It sounds as if it could be Francois Truffaut's " L'Amour en Fuite ",( " Love on the Run " ) the last film in his Antoine Doinel series. It, of course, starred Jean-Pierre Leaud who had played Doinel in Truffaut's first film " Les Quatre Cents Coups " ( " The Four Hundred Blows " ) also Claude Jade appearred as his ex-wife and Marie-France Pisier reprised the role of Collette from the second film in the series ( a short " Antoine and Collette " collected in the film  " Love at Twenty " ). Doinel's love interest in the film was played by the French pop-star Dorothee who played the owner of a record store.    