轉載自:http://blog.chinaunix.net/uid-8272118-id-2033248.html
網上有很多方法從麥克風讀取PCM數據，不想一一舉例。只是在這里發布一個我自己寫的directsound的麥克風PCM數據采集類，通過它，可以很方便的利用directsound技術把麥克風的數據采集到，而且本身，開發者不必太在意自己會不會directsound編程，可以很方便的讓開發者的主要精力集中于程序本身，而不是細節。
這個是頭文件：
#pragma once
#ifndef _CAPTURE_SOUND_H_
#define _CAPTURE_SOUND_H_
#include <mmsystem.h>
#include <dsound.h>
#define NUM_REC_NOTIFICATIONS 16
class CAdoFrameHandler 
{
public:
virtual void AdoFrameData(BYTE* pBuffer, long lBufferSize) = 0 ;
};
class CCaptureAudio
{
public:
BOOL m_bRecording ; //recording now ? also used by event recv thread
protected:
LPDIRECTSOUNDCAPTURE8 m_pCapDev ; //capture device ptr
LPDIRECTSOUNDCAPTUREBUFFER m_pCapBuf ; //capture loop buffer ptr
LPDIRECTSOUNDNOTIFY8 m_pNotify ; //capture auto-notify event callback handler ptr
GUID m_guidCapDevId ; //capture device id
WAVEFORMATEX m_wfxInput; //input wave format description struct
DSBPOSITIONNOTIFY m_aPosNotify[NUM_REC_NOTIFICATIONS + 1]; //notify flag array
HANDLE m_hNotifyEvent; //notify event
BOOL m_abInputFmtSupported[20];
DWORD m_dwCapBufSize; //capture loop buffer size
DWORD m_dwNextCapOffset;//offset in loop buffer
DWORD m_dwNotifySize; //notify pos when loop buffer need to emit the event
CAdoFrameHandler* m_frame_handler ; // outer frame data dealer ptr
public: // callback func to add enum devices string name
static BOOL CALLBACK enum_dev_proc(LPGUID lpGUID, LPCTSTR lpszDesc,
LPCTSTR lpszDrvName, LPVOID lpContext ) ;
static UINT notify_capture_thd(LPVOID data) ;
protected:
HRESULT InitDirectSound(GUID dev_id = GUID_NULL) ;
HRESULT FreeDirectSound() ;
HRESULT InitNotifications() ;
HRESULT CreateCaptureBuffer(WAVEFORMATEX * wfx) ;
HRESULT StartOrStopRecord(BOOL bStartRec) ;
HRESULT RecordCapturedData() ;
void SetWavFormat(WAVEFORMATEX * wfx) ;
public:
CCaptureAudio(void);
~CCaptureAudio(void);
BOOL EnumDevices(HWND hList) ;
BOOL Open(void) ;
BOOL Close() ;
void GrabAudioFrames(BOOL bGrabAudioFrames, CAdoFrameHandler* frame_handler) ;
};
#endif
下面這個是cpp文件：
#include "StdAfx.h"
#include ".\captureaudio.h"
#include <mmsystem.h>
#include <dsound.h>
#ifndef SAFE_DELETE
#define SAFE_DELETE(p) { if(p) { delete (p); (p)=NULL; } }
#endif
#ifndef SAFE_RELEASE
#define SAFE_RELEASE(p) { if(p) { (p)->Release(); (p)=NULL; } }
#endif
#ifndef MAX
#define MAX(a,b) ( (a) > (b) ? (a) : (b) )
#endif
CCaptureAudio::CCaptureAudio(void)
{
if(FAILED(CoInitialize(NULL))) /**//*, COINIT_APARTMENTTHREADED)))*/
{
AfxMessageBox("CCaptureAudio CoInitialize Failed!\r\n");
return;
}
m_pCapDev = NULL ;
m_pCapBuf = NULL ;
m_pNotify = NULL ;
// set default wave format PCM
ZeroMemory( &m_wfxInput, sizeof(m_wfxInput));
m_wfxInput.wFormatTag = WAVE_FORMAT_PCM;
m_guidCapDevId = GUID_NULL ;
m_bRecording = FALSE ;
m_hNotifyEvent = NULL ;
}
CCaptureAudio::~CCaptureAudio(void)
{
CoUninitialize() ;
}
BOOL CALLBACK CCaptureAudio::enum_dev_proc(LPGUID lpGUID, LPCTSTR lpszDesc,
LPCTSTR lpszDrvName, LPVOID lpContext)
{
HWND hList = (HWND)lpContext;
if(!hList) return FALSE ;
LPGUID lpTemp = NULL;
if (lpGUID != NULL) {
// NULL only for "Primary Sound Driver".
if ((lpTemp = (LPGUID)malloc(sizeof(GUID))) == NULL) return(TRUE);
memcpy(lpTemp, lpGUID, sizeof(GUID));
}
::SendMessage(hList, CB_ADDSTRING, 0,(LPARAM)lpszDesc);
::SendMessage(hList, LB_SETITEMDATA, 0, (LPARAM)lpTemp) ;
free(lpTemp);
return(TRUE);
}
UINT CCaptureAudio::notify_capture_thd(LPVOID data)
{
CCaptureAudio * pado = static_cast<CCaptureAudio *>(data) ;
MSG msg;
HRESULT hr ;
DWORD dwResult ;
while(pado->m_bRecording) {
dwResult = MsgWaitForMultipleObjects( 1, &(pado->m_hNotifyEvent), FALSE, INFINITE, QS_ALLEVENTS );
switch( dwResult ) {
case WAIT_OBJECT_0 + 0:
// g_hNotificationEvents[0] is signaled
// This means that DirectSound just finished playing
// a piece of the buffer, so we need to fill the circular
// buffer with new sound from the wav file
if( FAILED( hr = pado->RecordCapturedData() ) ) {
AfxMessageBox("Error handling DirectSound notifications.") ;
pado->m_bRecording = FALSE ;
}
break;
case WAIT_OBJECT_0 + 1:
// Windows messages are available
while( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) ) {
TranslateMessage( &msg );
DispatchMessage( &msg );
if( msg.message == WM_QUIT ) pado->m_bRecording = FALSE ;
}
break;
}
}
AfxEndThread(0, TRUE) ;
return 0 ;
}
BOOL CCaptureAudio::EnumDevices(HWND hList)
{
if (FAILED(DirectSoundCaptureEnumerate (
(LPDSENUMCALLBACK)(CCaptureAudio::enum_dev_proc),
(VOID*)&hList)))
{
return(FALSE);
}
return (TRUE) ;
}
BOOL CCaptureAudio::Open(void)
{
HRESULT hr ;
if(!m_bRecording) {
hr = InitDirectSound() ;
}
return (FAILED(hr)) ? FALSE : TRUE ;
}
BOOL CCaptureAudio::Close()
{
HRESULT hr ;
hr = FreeDirectSound() ;
CloseHandle(m_hNotifyEvent) ;
return (FAILED(hr)) ? FALSE : TRUE ;
}
HRESULT CCaptureAudio::InitDirectSound(GUID dev_id)
{
HRESULT hr ;
m_guidCapDevId = dev_id ;
ZeroMemory( &m_aPosNotify, sizeof(DSBPOSITIONNOTIFY) * (NUM_REC_NOTIFICATIONS + 1) ) ;
m_dwCapBufSize = 0 ;
m_dwNotifySize = 0 ;
// Create IDirectSoundCapture using the preferred capture device
hr = DirectSoundCaptureCreate(&m_guidCapDevId, &m_pCapDev, NULL ) ;
// init wave format
SetWavFormat(&m_wfxInput) ;
return (FAILED(hr)) ? S_FALSE : S_OK ;
}
HRESULT CCaptureAudio::FreeDirectSound()
{
// Release DirectSound interfaces
SAFE_RELEASE( m_pNotify ) ;
SAFE_RELEASE( m_pCapBuf ) ;
SAFE_RELEASE( m_pCapDev ) ;
return S_OK;
}
HRESULT CCaptureAudio::CreateCaptureBuffer(WAVEFORMATEX * wfx)
{
HRESULT hr;
DSCBUFFERDESC dscbd;
SAFE_RELEASE( m_pNotify );
SAFE_RELEASE( m_pCapBuf );
// Set the notification size
m_dwNotifySize = MAX( 1024, wfx->nAvgBytesPerSec / 8 ) ;
m_dwNotifySize -= m_dwNotifySize % wfx->nBlockAlign ;
// Set the buffer sizes
m_dwCapBufSize = m_dwNotifySize * NUM_REC_NOTIFICATIONS;
SAFE_RELEASE( m_pNotify );
SAFE_RELEASE( m_pCapBuf );
// Create the capture buffer
ZeroMemory( &dscbd, sizeof(dscbd) );
dscbd.dwSize = sizeof(dscbd);
dscbd.dwBufferBytes = m_dwCapBufSize;
dscbd.lpwfxFormat = wfx ; // Set the format during creatation
if( FAILED( hr = m_pCapDev->CreateCaptureBuffer( &dscbd, &m_pCapBuf, NULL ) ) )
return S_FALSE ;
m_dwNextCapOffset = 0;
if( FAILED( hr = InitNotifications() ) )
return S_FALSE ;
return S_OK;
}
HRESULT CCaptureAudio::InitNotifications()
{
HRESULT hr;
int i ;
if( NULL == m_pCapBuf )
return S_FALSE;
// create auto notify event
m_hNotifyEvent = CreateEvent( NULL, FALSE, FALSE, NULL );
// Create a notification event, for when the sound stops playing
if( FAILED( hr = m_pCapBuf->QueryInterface( IID_IDirectSoundNotify, (VOID**)&m_pNotify ) ) )
return S_FALSE ;
// Setup the notification positions
for( i = 0; i < NUM_REC_NOTIFICATIONS; i++ ) {
m_aPosNotify[i].dwOffset = (m_dwNotifySize * i) + m_dwNotifySize - 1;
m_aPosNotify[i].hEventNotify = m_hNotifyEvent;
}
// Tell DirectSound when to notify us. the notification will come in the from
// of signaled events that are handled in WinMain()
if( FAILED( hr = m_pNotify->SetNotificationPositions( NUM_REC_NOTIFICATIONS, m_aPosNotify ) ) )
return S_FALSE ;
return S_OK;
}
HRESULT CCaptureAudio::StartOrStopRecord(BOOL bStartRec)
{
HRESULT hr;
if( bStartRec ) {
// Create a capture buffer, and tell the capture
// buffer to start recording
if( FAILED( hr = CreateCaptureBuffer( &m_wfxInput ) ) )
return S_FALSE ;
if( FAILED( hr = m_pCapBuf->Start( DSCBSTART_LOOPING ) ) )
return S_FALSE ;
// create notify event recv thread
AfxBeginThread(CCaptureAudio::notify_capture_thd, (LPVOID)(this)) ;
} else {
// Stop the capture and read any data that
// was not caught by a notification
if( NULL == m_pCapBuf )
return S_OK;
// wait until the notify_event_thd thread exit and release the resources.
Sleep(500) ;
// Stop the buffer, and read any data that was not
// caught by a notification
if( FAILED( hr = m_pCapBuf->Stop() ) )
return S_OK ;
if( FAILED( hr = RecordCapturedData() ) )
return S_FALSE ;
}
return S_OK;
}
HRESULT CCaptureAudio::RecordCapturedData()
{
HRESULT hr;
VOID* pbCaptureData = NULL;
DWORD dwCaptureLength;
VOID* pbCaptureData2 = NULL;
DWORD dwCaptureLength2;
DWORD dwReadPos;
DWORD dwCapturePos;
LONG lLockSize;
if( NULL == m_pCapBuf )
return S_FALSE;
if( FAILED( hr = m_pCapBuf->GetCurrentPosition( &dwCapturePos, &dwReadPos ) ) )
return S_FALSE;
lLockSize = dwReadPos - m_dwNextCapOffset;
if( lLockSize < 0 )
lLockSize += m_dwCapBufSize;
// Block align lock size so that we are always write on a boundary
lLockSize -= (lLockSize % m_dwNotifySize);
if( lLockSize == 0 )
return S_FALSE;
// Lock the capture buffer down
if( FAILED( hr = m_pCapBuf->Lock( m_dwNextCapOffset, lLockSize,
&pbCaptureData, &dwCaptureLength,
&pbCaptureData2, &dwCaptureLength2, 0L ) ) )
return S_FALSE ;
// call the outer data handler
if(m_frame_handler) {
m_frame_handler->AdoFrameData((BYTE*)pbCaptureData, dwCaptureLength) ;
}
// Move the capture offset along
m_dwNextCapOffset += dwCaptureLength;
m_dwNextCapOffset %= m_dwCapBufSize; // Circular buffer
if( pbCaptureData2 != NULL ) {
// call the outer data handler
if(m_frame_handler) {
m_frame_handler->AdoFrameData((BYTE*)pbCaptureData, dwCaptureLength) ;
}
// Move the capture offset along
m_dwNextCapOffset += dwCaptureLength2;
m_dwNextCapOffset %= m_dwCapBufSize; // Circular buffer
}
// Unlock the capture buffer
m_pCapBuf->Unlock( pbCaptureData, dwCaptureLength, pbCaptureData2, dwCaptureLength2 );
return S_OK;
}
void CCaptureAudio::SetWavFormat(WAVEFORMATEX * wfx)
{
// get the default capture wave formate
ZeroMemory(wfx, sizeof(WAVEFORMATEX)) ;
wfx->wFormatTag = WAVE_FORMAT_PCM;
// 8KHz, 16 bits PCM, Mono
wfx->nSamplesPerSec = 8000 ;
wfx->wBitsPerSample = 16 ;
wfx->nChannels = 1 ;
wfx->nBlockAlign = wfx->nChannels * ( wfx->wBitsPerSample / 8 ) ;
wfx->nAvgBytesPerSec = wfx->nBlockAlign * wfx->nSamplesPerSec;
}
void CCaptureAudio::GrabAudioFrames(BOOL bGrabAudioFrames, CAdoFrameHandler* frame_handler)
{
m_frame_handler = frame_handler ;
m_bRecording = bGrabAudioFrames ;
StartOrStopRecord(m_bRecording) ;
}
使用的時候，也很簡單，我這里聲明了一個純虛類CAdoFrameHandler，這個類專門是用來讓使用者重載它的純虛函數的，只要重載了以后，設置正確，就可以自動開始采集音頻數據了。注意，在這個類里面，我用的是8KHz,16Bits,Mono單聲道的PCM數據采集。
使用的時候，首先：
#include "CaptureAudio.h" 然后：
class CMyClass : public CAdoFrameHandler {
public: // override the CAdoFrameHandler
void AdoFrameData(BYTE* pBuffer, long lBufferSize) ; // 這個類重載一下，就可以采集了
protected:
CCaptureAudio m_cap_ado ; // 這個對象就是用來采集音頻數據的
} ;
在OnInitDialog類中，我們可以使用如下初始化方法：
打開mic，同時初始化directsound：
m_cap_ado.Open() ;
開始采集聲音就是：
m_cap_ado.GrabAudioFrames(TRUE, this) ; 調用它以后，只要你重載了上面的那個函數，directsound就會周期性的從麥克采集數據，然后調用該函數。
停止聲音采集是：
m_cap_ado.GrabAudioFrames(FALSE, NULL) ;
關閉mic，同時釋放directsound：
m_cap_ado.Close() ;
就這么簡單的幾步，就可以完成麥克風的音頻數據采集。
有問題歡迎大家多多交流。