Variable transfer rate video coding apparatus

摘要

A variable transfer rate coding apparatus codes moving picture signals of groups of pictures (GOPs). The picture signals are quantized under control of quantization step width and coded. A first code amount per GOP and a second code amount of picture data included GOP are obtained from the coded picture signals. In response to the first code amount, a total code amount of the picture signals of the GOPs are calculated and the total code amount is compared with a reference total code amount, to decide a first target code amount per GOP in order that the total code amount becomes a maximum amount within the reference total code amount. Further, in response to the first target code amount and the second code amount, a second target code amount of the picture data included in each GOP is determined in accordance with the maximum amount. The quantization step width is varied on the basis of the second target code amount. <IMAGE>