| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To dynamically determine an acoustic frequency component to be encoded/transmitted in accordance with a network band without cutting off a telephone conversation when performing high-quality voice communications combining BGM (back ground music) and sound effect or the like with voice via the Internet. <P>SOLUTION: A VoIP (voice over Internet protocol) client applies high-efficiency compression encoding to data resulting from combining BGM or effective sounds with voice, makes the result into RTP (real-time transport protocol) packet and exchanges it with the other VoIP client who becomes a communicating party, to perform the telephone conversation. This VoIP client transmits to the other VoIP client an RTCP (real-time control protocol) APP packet describing control information such as an encode bandwidth designating the band to be encoded by the other VoIP client and the number of sub-band divided blocks resulting from dividing the encode bandwidth. The other VoIP client who receives this RTCP packet, changes a CODEC (coder-decoder) on the basis of the control information and transmits the RTP packet. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
