For example, the user may watch the VR video at 360 degrees. However, at each moment, a video display region viewed by the user is only a part of the VR video. Therefore, during content preparation, VR content is divided into plurality of regions, and each region corresponds to a group of adaptive bitstreams. The client selects, based on a region viewed by the user, a corresponding video bitstream for receiving and viewing. FIG. 6 is a diagram of a change of a 360-degree viewport according to an embodiment of the present disclosure. In FIG. 6, content in a left box and content in a right box are respectively two fields of view regions of a user. When the user watches a video, the user switches a viewport from the left box to the right box by using an operation (for example, by rotating a smart helmet). After the viewport of the user is switched to the right box, a client also needs to present video content of the corresponding viewport region. Because the user views content at an arbitrary viewport location, when the user views content at a viewport, content of the viewport appears in a plurality of regions obtained by dividing VR, and the user needs to obtain video streams of more regions. It can be understood that, in existing 2D picture mapping of a VR, besides being mapped to a coordinates graph (longitude and latitude graph), a spherical surface in FIG. 6 may be mapped to another geometrical body, such as a cube or a polyhedron. The following mainly describes a 2D mapping manner of being mapped to longitude and latitude graph. Other mapping manners also fall within the scope protected and covered by the present disclosure.
