【摘要】 根据流体流量控制机制和MPEG-4 FGS编码视频流精细分级的特点,提出了流式多播方法,该方法中数据不用分层组织且没有加入实验,极大地减少了网络开销。同时,针对视频图像组帧间编码的依赖关系,修正了视频质量PSNR的计算公式,较好地评价视频网络传输质量。对分层多播和流式多播的对比仿真实验表明,流式多播的性能稳定、扩展灵活,便于大规模扩展应用。更多还原

【Abstract】 A novel adaptive stream multicast is proposed for MPEG-4 FGS video.Based on the fine-granularity property of MPEG-4 FGS video coding technology,the scheme tries to delivery multimedia multicast service over the heterogeneous networks in a similar way as that to transport liquid in pipelines,where the valves in pipelines adjust water flux to next pipeline.A modified method of com-puting PSNR,which considered the dependence of frames in one GOP,is used to evaluate the MPEG-4 FGS video transmission.Simulated results indicate that the scheme dispose the heterogeneity of networks and end-systems freely,with permanentstability,flexible scalability.更多还原