| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To measure transmission quality regarding a stream of variable bit rate. <P>SOLUTION: A receiving section 320 receives IP packets constituting an MPEG stream. A rate calculation section 330 detects identification packets from among the IP packets, calculates a data amount of the MPEG stream between the identification packets, and divides the data amount by a time interval at which an identification packet is inserted to calculate a reproduction speed in each time zone. A buffer capacity calculation section 340 calculates a maximum value and a minimum value of a buffer data amount obtained by the repetition, for a measurement time zone, of adding a data amount of a packet to an initial value of the buffer data amount in the elapsed time from reception of the packet and subtracting a data amount corresponding to the lapse of time immediately before receiving a next packet and a reproduction speed within a time zone of the lapse of time from the initial value of the buffer data, and defines the difference between the maximum value and the minimum value as a buffer capacity. A buffer time calculation section 350 calculates a time required to reproduce MPERG streams for the calculated buffer capacity and defines the calculated time as a buffer time. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
