How to set default meta title and description for custom post type?

I’ve searched through the documentation and forums but I cannot find any way to set the default meta title and description for a custom post type.

For example, I have a custom post type – podcast – and when I view the podcast archive (archive-podcast.php) I’d like to be able to specify the title and description – either in WP Admin or the PHP template itself.

When I view a specific podcast category, the category title and description are used for the meta data as expected. But I cant find a way to set the meta data for the base post type.

FYI I am using CPT to create the custom post types.

Any help would be great