let ret = strmgr.add_stream(NAStream::new(StreamType::Video, stream_id, vinfo, tb_num, tb_den, (frm_per_chunk * num_chunks) as u64));
if ret.is_some() {
stream_id += 1;
let ret = strmgr.add_stream(NAStream::new(StreamType::Video, stream_id, vinfo, tb_num, tb_den, (frm_per_chunk * num_chunks) as u64));
if ret.is_some() {
stream_id += 1;