BeginInput
virtual BSimpleMediaInput* BeginInput();
BSimpleMediaInput* input = sConsumer->BeginInput();
BMediaInput* input = sConsumer->BeginInput();
BMediaInput* input = sConsumer->BeginInput();
BMediaInput* filterInput = sFilter->BeginInput();
assert(sFilter->Connect(output, sConsumers[i]->BeginInput()) == B_OK);
sFilter->BeginInput()) == B_OK);
BMediaInput* input = sFilter->BeginInput();
assert(sFilter->Connect(input, sConsumers[i]->BeginInput()) == B_OK);
assert(sConsumer->Connect(sConsumer->BeginInput(),