let nch = ainfo.get_channels() as usize;
let mut offs: Vec<usize> = Vec::with_capacity(nch);
for ch in 0..nch { offs.push($buf.get_offset(ch)); }
let nch = ainfo.get_channels() as usize;
let mut offs: Vec<usize> = Vec::with_capacity(nch);
for ch in 0..nch { offs.push($buf.get_offset(ch)); }