How can I restart synchronous reading from webcamera every time it fails? - ms-media-foundation

Question

I am trying to read from a web camera in synchronous mode using Microsoft Media Foundation:
#include <iostream>
#include <vector>
#include <sstream>
#include <atlbase.h>
#include <mfidl.h>
#include <Mfapi.h>
#include <Mfreadwrite.h>
#pragma comment(lib,"Mfplat.lib")
#pragma comment(lib,"Mf.lib")
#pragma comment(lib,"Mfreadwrite.lib")
#pragma comment(lib,"mfuuid.lib")
#pragma comment(lib,"shlwapi.lib")
int main()
{
HRESULT hr;
DWORD dwCoInit = COINIT_MULTITHREADED;
hr = CoInitializeEx(NULL, dwCoInit);
if (FAILED(hr))
return -1;
hr = MFStartup(MF_VERSION);
if (FAILED(hr))
return -2;
CComBSTR name("M034-WDR");
CComPtr<IMFMediaSource> pMediaSource;
CComPtr<IMFSourceReader> pSourceReader;
CComPtr<IMFMediaType> pMediaType;
// Find all camera sources:
CComPtr<IMFAttributes> pAttributes;
MFCreateAttributes(&pAttributes, 1);
pAttributes->SetGUID(MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE, MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID); // camera source
CComHeapPtr<IMFActivate*> ppActivates;
UINT32 nActivateCount = 0;
MFEnumDeviceSources(pAttributes, &ppActivates, &nActivateCount);
// Loop over the camera sources, find the one with correct name:
CComPtr<IMFActivate> pActivate;
for (UINT32 nIndex = 0; nIndex < nActivateCount; nIndex++) {
CComHeapPtr<WCHAR> name_i;
UINT32 length;
ppActivates[nIndex]->GetAllocatedString(MF_DEVSOURCE_ATTRIBUTE_FRIENDLY_NAME, &name_i, &length);
if (wcscmp(name_i, name) == 0) {
pActivate = ppActivates[nIndex];
}
reinterpret_cast<CComPtr<IMFActivate>&>(ppActivates[nIndex]).Release();
}
if (!pActivate) { // camera with name not found
return -3;
}
IMFMediaSource* source;
hr = pActivate->ActivateObject(__uuidof(IMFMediaSource), (VOID**)&source);
if (FAILED(hr))
return -4;
pMediaSource = source;
hr = MFCreateSourceReaderFromMediaSource(pMediaSource, NULL, &pSourceReader);
if (FAILED(hr))
return -5;
IMFMediaType* mediaType;
hr = pSourceReader->GetCurrentMediaType((DWORD)MF_SOURCE_READER_FIRST_VIDEO_STREAM, &mediaType);
if (FAILED(hr))
return -6;
unsigned int width, height;
hr = MFGetAttributeSize(mediaType, MF_MT_FRAME_SIZE, &width, &height);
if (FAILED(hr))
return -7;
while (true) {
CComPtr<IMFSample> pSample;
DWORD dwControlFlags = 0;
DWORD* pdwActualStreamIndex = NULL;
DWORD pdwStreamFlags;
LONGLONG timestamp;
OutputDebugStringA("MF:Before ReadSample()");
hr = pSourceReader->ReadSample(0,//dwStreamIndex,
dwControlFlags,
pdwActualStreamIndex,
&pdwStreamFlags,
&timestamp,
&pSample);
OutputDebugStringA("MF:After ReadSample()");
if (FAILED(hr)) {
std::stringstream ss;
ss << "MF:ReadSample() failed. hr = " << std::hex << hr << ".";
OutputDebugStringA(ss.str().c_str());
}
if (pSample == NULL) {
OutputDebugStringA("MF:ReadSample(): got null sample.");
}
}
}
The code above works fine on my laptop with one such webcam.
On another PC with another such webcam however; it runs fine for ca 1 minute before it starts to fail:
00000920 54.00323105 [7008] MF:Before ReadSample()
00000921 54.00324631 [7008] MF:After ReadSample()
00000922 54.00325012 [7008] MF:ReadSample() failed. hr = c00d3ea2.
00000923 54.00326538 [7008] MF:ReadSample(): got null sample.
Looking up the error code:
C:\temp>Err_6.4.5.exe c00d3ea2
# for hex 0xc00d3ea2 / decimal -1072873822
MF_E_VIDEO_RECORDING_DEVICE_INVALIDATED mferror.h
# The video recording device is no longer present.%0
Anyways the Microsoft Camera application also experiences problems. Every minute ca. the image goes black for 1 sec ca. before the camera appears to be restarted.
How can I restart my code like Microsoft Camera does?