Method CanGetFrame

This page is a copy of the original page on the AVObjects' web site and can also be viewed here.

The method checks the ability to get data from AV object.

HRESULT CanGetFrame(
    [in] int nStream,
    [in] DWORD nWait
    );

Parameters:

nStream Number of stream
nWait   Response time in microseconds.

Returns:

S_OK                                 Object ready for get data
S_FALSE                              Object is busy
HRESULT_FROM_WIN32(ERROR_HANDLE_EOF) End of stream
E_INVALIDARG                         One or more arguments are invalid
E_FAIL                               Object not initialized yet or other failure.

Copy stream

//BYTE* pbBuffer - pointer to frame buffer
//DWORD cbBuffer - size of frane buffer in bytes
//int nStream - index of stream
 
HRESULT hr = S_OK;
while(1)
{
  hr = spDest->CanPutFrame(nStream, INFINITE);
  if ( hr != S_OK )
     return hr;
 
  hr = spSource->CanGetFrame(nStream, INFINITE);
  if (hr != S_OK)
    return hr;
 
  DWORD cbActual = 0;
  REFERENCE_TIME tS = 0, tE = 0;
  DWORD dwFlags = 0;
 
  hr = spSource->GetFrame(nStream, pbBuffer, cbBuffer,
    &cbActual, &dwFlags, &tS, &tE, NULL);
  if (hr == S_OK)
  {
     hr = spDest->PutFrame(nStream, m_pbBuffer, cbActual, 
        dwFlags, tS, tE, NULL);
  }
  else if (hr == HRESULT_FROM_WIN32(ERROR_HANDLE_EOF))
  {
     // EOS, put empty frame to dest
     hr = spDest->PutFrame(nStream, NULL, 0, 0, 0, 0, NULL);
     if (hr == S_OK)
        return hr;
  }  
  if (FAILED(hr))
    return hr;
}