共查询到19条相似文献,搜索用时 109 毫秒
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例1 故障现象;新科330型VCD机,声音正常,但无图像。分析检修:由VCD解码音视频互锁原理可知,该机解码芯片ES3204正常,故障系发生在解码后的视频D/A转换或视频编码部分。该机视频D/A转换和视频编码共用一只集成电路CH7201A,用万用表测其第②、(36)、(42)等脚的供电电压为 5V正常,试换一只14.318MHz晶体,故障依旧。 相似文献
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建立了用于移动无线互联网接入的视频编码转换模型,提出了自适应运动矢量估值方法.将编码转换码率控制分为图像层控制和宏块层两级,首先在总体上对每帧图像的编码比特数进行预分配,然后采用小波变换系数来表征图像特征,为帧内不同特征的宏块选用不同的量化因子,提出了一种新的码率控制策略.模拟实验表明:该方法在视频图像质量没有明显失真的前提下,提高了视频编码转换速度;编码转换输出码流和编码转换缓冲区占用量较稳定,重建图像的信噪比得到了明显的改善. 相似文献
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针对原始视频数据量大,不利于存储与传输的问题,设计了基于TMS320DM365的视频压缩传输系统。实现将多路输入的模拟视频转换为数字视频,在TMS320DM365中压缩编码并打包成TS码流。提供帧率、分辨率、P/I比等参数的设置功能,能适应于多种应用场景。实验结果表明,系统可实现25帧/s、D1分辨率标清视频的压缩传输,满足视频监控的需求 相似文献
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《广播电视网络技术》2013,(4):92-94
作为业内技术和市场先驱,MatroxVideo(迈刨视频产品部)致力于开发与生产用于加速H.264编码、实时编辑、音/视频输入输出、流媒体、A/V信号转换、采集/播出服务器、全能制播一体系统和字幕机的标清及高清数字视频硬件与软件。 相似文献
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H.264视频编码的嵌入式系统实现 总被引:3,自引:0,他引:3
H.264是ITU-T组织针对实时视频通讯应用制定的新一代视频压缩标准,开发H.264的嵌入式视频系统有重要的意义.该文在深入研究H.264标准和嵌入式系统的基础上,设计了一种以TI公司的TMS320C6416DSP为核心处理器的嵌入式视频编码系统,系统主要包括视频解码,视频转换,采集视频缓冲区管理,编码及码流输出等.对于系统实现中所涉及的视频转换,内存管理机制,代码优化等进行了详细的讨论. 相似文献
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针对目前最流行的MPEG-2和MPEG-4两个压缩编码标准,就MPEG-2视频码流之间的转换编码、MPEG-2视频码流转换成MPEG-4码流以及MPEG-4视频码流之间的转换编码中的一些核心问题进行研讨。 相似文献
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Video transcoding is to create multiple representations of a video for content adaptation. It is deemed as a core technique in Adaptive BitRate (ABR) streaming. How to manage video transcoding affects the performance of ABR streaming in various aspects, including operational cost, streaming delays, Quality of Experience (QoE), etc. Therefore, the problems of implementing video transcoding in ABR streaming must be systematically studied to improve the overall performance of the streaming services. These problems become more worthy of investigation with the emergence of the edge-cloud continuum, which makes the resource allocation for video transcoding more complicated. To this end, this paper provides an investigation of the main technical problems related to video transcoding in ABR streaming, including designing a rate profile for video transcoding, providing resources for video transcoding in clouds, and caching multi-bitrate video contents in networks, etc. We analyze these problems from the perspective of resource allocation in the edge-cloud continuum and cast them into resource and Quality of Service (QoS) optimization problems. The goal is to minimize resource consumption while guaranteeing the QoS for ABR streaming. We also discuss some promising research directions for the ABR streaming services. 相似文献
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Shizhong Liu Alan C. Bovik 《Journal of Visual Communication and Image Representation》2005,16(6):643-667
Video transcoding is a key technology to support video communications over heterogeneous networks. Although quite a bit of research effort has been made in video transcoding due to its wide applications, most video transcoding techniques proposed in the literature are optimized based on the simple mean squared error (MSE) metric which does not correlate well with the human visual perception. In this paper, foveation, a property of the HVS, is exploited in video transcoding. The proposed foveation embedded DCT domain video transcoding can reduce the bit rate without compromising visual quality or achieve better subjective quality for a given bit rate by shaping the compression distortion according to the foveated contrast sensitivity function of the HVS. In addition, fast algorithms for video foveation filtering and DCT domain inverse motion compensation are developed, which significantly improve the efficiency of video transcoding. 相似文献
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The pros and cons of FGS-based MPEG-2 video transcoding are examined. An existing solution for elastic storage of media (Barrau, 2002) is reviewed. Its shortfalls in terms of picture drift are identified and addressed by means of proposing a modified transcoding architecture, which is then compared to SNR-based MPEG-2 multilayer transcoding. It is shown that the FGS-based MPEG-2 video transcoder has the advantage of simplified transcoding and decoding architectures. However, the SNR-based MPEG-2 transcoder is shown to produce higher quality reconstructed images with superior rate-distortion performance. 相似文献