unpack_sample.rs

// Samples are delta-encoded
pub fn unpack_sample<T: Default + ops::AddAssign + Clone>(input: &[u8])
                                                          -> Result<Vec<T>, &'static str> {
    if input.len() % mem::size_of::<T>() != 0 {
        return Err("packed sample data is not aligned");
    }

    let packed_sample: &[T] = unsafe {
        slice::from_raw_parts(input.as_ptr() as *const T,
                              input.len() / mem::size_of::<T>())
    };

    let mut unpacked_sample = Vec::<T>::with_capacity(packed_sample.len());
    let mut last_sample: T = T::default();
    for delta in packed_sample {
        last_sample += *delta;
        unpacked_sample.push(last_sample);
    }
    Ok(unpacked_sample)
}