Details of Research Outputs

针对多方会议的实际应用需求,同时兼顾PDA等小设备的个性特征,提出一种新颖而简单的快速实时自适应跨平台多方会议方案。该方案采用概率决策优先权的方式,即各客户端根据语音能量值和编码后帧长度计算其语音概率值,服务器由语音概率值决策出当前发言者的语音流,并使用叠加原理将选出的多路流进行混音,最后转发混音后的语音包。该方案弥补了PDA等小设备计算能力弱的缺陷,同时又降低了服务器进行混音操作的运算量。实验结果表明该方案具有算法复杂度低、听觉主观效果好、易在PDA以及手机等硬件设备上实现等特点,可广泛应用在多媒体多方会议跨平台系统的实现中。

Based on the practical application and the characteristics of some small devices, such as PDA, a new and simple fast real-time adaptive cross-platform conference scheme was put forward. In the proposed scheme, priority was decided by probability, namely, the client calculated its audio probability according to energy value and the coded frame length, then the server decided the current speakers and mixed the streams by audio probability, finally transmitted mixed packages. The scheme skillfully offsets the weak computation of PDA and other small devices, at the same time reduces the calculation complexity of the server. The simulation results show that the proposed scheme has a low complexity and good hearing perceptibility. It can be easily implemented in hardware, such as PDA and mobile phone, and can be widely applied in cross-platform multimedia conference system.