The accuracy of the traditional assessment method of the quality of experience(Qo E) has been facing challenges with the growth of high-definition(HD) video streaming services.Image display-quality damage is the main ...The accuracy of the traditional assessment method of the quality of experience(Qo E) has been facing challenges with the growth of high-definition(HD) video streaming services.Image display-quality damage is the main factor that affects the Qo E in HD video services through UDP network transmission.In this paper,we introduce a novel objective factor known as image damage accumulation(IDA) to assess user's Qo E in HD video services.First,this paper quantitatively analyzed the effect on user quality of experience by IDA and established a mapping relationship between mean opinion scores and IDA.Furthermore,the probability of image damage caused by compression and transmission were analyzed.Based on this analysis,an objective Qo E assessment and prediction method for HD video stream service that evaluated the user experience according to IDA are proposed.The proposed method can achieve assessment and prediction accuracy on three distinct subjective tests.展开更多
There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great ...There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.展开更多
2008年5月8日，全球闪存供货商SanDisk宣布推出Video HD高清视频存储卡。使用闪存卡为储存媒体的摄像机用户，将可依据录像时间选择最适当的储存媒体。首批上市的SanDisk Video HD存储卡系列将分别支持SDHC与Memory Stick PRO Duo格式...2008年5月8日，全球闪存供货商SanDisk宣布推出Video HD高清视频存储卡。使用闪存卡为储存媒体的摄像机用户，将可依据录像时间选择最适当的储存媒体。首批上市的SanDisk Video HD存储卡系列将分别支持SDHC与Memory Stick PRO Duo格式，存储卡上会清楚地标示摄像时间及储存容量。SanDisk存储卡与配件事业部资深产品营销经理Susan Park表示：“SanDisk Video HD产品线让选购新式录像机储存设备的工作更轻松。”展开更多
为实现远距离、高可靠性传输,并减小复杂度,对Camera Link Full接口数据的HD-SDI传输显示进行了深入研究。采用FPGA作为核心处理器,考虑相机输出具有多种帧频,采取帧频检测及充分降频策略,并通过3个SRAM进行缓存以实现帧频转换,以满足HD...为实现远距离、高可靠性传输,并减小复杂度,对Camera Link Full接口数据的HD-SDI传输显示进行了深入研究。采用FPGA作为核心处理器,考虑相机输出具有多种帧频,采取帧频检测及充分降频策略,并通过3个SRAM进行缓存以实现帧频转换,以满足HD-SDI帧频25Hz的要求。考虑到SRAM数据宽度,采取FIFO行缓存策略将Camera Link Full80输出的10tap、80bits图像数据转换成单通道的8bits图像数据。最后,完成系统设计并进行实验验证。实验结果表明:系统实现了图像数据从50Hz、100Hz、500 Hz等多种帧频的Camera Link Full80到25帧HD-SDI接口1080i的格式转换及实时显示,且图像层次丰富,无失真。展开更多
基金supported by the 863 Program(2014AA01A701)NSFC(61271187)+1 种基金the PAPD fundthe CICAEET fund
文摘The accuracy of the traditional assessment method of the quality of experience(Qo E) has been facing challenges with the growth of high-definition(HD) video streaming services.Image display-quality damage is the main factor that affects the Qo E in HD video services through UDP network transmission.In this paper,we introduce a novel objective factor known as image damage accumulation(IDA) to assess user's Qo E in HD video services.First,this paper quantitatively analyzed the effect on user quality of experience by IDA and established a mapping relationship between mean opinion scores and IDA.Furthermore,the probability of image damage caused by compression and transmission were analyzed.Based on this analysis,an objective Qo E assessment and prediction method for HD video stream service that evaluated the user experience according to IDA are proposed.The proposed method can achieve assessment and prediction accuracy on three distinct subjective tests.
文摘There is an increasing demand for supporting high-quality real-time audiovisual services for the next generation wired and wireless networks. However, due to variety of bandwidths of different networks, it is a great challenge for deployment. In this paper, a novel high-definition (HD) video transmission system was proposed which depends upon reliable compound multicast protocols and QoS control over the various kinds of networks. This system detects client's network condition and assigns it to a proper proxy. Each proxy is capable of detecting network parameters and adaptively tuning such transport parameters as bit rate, video resolution, frame rate and QoS mechanisms to this condition. It also provides FEC error recovery under consideration of characteristics of MPEG4 video codec. Our simulation demonstrates that different network clients such as ADSL, CERNET, and CERNET2 can receive more video reliability with less delay.
文摘2008年5月8日，全球闪存供货商SanDisk宣布推出Video HD高清视频存储卡。使用闪存卡为储存媒体的摄像机用户，将可依据录像时间选择最适当的储存媒体。首批上市的SanDisk Video HD存储卡系列将分别支持SDHC与Memory Stick PRO Duo格式，存储卡上会清楚地标示摄像时间及储存容量。SanDisk存储卡与配件事业部资深产品营销经理Susan Park表示：“SanDisk Video HD产品线让选购新式录像机储存设备的工作更轻松。”
文摘为实现远距离、高可靠性传输,并减小复杂度,对Camera Link Full接口数据的HD-SDI传输显示进行了深入研究。采用FPGA作为核心处理器,考虑相机输出具有多种帧频,采取帧频检测及充分降频策略,并通过3个SRAM进行缓存以实现帧频转换,以满足HD-SDI帧频25Hz的要求。考虑到SRAM数据宽度,采取FIFO行缓存策略将Camera Link Full80输出的10tap、80bits图像数据转换成单通道的8bits图像数据。最后,完成系统设计并进行实验验证。实验结果表明:系统实现了图像数据从50Hz、100Hz、500 Hz等多种帧频的Camera Link Full80到25帧HD-SDI接口1080i的格式转换及实时显示,且图像层次丰富,无失真。
