assert (mixdown_buffer && gain_buffer);
for (size_t channel = 0; channel < n_channels; ++channel) {
memset (mixdown_buffer.get(), 0, sizeof (Sample) * frames);
assert (mixdown_buffer && gain_buffer);
for (size_t channel = 0; channel < n_channels; ++channel) {
memset (mixdown_buffer.get(), 0, sizeof (Sample) * frames);