期刊文献+
共找到1,673篇文章
< 1 2 84 >
每页显示 20 50 100
Real-time Audio &Video Transmission System Based on Visible Light Communication 被引量:3
1
作者 Yingjie He Liwei Ding +1 位作者 Yuxian Gong Yongjin Wang 《Optics and Photonics Journal》 2013年第2期153-157,共5页
With the increasing popularity of solid sate lighting devices, Visible Light Communication (VLC) is globally recognized as an advanced and promising technology to realize short-range, high speed as well as large capac... With the increasing popularity of solid sate lighting devices, Visible Light Communication (VLC) is globally recognized as an advanced and promising technology to realize short-range, high speed as well as large capacity wireless data transmission. In this paper, we propose a prototype of real-time audio and video broadcast system using inexpensive commercially available light emitting diode (LED) lamps. Experimental results show that real-time high quality audio and video with the maximum distance of 3 m can be achieved through proper layout of LED sources and improvement of concentration effects. Lighting model within room environment is designed and simulated which indicates close relationship between layout of light sources and distribution of illuminance. 展开更多
关键词 VISIBLE LIGHT Communications LED real-time video and audio BROADCAST System LIGHT Source Arrangement ILLUMINANCE Distribution
下载PDF
Research on fast real-time adaptive audio mixing in multimedia conference 被引量:2
2
作者 樊星 顾伟康 叶秀清 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第6期507-512,共6页
In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixin... In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixing schemes using weighted algorithm, which meet the demand of practical needs for real-time multipoint speech mixing, for which the ASW and AEW schemes are especially recommended. Applying the adaptive algorithms, the high-performance schemes we provide do not use the saturation operation widely used in multimedia processing. Therefore, no additional noise will be added to the output. The above adaptive algorithms have relatively low computational complexity and good hearing perceptibility. The schemes are designed for parallel processing, and can be easily implemented with hardware, such as DSPs, and widely applied in multimedia conference systems. 展开更多
关键词 Multimedia conference MCU real-time ADAPTIVE audio mixing Aligned-to-self Aligned-to-energy
下载PDF
Two-Phase Rate Adaptation Strategy for Improving Real-Time Video QoE in Mobile Networks 被引量:3
3
作者 Ailing Xiao Jie Liu +2 位作者 Yizhe Li Qiwei Song Ning Ge 《China Communications》 SCIE CSCD 2018年第10期12-24,共13页
With the popularity of smart handheld devices, mobile streaming video has multiplied the global network traffic in recent years. A huge concern of users' quality of experience(Qo E) has made rate adaptation method... With the popularity of smart handheld devices, mobile streaming video has multiplied the global network traffic in recent years. A huge concern of users' quality of experience(Qo E) has made rate adaptation methods very attractive. In this paper, we propose a two-phase rate adaptation strategy to improve users' real-time video Qo E. First, to measure and assess video Qo E, we provide a continuous Qo E prediction engine modeled by RNN recurrent neural network. Different from traditional Qo E models which consider the Qo E-aware factors separately or incompletely, our RNN-Qo E model accounts for three descriptive factors(video quality, rebuffering, and rate change) and reflects the impact of cognitive memory and recency. Besides, the video playing is separated into the initial startup phase and the steady playback phase, and we takes different optimization goals for each phase: the former aims at shortening the startup delay while the latter ameliorates the video quality and the rebufferings. Simulation results have shown that RNN-Qo E can follow the subjective Qo E quite well, and the proposed strategy can effectively reduce the occurrence of rebufferings caused by the mismatch between the requested video rates and the fluctuated throughput and attains standout performance on real-time Qo E compared with classical rate adaption methods. 展开更多
关键词 continuous quality of experience (QoE) model recurrent neural network(RNN) real-time video QoE improving dynamic adaptive streaming over HTTP (DASH)
下载PDF
Audio Description for Educational Videos on COVID-19 Response:A Corpus-Based Study on Linguistic and Textual Idiosyncrasies
4
作者 XIONG Ling-song 《Journal of Literature and Art Studies》 2023年第4期276-285,共10页
Audio description(AD),unlike interlingual translation and interpretation,is subject to unique constraints as a spoken text.Facilitated by AD,educational videos on COVID-19 anti-virus measures are made accessible to th... Audio description(AD),unlike interlingual translation and interpretation,is subject to unique constraints as a spoken text.Facilitated by AD,educational videos on COVID-19 anti-virus measures are made accessible to the visually disadvantaged.In this study,a corpus of AD of COVID-19 educational videos is developed,named“Audio Description Corpus of COVID-19 Educational Videos”(ADCCEV).Drawing on the model of Textual and Linguistic Audio Description Matrix(TLADM),this paper aims to identify the linguistic and textual idiosyncrasies of AD themed on COVID-19 response released by the New Zealand Government.This study finds that linguistically,the AD script uses a mix of complete sentences and phrases,the majority being in Present Simple tense.Present participles and the“with”structure are used for brevity.Vocabulary is diverse,with simpler words for animated explainers.Third-person pronouns are common in educational videos.Color words are a salient feature of AD,where“yellow”denotes urgency,and“red”indicates importance,negativity,and hostility.On textual idiosyncrasies,coherence is achieved through intermodal components that align with the video’s mood and style.AD style varies depending on the video’s purpose,from informative to narrative or expressive. 展开更多
关键词 audio Description COVID-19 educational videos corpus-based study
下载PDF
访森海塞尔中国内地地区专业音频Audio for Video销售负责人贾毅阳及诺音曼中国内地地区销售负责人储海涛
5
作者 曹徐洋 《现代电视技术》 2023年第9期48-49,共2页
BIRTV2023期间,在中央广播电视总台展台《现代电视技术》现场访谈间,本刊对森海塞尔中国内地地区专业音频Audio for Video销售负责人贾毅阳以及诺音曼中国内地地区销售负责人储海涛进行了采访,采访围绕两个品牌的产品亮点、优势及市场... BIRTV2023期间,在中央广播电视总台展台《现代电视技术》现场访谈间,本刊对森海塞尔中国内地地区专业音频Audio for Video销售负责人贾毅阳以及诺音曼中国内地地区销售负责人储海涛进行了采访,采访围绕两个品牌的产品亮点、优势及市场定位等话题展开。曹徐洋:在今年的BIRTV展会上,森海塞尔和诺音曼的展台都展出了大量优秀的产品,这些产品里有哪些是重点推出的?请介绍一下它们的主要亮点。 展开更多
关键词 专业音频 森海塞尔 BIRTV 现场访谈 市场定位 audio video 广播电视总台
下载PDF
VB环境下Audio/Video压缩数据流播放技术的应用
6
作者 顾善发 张中元 《青岛建筑工程学院学报》 2001年第3期56-59,共4页
介绍了在 Windwos操作系统中 ,利用 VB自身条件和原有控件 ,灵活调用 Windows下的动态链接库开发
关键词 MPEG audio/video数据流 动态链接库
下载PDF
Integrating Audio-Visual Features and Text Information for Story Segmentation of News Video 被引量:1
7
作者 Liu Hua-yong, Zhou Dong-ru School of Computer,Wuhan University,Wuhan 430072, Hubei, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第04A期1070-1074,共5页
Video data are composed of multimodal information streams including visual, auditory and textual streams, so an approach of story segmentation for news video using multimodal analysis is described in this paper. The p... Video data are composed of multimodal information streams including visual, auditory and textual streams, so an approach of story segmentation for news video using multimodal analysis is described in this paper. The proposed approach detects the topic-caption frames, and integrates them with silence clips detection results, as well as shot segmentation results to locate the news story boundaries. The integration of audio-visual features and text information overcomes the weakness of the approach using only image analysis techniques. On test data with 135 400 frames, when the boundaries between news stories are detected, the accuracy rate 85.8% and the recall rate 97.5% are obtained. The experimental results show the approach is valid and robust. 展开更多
关键词 news video story segmentation audio-visual features analysis text detection
下载PDF
Content-Based Hierarchical Analysis of News Video Using Audio and Visual Information
8
作者 Yu Jun-qing Zhou Dong-ru +1 位作者 Jin Ye Liu Hua-yong 《Wuhan University Journal of Natural Sciences》 EI CAS 2001年第4期779-783,共5页
A schema for content-based analysis of broadcast news video is presented. First, we separate commercials from news using audiovisual features. Then, we automatically organize news programs into a content hierarchy at ... A schema for content-based analysis of broadcast news video is presented. First, we separate commercials from news using audiovisual features. Then, we automatically organize news programs into a content hierarchy at various levels of abstraction via effective integration of video, audio, and text data available from the news programs. Based on these news video structure and content analysis technologies, a TV news video Library is generated, from which users can retrieve definite news story according to their demands. 展开更多
关键词 CONTENT-BASED audio news video SEGMENTATION
下载PDF
Study on an Audio and Video Network Monitoring System for Weather Modification Operation
9
作者 Yilin Wang Xueyi Xu +2 位作者 Desheng Xu Changzong Miao Gang Zhao 《Meteorological and Environmental Research》 CAS 2013年第1期5-7,共3页
An audio and video network monitoring system for weather modification operation transmitting information by 3G, ADSL and Internet has been developed and applied in weather modification operation of Tai'an City. The a... An audio and video network monitoring system for weather modification operation transmitting information by 3G, ADSL and Internet has been developed and applied in weather modification operation of Tai'an City. The all-in-one machine of 3G audio and video network highly integrates all front-end devices used for audio and video collection, communication, power supply and information storage, and has advantages of wireless video transmission, clear two-way voice intercom with the command center, waterproof and dustproof function, simple operation, good portability, and long working hours. Compression code of the system is transmitted by dynamic bandwidth, and compression rate varies from 32 kbps to 4 Mbps under different network conditions. This system has forwarding mode, that is, monitoring information from each front-end monitoring point is trans- mitted to the server of the command center by 3G/ADSL, and the server codes'and decodes again, then beck-end users call images from the serv- er, which can address 3G network stoppage caused by many users calling front-end video at the same time. In addition, the system has been ap- plied in surface weather modification operation of Tai'an City, and has made a great contribution to transmitting operation orders in real time, monitoring, standardizing and recording operating process, and improving operating safety. 展开更多
关键词 Weather modification operation Network monitoring audio and video INTEGRATION China
下载PDF
audio和video
10
作者 杨承辉 《语言教育》 1993年第8期32-32,共1页
电视上看到一则某种牌子的电器之广告,内中有audio和video两个字,借贵刊一角谈一谈。不用说,这两个字都是和电器有关的。audio与“音”有关系,video则和“影”有关。 audio是指由声音、机械、或电力所造成的频率(audio frs-quency),具... 电视上看到一则某种牌子的电器之广告,内中有audio和video两个字,借贵刊一角谈一谈。不用说,这两个字都是和电器有关的。audio与“音”有关系,video则和“影”有关。 audio是指由声音、机械、或电力所造成的频率(audio frs-quency),具有这种频率的声波每秒钟振动十五至二万次,也就是所谓低周波,是人类所能听得见的。在电器制品中,andio 特指电唱机、收音机或电视机的发音部分,平常人们所说的音响设备就叫audio equipment。因此,audio现用来泛指一般与音响有关的东西。 展开更多
关键词 audio video 音响设备 低周波 TELEVISION 二万 迪安
下载PDF
Stylistic Analysis of Internet News——Taking Internet Video Newsand Internet Audio News as Examples
11
作者 周逸轩 《海外英语》 2019年第9期212-213,共2页
With the rapid development of Internet around the world, network is transmitting all kinds of information to human beings nowadays. Net news, also called cyber news is affecting people’s expression of daily English. ... With the rapid development of Internet around the world, network is transmitting all kinds of information to human beings nowadays. Net news, also called cyber news is affecting people’s expression of daily English. A large number of cyber words, phrases even sentences, which are different from conventional English, are formed and become popular in the cyber world. This paper discusses different markers of net news by taking Internet video news and Internet audio news as examples so that the readers can fully understand the properties of net news. 展开更多
关键词 INTERNET NEWS INTERNET video NEWS INTERNET audio NEWS STYLISTICS features of INTERNET NEWS
下载PDF
麦景图(McIntosh)MVP851 DVD Audio/Video碟机
12
《音响世界》 2003年第9期7-7,共1页
关键词 麦景图公司 MVP851 DVD audio/video碟机 功能
下载PDF
跃威USB VIDEO AUDIO延长器
13
作者 Shawn 《数字世界》 2007年第8期67-67,共1页
亲爱的,俺把电脑延长了科技的发展有时候总会让人措手不及。当我还在犹豫到底是否需要斥“巨资”购买一台HDTV的时候,发现只需要用USB VIDEO AUDIO延长器就可以把书房的电脑延伸到客厅中,—切问题都迎刃而解了。
关键词 video audio
下载PDF
DVD AUDIO/VIDEO碟机
14
《音响世界》 2004年第1期26-28,共3页
关键词 DVD audio/video碟机 SONY DVP-NS999ES DENON DVD-2900 ONKYO DV-SP800
下载PDF
安捷伦为93000 SOC系统推出Audio/Video 8模拟卡
15
《电子产品与技术》 2004年第10期87-87,共1页
关键词 安捷伦科技公司 audio/video8 SOC 93000系列 测试模拟卡
下载PDF
PIONEER先锋DV—S733A逐行扫描DVD AUDIO/VIDEO/SACD碟机
16
《音响世界》 2002年第8期6-6,共1页
关键词 先锋公司 DV-S733A 逐行扫描 DVD audio/video/SACD
下载PDF
Adaptive Learning Video Streaming with QoE in Multi-Home Heterogeneous Networks
17
作者 S.Vijayashaarathi S.NithyaKalyani 《Computer Systems Science & Engineering》 SCIE EI 2023年第9期2881-2897,共17页
In recent years,real-time video streaming has grown in popularity.The growing popularity of the Internet of Things(IoT)and other wireless heterogeneous networks mandates that network resources be carefully apportioned... In recent years,real-time video streaming has grown in popularity.The growing popularity of the Internet of Things(IoT)and other wireless heterogeneous networks mandates that network resources be carefully apportioned among versatile users in order to achieve the best Quality of Experience(QoE)and performance objectives.Most researchers focused on Forward Error Correction(FEC)techniques when attempting to strike a balance between QoE and performance.However,as network capacity increases,the performance degrades,impacting the live visual experience.Recently,Deep Learning(DL)algorithms have been successfully integrated with FEC to stream videos across multiple heterogeneous networks.But these algorithms need to be changed to make the experience better without sacrificing packet loss and delay time.To address the previous challenge,this paper proposes a novel intelligent algorithm that streams video in multi-home heterogeneous networks based on network-centric characteristics.The proposed framework contains modules such as Intelligent Content Extraction Module(ICEM),Channel Status Monitor(CSM),and Adaptive FEC(AFEC).This framework adopts the Cognitive Learning-based Scheduling(CLS)Module,which works on the deep Reinforced Gated Recurrent Networks(RGRN)principle and embeds them along with the FEC to achieve better performances.The complete framework was developed using the Objective Modular Network Testbed in C++(OMNET++),Internet networking(INET),and Python 3.10,with Keras as the front end and Tensorflow 2.10 as the back end.With extensive experimentation,the proposed model outperforms the other existing intelligentmodels in terms of improving the QoE,minimizing the End-to-End Delay(EED),and maintaining the highest accuracy(98%)and a lower Root Mean Square Error(RMSE)value of 0.001. 展开更多
关键词 real-time video streaming IoT multi-home heterogeneous networks forward error coding deep reinforced gated recurrent networks QOE prediction accuracy RMSE
下载PDF
基于NBVTH算法的军用窄带信道视频传输研究
18
作者 王超 马驰 +2 位作者 刘荣 汪磊 李东 《火力与指挥控制》 CSCD 北大核心 2024年第1期139-143,150,共6页
随着信息技术快速发展,音视频传输广泛应用在军民用领域。针对军用环境通信传输带宽窄、电磁干扰强、网络稳定性低等特点,迫切需要对军用窄带信道下音视传输频编码进行优化。介绍了适应军用窄带信道传输的视频编码框架和最新技术,提出... 随着信息技术快速发展,音视频传输广泛应用在军民用领域。针对军用环境通信传输带宽窄、电磁干扰强、网络稳定性低等特点,迫切需要对军用窄带信道下音视传输频编码进行优化。介绍了适应军用窄带信道传输的视频编码框架和最新技术,提出了基于HEVC标准优化的窄带视频传输(NBVTH)算法,并在压缩比、压缩图像质量、编码时延等关键技术指标方面,将NBVTH算法与常用的H.264/AVC编码进行了性能对比分析。试验结果表明,NBVTH算法明显提升了编码性能,更加适用于军用窄带信道的视频传输。 展开更多
关键词 视频编码 窄带信道传输 音视频编码 性能对比
下载PDF
天津市地震局应急视频会议系统组网研究
19
作者 马蕴玢 赵士达 +3 位作者 杨朝 朱宏 孙选超 赵博宇 《华南地震》 2024年第1期100-104,共5页
为全面提升地震应急指挥能力和协同应急通讯效率,天津市地震局应急指挥大厅基于跨网段多层级视频融合技术完善天津市地震应急视频指挥调度网络,构建“平战结合”双模式。通过探究跨网段通讯、多层级音视频信号转发、多点控制单元(MCU)... 为全面提升地震应急指挥能力和协同应急通讯效率,天津市地震局应急指挥大厅基于跨网段多层级视频融合技术完善天津市地震应急视频指挥调度网络,构建“平战结合”双模式。通过探究跨网段通讯、多层级音视频信号转发、多点控制单元(MCU)级联等技术,实现天津局与中国局、市政府、市应急管理局以及辖区内各应急视频节点互连互通,为天津市地震应急快速响应提供高效的通信保障。 展开更多
关键词 视频会议 地震应急 应急通讯 跨网段组会 音视频转发
下载PDF
面向视频会议的音频辅助视频编码方法
20
作者 徐盛鹏 覃浩峻 +4 位作者 宋晓丹 左旭光 高大化 谢雪梅 石光明 《移动通信》 2024年第2期77-82,共6页
目前视频会议所包含的视频和音频通常是使用传统的编码标准分别进行压缩。然而从语义层面看,音频和视频存在强相关性,都是对与会者所要表述内容的表征。因此,对两者分开编码是次优的。针对此问题,提出了一种音频辅助的视频编码框架。该... 目前视频会议所包含的视频和音频通常是使用传统的编码标准分别进行压缩。然而从语义层面看,音频和视频存在强相关性,都是对与会者所要表述内容的表征。因此,对两者分开编码是次优的。针对此问题,提出了一种音频辅助的视频编码框架。该框架中视频只传输少量的关键帧以提供必要的纹理参考,利用从重建音频中推理得到时序信息和关键帧来重建其余帧。实验结果表明,与通用视频编码方法相比,该框架在指标DISTS下取得了-89.81%的BD-rate结果。 展开更多
关键词 多模态信源编码 音频辅助视频编码 视频会议 低码率 语义保真度
下载PDF
上一页 1 2 84 下一页 到第
使用帮助 返回顶部