Default values for fields on an inline form

I have created an app for multitext. Django provides great tools for making everything on the website multilingual. I wanted the models that I use to display text on the website to be able to display different text versions depending on language as well.
So I have a multitext model which basically knows it’s language and it’s text. The multitext model has a foreign key relation to the headline model which lives in another app. I created an inline form for the admin page.
The app is configured like this in django settings:
# multitext configuration
‘UNIVERSAL’: ‘unive’,
‘ENGLISH’: ‘en-us’, }
# (Language, _(‘Display Name’)),

So, there is a list of the languages. At 0 index is universal which is a fall back value for languages that are not available. At 1 index is english and the list could be extended as desired.
Back to the admin form, I want the language choice fields on the inlined form to have default values. Each instance of an inline form is a formset with an index. The indeces already match. Check out this screenshot of a headline filled with values:

Universal is in the first formset with index 0, English is in the second formset with index 1. I want the default form for adding a new model to look like this. So each formset could get the language default value from MULTITEXT_CHOICES with it’s on index. However, I have no idea where to insert that code. In the admin documentation I found the method get_prepopulated_fields() (, but by it’s explanation it seems to be made for a different purpose. Also, I have no idea how I might be able to use the request object to access the fields of the inline forms.

Any hints are very welcome.