You can use hook_form_alter(), there is no any built-in option to do that.
You can also use the Field collection module to create a new field collection with a text field, and the video field.
Provides a field-collection field, to which any number of fields can be attached.
A field collection is internally represented as an entity, which is embedded in the host entity. Thus, if desired field collections may be viewed and edited separately too.
