AEC回声抑制算法
AEC回声抑制算法，这个比较难，目前可以使用directsound进行处理，不过只能在xp下使用，别的系统不支持！ 目前gips对本算法有出色的实现，skype就是使用的该引擎！ 要想自己实现，恐怕很困难！
AEC 模块是 Microsoft DirectSound 底层结构的一部分。该组件包括下列特性和限制：
AEC只在不超过 25×15×9 英尺的小房间才会有效； AEC只对单声道有效，当输出是多个通道的立体声的时候，只有一个通道能够具有回波抵消的效果； AEC不能抵消来自其它声音源的声音，比如背景中收音机放出来的歌曲； IDirectSoundFullDuplex8* DirectSoundFD;// IDirectSoundCaptureBuffer8* DirectSoundCaptureBuf8;//捕捉缓冲区接口指针 IDirectSoundBuffer8* DirectSoundBuf8;//回放缓冲区接口指针 IDirectSoundBuffer8* pIUnkown;//回放缓冲区接口指针
extern "C" const GUID IID_IDirectSoundBuffer8 = {0x6825a449, 0x7524, 0x4d82,{ 0x92, 0x0f, 0x50, 0xe3, 0x6a, 0xb3, 0xab, 0x1e}}; extern "C" const GUID GUID_DSCFX_MS_NS = {0x11c5c73b, 0x66e9, 0x4ba1, {0xa0, 0xba, 0xe8, 0x14, 0xc6, 0xee, 0xd9, 0x2d}}; extern "C" const GUID GUID_DSCFX_CLASS_NS = {0xe07f903f, 0x62fd, 0x4e60, {0x8c, 0xdd, 0xde, 0xa7, 0x23, 0x66, 0x65, 0xb5}}; extern "C" const GUID GUID_DSCFX_MS_AEC = {0xcdebb919, 0x379a, 0x488a, {0x87, 0x65, 0xf5, 0x3c, 0xfd, 0x36, 0xde, 0x40}}; extern "C" const GUID GUID_DSCFX_CLASS_AEC = {0xBF963D80L, 0xC559, 0x11D0, {0x8A, 0x2B, 0x00, 0xA0, 0xC9, 0x25, 0x5A, 0xC1}}; extern "C" const GUID DAlgorithm ={0x00000000, 0x0000, 0x0000, {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}};
//1.创建及初始化DirectSound WAVEFORMATEX WaveDataFormat={WAVE_FORMAT_PCM, 1,8000,16000,2,16, 0}; //回放缓冲区。render buffer DSBUFFERDESC desc; memset(&desc, 0, sizeof(desc)); desc.dwSize = sizeof(desc); desc.dwFlags = DSBCAPS_CTRLFX | DSBCAPS_GLOBALFOCUS; desc.dwBufferBytes = 2000 * NUM_REC_NOTIFICATIONS;//待定 desc.dwReserved = 0; desc.lpwfxFormat = &WaveDataFormat;
//捕捉缓冲区AEC和NS效果。 DSCEFFECTDESC efft[2]; memset(efft, 0, sizeof(efft)); //AEC效果 efft[0].dwSize = sizeof(efft[0]); efft[0].dwFlags = DSCFX_LOCSOFTWARE; efft[0].guidDSCFXClass = GUID_DSCFX_CLASS_AEC; efft[0].guidDSCFXInstance = GUID_DSCFX_MS_AEC; //NS效果 efft[1].dwSize = sizeof(efft[1]); efft[1].dwFlags = DSCFX_LOCSOFTWARE; efft[1].guidDSCFXClass = GUID_DSCFX_CLASS_NS; efft[1].guidDSCFXInstance = GUID_DSCFX_MS_NS; //捕捉缓冲区。capture buffer DSCBUFFERDESC cdesc; memset(&cdesc, 0, sizeof(cdesc)); cdesc.dwSize = sizeof(cdesc); cdesc.dwFlags = DSCBCAPS_CTRLFX; cdesc.dwBufferBytes = 2000 * NUM_REC_NOTIFICATIONS;//待定 cdesc.lpwfxFormat = &WaveDataFormat; cdesc.dwFXCount = 2; cdesc.lpDSCFXDesc = efft;
HWND win = AfxGetApp()->m_pMainWnd->m_hWnd; hr = DirectSoundFullDuplexCreate8(0, 0,&cdesc, &desc,win, DSSCL_PRIORITY,&DirectSoundFD, &DirectSoundCaptureBuf8,&DirectSoundBuf8, 0); DXTRACE_ERR( TEXT("DirectSoundFullDuplexCreate8"), hr ); //成功创建DirectSoundFD，DirectSoundCaptureBuf8，DirectSoundBuf8，均不为零。
if(!FAILED(hr)) DirectSoundFD->QueryInterface(IID_IDirectSoundBuffer8, (void**)pIUnkown); //发现上面的pIUnkown=0，查询失败，为什么？ AfxMessageBox("失败");