Your YI camera will record both a standard-definition and high-definition video simultanously. See the chart below for approximate recording time based on the size of your microSD memory card (1080P@25FPS only applies to the Home 2 1080p model).
Note: Your camera has a loop-recording feature. When the memory card is full, it will automatically overwrite the oldest video. This feature is turned on by default and cannot be turned off.