The rules of this Chapter shall be applied in all criminal cases tried in the district, parish, and city courts. They shall be applicable following the institution of prosecution by the return of a grand jury indictment, the filing of a bill of information, or the filing of an affidavit charging an offense. However, the rules of this Chapter do not apply in city and parish courts to cases in which prosecution is instituted by affidavit for violations of city or parish ordinances defining traffic offenses.