Audio and Video
Apps can play short video and audio clips while the app is active and running in the foreground. You can embed clips directly in your interface using a movie element and play video inline or using a separate interface.
Apps can play longer audio-only content through a connected Bluetooth headset when the app is inactive. Long audio clips are played in the background and are intended for apps that play music, audio books, or other long forms of audio content. Your app initiates audio playback but the system manages it.
Keep foreground audio and video clips short. The media clips in your app’s interface should be no more 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.
Use the previous end time when resuming playback of a long audio or video clip. Resuming playback at the previous stopping point lets the user quickly continue where they left off.
Use the proper encoding values for media assets. The following table lists the recommended encoding values for audio and video assets. The audio encoding values apply both to movies and audio-only assets.
|Video codec||H.264 High Profile|
|Video bit rate||160 kbps at up to 30 fps|
|Resolution (full-screen)||208px × 260px (portrait orientation)|
|Resolution (16:9)||320px × 180px (landscape orientation)|
|Audio||32 kbps stereo|