ISampleGrabber接口能否用于音频抓取？？

[xmusmart]

我知道ISampleGrabber可以用于视频采集，但是不知道能不能用于音频，请教高手们啦，谢谢！

[fenglianghuai]

可以。
1、先建类，例：
class CSampleGrabberCallback : public ISampleGrabberCB
{
public:

int nFrame;
CSampleGrabberCallback()
{
nFrame=0;
}
~CSampleGrabberCallback()
{
}
// Fake referance counting.
STDMETHODIMP_(ULONG) AddRef() { return 1; }
STDMETHODIMP_(ULONG) Release() { return 2; }

STDMETHODIMP QueryInterface(REFIID riid, void **ppvObject)
{
if (NULL == ppvObject) return E_POINTER;
if (riid == __uuidof(IUnknown))
{
*ppvObject = static_cast<IUnknown*>(this);
return S_OK;
}
if (riid == __uuidof(ISampleGrabberCB))
{
*ppvObject = static_cast<ISampleGrabberCB*>(this);
return S_OK;
}
return S_OK;
}

STDMETHODIMP SampleCB(double Time, IMediaSample *pSample)
{
if(bStop)return S_OK;
long Size=pSample->GetActualDataLength ();
BYTE * pBuf;
pSample->GetPointer(&pBuf);
return S_OK;
}

STDMETHODIMP BufferCB(double Time, BYTE *pBuffer, long BufferLen)
{
TRACE("BufferCB nFrame=%d\n",nFrame);
return S_OK;
}
};


2、然后设置回调
CSampleGrabberCallback g_CapCB;

CComQIPtr<ISampleGrabber>pGrabber;
CComQIPtr<IBaseFilter>pGrabberF;

JIF(AddFilterByCLSID(m_pGB, CLSID_SampleGrabber, L"Grabber", &pGrabberF));

pGrabberF->QueryInterface(IID_ISampleGrabber, (void**)&pGrabber);
AM_MEDIA_TYPE mt;
ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
mt.majortype = MEDIATYPE_Audio;
mt.subtype = MEDIASUBTYPE_NULL;
mt.formattype = FORMAT_WaveFormatEx;
JIF( pGrabber->SetMediaType(&mt));
JIF(pGrabber->SetCallback(&g_CapCB, 0));

[xmusmart]

感谢你的回复，不胜感激！
请问一下，应用ISampleGrabber采集的数据该怎么压缩呢？
经过传送后，能否用waveoutwrite播放呢？？

[xmusmart]

应该说数据怎么编码吧，应该用哪些函数？

[liming049]

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