title: How to use the libspotify api？
body: <p>This is the version of libspotify which I have download:libspotify-12.1.51-win32-release.There are an example named "spshell".
  when I test the track playing and sp_session_player_play(g_session, 1) be called,I can not heard any voice.</p>
  
  <p>Another question,what's the relationship between notify_main_thread and sp_session_process_events.when  sp_session_process_events (sp_session *session, int *next_timeout) is called what actually has been done and what's the effect of the second parameter.</p>