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The paper discusses the problem of video transmission in an IP network. The authors consider the ability of using the most popular video codecs that use both the MPEG2 Transport Stream and Dynamic Adaptive Streaming over Hypertext Transfer Protocol (DASH). The main emphasis was given to ensuring the quality of service and quality assessment methods, taking into account not only the service- or network provider’s point of view but also the end user’s perspective. Two quality assessment approaches were presented, i.e. objective and subjective methods. The authors presented the results of the quality evaluation for H.264/MPEG-4, H.265/HEVC and VP9 codecs.The objective measurements, proved by statistic alanalysis of user opinion scores, confirmed the ability of using H.265 and VP9 codecs in both real time and streaming transmissions, while the quality of video streaming over HTTP with the H.264 codec proved inadequate. The authors also presented a connection between the dynamics of network bandwidth changing and MPEG-DASH mechanism operation and their influence on the quality experienced by users.
Transmisja wideo generuje w Internecie znaczący ruch. Jest ona stosowana zarówno w usługach czasu rzeczywistego jak i w usługach streamingowych, w których czas rzeczywisty nie odgrywa pierwszoplanowej roli. Internet jest zawodną platformą transportową. To może powodować obniżenie jakości usług. Aby wyjść temu naprzeciw, potrzebne są odpowiednio dobrane techniki transportowe dla strumieni wideo. Najczęściej używane są obecnie: MPEG2-TS i MPEG-DASH. Niniejsza praca zawiera wyniki badań oceniających wydajność obu tych technik transportowych w środowisku IP w powiązaniu z najnowszymi kodekami wideo, tj. H.265 i VP9.
Video applications generate considerable traffic in the Internet. The video service is used for both real-time services and streaming services where time does not play primary role. The Internet is an unreliable transport platform. It can cause deterioration in quality of service. Excellently tuned transport techniques are needed to counter this. Currently, MPEG2-TS and MPEG-DASH are two such techniques. This paper contains analysis results that prove the capabilities of both transport techniques when used in conjunction with modern video codecs, namely H.265 and VP9.
IP networks are indispensable nowadays and they are some of the most efficient platforms. The constantly growing number of users and new services in these networks – the largest being the Internet – require a satisfactory quality of service from any application they use. So, determining the QoS in real-time services is particularly important. This work shows how to quantify the suitability of reference signals for analyzing the quality of video streaming in IPTV. The assessment relies on two different algorithms: PEVQ and VQuad-HD. Three different reference signals – two real ones and an artificial one – are used in this study, and a numerical measurement system is used, which simulates mean network impairments. These measurements provide valuable information for determining the QoS of actual IPTV services in practice.
Content available New Tool for Examining QoS in the VToIP Service
This paper is dedicated to the subject of measuring QoS in the Video Telephony over IP (VToIP) service. QoS measurement models in general and then models designed specifically for measuring QoS in the VToIP service are presented. A new numerical tool for examining the quality of VToIP video streams VToIP is described. The tool’s functionality is then put to the test in a number of analysis scenarios. The results and insights gained from the analyses are then presented in several diagrams, and interpreted. The paper concludes with a summary and an outlook on further areas of work.
This paper describes a new method for measuring and appraising the quality of the video stream in the video-telephony service in IP environments (VToIP). The method uses the so-called VS Model and belongs to the group of parameter-based measurement techniques (offline operation, i.e. without active measurement). It delivers results that come extremely close to those contained in the corresponding Perceptual Evaluation of Video Quality (PEVQ) curves. The method is quick and easy to use - a convincing argument for using this new QoS measuring method.
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