共查询到20条相似文献,搜索用时 171 毫秒
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基于Virtex-6的PCI Express高速采集卡设计 总被引:1,自引:0,他引:1
为了提高数据采集速率,适应大数据量交互处理要求,介绍了一种应用Virtex-6芯片的PCI Express高速采集卡设计。Virtex-6内嵌PCIE协议硬核能完成完整的PCIE分层协议,实现与上位机通信。设计了DMA控制器,作为采集卡数据传输主控,实现基于PCI Express总线的DMA高速数据传输方案。主机软件系统包括驱动程序和应用软件2部分。经实验测试,该采集卡能完成对外部高速数据的实时采集,性能稳定可靠。 相似文献
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在面向多媒体数据流的计算密集型的应用中,不仅要求DSP(数字信号处理器)有非常强大的数据处理能力,还要求其具有高速的数据输入、输出接口带宽。本文在传统DSP常用的增强型哈佛结构的基础上,提出一种DSP处理器DMA接口结构的设计方案.实现了基于指令并行和任务并行的DMA并行传输模式。通过6个常用的DSP算法程序实验验证.在片上存储器使用单口RAM的前提下,指令中带有片上Memory访存操作的指令占总指令的42.2%-94.3%时.这种方法设计的。DMA接口能够在DSP零开销的情况下,完成必要的数据传输。而且能够实现对Host处理器程序员透明的。DMA数据传输操作.有效地提高了DSP系统的性能。 相似文献
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基于802.11e的无线Mesh网络中视频传输优化方案 总被引:1,自引:1,他引:0
针对无线Mesh网络环境下视频数据传输的延迟、吞吐量、丢包率等问题,改进了一种数据映射方案,将不同重要程度的数据与IEEE 802.11e中的接入类别相对应,优先发送级别高的数据。对压缩视频数据传输进行了仿真实验,并对仿真结果进行了分析,证明了在不同的网络业务负载下,改进的映射方案对网络性能有一定的改善。 相似文献
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文章对高速的10位A/D芯片AD9203进行了全面介绍,并结合ADSP219l的DMA高速数据传输模式,给出了AD9203与ADS2191两种DMA方式下的通信接口电路。 相似文献
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文章针对双处理器设备间的数据通信提出了基于PCIe非透明桥的高速传输系统的设计方法。该方法应用于视频转码设备,实验结果表明当转码设备作为外设与PC主机进行通信时,采用多路虚拟DMA方法的数据传输总带宽可以稳定的达到1100MB/s,为实现多路实时转码提供了前提保证。文中还重点介绍了虚拟DMA通道的实现、双系统间通信模型的设计及传输系统性能优化分析。 相似文献
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Rate control has a critical influence on the video encoder design, and MB-level rate control is more flexible to control the spatial coding performance. However, most existing MB-level rate control methods are not designed for hardware implementation, and are too complex for practical use in real-time video coding. In this paper, a simple and effective MB-level rate control scheme is proposed that uses historical rate information to directly assign a QP value to a class of MBs. This paper will also introduce a method to realize the idea and make the pipeline data dependency applicable in circuit design. Experiments show that the proposed classification-based MB-level rate control algorithm can achieve a coding gain up to 0.6 dB and an averaging gain of 0.18 dB. 相似文献
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Luo Ning Chen Li Fang Xiangzhong Zhang Wenjun 《Circuits, Systems, and Signal Processing》2006,25(3):343-360
The digital standard definition television (SDTV) encoder is a very important part of the digital TV broadcast chain. Most
real-time MPEG-2 encoders are designed to perform in a constant bit-rate (CBR) mode. But an even better compressed stream
can be created by employing a variable bit-rate (VBR) encoding algorithm. VBR can be exploited as a means of achieving statistical
multiplexing for digital broadcast satellites. This paper suggests an implementation procedure of an SDTV video encoder and
proposes a novel VBR bit-allocation strategy that could be implemented in this encoder system. First, using a rate-quantization
model and rate-quantization perceptual model, a real-time VBR bit-allocation strategy is deduced. In this strategy, more (or
fewer) bits are allocated to "difficult-to-encode" (or "easy-to-encode") groups of pictures (GOPs), which are distinguished
according to the estimated encoding complexity of the GOPs. After allocating an appropriate number of bits to each GOP by
using this VBR bit-allocation strategy, we use a CBR rate control algorithm to allocate a number of bits and select a quantization
scaler for each picture of a GOP. Then smooth visual quality is achieved not only in a GOP but also in the whole video sequence.
Second, the system implementation of an SDTV video encoder including a video input module, a video encoding module, a system
control and rate control module (SCRCM), and a PES packetizing module is described. We also discuss in detail how to implement
our real-time VBR bit-allocation strategy in the SCRCM. Finally, experimental results demonstrate that our proposed VBR encoder
displays a better performance than the CBR encoder. 相似文献
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Ramdas Satyan Sunday Nyamweno Fabrice Labeau 《Signal Processing: Image Communication》2010,25(9):648-659
A conventional video codec uses encoder reconstruction of previous frames for motion compensated prediction. This is designed to minimize the encoder prediction error and assumes error free transmission. In this paper we use a modified prediction mechanism both at the encoder and decoder and propose techniques to improve the error resilience of H.264/AVC when transmitted over error prone networks. In our schemes we provide greater emphasis on Intra pixels during the formation of the reference frame used for prediction, thereby achieving better resilience. We also incorporate leaky prediction to further improve the robustness. We apply leaky prediction selectively at a macroblock level based on a simple mean square error metric in order to reduce the bit-rate penalty. Substantial performance gains have been observed in simulations. The effectiveness of using leaky prediction can be observed in medium and fast moving video sequences. 相似文献
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设计了基于S3C2410嵌入式处理器、AT2042双通道视频编码器和CDMA数据模块的无线视频监控终端,介绍了硬件结构和软件系统设计,并给出了测试结果. 相似文献
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Saw Y.-S. Grant P.M. Hannah J.M. 《Vision, Image and Signal Processing, IEE Proceedings -》1998,145(3):179-186
Fuzzy logic control has been employed to improve the rate control mechanism for a MPEG2 video encoder. The data rate of compressed video is controlled by video encoders for either variable bit rate (VBR) or constant bit rate (CBR) applications. In VBR video transmission, it is considered to be more efficient to regulate the video rate by the video coder than by network management in order to avoid network congestion and maintain stable video quality. This rationale can also be applied to CBR transmission. Two fuzzy-logic-based rate control techniques are proposed which maintain the buffer occupancy within a specified range. In the proposed technique for VBR applications, a video quality measure is taken as the crucial control parameter. In CBR rate control, the video data rate or the buffer occupancy is also considered as a fuzzy logic variable. Proposed techniques are designed to control either data rate or video quality, depending on the mode of transmission, i.e. CBR or VBR for the MPEG2 encoder. The performance is compared to a typical VBR MPEG video coder with fixed quantiser step sizes for VBR and also to the CBR video coder with MPEG2 TM5 at typical channel rates. Simulation results are presented with peak signal-to-noise ratio, data rate variation and buffer occupancy as the performance measures 相似文献
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数据分割是在无线移动信道等传输视频码流时用于抵御信道误码、提高编码比特流健壮性的一种机制.在对现在流行的视频编码标准中数据分割方案进行研究的基础上,文中提出了一种视频编码中数据分割的新方案.在该方案中,运动矢量信息和头信息分割于不同部分;而且运动矢量的水平和垂直分量也可以分割到不同的部分,从而可以更好地抵御信道误码.在这种分割方案下,又提出了可以改进运动矢量编码效率的新编码方法.实验表明该方法对具有尖峰概率密度函数的情形尤为有效.采用文中数据分割方案具有抗信道误码能力强、运动矢量编码比特位数少、编码效率高等优点. 相似文献
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国内外研究人员对图像目标分类识别和视频编码传输问题都分别进行了大量研究,但是对于视频编码参数对目标识别性能影响的定量关系,还没有公开的文献报导。针对这一问题,该文选择典型的目标识别算法可变部件模型(DPM)和最常用的视频编码方法H.264/AVC作用测试对象,通过设计的编码和检测实验,研究了码率和分辨率参数对视频目标识别性能的影响,并拟合了识别性能随码率和分辨率变化的函数关系。通过选取编码器合适的码率和分辨率工作参数,可以获得信道带宽与视频目标识别性能的折中,为设计不同视频应用的编码优化目标函数提供了依据。 相似文献
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本文完成了运动图像实时传输系统的设计,并对其核心部分视频编码器和视频解码器进行了详细的分析和设计.实现了运动图像的实时窄带传输。 相似文献
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为满足发展迅猛的广电行业对电视频道节目内容的实时监测,提出并设计了一种针对全媒体监播系统的模拟信号关键帧抽取器.该设备采用运行嵌入式Linux系统的ARM处理器S3C2440作为主处理器,同时FPGA芯片EP3C25作为协处理器,极大地提高了设计灵活性和系统的实时处理性能.抽取的视频图像通过视频解码器ADV212压缩后,最终存储到本地SATA硬盘.在验证部分中,闭环测试的试验结果证明了这种设备的正确性和工程实用性. 相似文献