the issue (zero-copy effect) is about having one single connection to an input/writable port, so that technically the audio data that goes from the output/readable port buffer is exactly one and the same as the target input/writable buffer ie. data is there passed by reference instead of passed by value (copy).
adding one more connection to that precise input/writable port makes the issue disappear. data is copied and added (mixed) as usual.
the issue (zero-copy effect) is about having one single connection to an input/writable port, so that technically the audio data that goes from the output/readable port buffer is exactly one and the same as the target input/writable buffer ie. data is there passed by reference instead of passed by value (copy).
adding one more connection to that precise input/writable port makes the issue disappear. data is copied and added (mixed) as usual.
hth.