pulseaudio 相关网页
https://www.freedesktop.org/wiki/Software/PulseAudio/
https://gavv.github.io/articles/pulseaudio-under-the-hood/
https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/
https://freedesktop.org/software/pulseaudio/doxygen/
• alsa 官网
https://www.alsa-project.org/main/index.php/Main_Page
http://equalarea.com/paul/alsa-audio.html
• alsa doc
https://www.alsa-project.org/alsa-doc/alsa-lib/index.html