There is provided according to embodiments of the invention a method of changing channels in a hybrid multicast video distribution environment, which is carried out by receiving a plurality of multicast video streams concurrently in a server, buffering first segments of the video streams respectively, wherein the first segments comprise an independently decodable frame and zero or more predicted frames, encoding the first segments to form new segments having new frame quality parameters that are less than the frame quality parameters of the first segments, assembling the first segments and the new segments into respective channel packs of the video streams, and responsively to a request, identifying one of the video streams and transmitting at least a portion of the oldest stored channel pack of the one video stream from the server to a receiving device. Related apparatus and methods are also described.