I'd like to use the DAC+ADC to make some measurements, and in order to do so, I need to capture and playback audio simultaneously - ideally aligned sample for sample between capture and playback. This is different from the alsaloop example because I need to play a fixed test signal rather than just send the captured signal straight out to the output. Is there a simple way to do this on the DAC+ADC? Perhaps writing some C code with the ALSA sound library? Or perhaps there's a better library to use? I'm just looking for some advice about where to start.