FIND

Code:
{if $html_keywords ne ""}<META NAME="Keywords" CONTENT="{$html_keywords}">{/if}
{if $html_description ne ""}<META NAME="Description" CONTENT="{$html_description}">{/if}
REPLACE WITH

{if $html_keywords ne ""}<META NAME="Keywords" CONTENT="{$html_keywords}">{else}<META NAME="Keywords" CONTENT="ENTER YOUR KEYWORDS">{/if}
{if $html_description ne ""}<META NAME="Description" CONTENT="{$html_description}">{else}<META NAME="Description" CONTENT="ENTER YOUR DESCRIPTION">{/if}
This will allow you to specify keyword for other pages. This is not per page, but will allow you to specify keywords and description for non video pages.