No sound output with WASAPI - visual-c++

Question

I am having trouble with WASAPI. It do not output any sound and I have been checked the data that writing to the buffer.
Because of it does not output any sound, I haven't any idea to find out the problem.
It may have some problems in following code.
SoundStream::SoundStream() : writtenCursor(0), writeCursor(0), distroy(false)
{
IMMDeviceEnumerator * pEnumerator = nullptr;
HResult(CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_ALL, IID_PPV_ARGS(&pEnumerator)));
IMMDevice * pDevice = nullptr;
HResult(pEnumerator->GetDefaultAudioEndpoint(eRender, eMultimedia, &pDevice));
SafeRelease(&pEnumerator);
HResult(pDevice->Activate(__uuidof(IAudioClient), CLSCTX_ALL, NULL, (void**)&pAudioClient));
SafeRelease(&pDevice);
WAVEFORMATEXTENSIBLE * pwfx = nullptr;
hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);
REFERENCE_TIME hnsRequestedDuration = REFTIMES_PER_SEC * 2;
HResult(pAudioClient->GetMixFormat((WAVEFORMATEX**)&pwfx));
HResult(pAudioClient->Initialize(
AUDCLNT_SHAREMODE_SHARED,
AUDCLNT_STREAMFLAGS_EVENTCALLBACK,
hnsRequestedDuration,
0,
(WAVEFORMATEX*)pwfx,
NULL));
pAudioClient->SetEventHandle(hEvent);
channel = (size_t)pwfx->Format.nChannels;
bits = (size_t)pwfx->Format.wBitsPerSample;
validBits = (size_t)pwfx->Samples.wValidBitsPerSample;
frequency = (size_t)pwfx->Format.nSamplesPerSec;
buffer.reshape({ 0, channel, bits >> 3 });
CoTaskMemFree(pwfx);
HResult(pAudioClient->GetBufferSize(&bufferFrameCount));
HResult(pAudioClient->Start());
if (pAudioClient)
{
thread = std::thread([&]()
{
this->Sync();
});
}
}

Answer 1

You could look at my WASAPI.cpp code at http://jdmcox.com (which works fine).
You should also check if the expected wave format is float:
//SubFormat 00000003-0000-0010-8000-00aa00389b71 defines KSDATAFORMAT_SUBTYPE_IEEE_FLOAT
//SubFormat 00000001-0000-0010-8000-00aa00389b71 defines KSDATAFORMAT_SUBTYPE_PCM
GUID G;
WORD V;
WAVEFORMATEX *pwfx = NULL;
bool itsfloat;
pAudioClient->GetMixFormat(&pwfx);
// Do we received a WAVEFORMATEXTENSIBLE?
if(pwfx.cbSize >= 22) {
G = ((WAVEFORMATEXTENSIBLE*)pwfx)->SubFormat;
V = ((WAVEFORMATEXTENSIBLE*)pwfx)->Samples.wValidBitsPerSample;
if (G.Data1 == 3) itsfloat = true;
else if (G.Data1 == 1) itsfloat = false;
}
You know you received a WAVEFORMATEXTENSIBLE and not a simple WAVEFORMATEX because the "pwfx.cbSize >= 22".
See more at:
IAudioClient::GetMixFormat
https://learn.microsoft.com/en-us/windows/win32/api/audioclient/nf-audioclient-iaudioclient-getmixformat
WAVEFORMATEXTENSIBLE
https://learn.microsoft.com/en-us/windows/win32/api/mmreg/ns-mmreg-waveformatextensible

Answer 2

You could look at my WASAPI.cpp code at http://jdmcox.com AGAIN.
Now it works in shared mode as well as exclusive mode.
I should note that no conversion of wave format or wave is necessary in shared mode -- Windows takes care of both converting to and from their format used to mix waves.