The present invention concerns a method of encoding a media bitstream of a media content. The media bitstream comprises a payload portion for the media content, and an overhead portion, different from the payload portion. The method comprises the steps of: modifying a part of the payload portion of the media bitstream, the modified part representing a region of the media content; and inserting the said part, as unmodified, into the overhead portion of the modified media bitstream for later reconstruction of the unmodified payload portion, such that the modified part in the media bitstream can be decoded without decoding the part as unmodified from the overhead portion. The invention also relates to a method of decoding, to an encoder and to a decoder.