undefined.
http://www.alsa-project.org/main/index.php/Changes_v1.0.18_v1.0.19 http://www.alsa-project.org/main/index.php/Changes_v1.0.19_v1.0.20 http://www.alsa-project.org/main/index.php/Changes_v1.0.20_v1.0.21 contain ~300kB of changes.