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WMA流媒体是一种目前电台及多媒体网站使用最为广泛的音频直播、点播及下载的主要音频传输格式,通过对不同码率WMA音频的主观评价,并针对波形统计、光谱图对比及频谱分析三种客观数据对比,对主观评价与客观数据之间的关系进行分析论述,并对WMA流媒体的应用进行指导。 相似文献
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随着3G时代的愈行愈近,其所提供的丰富多彩的业务内容为人们所期待.以流媒体为代表的视讯业务更是频频亮相预热.无疑已经成为一道亮丽的风景线。流媒体是把数据(通常是音频和视频)实时从服务端传送到客户端(手机终端).客户端收到数据后.对其进行译码及播放。流媒体是未来移动通信的主流业务之一。 相似文献
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移动流媒体关键技术及其平台实现 总被引:1,自引:0,他引:1
随着移动通信的迅速发展,移动流媒体成为移动通信发展的新热点,第三代移动通信(3G)标准的制订使得通过无线信道传输视频信息成为可能.介绍了移动流媒体技术的基本特征,阐述了移动流媒体的关键技术,包括网络协议、系统结构、QoS控制等,最后介绍了基于RealSystem的移动流媒体平台的实现. 相似文献
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流媒体在移动通信中的应用将是3G和3G后移动通信增值的主要方式。文章介绍了流媒体与移动流媒体的基本原理,阐述了移动流媒体的主要实现技术——高容错性、H.264视频压缩标准和传输协议,简要分析了移动流媒体业务发展的制约因素。 相似文献
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无线实时数据通信对等网络构架方案 总被引:1,自引:0,他引:1
基于移动通信网络的P2P流媒体共享系统,能实现网络中任意用户可以搜索到并且快速共享其所需要的流媒体资源,这对于网络信息交流和高效合理地利用网络资源有着重要的意义。文章提出了一种基于移动通信网络的对等流媒体覆盖网络方案,阐述了对等流媒体覆盖网络的可实现性和有效运行的一些必要条件,最后提出了基于提高服务质量的系统优化思路。 相似文献
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移动通信网络流媒体服务资费较高,限制了人们在没有有线电视、宽带互联网连接、无线WiFi互联网连接的地方用手机收看视音频节目.针对这一现状,提出了一种基于嵌入式流媒体服务器的多功能视频点播系统.以ARM板和WiFi网络适配器作为流媒体服务器,设计一款Android手机播放器作为客户端,实现在智能手机上、多个客户端同时免流量接收服务器本地或外接设备推送的高清、超高清视频.该系统适用于公交、广场、电梯、商场、景区等场合,人们用手机观看视音频,实现不用耗费自己的流量,自由快速地选择自己喜欢的节目. 相似文献
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Extended AMR-WB for high-quality audio on mobile devices 总被引:2,自引:0,他引:2
Salami R. Lefebvre R. Lakaniemi A. Kontola K. Bruhn S. Taleb A. 《Communications Magazine, IEEE》2006,44(5):90-97
This article presents the architecture, performance, and application scenarios of the AMR-WB+ (extended AMR-WB) audio codec, which provides high quality at exceptionally low rates, and consistent quality over all audio types. This codec was recently selected by 3GPP and DVB to support low-bit-rate audio and audiovisual applications on mobile networks. 相似文献
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本文描述了AMR—WB+音频编解码的结构框架,复杂性,移植和优化。AMR—WB+编解码在低码率范围内表现出相当优秀的品质,并且在各种音频类型上都有一致的高性能。因此被3GPP和DVB选定为移动网络中低码率音频指定编解码算法。 相似文献
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基于语音和音频信号的固有周期性特征,本文构建了一种适合语音和音频信号的统一分析/合成模型,并分别在24kbps和32kbps码率下,实现了对宽带语音和音频信号的高质量分层编码.首先,本文将具有时变周期的输入信号规整为具有固定周期的信号,并对规整后的周期信号构建规整矩阵;其次,对规整矩阵的行和列分别进行调制叠接变换(MLT)和离散余弦变换(DCT),完成规整矩阵的稀疏化;最后,利用分带量化和矢量哈夫曼编码完成稀疏矩阵元素的量化和编码.主客观测试结果表明,本文所提方法的语音、音频及其混合信号的编码质量均优于同等速率下的ITU-T G.722.1和AMR-WB编码器. 相似文献
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Wideband speech is the major differentiation and attraction of third-generation network services in both the circuit and packet switched domain. Increased audio bandwidth introduces a significant leap in perceived quality of service compared to currently utilized narrowband telephony in second-generation mobile communications and the PSTN. The adaptive multirate wideband (AMR-WB) speech codec is the service enabler for improved user experience. It is an established 3GPP and ITU-T wideband speech codec standard and represents the state-of-the-art in speech quality as well as robustness in error prone radio channels. It is also the first codec algorithm standardized for wideband speech for mobile communications. 相似文献
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《Communications Magazine, IEEE》2009,47(10):117-123
This article is an overview of the standardization, architecture, and performance of the new ITU-T Recommendation G.718. G.718 is an embedded variable bit rate codec providing a scalable solution for compression of 8 and 16 kHz sampled speech and audio signals at rates between 8 kb/s and 32 kb/s. It comprises five layers where higher-layer bitstreams can be discarded without affecting the lower layersiquest decoding. The codec also has an optional core layer interoperable with ITU-T G.722.2 (3GPP AMR-WB) at 12.65 kb/s. G.718 was designed to provide high speech quality at low bit rates and to be robust to significant rates of frame erasures or packet losses. It is also targeting good quality for generic audio at higher rates. 相似文献
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The standardization of the AMR-WB speech codec by 3GPP opens a new area on audio pre-and post-processing integrated in telecommunication terminals. It appears that the transition from narrowband to wideband signals is not a trivial task, but can rather be seen as a challenge, as acoustic quality requirements, scalability and computational limitations have to be faced at the same time. This article presents key examples to address the transition issue as well as proposals for low-complexity implementations of acoustic echo cancellation and noise reduction. 相似文献
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Tatsuji Moriyoshi Hiroshi Shinohara Takashi Miyazaki Ichiro Kuroda 《The Journal of VLSI Signal Processing》2001,29(3):239-245
A PC-based real-time software MPEG-4 video codec with a fast adaptive motion vector search is presented. In a fast adaptive motion estimation (ME) technique, the search order is dynamically changed in according with the motion of objects. This technique suppresses load fluctuation in the ME and contributes to the stable real-time work of the software codec. MMX instructions are used to increase the codec speed. On a portable PC, the software video codec supports satisfactory mobile visual communication at 64 kbps and 128 kbps, for example, at QCIF 15 fps. The codec on a 450 MHz PentiumII processor can encode and decode 30 CIF frames in real-time. 相似文献
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Sheffield E.G. Kean J. Starling M. Andrews J. Evans K. Khemlani S. 《Broadcasting, IEEE Transactions on》2006,52(2):219-222
As continuing support of National Public Radio's Tomorrow Radio project, this paper presents results from a consumer study conducted with iBiquity's HD Radio codec. Forty participants judged the quality of the HD codec (HDC) at various bit rates, ranging from 16 kbps to 96 kbps. A range of musical and speech genres were tested. This study provides in-depth information intended to help broadcasters select optimal bit rates when HD Radio's 96 kbps data stream is shared between primary and supplemental channels. 相似文献