| 摘要 |
<p>PURPOSE:To prevent the deterioration of the performance of a device due to the change of a code amount caused by the inappropriate setting of a quantize step width by considering the characteristic of the picture of a processing block to be quantized in order to hold the code amount to be constant, at the time of deciding the quantize step width. CONSTITUTION:A code amount control means 20 supplies the code amount BR(m) of coded data which are coded from the start time of coding to the input time of the data of a processing block to be encoded. When the BR(m) is larger than a preliminarily set standard code amount BS, or when the BR(m) is assumed to be larger based on code amount presuming information S21, a quantize step width S22 applied to a quantizing means 7 is made to be increased. And also, when the BR(m) is smaller than the BS, or when the BR(m) is assumed to be smaller based on the S21, the S22 is made to be decreased. Thus, the appropriate setting of the S22 can be attained by considering the characteristic of the picture of the processing block to be quantized.</p> |
