Before smart phones and other portable playback devices were widespread, people only could watch their purchased Blu-ray/DVD discs on DVD players at home, and then put those optical discs away safely and watched them again later on. However, the popularity of smart phones has completely changed this situation in recent years, , apart from watching on Blu-ray/DVD player at home, people can re-distribute Blu-rays/DVDs onto iPad, iPhone, iPod, PSP, or other portable devices and watch movies whenever and wherever they…