Question: The 70th Cannes Film Festival took place from 17 to 28 May 2017, in Cannes, France featured what opening film, a 2017 French drama film directed by Arnaud Desplechin and starred Mathieu Amalric, Marion Cotillard, Charlotte Gainsbourg and Louis Garrel?

Context paragraphs:
Frontier of the Dawn: Frontier of the Dawn (French: La Frontiere de l'Aube ) is a 2008 French drama film directed by Philippe Garrel.  The film stars Louis Garrel, Laura Smet, and Clémentine Poidatz and was photographed by cinematographer William Lubtchansky in black and white.  It premiered at the 2008 Cannes Film Festival in competition.

2017 Cannes Film Festival: The 70th Cannes Film Festival took place from 17 to 28 May 2017, in Cannes, France.  Spanish film director and screenwriter Pedro Almodóvar was the President of the Jury for the festival and Italian actress Monica Bellucci hosted the opening and closing ceremonies. " Ismael's Ghosts", directed by French director Arnaud Desplechin, was the opening film for the festival.

Playing 'In the Company of Men': Playing <nowiki>'In the Company of Men'</nowiki> (French: "En jouant <nowiki>'Dans la compagnie des hommes'</nowiki>" or French: "Léo, en jouant <nowiki>'Dans la compagnie des hommes'</nowiki>" ) is a 2003 French drama film directed by Arnaud Desplechin.  It was screened in the Un Certain Regard section at the 2003 Cannes Film Festival.

Mon Roi: Mon Roi, also known as My King, is a 2015 French drama film directed by Maïwenn.  The film stars Vincent Cassel, Emmanuelle Bercot, Louis Garrel and Isild Le Besco (Maïwenn's sister).  It was selected to compete for the Palme d'Or at the 2015 Cannes Film Festival.  At Cannes, Bercot won the award for Best Actress.

Barbara (2017 film): Barbara is a 2017 French drama film directed by Mathieu Amalric.  It was screened in the Un Certain Regard section at the 2017 Cannes Film Festival where it won The Poetry of Cinema Award.

Lover for a Day: Lover for a Day (French: L'Amant d'un jour ) is a 2017 French drama film directed by Philippe Garrel.  It was screened in the Directors' Fortnight section at the 2017 Cannes Film Festival.  At Cannes in won the SACD Award.

My Golden Days: My Golden Days (French title: Trois souvenirs de ma jeunesse; also titled My Golden Years) is a 2015 French drama film directed by Arnaud Desplechin.  It is a prequel to the 1996 film "My Sex Life... or How I Got into an Argument".  It was screened as part of the Directors' Fortnight section of the 2015 Cannes Film Festival where it won the SACD Prize.

My Sex Life... or How I Got into an Argument: My Sex Life... or How I Got into an Argument (French: "Comment je me suis disputé... (ma vie sexuelle)" ) is a 1996 French drama film directed by Arnaud Desplechin.  It was entered into the 1996 Cannes Film Festival.  It won the César Award for Most Promising Actor (Mathieu Amalric) and was also nominated for Most Promising Actress (Emmanuelle Devos and Jeanne Balibar).

A Christmas Tale: A Christmas Tale (French: Un conte de Noël ) is a 2008 French comedy-drama film by Arnaud Desplechin, starring Catherine Deneuve, Jean-Paul Roussillon, Mathieu Amalric, Anne Consigny, Melvil Poupaud, Emmanuelle Devos and Chiara Mastroianni.  It tells the story of a family with strained relationships which gathers at the parents' home for Christmas, only to learn that their mother has leukemia.  It was in competition for the Palme d'Or at the 2008 Cannes Film Festival.

Ismael's Ghosts: Ismael's Ghosts (French: Les Fantômes d'Ismaël ) is a 2017 French drama film directed by Arnaud Desplechin, starring Mathieu Amalric, Marion Cotillard, Charlotte Gainsbourg and Louis Garrel.  The film follows a filmmaker whose life is sent into a tailspin, just as he is about to start shooting a new film, by the return of his wife, who disappeared 20 years ago and whom he thought dead.  "Ismael's Ghosts" premiered at the 2017 Cannes Film Festival as the opening film.

Supporting paragraphs: 2017 Cannes Film Festival Ismael's Ghosts
Answer: Ismael's Ghosts