Methods and systems described herein provide for combining multiple data streams representing respective videos into an output data stream. An example implementation may involve receiving a first data stream that represent a first video and a second data stream that represent a second video. The first data stream and the second data stream may include a first sequence of frames that includes first intra-coded frames and a second sequence of frames that includes second intra-coded frames, respectively. The example implementation may further involve combining the received first data stream and the received second data stream to obtain an output data stream of encoded output frames such that an encoded output frame includes a respective frame of the first sequence and a respective frame of the second sequence and that first intra-coded frames are combined with respective second intra-coded frames in respective encoded output frames within the output stream.