아이폰 동영상에 자막 넣는 방법을 잘 설명해주네요~
http://1manshow.net/entry/%EC%95%84%EC%9D%B4%ED%8F%B0%EB%B6%80%ED%84%B0-%EC%95%84%EC%9D%B4%ED%8C%A8%EB%93%9C%EA%B9%8C%EC%A7%80-%EC%9E%90%EB%A7%89-%EC%BC%B0%EB%8B%A4%EA%BB%8F%EB%8B%A4%EB%A5%BC-%EB%8D%94-%EC%89%BD%EA%B2%8C-MP4-Track-Editor