Facebook is making several big changes to how it treats video on mobile devices. First, sound will fade in and fade out as users scroll past videos in their News Feed as long as the phone's volume is turned on. Videos will not automatically play sound when the phone's volume is set to off unless users tap on the video to hear it. People who never want to hear sound from News Feed videos can turn sound off entirely via the app's settings. Second, Facebook is taking advantage of mobile devices' form factor to make vertical videos look better. Moving forward, vertical videos will display a larger preview windows that fill more of the phone's screen. The larger format is available to all users on Android and iOS. Third, Facebook is making it easier to watch a video and scroll through the News Feed at the same time. People can minimize videos into a picture-in-picture format that will continue to play in one corner of the screen as they browse through their Feed. Facebook says Android device users will be able to keep picture-in-picture videos playing in the background even if they exit the Facebook app. Last, Facebook plans to bring its video to smart TVs and other big screens. The Facebook video app for TV will roll out soon to app stores for Apple TV, Amazon Fire TV, and Samsung Smart TV. Facebook says support for more platforms will follow. The TV app will let people watch videos from their News Feed, as well as those shared by friends, pages, or live broadcasts.