDescend(hFile, &＃64;ckiFmt, &＃64;ckiRIFF, MMIO_FINDCHUNK) &＃61; MMSYSERR_NOERROR) (mmioRead(hFile, &＃64;fmt, ckiFmt.cksize) &＃61; ckiFmt.cksize) (mmioAscend(hFile, &＃64;ckiFmt, ) &＃61; MMSYSERR_NOERROR) (mmioDescend(hFile, &＃64;ckiData, &＃64;ckiRIFF, MMIO_FINDCHUNK) &＃61; MMSYSERR_NOERROR) SetLength(buf, ckiData.cksize);Result :&＃61; (mmioRead(hFile, PAnsiChar(buf), ckiData.cksize) &＃61; ckiData.cksize);;mmioClose(hFile, );
;wh: TWaveHdr;hWaveOut: HWAVE;fmt: TWaveFormatEx;buf: TBytes;TForm1.FormCreate(Sender: TObject);Button1.Caption :&＃61; ;Button2.Caption :&＃61; ;Button3.Caption :&＃61; ;ScrollBar1.Min :&＃61; ;ScrollBar1.Max :&＃61; ;ScrollBar2.Min :&＃61; ;ScrollBar2.Max :&＃61; ;ScrollBar2.OnChange :&＃61; ScrollBar1.OnChange;
;TForm1.ScrollBar1Change(Sender: TObject);L,R: Word;hWaveOut &＃61; Exit;L :&＃61; Trunc(ScrollBar1.Position / * MAXWORD);R :&＃61; Trunc(ScrollBar2.Position / * MAXWORD);waveOutSetVolume(hWaveOut, MakeLong(L, R));
;WaveProc(hWave: HWAVE; uMsg, dwInstance, dwParam1, dwParam2: DWORD); ;uMsg MM_WOM_DONE: waveOutUnprepareHeader(hWave, PWaveHdr(dwParam1), SizeOf(TWaveHdr));;
;TForm1.Button1Click(Sender: TObject);path &＃61; ;volume: DWORD;GetWaveFmtData(path, fmt, buf);wh.lpData :&＃61; PAnsiChar(buf);wh.dwBufferLength :&＃61; Length(buf);wh.dwBytesRecorded :&＃61; ;wh.dwUser :&＃61; ;wh.dwFlags :&＃61; WHDR_BEGINLOOP WHDR_ENDLOOP;wh.dwLoops :&＃61; ;wh.lpNext :&＃61; ;wh.reserved :&＃61; ;waveOutOpen(&＃64;hWaveOut, WAVE_MAPPER, &＃64;fmt, DWORD(&＃64;WaveProc), , CALLBACK_FUNCTION);waveOutGetVolume(hWaveOut, &＃64;volume);ScrollBar1.Position :&＃61; Trunc(LoWord(volume) / MAXWORD * );ScrollBar2.Position :&＃61; Trunc(HiWord(volume) / MAXWORD * );waveOutPrepareHeader(hWaveOut, &＃64;wh, SizeOf(TWaveHdr));waveOutWrite(hWaveOut, &＃64;wh, SizeOf(TWaveHdr));
;TForm1.Button2Click(Sender: TObject);waveOutPause(hWaveOut);
;TForm1.Button3Click(Sender: TObject);waveOutRestart(hWaveOut);
;TForm1.FormDestroy(Sender: TObject);hWaveOut <> waveOutClose(hWaveOut);
;.

窗体文件:

Form1: TForm1Left &＃61; Top &＃61; Caption &＃61; ClientHeight &＃61; ClientWidth &＃61; Color &＃61; clBtnFaceFont.Charset &＃61; DEFAULT_CHARSETFont.Color &＃61; clWindowTextFont.Height &＃61; -Font.Name &＃61; Font.Style &＃61; []OldCreateOrder &＃61; FalseOnCreate &＃61; FormCreateOnDestroy &＃61; FormDestroyPixelsPerInch &＃61; TextHeight &＃61; Button1: TButtonLeft &＃61; Top &＃61; Width &＃61; Height &＃61; Caption &＃61; TabOrder &＃61; OnClick &＃61; Button1ClickButton2: TButtonLeft &＃61; Top &＃61; Width &＃61; Height &＃61; Caption &＃61; TabOrder &＃61; OnClick &＃61; Button2ClickButton3: TButtonLeft &＃61; Top &＃61; Width &＃61; Height &＃61; Caption &＃61; TabOrder &＃61; OnClick &＃61; Button3ClickScrollBar1: TScrollBarLeft &＃61; Top &＃61; Width &＃61; Height &＃61; PageSize &＃61; TabOrder &＃61; OnChange &＃61; ScrollBar1ChangeScrollBar2: TScrollBarLeft &＃61; Top &＃61; Width &＃61; Height &＃61; PageSize &＃61; TabOrder &＃61;