Question

我尝试写一个音调发生器。我只是想输出一个440Hz的正弦波，这种方法很有效，但每当我更新缓冲区时我都会听到咔哒声（我猜）。

这是我的更新代码：

HANDLE hEvent[2];
hEvent[0] = CreateEvent(NULL, FALSE, FALSE, L"NOTIFY0");
hEvent[1] = CreateEvent(NULL, FALSE, FALSE, L"NOTIFY1");


LPDIRECTSOUNDNOTIFY8 lpDsNotify;
DSBPOSITIONNOTIFY PositionNotify[2];
HRESULT hr;

if (SUCCEEDED(
    hr = lpDsbSecondary->QueryInterface(IID_IDirectSoundNotify8,
    (LPVOID*)&lpDsNotify)))
{
    PositionNotify[0].dwOffset = 0;
    PositionNotify[0].hEventNotify = hMyEvent[0];
    PositionNotify[1].dwOffset = 5000;
    PositionNotify[1].hEventNotify = hMyEvent[1];
    hr = lpDsNotify->SetNotificationPositions(2, PositionNotify);
    lpDsNotify->Release();
}

long time = 0;
short* waveData = new short[5000];
m_secondaryBuffer1->SetCurrentPosition(0);
m_secondaryBuffer1->SetVolume(DSBVOLUME_MAX);
m_secondaryBuffer1->Play(0, 0, DSBPLAY_LOOPING);

while (true)
{
    HRESULT hr = WaitForMultipleObjects(2, hEvent, FALSE, 0);
    if (hr == WAIT_OBJECT_0)
    {
        for (int x = 0; x<5000; x++)
        {
            waveData[x] = createWave(time, 440.0f);
            time++;
        }
        IFA->UpdateBufferData(&(m_secondaryBuffer1), 5000, waveData, 5000);
    }
    if (hr == WAIT_OBJECT_0 + 1)
    {
        for (int x = 0; x<5000; x++)
        {
            waveData[x] = createWave(time, 440.0f);
            time++;
        }
        IFA->UpdateBufferData(&(m_secondaryBuffer1), 0, waveData, 5000);
    }
}

创建二级缓冲区：

    int error;
FILE* filePtr;
unsigned int count;
WaveHeaderType waveFileHeader;
WAVEFORMATEX waveFormat;
DSBUFFERDESC bufferDesc;
HRESULT result;
IDirectSoundBuffer* tempBuffer;
unsigned char* bufferPtr;
unsigned long bufferSize;


waveFormat.wFormatTag = WAVE_FORMAT_PCM;
waveFormat.nSamplesPerSec = 44100;
waveFormat.wBitsPerSample = 16;
waveFormat.nChannels = 1;
waveFormat.nBlockAlign = (waveFormat.wBitsPerSample / 8) * waveFormat.nChannels;
waveFormat.nAvgBytesPerSec = waveFormat.nSamplesPerSec * waveFormat.nBlockAlign;
waveFormat.cbSize = 0;

bufferDesc.dwSize = sizeof(DSBUFFERDESC);
bufferDesc.dwFlags = DSBCAPS_CTRLVOLUME | DSBCAPS_GLOBALFOCUS | DSBCAPS_CTRLPOSITIONNOTIFY;
bufferDesc.dwBufferBytes = 100000;
bufferDesc.dwReserved = 0;
bufferDesc.lpwfxFormat = &waveFormat;
bufferDesc.guid3DAlgorithm = GUID_NULL;

result = m_DirectSound->CreateSoundBuffer(&bufferDesc, &tempBuffer, NULL);
if(FAILED(result)) return;

result = tempBuffer->QueryInterface(IID_IDirectSoundBuffer8, (void**)&*secondaryBuffer);
if(FAILED(result)) return;

tempBuffer->Release();
tempBuffer = 0;

这是createWave：

short waveSIN(int x, float frequency)
{
return (short)(32767.0f * sinf(frequency * 2.0f * M_PI * ( ( float ) x / 44100.0f )     ));
}

我做错了什么？

DirectSound Stream-Buffer点击噪音

0 个答案: