Patent ID: 8036268

Claim:
A moving image/picture encoding apparatus configured to transcode an input stream into an output stream, the input stream being a fixed-rate MPEG-2 stream whose bit-rate is controlled to be constant by changing a quantization parameter, the apparatus comprising: an information acquisition module configured to acquire information on a quantization scale, a num of generated bits and a picture type for each frame from the input stream; an encoding complexity calculation module configured to calculate, for each of the frames, encoding complexity represented in a form of S X Q gi by using the information acquired in the information acquisition module, where Q denotes an average quantization scale of the frame, S denotes a num of bits of the frame, gi denotes a fixed value determined for each picture type and being independent of image as long as the picture type is same, postfix i of the fixed value gi indicates the picture type, and X denotes a product; an encoding complexity conversion module configured to convert the encoding complexity calculated by the encoding complexity calculation module into encoding complexity of the output stream by using a linear function prepared for each of the picture types and indicating a relation between the encoding complexity of the input stream and the encoding complexity of the output stream, where the encoding complexity of the input stream is a function of the fixed value gi being independent of the image as long as the picture type is same, and the linear function shows a linearity within a changeable range of the encoding complexity of the input stream; and a transcode module configured to re-encode the input stream into the output stream by using the encoding complexity of the output stream converted by the encoding complexity conversion module, wherein the re-encoding by the transcode module is performed for each of the frames by using the linear function prepared for each of the picture types, and the transcode module includes a num of bits allocation module configured to allocate a num of bits to be used in the re-encoding to each of group of pictures contained in a sequence of the input stream.