Question: Ryu Seung-soo was in the 2011 war film directed by whom?

Context paragraphs:
Ryu Seung-soo: Ryu Seung-soo (born August 12, 1971) is a South Korean actor.  Ryu made his acting debut in 1997 with a minor role in Park Chan-wook's film "Trio", and has been active as a supporting actor on film and television since.  Among his notable films are the monks-versus-gangsters comedy "Hi!  Dharma! " (2001), "kimchi" western "The Good, the Bad, the Weird" (2008), and Korean War movie "The Front Line" (2011).  He also appeared on TV in the quirky series "Evasive Inquiry Agency" (also known as "Four Gold Chasers", 2007), revenge drama "The Chaser" (2012), and power-struggle saga "Empire of Gold" (2013).

The Front Line (2011 film): The Front Line (; also known as "Battle of Highlands") is a 2011 South Korean war film directed by Jang Hoon, set during the 1953 ceasefire of the Korean War.  This is the third film by director Jang Hoon, after completing "Secret Reunion" and "Rough Cut".  It was selected as South Korea's submission to the 84th Academy Awards for Best Foreign Language Film, but did not make the final shortlist.  It also won four Grand Bell Awards, including Best Film.

Battlefield Heroes (film): Battlefield Heroes () is a 2011 South Korean war comedy film directed by Lee Joon-ik.  The film is a sequel to the 2003 film "Once Upon a Time in a Battlefield" and stars Jung Jin-young, Lee Moon-sik and Ryu Seung-ryong.  The film is set in 668 and chronicles the war between the southern Korean state of Shilla against the larger northern Korean state of Goguryeo.  The film's box office returns were lower than expected in South Korea, which prompted Lee Joon-ik to announce his retirement shortly after the film's release.  The film has been shown at the New York Asian Film Festival and Fantasia Festival.

The Devil's Rock: The Devil's Rock is a 2011 New Zealand supernatural horror war film produced by Leanne Saunders, directed by Paul Campion, written by Campion, Paul Finch, and Brett Ihaka, and starring Craig Hall, Matthew Sunderland, Gina Varela, and Karlos Drinkwater.  It is set in the Channel Islands on the eve of D-Day and tells the story of two New Zealand commandos who discover a Nazi occult plot to unleash a demon to win World War II.  The film combines elements of war films and supernatural horror films.  The film was theatrically released on July 8, 2011 in the United Kingdom and September 22, 2011 in New Zealand.  The film received mixed reviews from critics with the majority rating it average to above average and with many audience viewers on IMDB giving it a higher than average review.

Saints and Soldiers: Airborne Creed: Saints and Soldiers: Airborne Creed is a 2012 religious-themed war film set during the invasion of Southern France in World War II.  An example of LDS cinema from Excel Entertainment Group, it was directed by Ryan Little, written by Lamont Gray and Lincoln Hoppe and starring Corbin Allred, David Nibley, and Jasen Wade.  The film's story has no relation to the events or characters portrayed in the 2003 war film "Saints and Soldiers", although both films feature actor Corbin Allred and share a director.  It was inspired by a true story.

Jump into Hell: Jump into Hell is a 1955 war film directed by David Butler.  The film stars Jacques Sernas (billed as "Jack Sernas") and Kurt Kasznar.  The first contemporary Hollywood war film of the war in Indochina, the story is a fictionalized account of the Battle of Dien Bien Phu.

Aakraman: Aakraman is a 1975 Hindi war film.  Produced by Jagdish Kumar and directed by J. Om Prakash.  The war film stars Ashok Kumar, Sanjeev Kumar, Rekha, Rakesh Roshan, Farida Jalal, Sujit Kumar, Asrani, Keshto Mukherjee, Mumtaz Shanti and Rajesh Khanna.  The music is by Laxmikant Pyarelal.  The "Hindustan Times" noted that Rajesh Khanna in his cameo in the 1975 movie 'Aakraman' as the disabled Punjabi soldier was inspiring and motivational enhanced by the two emotional songs picturised on him.  There were 2 songs picturised on Rajesh Khanna, though he was in guest appearance in the film, playing a soldier disabled in the 1965 India-Pakistan war.

Pork Chop Hill: Pork Chop Hill is a 1959 American Korean War film starring Gregory Peck, Rip Torn and George Peppard.  The film, which was the final war film directed by Lewis Milestone, is based upon the book by U.S. military historian Brigadier General S. L. A. Marshall.  It depicts the first fierce Battle of Pork Chop Hill between the U.S. Army's 7th Infantry Division, and Chinese and North Korean forces in April 1953.

Judas Kiss (2011 film): Judas Kiss is a 2011 U.S. drama film directed by J.T. Tepnapa and written by Tepnapa and Carlos Pedraza.  It stars Charlie David, Richard Harmon, Sean Paul Lockhart, and Timo Descamps.  The film is the story of a disillusioned filmmaker’s visit to his peculiar alma mater, where he is trapped in a tug of war between his tortured past and a troubling future.

Onna no Ana: Onna no Ana (女の穴 ) is a Japanese manga written and illustrated by Fumiko Fumi and published by Tokuma Shoten on the Ryu Comics imprint on September 13, 2011.  It was adapted into a live action youth erotic science fiction film directed by Kōta Yoshida and release on June 28, 2014.

Supporting paragraphs: Ryu Seung-soo The Front Line (2011 film)
Answer: Jang Hoon