let _bytes_per_packet = br.read_u32be()?;
let bytes_per_frame = br.read_u32be()?;
let _bytes_per_sample = br.read_u32be()?;
track.bsize = bytes_per_frame as usize;
let _bytes_per_packet = br.read_u32be()?;
let bytes_per_frame = br.read_u32be()?;
let _bytes_per_sample = br.read_u32be()?;
track.bsize = bytes_per_frame as usize;