Patent ID: 6625211
Filing Date: 2003-09-23
Classification: H04N

Abstract:
A method for transforming a first data sequence generated by a first moving picture coding system having an intra-frame coding mode and an inter-frame coding mode to a second data sequence generated by a second moving picture coding system having an intra-frame coding mode and an inter-frame coding mode, the method comprising:prereading a coding mode of a successive frame succeeding a present frame from the first data sequence; judging whether or not a preread coding mode of the successive frame is the intra-frame coding mode; determining whether or not to code the present frame by the second moving picture coding system corresponding to a generated code amount of the second data sequence when the coding mode of the successive frame is the intra-frame coding mode; recording a code amount on a coding-unit basis in reading data on the coding-unit basis from the first data sequence; determining a target value of the generated code amount of the second data sequence on the coding-unit basis, the target value being obtained by multiplying a recorded code amount by a factor; performing a rate control so that the generated code amount of the second data sequence approaches the target value in generating the second data sequence from the data on the coding-unit basis by the second moving picture coding system, wherein data coded by the intra-frame coding mode existing in the first data sequence is transformed to the second data sequence, and wherein a ratio of code amounts, on the coding-unit basis, of data comprising the first data sequence approaches a ratio of code amounts, on the coding-unit basis, of data comprising the second data sequence corresponding to the first data sequence.