Function sphinxad_sys::ad_read

pub unsafe extern fn ad_read(dev: *const ad_rec_t,
                             buf: *mut i16,
                             max: u32)
                             -> i32

Read next block of audio samples while recording; read upto max samples into buf.

# Safety

Return # samples actually read (could be 0 since non-blocking); AD_EOF if not recording and no more samples remaining to be read from most recent recording.