void CStreamSwitcherFilter::SelectInput(CStreamSwitcherInputPin* pInput)
{
// make sure no input thinks it is active
m_pInput = nullptr;
// release blocked GetBuffer in our own allocator & block all Receive
POSITION pos = m_pInputs.GetHeadPosition();
while (pos) {
CStreamSwitcherInputPin* pPin = m_pInputs.GetNext(pos);
pPin->Block(false);
// a few Receive calls can arrive here, but since m_pInput == nullptr neighter of them gets delivered
pPin->Block(true);
}
// this will let waiting GetBuffer() calls go on inside our Receive()
if (m_pOutput) {
m_pOutput->DeliverBeginFlush();
m_pOutput->DeliverEndFlush();
}
if (!pInput) {
return;
}
// set new input
m_pInput = pInput;
// let it go
m_pInput->Block(false);
}
