Movie elements display a poster image and, when tapped, present audio or video modally. Inline movie elements present audio or video inline without displaying a modal interface. Use these elements to incorporate short media clips into the rest of your content. Playback of media files is managed by the system
Keep audio and video clips short. Clips should be no longer than 30 seconds, and shorter is preferred. Long clips consume more disk space and require users to keep their wrists raised for longer periods of time, which can cause fatigue.
Size video clips appropriately. Use the recommended sizes for clips whenever possible. Scaling video clips affects performance and results in a suboptimal appearance. For information about the recommended sizes and encoding values, see Audio and Video.
Use a poster image that is representative of the clip’s contents. Poster images let people make informed decisions about whether to view the clip associated with a movie. Do not use images that have nothing to do with the clip.
Do not create poster images that look like system controls. For movie elements, make audio and video content feel like part of your interface. Don’t hide them by making them look like something else.