| 摘要 |
<p>PURPOSE:To prevent the deterioration in the quality of a picture by stopping the decoding when the accumulated quantity of a memory storing sent signals smaller than a set value, and accelerating the rate of decoding when said quan tity is larger than the set value. CONSTITUTION:The quantity of information of signals transmitted from the transmission side and stored in a buffer memory 11 is detected by an address detection circuit 13, and a comparator 14 supplies stop signals as long as an address from the circuit 13 reaches the set value to stop a decoding circuit 12. Meanwhile, an integrating circuit 15 integrates the quantity in the memory 11 for a fixed time, and thus obtained integral value is used to control the frequency of a voltage controlled crystal oscillator VCXO 17 via a D/A con verter 16, and the decoding circuit 12 starts decoding at a rate in accordance with a clock from the VCXO 17 at a time when the address from the memory 11 reaches the set value. Thus, by coinciding the decoding rate with coding rate on the average, the overflow and the underflow of the received buffer can be prevented and the deterioration of the image quality can be also prevented.</p> |
