Access log in response begin

[Kalazath]

Our servers serving static and large size video files.  We can see the
accesslog details if the response is complete. 
Can i get log at the response is being sent to client? (not when request
recieved)


request
     |
     |
     v
call reverse porxy
||
||
v-------------------- v
response       response ---> ok, i don't want any action
code: 200      code: 404
    |
    |
    v
Accesslog entry
    |
    |
   v
response is being sent to client


ps: if i am wrong, you can fix.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,225177,225177#msg-225177