As shown, change WAV file content is repeated three times, the last time, after calling pcm_writei, immediately call the pcm_close,
So the last part is not fully play out, but has not found in the tinyalsa like snd_pcm_drain interface, then,
I call delay again after 1 s pcm_close directly, found in the following part was repeatedly broadcast a final time,

I ask, is there any interface can accurate know tinyalsa buff interface, the audio data is all the air in
Or where I might be an error,