How to make jointure query on laravel morphTo relation with conditions on custom model

I don't know if the title is clear, but I have some tables like : - video - post - comment with commentable_id, commentable_type. How to count videos with comments and with specific attribute like size (eg: between 10 and 25), and count posts with comments from specific author? This is a simple example. I just want to means that the condition for videos query is based on specific videos field and same for posts. I do not want to check with similare field like "id" or created_at, updated_by. How could this be possible? Thank you

via Chebli Mohamed