Mine

in HTTP VHOST
RewriteCond %{HTTPS} !=on
RewriteCond %{REQUEST_URI} !^/ampache/.*\.(m3u|pls|mp3)
RewriteRule ^/(.*) https://%{SERVER_NAME}/$1 [L,R]

in SSL VHOST
RewriteCond %{REQUEST_URI} ^/ampache/!.(m3u|pls|mp3)
RewriteRule !.(m3u|pls|mp3)$ http://%{SERVER_NAME}/$1 [L,R,NC]