Presented herein are techniques for creating video for participants in a video conference. A designated primary video stream is decoded and the resulting video composed in accordance with a primary sub-picture portion of a frame. Other video streams are designated as secondary video streams output by secondary entities, and are decoded and composed in accordance with a secondary sub-picture portion of the frame structured for the secondary entities. The composed primary video stream is encoded for display at each secondary entity, to obtain encoded slices of a primary video stream. The composed secondary video stream is encoded for display at one of the secondary entities, to obtain encoded slices of a secondary video stream. The encoded primary and secondary video streams are combined at the encoded slice level into a single video stream for transmission to, and decode and display at, the one of the secondary entities.