waveInClose/Reset/Stop - no msg

Question

我正在用waveInProc回調進行音頻採樣。問題是，當我試圖停止採樣並關閉音頻設備時，我在回調中沒有找到味精 - 嘗試過waveInStop，waveInClose，waveInReset。

請指教。 10xs， 那鴻

HWAVEIN hWaveIn 
waveInOpen(&hWaveIn,WAVE_MAPPER,&waveform,(DWORD)waveInProc,0, CALLBACK_FUNCTION); 
waveInStart(hWaveIn); 

waveInStop(hWaveIn); //OR 
waveInClose(hWaveIn); //OR 
waveInReset(hWaveIn); //OR 

更新：這裏是代碼：

開始：

waveInOpen(&hWaveIn,WAVE_MAPPER,&waveform,(DWORD)waveInProc,0, CALLBACK_FUNCTION); 
waveInPrepareHeader(hWaveIn,pWaveHdr1,sizeof(WAVEHDR)); 
waveInAddBuffer(hWaveIn,pWaveHdr1,sizeof(WAVEHDR)); 
waveInStart(hWaveIn); 

---

void CALLBACK waveInProc( HWAVEIN hwi, UINT uMsg, DWORD dwInstance, 
          DWORD dwParam1, DWORD  dwParam2 ) 
    { 

    if (uMsg == WIM_OPEN) 
    { 
    return; 
    } 
    if (uMsg == WIM_DATA) 
    { 
    //process data 
    waveInAddBuffer(hWaveIn,(PWAVEHDR)dwParam1,sizeof(WAVEHDR)); 
    return; 
    } 
    if (uMsg == WIM_CLOSE) //NOT GETTING THIS MSG 

    { 
     printf("*****************got WIM_CLOSE\n"); 
    } 
} 

---

那麼如何停止採樣，並關閉音頻設備？

---

下面是代碼： 開始：

waveInOpen(&hWaveIn,WAVE_MAPPER,&waveform,(DWORD)waveInProc,0, CALLBACK_FUNCTION); 
waveInPrepareHeader(hWaveIn,pWaveHdr1,sizeof(WAVEHDR)); 
waveInAddBuffer(hWaveIn,pWaveHdr1,sizeof(WAVEHDR)); 
waveInStart(hWaveIn); 

---

void CALLBACK waveInProc( HWAVEIN hwi, UINT uMsg, DWORD dwInstance, 
          DWORD dwParam1, DWORD  dwParam2 ) 
    { 

    if (uMsg == WIM_OPEN) 
    { 
    return; 
    } 
    if (uMsg == WIM_DATA) 
    { 
    //process data 
    waveInAddBuffer(hWaveIn,(PWAVEHDR)dwParam1,sizeof(WAVEHDR)); 
    return; 
    } 
    if (uMsg == WIM_CLOSE) //NOT GETTING THIS MSG 

    { 
     printf("*****************got WIM_CLOSE\n"); 
    } 
} 

---

那麼如何停止採樣，並關閉音頻設備？

10xs， 那鴻

Answer 1

你檢查你的waveInOpen結果呢？

因爲它按預期工作：

hWaveIn 0x005B7768, nMessage 0x03BE, nInstance 0, nParameter1 0, nParameter2 0 
nWaveInOpenResult 0, hWaveIn 0x005B7768 
hWaveIn 0x005B7768, nMessage 0x03BF (WIM_CLOSE), nInstance 0, nParameter1 0, nParameter2 0 

代碼：

#include "stdafx.h" 
#include <mmsystem.h> 

#pragma comment(lib, "winmm.lib") 

VOID CALLBACK waveInProc(HWAVEIN hWaveIn, UINT nMessage, DWORD_PTR nInstance, DWORD_PTR nParameter1, DWORD_PTR nParameter2) 
{ 
    _tprintf(_T("hWaveIn 0x%p, nMessage 0x%04X, nInstance %d, nParameter1 %d, nParameter2 %d\n"), hWaveIn, nMessage, nInstance, nParameter1, nParameter2); 
} 

int _tmain(int argc, _TCHAR* argv[]) 
{ 
    WAVEFORMATEX Format = { WAVE_FORMAT_PCM, 1, 8000, 16000, 2, 16, 0 }; 
    HWAVEIN hWaveIn = NULL; 
    const MMRESULT nWaveInOpenResult = waveInOpen(&hWaveIn, WAVE_MAPPER, &Format, (DWORD_PTR) &waveInProc, 0, CALLBACK_FUNCTION); 
    _tprintf(_T("nWaveInOpenResult %d, hWaveIn 0x%p\n"), nWaveInOpenResult, hWaveIn); 
    waveInStart(hWaveIn); 
    waveInStop(hWaveIn); 
    waveInClose(hWaveIn); 
    return 0; 
} 

而在實際的代碼處理數據一定要考慮到這一點：within the callback function：

應用不應該調用任何系統定義的函數期從內部 的回調函數，除了EnterCriticalSection的， LeaveCriticalSection，midiOutLongMsg，midiOutShortMsg， OutputDebugString的，PostMessage的，PostThreadMessage，SetEvent的， timeGetSystemTime，timeGetTime，timeKillEvent，和的timeSetEvent。 調用其他波函數將導致死鎖。

要重新添加緩衝，則需要通過信令到另一個線程，使用PostMessage或SetEvent來表示，如需要，所以回調之外您的代碼可以接收該指示，並從重新添加空緩衝區那裏。