staircase->set_trim_start (ContentTime::from_frames (12, 48000));
staircase->set_trim_end (ContentTime::from_frames (35, 48000));
staircase->audio->set_gain (20 * log10(2));
staircase->set_trim_start (ContentTime::from_frames (12, 48000));
staircase->set_trim_end (ContentTime::from_frames (35, 48000));
staircase->audio->set_gain (20 * log10(2));