CoursePress allow more file type on upload

I want to give users upload video file at some unit. I tried this codes but didn't help. How can I solve this?
add_filter('upload_mimes', 'custom_upload_mimes');
function custom_upload_mimes ( $existing_mimes = array() ) {
$existing_mimes['flv'] = 'video/x-flv';
$existing_mimes['mp4'] = 'video/mp4';
$existing_mimes['3gp'] = 'video/3gpp';
$existing_mimes['mov'] = 'video/quicktime';
$existing_mimes['wmv'] = 'video/x-ms-wmv';
$existing_mimes['webm'] = 'video/webm';
$existing_mimes['ogg'] = 'video/ogg';

return $existing_mimes;
}