Problem rewriting links in htaccess

Hey, I have "index.php?" in my links, I have searched for a solution all over the forum
and I could'nt find something that works for me.

"http://mywebsite.com/index.php?video/xxxxxx"
I am trying to change it to "http://mywebsite.com/video/xxxxxx"

now, I have tried to it in htaccess with no success.

RewriteEngine on
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ /index.php?/$1 [L]

What I am doing wrong? HELP