Method and arrangement for personalized video encoding

When generating an encoded composed video stream based on a common video stream and at least one input stream of personalized information, at least one intermediate stream is generated by mixing the at least one input stream into the common video stream in predetermined positions of the common video stream, taking into account a macroblock grouping in slices, and the at least one intermediate stream is encoded, thereby generating at least one encoded intermediate stream by using the macroblock grouping. The common video stream is encoded using the macroblock grouping, thereby generating an encoded common video stream. The encoded common video stream and the at least one encoded intermediate stream are combined and filtered such that per frame and per slice sequence number only one slice of one stream is selected for forming the encoded composed video stream.