let length = ainfo.format.get_audio_size(len.unwrap() as u64);
let data: Vec<u8> = vec![0; length];
let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride: 0, step: 0 };
let length = ainfo.format.get_audio_size(len.unwrap() as u64);
let data: Vec<u8> = vec![0; length];
let buf: NAAudioBuffer<u8> = NAAudioBuffer { data: NABufferRef::new(data), info: ainfo, offs, chmap, len: nsamples, stride: 0, step: 0 };