auto L = make_shared<FFmpegContent>("test/data/test.mp4");
film->examine_and_add_content (L);
auto R = make_shared<FFmpegContent>("test/data/test.mp4");
auto L = make_shared<FFmpegContent>("test/data/test.mp4");
film->examine_and_add_content (L);
auto R = make_shared<FFmpegContent>("test/data/test.mp4");