| 摘要 |
<p>PURPOSE: To keep the degradation of picture quality and tone quality at the time of decoding irreversibly encoded moving pictures and music, performing an editing processing and then irreversibly encoding them within a certain limit. CONSTITUTION: At the time of taking out and decoding irreversibly encoded compression data or self-concluded partial data (example: GOP unit) in the compression data, the history of the number of times of the decoding/encoding processings of the data is referred to and the propriety of decoding is determined. In the case of being suitable, a desired editing processing (example: superimposed character insertion or the like) is performed to the decoded data and thereafter, irreversible encoding is performed again. At the time, history information is updated and added. The history information is written in the user area of a GOP layer in the case of being based on MPEG. Also, in the case of taking out partial data, they are returned to an original position where the partial data were present before being taken out.</p> |
