【win32 】 波形声音

20Hz  振幅127    波形如下图



80Hz  振幅127    波形如下图



440Hz  振幅127    波形如下图



5000Hz  振幅127    波形如下图



程序代码如下

#include <windows.h>
#include <math.h>
#include "resource.h"
#pragma comment(lib,"winmm.lib")

#define SAMPLE_RATE 11025
#define FREQ_MIN 20
#define FREQ_MAX 5000
#define FREQ_INIT 440
#define OUT_BUFFER_SIZE 4096
#define PI 3.14159

TCHAR szAppName[] = TEXT("SineWave");
VOID FillBuffer(PBYTE pBuffer, int iFreq)
{
static double fAngle;
int i;
for (i = 0; i < OUT_BUFFER_SIZE; i++)
{
pBuffer[i] = (BYTE)(127 + 127 * sin(fAngle));
fAngle += 2 * PI * iFreq / SAMPLE_RATE;
if (fAngle > 2 * PI)
fAngle -= 2 * PI;
}
}
BOOL CALLBACK DlgProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static BOOL bShutOff, bClosing;
static HWAVEOUT hWaveOut;
static HWND hwndScroll;
static int iFreq = FREQ_INIT;
static PBYTE pBuffer1, pBuffer2;
static PWAVEHDR pWaveHdr1, pWaveHdr2;
static WAVEFORMATEX waveformat;
int iDummy;

switch (message)
{
case WM_INITDIALOG:
hwndScroll = GetDlgItem(hwnd, IDC_SCROLL);
SetScrollRange(hwndScroll, SB_CTL, FREQ_MIN, FREQ_MAX, FALSE);
SetScrollPos(hwndScroll, SB_CTL, FREQ_INIT, TRUE);
SetDlgItemInt(hwnd, IDC_TEXT, FREQ_INIT, FALSE);
return TRUE;
case WM_HSCROLL:
switch (LOWORD(wParam))
{
case SB_LINELEFT: iFreq -= 1; break;
case SB_LINERIGHT: iFreq += 1; break;
case SB_PAGELEFT: iFreq /= 2; break;
case SB_PAGERIGHT: iFreq *= 2; break;

case SB_THUMBTRACK:
iFreq = HIWORD(wParam);
break;
case SB_TOP:
GetScrollRange(hwndScroll, SB_CTL, &iFreq, &iDummy);
break;
case SB_BOTTOM:
GetScrollRange(hwndScroll, SB_CTL, &iDummy, &iFreq);
break;
}
iFreq = max(FREQ_MIN, min(FREQ_MAX, iFreq));
SetScrollPos(hwndScroll, SB_CTL, iFreq, TRUE);
SetDlgItemInt(hwnd, IDC_TEXT, iFreq, FALSE);
return TRUE;
case WM_COMMAND:
switch (LOWORD(wParam))
{
case IDC_ONOFF:
if (hWaveOut == NULL)
{
// Allocate memory for 2 headers and 2 buffers
pWaveHdr1 = malloc(sizeof(WAVEHDR));
pWaveHdr2 = malloc(sizeof(WAVEHDR));
pBuffer1 = malloc(OUT_BUFFER_SIZE);
pBuffer2 = malloc(OUT_BUFFER_SIZE);
// Variable to indicate Off button pressed
bShutOff = FALSE;
// Open waveform audio for output
waveformat.wFormatTag = WAVE_FORMAT_PCM;
waveformat.nChannels = 1;
waveformat.nSamplesPerSec = SAMPLE_RATE;
waveformat.nAvgBytesPerSec = SAMPLE_RATE;
waveformat.nBlockAlign = 1;
waveformat.wBitsPerSample = 8;
waveformat.cbSize = 0;
if (waveOutOpen(&hWaveOut, WAVE_MAPPER, &waveformat,(DWORD)hwnd, 0, CALLBACK_WINDOW)!= MMSYSERR_NOERROR)
{
free(pWaveHdr1);
free(pWaveHdr2);
free(pBuffer1);
free(pBuffer2);

hWaveOut = NULL;
MessageBeep(MB_ICONEXCLAMATION);
MessageBox(hwnd,TEXT("Error opening waveform audio device!"),szAppName, MB_ICONEXCLAMATION | MB_OK);
return TRUE;
}
// Set up headers and prepare them
pWaveHdr1->lpData = pBuffer1;
pWaveHdr1->dwBufferLength = OUT_BUFFER_SIZE;
pWaveHdr1->dwBytesRecorded = 0;
pWaveHdr1->dwUser = 0;
pWaveHdr1->dwFlags = 0;
pWaveHdr1->dwLoops = 0;
pWaveHdr1->lpNext = NULL;
pWaveHdr1->reserved = 0;
waveOutPrepareHeader(hWaveOut, pWaveHdr1,sizeof(WAVEHDR));

pWaveHdr2->lpData = pBuffer2;
pWaveHdr2->dwBufferLength = OUT_BUFFER_SIZE;
pWaveHdr2->dwBytesRecorded = 0;
pWaveHdr2->dwUser = 0;
pWaveHdr2->dwFlags = 0;
pWaveHdr2->dwLoops = 0;
pWaveHdr2->lpNext = NULL;
pWaveHdr2->reserved = 0;
waveOutPrepareHeader(hWaveOut, pWaveHdr2,sizeof(WAVEHDR));
}
else
{
bShutOff = TRUE;
waveOutReset(hWaveOut);
}
return TRUE;
}
break;
// Message generated from waveOutOpen call
case MM_WOM_OPEN:
SetDlgItemText(hwnd, IDC_ONOFF, TEXT("Turn Off"));
// Send two buffers to waveform output device
FillBuffer(pBuffer1, iFreq);
waveOutWrite(hWaveOut, pWaveHdr1, sizeof(WAVEHDR));
FillBuffer(pBuffer2, iFreq);
waveOutWrite(hWaveOut, pWaveHdr2, sizeof(WAVEHDR));
return TRUE;
// Message generated when a buffer is finished
case MM_WOM_DONE:
if (bShutOff)
{
waveOutClose(hWaveOut);
return TRUE;
}
// Fill and send out a new buffer
FillBuffer(((PWAVEHDR)lParam)->lpData, iFreq);
waveOutWrite(hWaveOut, (PWAVEHDR)lParam, sizeof(WAVEHDR));
return TRUE;
case MM_WOM_CLOSE:
waveOutUnprepareHeader(hWaveOut, pWaveHdr1, sizeof(WAVEHDR));
waveOutUnprepareHeader(hWaveOut, pWaveHdr2, sizeof(WAVEHDR));
free(pWaveHdr1);
free(pWaveHdr2);
free(pBuffer1);
free(pBuffer2);
hWaveOut = NULL;
SetDlgItemText(hwnd, IDC_ONOFF, TEXT("Turn On"));
if (bClosing)
EndDialog(hwnd, 0);
return TRUE;
case WM_SYSCOMMAND:
switch (wParam)
{
case SC_CLOSE:
if (hWaveOut != NULL)
{
bShutOff = TRUE;
bClosing = TRUE;
waveOutReset(hWaveOut);
}
else
EndDialog(hwnd, 0);
return TRUE;
}
break;
}
return FALSE;
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
DialogBox(hInstance, szAppName, NULL, DlgProc);
return 0;
}