VoIP语音评价模型分析

文章介绍了基于IP的语音通信(VoIP)中语音质量的评价方法.通过研究语音质量的评价方法来达到对VoIP语音质量的监控,并使之能够保持一定的服务水平是很有必要的.文章还分析了主观评价模型与客观评价模型的实现原理,最后给出了主观评价模型与客观评价模型试验的量化比较结果以及不同客观评价模型试验的量化比较结果.     

基于E-Model的VoIP语音质量测量

基于E-Model的语音质量测量方法是一种客观测试方法,它克服了传统语音质量测试在数据网络测量中的不足。为了能够准确评估VoIP语音质量,在E-Model算法的基础之上,探讨了延时、噪声、回音、语音压缩等损伤因素对VoIP语音质量的影响。     

VoIP语音时延的分析和研究

文章介绍了VoIP(IP网络上传送语音)语音质量的测试方法,分析了影响VoIP语音质量的主要因素:延迟、抖动、丢包率和时延.利用E模型定量地分析了语音质量与端到端时延的关系,通过建立数学模型,指出了VoIP 系统中主要的时延分量,并研究了这些时延分量产生的机理和影响它们的参数.在设计实际的VoIP系统时,可以通过优化影响时延分量的主要参数,改善VoIP系统的时延.     

分布式VoIP监管系统的设计与实现

VoIP技术的发展和广泛应用对网络信息内容监管提出了新的挑战。针对网络VoIP监管所存在的数据流量大、编解码速度慢等问题，提出一种分布式VoIP监管模型，该模型采用快速截包、自适应语音编码和语音会话同步等关键技术．实现了一个快速实时语音监管系统。对系统的监管效率和语音延时状况也进行了详细测试，结果表明．该监管模型在保证较好语音回放质量的基础上，实现了实时在线监听语音会话功能。     

短波地空语音组网中VoIP语音质量评估

短波地空话音组网是短波话音通信发展的必然趋势,组网后VoIP技术的引入会为短波语音通信带来很大的便利,但同时语音质量会受到影响,其中VoIP编码技术是影响语音质量的主要因素之一。通过Matlab对采用不同编码技术重构后的语音,经过基于Watterson模型的短波信道传输后到达接收端的质量进行了PESQ评估,并仿真分析了丢包率对不同编码语音质量的影响,得出了不同编码的优劣性。     

战场网络环境下的VoIP技术研究

随着战术互联网等军用网络技术的迅速发展,军用网络电话（VoIP）技术成为近来语音处理与通信领域的一个研究热点。针对军事通信的特点,对VoIP在战场网络环境下的应用进行了有益的探索。介绍了VoIP的概念、原理,研究了战场网络环境下影响VoIP语音质量的主要因素并分析了其对语音质量影响的方式和程度,在此基础上提出了解决军用VoIP语音质量问题的方案：语音编码、丢包处理和抗抖动缓冲。     

VoIP语音服务质量评测

介绍了VoIP语音服务连接方式、VoIP语音质量的分级、VoIP语音服务质量评测的基本方法、传输性能评价,分析了E-Model作为一个网络传输规划工具在VoIP语音服务质量评测中起的作用及其巨大的局限性。     

mSwitch系统VoIP语音质量测量方法研究

首先介绍了mSwitch系统当前对VoIP语音质量的监控情况；然后就语音质量的衡量标准MOS进行了简要描述；同时对现有的语音质量测量方法PSQM／PSQM＋，PESQ，PAMS，E-Model的发展作了相关阐述；其中对E-Model方法进行了较为详细的介绍；最后对mSwitch系统对VoIP语音质量的监控提出了几点展望。     

可堆叠VoIP语音板卡的固件程序设计

本文提出了基于口可堆叠式的VoIP通信应用系统的系统架构,重点介绍了面向IP可堆叠式的VoIP语音板卡的固件程序设计.每块VoIP语音板卡支持8路语音,通过自定义的通信协议可使不同的VoIP语音板卡独立地通过IP互联,实现基于IP可堆叠.自定义通信协议实现了VoIP语音板卡中芯片内部通道之间、VoIP语音板卡上芯片之间、不同VoIP语音板卡之间,以及VoIP语音板卡与管理PC间的通信.VoIP语音板卡控制软件以内核模块方式运行,并在内核模块方式下由VINETIC-2CPE语音芯片中断服务程序激活回调函数,提高了实时性.     

Speex中语音增强算法的仿真与评估

随着VoIP技术在近年来的快速发展,互联网语音通信得到了越来越多的应用,IP电话的语音通信质量成为制约其发展的重要因素,因此应用了许多新技术使其语音质量更符合用户的要求。在VoIP系统中使用语音增强算法,可以消除发送端噪声干扰,提高通话质量。研究的Speex算法中的STSA-MMSE语音增强算法是在计算先验和后验信噪比的基础上估计噪声,再通过计算得出一个增益值,作用于带噪语音,对噪声段进行抑制,对叠加了噪声的语音尽可能分离噪声,最终达到增强语音清晰度,提高语音舒适度的目的。     

交互式视频质量评价方法研究进展

在交互式视频应用快速发展的同时,如何评价视频质量成为当前亟待解决的挑战性难题,其成果对整个多媒体通信系统的各环节技术发展具有关键作用。从主观质量评价、客观质量评价两个角度综述了当前交互式视频质量评价的研究与应用现状,其中主观质量评价方法包括主观视频质量评价数据库、主观视频质量评价打分与计算机制,客观质量评价方法则包括视觉信号处理与分析、深度学习机制下的评价与建模方法等。在总结上述研究方法与成果的基础上,展望了本领域的研究与发展。     

Quality assessment of speech coding and speech synthesis systems

The concept of speech quality assessment is examined. Quality assessment methodologies for speech waveform coding, source coding, and speech synthesis by rule from the viewpoints of naturalness and intelligibility are reviewed. Both subjective and objective measures are considered     

Standardization activities in the ITU for a QoE assessment of IPTV

This article gives an overview of the state of the art of objective quality assessment of audio and visual media and its standardization activities in the ITU. IPTV services are becoming one of the most promising applications over next generation networks. To provide end users with comfortable, stable, and economical services, QoE assessment methodologies for quality design and management are indispensable.     

On the performance of objective quality metrics for lightfields

Lightfield (LF) technology has attained significant attention in recent years due to its capability to capture much richer textural and geometric information in the scene compared to the classical 2D representation. The resampling and compression operations on LFs often lead to visual quality degradation, thus, sophisticated visual quality assessment methods play a crucial role to ensure a pleasant viewing experience. To this end, it is necessary to examine the performance of quality assessment methods for LF contents. The paper provides a comprehensive study on the reliability of various objective algorithms for LF quality prediction. Three subjectively-annotated LF data sets were selected and an extensive quality estimation analysis has been conducted using several objective quality assessment methods. In total, 250 LFs (more than 48000 perspective images) were evaluated. The results were compared against human opinion scores using various correlation indices and their statistical significance. Next, a decision-making strategy was adopted to choose the most reliable quality metrics for evaluation of LFs and finally, a metric fusion framework was proposed to further improve the quality prediction accuracy. To best of our knowledge, the benchmark and the analytical methodologies used in this paper are the most comprehensive study on the objective quality assessment methods for LF application.     

视频通信业务质量客观评价方法综述

给出了多媒体通信中视频客观质量评价方法的综述及其在ITU中的标准制定进程.首先介绍了视频质量客观评价模型的分类,之后分别针对网络规划和网络监控的应用介绍了各类模型的应用和发展状况,最后展望了用于网络监控的质量评价模型未来的发展方向.     

A new objective stereoscopic image assessment model based on stereoscopic perception

In order to establish a stereoscopic image quality assessment method which is consistent with human visual perception, we propose an objective stereoscopic image quality assessment method. It takes into account the strong correlation and high degree of structural between pixels of image. This method contains two models. One is the quality synthetic assessment of left-right view images, which is based on human visual characteristics, we use the Singular Value Decomposition （SVD） that can represent the degree of the distortion, and combine the qualities of left and right images by the characteristics of binocular superposition. The other model is stereoscopic perception quality as- sessment, due to strong stability of image＇s singular value characteristics, we calculate the distance of the singular values and structural characteristic similarity of the absolute difference maps, and utilize the statistical value of the global error to evaluate stereoscopic perception. Finally, we combine two models to describe the stereoscopic image quality. Experimental results show that the correlation coefficients of the proposed assessment method and the human subjective perception are above 0.93, and the mean square errors are all less than 6.2, under JPEG, JP2K compression, Gaussian blurring, Gaussian white noise, H.264 coding distortion, and hybrid cross distortion. It indicates that the proposed stereoscopic objective method is consistent with human visual properties and also of availability.     

全媒体内容质量评价研究综述

在全媒体时代,媒体内容的表现形式逐渐丰富,开始成为影响信息传播的一个重要因素。内容质量评价仍停留在“流量思维”阶段,难以客观评价内容质量,亟需发展以用户为中心的全媒体内容质量评价方法。本文主要概述近十年来国内外公开发表的不同媒介的评价模型,回顾了图像、视频、音频、文本四类的客观质量评价在全媒体数据中的研究工作及相应的应用,主要介绍基于传统方法和基于深度学习方法两大方向中一些影响力较大的方法,每类方法有分成有参考和无参考的方法,对此总结了各方法特点,对一些具有代表性的方法进行了实验对比分析。最后对四种媒介内容质量评价领域仍面临的问题进行了总结并展望未来可能的发展方向。      

Resolution measure criteria for the objective assessment of the performance of quadratic time-frequency distributions

This paper presents the essential elements for developing objective methods of assessment of the performance of time-frequency signal analysis techniques. We define a measure for assessing the resolution performance of time-frequency distributions (TFDs) in separating closely spaced components in the time-frequency domain. The measure takes into account key attributes of TFDs, such as components mainlobes and sidelobes and cross-terms. The introduction of this measure allows to quantify the quality of TFDs instead of relying solely on visual inspection of their plots. The method of assessment of performance of TFDs also allows the improvement of methodologies for designing high-resolution quadratic TFDs for time-frequency analysis of multicomponent signals. Different TFDs, including the modified B distribution, are optimized using this methodology. Examples of a performance comparison of quadratic TFDs in resolving closely spaced components in the time-frequency domain, using the proposed resolution measure, are provided.     

基于BP算法的信息化厂商评价模型研究

信息化厂商质量评价是供电企业信息系统运维的重要工作,其中关键的一项就是对信息化厂商质量进行分析评估,这对于信息系统运行可靠具有重要意义。将遗传算法神经网络原理引入信息化厂商质量评价领域,构建了基于遗传算法和神经网络的信息化厂商质量评价模型,为供电企业的信息化厂商质量评估研究提供模型和方法的支撑。实证结果表明,模型具有较强的自组织、自学习和自适应能力,模型评估结果比较客观合理。     

An objective and subjective quality assessment study of passive gaming video streaming

Passive gaming video‐streaming applications have recently gained much attention as evident with the rising popularity of many Over The Top (OTT) providers such as Twitch.tv and YouTube Gaming. For the continued success of such services, it is imperative that the user Quality of Experience (QoE) remains high, which is usually assessed using subjective and objective video quality assessment methods. Recent years have seen tremendous advancement in the field of objective video quality assessment (VQA) metrics, with the development of models that can predict the quality of the videos streamed over the Internet. A study on the performance of objective VQA on gaming videos, which are artificial and synthetic and have different streaming requirements than traditionally streamed videos, is still missing. Towards this end, we present in this paper an objective and subjective quality assessment study on gaming videos considering passive streaming applications. Subjective ratings are obtained for 90 stimuli generated by encoding six different video games in multiple resolution‐bitrate pairs. Objective quality performance evaluation considering eight widely used VQA metrics is performed using the subjective test results and on a data set of 24 reference videos and 576 compressed sequences obtained by encoding them in 24 resolution‐bitrate pairs. Our results indicate that Video Multimethod Assessment Fusion (VMAF) predicts subjective video quality ratings the best, while Naturalness Image Quality Evaluator (NIQE) turns out to be a promising alternative as a no‐reference metric in some scenarios.