First I have to thank Joe Herman for his project https://github.com/jphfilm/rpi-film-capture. My project is not a fork because all the software part has been rewritten. However, the concept and whole hardware part takes up Joe's ideas.
The app works for me and I captured several hours of movies. However the code is still experimental and requires some polishing.
Documentation (in french ! Google translate is your best friend)
Note that this documentation dates from the beginning of the project and may be obsolete at some points. It is essential to consult the Google group, which contains all the advice and experiences of the users.
Google group