| 摘要 |
Blocks of each of successive frames of a motion picture signal are classified into classified blocks in accordance either with selected schemes for use in adaptive prediction encoding the signal or with whether the selected schemes are restricted or not. On encoding each classified block, a quantization parameter is decided based on an amount of codes produced per classified block. The codes are stored in a buffer, and delivered outwardly of the buffer at a predetermined code rate while the remaining codes are reserved in the buffer. The quantization parameter is also based on an initial amount of the reserved codes kept in the buffer at a beginning of each frame, a code amount characteristic value, and an amount of codes assigned to each classified block. The code amount characteristic value is calculated by a product of the quantization parameter and the amount of codes produced. The amount of codes assigned to each classified block is based on the amount of codes produced, an individual amount of the reserved codes kept for each classified block, and the code amount characteristic value. This makes it possible to maintain the quantization parameter substantially constant throughout the successive frames and to reduce delays caused by the buffer.
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