This disclosure relates to the field of video processing technologies. The method includes: receiving, by the media asset subsystem, an indication message, where the indication message is used to indicate to add a medium file corresponding to a second video stream to the target media asset medium; obtaining a content source medium of the target video based on the indication message; sending the content source medium of the target video to a transcoding subsystem, so that the transcoding subsystem generates the medium file corresponding to the second video stream, where first information of the second video stream is the same as first information of the first video stream, and the first information includes whether a key frame is an IDR frame and location information of the key frame; and receiving the medium file that corresponds to the second video stream and that is sent by the transcoding subsystem.