void make_silent (int from, int frames);
void apply_gain (float);
void copy_from (AudioBuffers const * from, int frames_to_copy, int read_offset, int write_offset);
void copy_channel_from (AudioBuffers const * from, int from_channel, int to_channel);
void make_silent (int from, int frames);
void apply_gain (float);
void copy_from (AudioBuffers const * from, int frames_to_copy, int read_offset, int write_offset);
void copy_channel_from (AudioBuffers const * from, int from_channel, int to_channel);