Adaptive Hybrid Forward Error Correction Coding Scheme for Video Transmission

This paper proposes an adaptive hybrid forward error correction(AH-FEC)coding scheme for coping with dynamic packet loss events in video and audio transmission.Specifically,the proposed scheme consists of a hybrid Reed-Solomon and low-density parity-check(RS-LDPC)coding system,combined with a Kalman filter-based adaptive algorithm.The hybrid RS-LDPC coding accommodates a wide range of code length requirements,employing RS coding for short codes and LDPC coding for medium-long codes.We delimit the short and medium-length codes by coding performance so that both codes remain in the optimal region.Additionally,a Kalman filter-based adaptive algorithm has been developed to handle dynamic alterations in a packet loss rate.The Kalman filter estimates packet loss rate utilizing observation data and system models,and then we establish the redundancy decision module through receiver feedback.As a result,the lost packets can be perfectly recovered by the receiver based on the redundant packets.Experimental results show that the proposed method enhances the decoding performance significantly under the same redundancy and channel packet loss.

SST-V:A Scalable Semantic Transmission Framework for Video

The emerging new services in the sixth generation(6G)communication system impose increasingly stringent requirements and challenges on video transmission.Semantic communications are envisioned as a promising solution to these challenges.This paper provides a highly-efficient solution to video transmission by proposing a scalable semantic transmission algorithm,named scalable semantic transmission framework for video(SST-V),which jointly considers the semantic importance and channel conditions.Specifically,a semantic importance evaluation module is designed to extract more informative semantic features according to the estimated importance level,facilitating high-efficiency semantic coding.By further considering the channel condition,a cascaded learning based scalable joint semanticchannel coding algorithm is proposed,which autonomously adapts the semantic coding and channel coding strategies to the specific signalto-noise ratio(SNR).Simulation results show that SST-V achieves better video reconstruction performance,while significantly reducing the transmission overhead.

Joint resource allocation for MIMO-OFDM video transmission systems with unequal error protection

To improve the performance of MIMO-OFDM video transmission systems on the limitation of wireless bandwidth and transmitting power,we propose an adaptive joint resource allocation algorithm with unequal error protection(UEP) based on joint source-channel coding(JSCC) according to H.264 video compression standard and RCPT channel coding.According to different thresholds of the average SNR of subchannels,the algorithm dynamically allocates the source coding parameters of original video data and the channel coding parameters of RCPT,which realizes UEP for the compressed video data of different importance.Through the bit and power allocation based on MQAM modulation and the subspace allocation based on beamforming technology for different subcarriers,an adaptive joint resource allocation making full use of space-frequency domain resources have been realized.The simulation results indicate that the algorithm improves the adaptability of video transmission systems in different wireless environments and the quality of video retrieval.

Generative Multi-Modal Mutual Enhancement Video Semantic Communications

Recently,there have been significant advancements in the study of semantic communication in single-modal scenarios.However,the ability to process information in multi-modal environments remains limited.Inspired by the research and applications of natural language processing across different modalities,our goal is to accurately extract frame-level semantic information from videos and ultimately transmit high-quality videos.Specifically,we propose a deep learning-basedMulti-ModalMutual Enhancement Video Semantic Communication system,called M3E-VSC.Built upon a VectorQuantized Generative AdversarialNetwork(VQGAN),our systemaims to leverage mutual enhancement among different modalities by using text as the main carrier of transmission.With it,the semantic information can be extracted fromkey-frame images and audio of the video and performdifferential value to ensure that the extracted text conveys accurate semantic information with fewer bits,thus improving the capacity of the system.Furthermore,a multi-frame semantic detection module is designed to facilitate semantic transitions during video generation.Simulation results demonstrate that our proposed model maintains high robustness in complex noise environments,particularly in low signal-to-noise ratio conditions,significantly improving the accuracy and speed of semantic transmission in video communication by approximately 50 percent.

An optimal quality adaptation mechanism for end-to-end FGS video transmission

In this paper, we propose a novel optimal quality adaptation algorithm for MPEG-4 fine granular scalability (FGS)stream over wired network. Our algorithm can maximize perceptual video quality by minimizing video quality variation and increasing available bandwidth usage rate. Under the condition that the whole bandwidth evolution is known, we design an optimal algorithm to select layer. When the knowledge of future bandwidth is not available, we also develop an online algorithm based on the optimal algorithm. Simulation showed that both optimal algorithm and online algorithm can offer smoothed video quality evolution.

Implementation of IP Multicast in LAN Video Transmission Based on Winsock2

With the development of IP multicast technology, the best use of network bandwidth can be achieved, and IP video broadcasting can be implemented. This paper introduces the principle of IP multicast technology, and presents an implementation of IP video multicasting in LAN based on Winsock2. Problems in IP multicast are also analyzed in brief.

A NOVEL CROSS-LAYER STRATEGY OF VIDEO TRANSMISSION TO SOLVE PERFORMANCE ANOMALY IN MULTI-RATE IEEE 802.11 NETWORKS

When wireless hosts use different rates to transmit data in IEEE 802.11 networks, it will take on the state of performance anomaly which will severely decrease the throughputs of all the higher rate hosts. Hence, it is bad for video service transmission. Considering that video is very sensitive to packet delivery delay but can tolerate some packet losses, we propose a novel cross-layer scheme which takes these two characteristics into consideration. Firstly, the maximum number of retransmissions for a video Medium Access Control (MAC) frame is computed in MAC layer according to video frame rate requirement of application layer and current access delay of MAC layer. Secondly, within the margin of the tolerant Packet Loss Rate (PLR) of application layer, several video MAC frames are allowed to drop so that we can adaptively select the transmission rate as high as possible for the rest of video MAC frames in terms of current channel quality and the maximum number of retransmissions. Experiment results show that the proposed method can reduce the delay and jitter of video service and improve the throughputs of fast hosts. Therefore, it increases the quality of reconstructed video to a certain extent and relieves the performance anomaly of network effectively.

Evolution Handoff Strategy for Real-Time Video Transmission over Practical Cognitive Radio Networks

The transmission delay of realtime video packet mainly depends on the sensing time delay(short-term factor) and the entire frame transmission delay(long-term factor).Therefore,the optimization problem in the spectrum handoff process should be formulated as the combination of microscopic optimization and macroscopic optimization.In this paper,we focus on the issue of combining these two optimization models,and propose a novel Evolution Spectrum Handoff(ESH)strategy to minimize the expected transmission delay of real-time video packet.In the microoptimized model,considering the tradeoff between Primary User's(PU's) allowable collision percentage of each channel and transmission delay of video packet,we propose a mixed integer non-linear programming scheme.The scheme is able to achieve the minimum sensing time which is termed as an optimal stopping time.In the macro-optimized model,using the optimal stopping time as reward function within the partially observable Markov decision process framework,the EHS strategy is designed to search an optimal target channel set and minimize the expected delay of packet in the long-term real-time video transmission.Meanwhile,the minimum expected transmission delay is obtained under practical cognitive radio networks' conditions,i.e.,secondary user's mobility,PU's random access,imperfect sensing information,etc..Theoretical analysis and simulation results show that the ESH strategy can effectively reduce the transmission delay of video packet in spectrum handoff process.

Bandwidth-Efficient Transmission Method for User View-Oriented Video Services

The trend in video viewing has been evolving beyond simply providing a multi-view option.Recently,a function that allows selection and viewing of a clip from a multi-view service that captures a specific range or object has been added.In particular,the free-view service is an extended concept of multi-view and provides a freer viewpoint.However,since numerous videos and additional data are required for its construction,all of the clips constituting the content cannot be simultaneously provided.Only certain clips are selected and provided to the user.If the video is not the preferred video,change request is made,and a delay occurs during retransmission from the server.Delays due to frequent re-requests degrade the overall quality of service.For free-view services,selectively transmitting the video according to the user’s desired viewpoint and region of interest within the limited network of available videos is important.In this study,we propose a method of screening and providing the correct video based on objects in the contents.Based on the method of recognizing the object in each clip,we designed a method of setting its priority based on information about the object’s location for each viewpoint.During the transmission and receiving process using this information,the selected video can be rapidly recognized and changed.Herein,we present a service system configuration method and propose video selection examples for free-view services.

Joint Optimization Strategy for Video Transmission over Distributed Cognitive Radio Networks

A novel joint optimization strategy for the secondary user( SU) was proposed to consider the short-term and long-term video transmissions over distributed cognitive radio networks( DCRNs).Since the long-term video transmission consisted of a series of shortterm transmissions, the optimization problem in the video transmission was a composite optimization process. Firstly,considering some factors like primary user's( PU's) collision limitations,non-synchronization between SU and PU,and SU's limited buffer size, the short-term optimization problem was formulated as a mixed integer non-linear program( MINLP) to minimize the block probability of video packets. Secondly,combining the minimum packet block probability obtained in shortterm optimization and SU's constraint on hardware complexity,the partially observable Markov decision process( POMDP) framework was proposed to learn PU's statistic information over DCRNs.Moreover,based on the proposed framework,joint optimization strategy was designed to obtain the minimum packet loss rate in long-term video transmission. Numerical simulation results were provided to demonstrate validity of our strategies.

Real-Time Video Transmission of Visible Light Communication Based on LED

In order to realize the video image transmission and the excellent lighting function of the visible light communication system, a LED-based visible light communication method and system is proposed. Based on the field programmable gate array (FPGA) hardware, the RS channel coding is applied to the visible light communication system. A pulse position decision algorithm is proposed, which is applied to the receiver of the visible light communication system to meet the error-free decision of the signal. The design of the system is based on the analog-to-digital conversion circuit, which provides a large signal dynamic range for the pulse position decision algorithm, and designs the LED driver based on the bias circuit to realize the fast broadband modulation of the signal. The test results show that the combined application of pulse position decision algorithm and Reed-Solomon codec can reduce the error of system signal and meet the real-time and reliable transmission of signal. The system can display the received video in real time from the receiver, and the whole system communication distance up to 5 m.

QoS Aware Multicast Routing Protocol for Video Transmission in Smart Cities

In recent years,Software Defined Networking(SDN)has become an important candidate for communication infrastructure in smart cities.It produces a drastic increase in the need for delivery of video services that are of high resolution,multiview,and large-scale in nature.However,this entity gets easily influenced by heterogeneous behaviour of the user’s wireless link features that might reduce the quality of video stream for few or all clients.The development of SDN allows the emergence of new possibilities for complicated controlling of video conferences.Besides,multicast routing protocol with multiple constraints in terms of Quality of Service(QoS)is a Nondeterministic Polynomial time(NP)hard problem which can be solved only with the help of metaheuristic optimization algorithms.With this motivation,the current research paper presents a new Improved BlackWidow Optimization with Levy Distribution model(IBWO-LD)-based multicast routing protocol for smart cities.The presented IBWO-LD model aims at minimizing the energy consumption and bandwidth utilization while at the same time accomplish improved quality of video streams that the clients receive.Besides,a priority-based scheduling and classifier model is designed to allocate multicast request based on the type of applications and deadline constraints.A detailed experimental analysis was carried out to ensure the outcomes improved under different aspects.The results from comprehensive comparative analysis highlighted the superiority of the proposed IBWO-LD model over other compared methods.

VIDEO TRANSMISSION SYSTEM IN ITV APPLICATION

The transmission characteristics of video transmission mediums,coaxial ca ble and optical fiber,are discussed in the paper. The formulas for frequency bandwidth are given to evaluate the video transmission distance. For typical video transmission systems with BB/IM and PFM/IM tising optical fiber as the channel, expressions and calculating results for both S/N and sensitivity are given. Finally, the principle for se lecting different type of transmission systems according to transmission distances of the industrial TV is presented.

基于NBVTH算法的军用窄带信道视频传输研究

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。

短视频传播对大学生网络道德教育的影响及对策

随着互联网信息技术的发展,短视频平台迎来了高速发展时期,其中以抖音、快手等为代表的自媒体平台凭借其用户定位精准化、内容呈现多样化、产品设计新颖化等特性,潜移默化地渗透到人们的日常生活当中。而在其广泛的受众群体里,青年大学生由于自身和社会等多方面因素跻身为短视频平台的主要用户群体。基于网络短视频的广泛化传播和爆发式发展,短视频传播一方面以其形式和内容丰富了大学生的日常生活,另一方面又以其多元化内容对大学生的网络道德认知和网络道德实践产生了深远影响。短视频传播的对象、内容、过程、效果等与网络道德教育的诸多方面有较高的耦合性和一致性。为了推进大学生网络道德教育发展,基于短视频传播特征、短视频在大学生中的传播现状等维度,全面分析短视频传播给大学生网络道德教育带来的挑战和机遇,并结合大学生身心特征、社会现实状况等因素,从短视频传播的引领力、感染力、互动性、反馈性等方面提出了具有针对性的建议。

多基站无线非正交多址接入的平滑视频流传输算法

视频服务需求的快速增长对于视频流畅播放提出了巨大挑战,从用户体验角度分析,视频播放中的卡顿时间可能是最重要指标之一。随着5G网络技术的发展,非正交多址接入(NOMA)技术被重点关注,NOMA技术具有叠加编码和连续干扰消除2个特点,根据这2个特点实现数据的并行传输。利用NOMA技术的并行传输能力来提高基站为用户提供视频的实时性。在用户需求视频名称和视频分辨率给定的情况下,通过联合基站-用户配对方式和基站功率分配来降低视频播放时的卡顿时间。通过对问题进行建模,并提出1个两步启发式算法对问题进行求解,第1步为确定基站与用户的配对方式,第2步为分配基站的发射功率。实验结果表明,基于NOMA的传输调度方案与传统的传输调度方案相比,用户需求的平均卡顿时间有明显的下降,相对于在不采用NOMA机制时,在2-SIC接收机情况下,用户平均卡顿时间减少了55.56%。

基于毫米波通信技术的超高清视频传输方法研究

为了提高对超高清视频传输能力,提出基于毫米波通信的超高清视频传输方法。采用多频调制通信组网技术构建超高清视频传输的信道模型,建立超高清视频毫米波通信传输的自适应图像信息交互和采集模型;结合Lyapunov指数谱密度特征分析,实现谱特征分解和信道均衡模型构建;建立视频传输的视景转换和高阶谱特征提取模型;采用毫米波通信技术,实现滤波补偿和反馈增益调节;采用联合自相关的统计特征分析方法,得到动态均衡迭代函数,通过复杂信道环境下的抗干扰抑制和均衡调度,实现对超高清视频的无损传输和编码解码。实验结果表明,该方法进行超高清视频传输的误码率较低,平均为0.058 2,传输时延较低,平均为248.4 ms,峰值信噪比为49 dB。

文化传播视域下北京冬奥会宣传片的多模态话语分析

流媒体时代,奥运会宣传片凭借其覆盖范围广、传播速度快等特点对于国家形象塑造起到了重要作用。基于Kress and Van Leeuwen的视觉分析语法及张德禄多模态话语分析综合理论框架,分析了2022年2月3日《人民日报》在新媒体上发布的冬奥会倒计时宣传片《一起向未来》中所传递的理念、跨文化交际意义构建及国家形象塑造的手段。该宣传片以习近平主席新年致辞为线索,通过中国文化元素呈现,参与者的互动,拍摄视角的转换以及视听效果的融合,既突出了奥运主题,又塑造了“合”与“和”为贵的中国形象,强化了中国“和平崛起”的理念,对国家形象提升起到重要作用。

基于GNURadio与USRP的OFDM无线通信系统实验

针对目前无线通信课程内容侧重讲述基本理论推导,相关实验多关注模块功能仿真,缺乏系统性和真实场景的问题,提出了以GNURadio软件和通用软件无线电外设(USRP)硬件平台为基础的正交频分复用(OFDM)无线通信系统实验。该实验内容包括掌握OFDM的基本原理、搭建OFDM收发系统、分析相关通信性能和完成硬件系统,最后在实际无线通信场景中完成测试,实现实时视频传输。通过软件系统和硬件平台的协同,学生能充分了解无线通信的基本原理、各通信模块的使用、无线通信系统的架构以及相关的性能分析方法,完成从理论基础到工程应用、从模块验证到系统实现、从理想环境仿真到实际场景测试的跨越,从而全面提升工程素养。