Kindly help me convert this htaccess to nginx directives?

ErrorDocument 404 /
ErrorDocument 500 /

Options +FollowSymlinks
RewriteEngine on
RewriteBase /

SecFilterEngine Off SecFilterScanPOST Off

RewriteCond %{SCRIPT_FILENAME} !-d
RewriteCond %{SCRIPT_FILENAME} !-f

RewriteRule ^([^./-]+)$ $1.php [L]

RewriteRule ^videos/([^./]+)$ /video-file.php?id=$1 [L]
RewriteRule ^audios/([^./]+)$ /audio-file.php?id=$1 [L]
RewriteRule ^notes/([^./]+)$ /note-file.php?id=$1 [L]
RewriteRule ^exercises/([^./]+)$ /exercise-file.php?id=$1 [L]
RewriteRule ^links/([^./]+)$ /link.php?id=$1 [L]
RewriteRule ^class/([^./]+)$ /class.php?slug=$1 [L]
RewriteRule ^subject/([^./]+)$ /subject.php?slug=$1 [L]
RewriteRule ^author/([^./]+)$ /author.php?username=$1 [L]

RewriteRule ^search/([^.]+)$ /search.php?query=$1 [L]

Posted at Nginx Forum:
http://forum.nginx.org/read.php?2,237098,237098#msg-237098

Why don’t you show us what you’ve tried; what hasn’t worked; and where
you got stuck?

That way, you get to learn about nginx, and we don’t waste our
time a) repeating things you’ve already managed to do and b) doing
your job for you!

Cheers,
Jonathan

Jonathan M. // Oxford, London, UK
http://www.jpluscplusm.com/contact.html