Patent ID: 6954499

Claim:
A bitstream conversion apparatus comprising: a bitstream receiver to receive an incoming first moving-picture bitstream at a first code transfer rate in which the incoming first moving-picture bitstream has already been obtained by coding first pictures set at a predetermined interval and used as reference pictures for inter-picture prediction of a moving picture to be coded and coding second pictures different from the first pictures; a motion amount detector to obtain motion activity from information on activity carried by the incoming first moving-picture bitstream; a decimation controller to set a decimation rate on the second pictures of the incoming first moving-picture bitstream according to at least the motion activity; and a bitstream decimator to decimate only bitstreams of the second pictures from the incoming first moving-picture bitstream at another predetermined interval according to the decimation rate, thus outputting a second moving-picture bitstream at a second code transfer rate different from the first code transfer rate.