/// <summary>
/// Begins an asynchronous read operation from the stream.
/// </summary>
/// <param name="pb">Pointer to a buffer that receives the data. The caller must allocate the buffer. [in]</param>
/// <param name="cb">Size of the buffer in bytes. [in]</param>
/// <param name="pCallback">Pointer to the IMFAsyncCallback interface of a callback object. The caller must implement this interface. [in]</param>
/// <param name="punkState">Pointer to the IUnknown interface of a state object, defined by the caller. This parameter can be NULL.
/// You can use this object to hold state information. The object is returned to the caller when the callback is invoked. [in]</param>
/// <returns>The result of the operation.</returns>
HRESULT StoreByteStream::BeginRead(
BYTE *pb,
ULONG cb,
IMFAsyncCallback *pCallback,
IUnknown *punkState)
{
HRESULT hr = S_OK;
// Create a new read byte container.
ReadByteContainer* readBytes = new ReadByteContainer(pb, cb);
ReadByteAsyncCallback* readCallback = new ReadByteAsyncCallback(this);
// If not created.
if (readBytes == NULL)
{
return E_OUTOFMEMORY;
}
// If not created.
if (readCallback == NULL)
{
return E_OUTOFMEMORY;
}
IMFAsyncResult *pResult = NULL;
readBytes->_readCallback = readCallback;
// Creates an asynchronous result object. Use this function if you are implementing an asynchronous method.
hr = MFCreateAsyncResult(readBytes, pCallback, punkState, &pResult);
if (SUCCEEDED(hr))
{
// Start a new work item thread.
hr = MFPutWorkItem(MFASYNC_CALLBACK_QUEUE_STANDARD, readCallback, pResult);
pResult->Release();
}
// Return the result.
return hr;
}
/** Begins an asyncronous read */
STDMETHODIMP FImfByteStream::BeginRead( BYTE* pb, ULONG cb, IMFAsyncCallback* pCallback, IUnknown* punkState )
{
HRESULT HResult = S_OK;
if( !pCallback || !pb )
return E_INVALIDARG;
IMFAsyncResult* Result = NULL;
AsyncReadState* State = new( std::nothrow ) AsyncReadState( pb, cb );
if( State == NULL )
return E_OUTOFMEMORY;
HResult = MFCreateAsyncResult( State, pCallback, punkState, &Result );
State->Release( );
if( SUCCEEDED( HResult ) )
{
IsCurrentlyReading = true;
HResult = MFPutWorkItem( MFASYNC_CALLBACK_QUEUE_STANDARD, this, Result );
Result->Release( );
}
return HResult;
}
