Article in English: You’ll usually find this app on the home screen. This method will help you change the file format in which your videos and photos are saved.   Most Compatible results in higher-quality photos because it saves to the JPEG format. The trade-off is that this decreases the resolution of your videos.  High Efficiency: This increases video resolution (up to 4K, depending on your phone or tablet), but photos will be saved in a slightly lower-resolution format.

Summary in Chinese:
打开iPhone的“设置”菜单。 向下滚动并点击相机。 点击格式。 根据需要选择最合适的格式。