Abstract: An apparatus for forming a plug in a casing includes a body of plug material and a carrier for insertion into a casing. The carrier supports the body of plug material. The carrier includes a mandrel and at least two circular flanges spaced apart along the mandrel. The carrier also includes a heater for heating the mandrel. The mandrel is heated to a temperature above the melting point of the material and the plug material slumps into the casing between the at least two circular flanges. The at least two circular flanges force the expanded solidifying plug material against the casing which aids the transfer of heat between the mandrel and the plug material, and resists creep of the solidified material along the casing.

Abstract: Disclosed is a method for coding video in which a predetermined algorithm is used to predict portions of the image based on information that will already be available to the decoder at the time of decoding the image. By using known corresponding algorithms in both coder and decoder, and only information that will be available to the decoder, the need to transmit detailed information regarding choices made in coding, e.g. motion vectors is avoided. However, a vector relationship can still be derived for use in the prediction. Prediction can be made based on an assumption that the content of the portion to be coded is similar to the content of an associated image portion, and by determining a vector relating the associated image portion to a reference image (both of which will be available to the decoder), the current image portion can be predicted from a further part of the reference image. The invention can be used in a form of modified pyramid coding.