quality of experience of web-based adaptive http streaming clients in real-world environments using...
DESCRIPTION
Multimedia streaming over HTTP has gained momentum with the approval of the MPEG-DASH standard and many research papers evaluated various aspects thereof but mainly within controlled environments. However, the actual behaviour of a DASH client within real-world environments has not yet been evaluated. The aim of this paper is to compare the QoE performance of existing DASH-based Web clients within real-world environments using crowdsourcing. Therefore, we select Google’s YouTube player and two open source implementations of the MPEG-DASH standard, namely DASH-JS from Alpen-Adria-Universitaet Klagenfurt and dash.js which is the official reference client of the DASH Industry Forum. Based on a predefined content con- figuration, which is comparable among the clients, we run a crowdsourcing campaign to determine the QoE of each implementation in order to determine the current state-of- the-art for MPEG-DASH systems within real-world environments. The gathered data and its analysis will be presented in the paper. It provides insights with respect to the QoE performance of current Web-based adaptive HTTP stream- ing systems.TRANSCRIPT
Quality of Experience of Web-‐based Adap8ve HTTP Streaming Clients in Real-‐World Environments using Crowdsourcing
Benjamin Rainer and Chris8an Timmerer
Alpen-‐Adria-‐Universität Klagenfurt (AAU) w Faculty of Technical Sciences (TEWI) w Department of Informa8on Technology (ITEC) w Mul8media Communica8on (MMC) w Sensory Experience Lab (SELab)
h"p://blog.+mmerer.com w h"p://dash.itec.aau.at/ w h"p://selab.itec.aau.at mailto:[email protected]‐klu.ac.at
December 2, 2014
Slides: hVp://www.slideshare.net/chris8an.8mmerer
Outline
• Introduc+on • How to evaluate DASH and QoE • Methodology • Results • Conclusions
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Mul+media is Predominant on the Internet
• Real-‐+me entertainment – Streaming video and audio – More than 50% of Internet traffic at peak periods
• Popular services – NeVlix (34.9%), YouTube (14.0%), Amazon Video (2.6%), Hulu (1.4%)
– All delivered over-‐the-‐top (OTT)
– MPEG Dynamic Adap+ve Streaming over HTTP
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Global Internet Phenomena Report: 2H 2014
Over-‐The-‐Top – Adap+ve Media Streaming
• In a nutshell …
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C. Timmerer and A. C. Begen, “Over-‐the-‐Top Content Delivery: State of the Art and Challenges Ahead”, In Proceedings of the ACM interna+onal conference on Mul+media (MM '14), Orlando, FL, USA, Nov. 2014. h"p://www.slideshare.net/chris+an.+mmerer/over-‐the-‐top-‐content-‐delivery-‐state-‐of-‐the-‐art-‐and-‐challenges-‐ahead
Adapta8on logic is within the client, not norma8vely specified
by the standard, subject to research and development
MPEG Dynamic Adap+ve Streaming over HTTP
What is specified – and what is not?
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Media Presenta+on on HTTP Server
DASH-‐enabled Client Media Presenta8on Descrip8on
. . .
Segment
…
.
.
. Segment
…
. . .
Segment
…
.
.
. Segment
…
…
Segments located by HTTP-‐URLs
DASH Control Engine
HTTP/1.1 HTTP Client
MPD Parser
Media Engine
On-‐8me HTTP requests to segments
MPEG Dynamic Adap+ve Streaming over HTTP
What is specified – and what is not?
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Media Presenta+on on HTTP Server
DASH-‐enabled Client Media Presenta8on Descrip8on
. . .
Segment
…
.
.
. Segment
…
. . .
Segment
…
.
.
. Segment
…
…
Segments located by HTTP-‐URLs
DASH Control Engine
HTTP/1.1 HTTP Client
MPD Parser
Media Engine
On-‐8me HTTP requests to segments
DASH Data Model
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Segment Info
Initialization Segment http://bitmov.in/500/init.mp4
Media Presentation
Period, start=0s
…
Period, start=100s
…
Period, start=200s
…
…
Period start=100 baseURL=http://bitmov.in/
AdaptationSet 1 500-1500 kbit/s
…
AdaptationSet 2 1500-3000 kbit/s
…
Media Segment 1 start=100s http://bitmov.in/500/seg-1.m4s
Media Segment 2 start=102s http://bitmov.in/500/seg-2.m4s
Media Segment 3 start=104s http://bitmov.in/500/seg-3.m4s
Media Segment 50 start=198s http://bitmov.in/500/seg-50.m4s
AdaptationSet 1 width=640-1280 height=360-720 …
Representation 1 500 Kbit/s
Representation 2 1500 Kbit/s
…
Representation 2 bandwidth=1500 kbit/s width=960, height=540
Segment Info duration=2s
Template: 500/seg-$Number$.m4s
Initialization: 500/init.mp4
…
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How to evaluate DASH? • Methodology
– Dataset, tools (see backup slides for details) – Common evalua+on setup – Bandwidth traces (real/synthe+c) vs. models
• Metrics – Average media bitrate/throughput at the client – Number of representa+on/quality switches – Number of stalls (in seconds) – buffer level
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C. Mueller, S. Lederer, C. Timmerer, “An Evalua+on of Dynamic Adap+ve Streaming over HTTP in Vehicular Environments”, In Proceedings of the Fourth Annual ACM SIGMM Workshop on Mobile Video (MoVid12), Chapel Hill, North Carolina, February 2012.
Quality of Experience • Quality of Experience
– “… is the degree of delight or annoyance of the user of an applica+on or service…”
– Factors influencing / features of QoE may lead to applica+on-‐specific defini+ons
• Subjec+ve quality assessments – Laboratory environment [ITU-‐T B.500 / P.910] – Crowdsourcing with special plaVorms or social networks
• QoE of DASH-‐based services – Startup delay (low) – Buffer underrun / stalls (zero) – Quality switches (low) and media throughput (high)
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P. Le Callet, S. Möller and A. Perkis, eds., “Qualinet White Paper on Defini+ons of Quality of Experience (2012)”, European Network on Quality of Experience in Mul>media Systems and Services (COST Ac>on IC 1003), Lausanne, Switzerland, Version 1.2, March 2013."
Methodology • Quality of Experience …
– Mean Opinion Score [0..100] – [other objec+ve metrics:
start-‐up +me, throughput, number of stalls] • … Web-‐based Adap+ve HTTP Streaming Clients …
– HTML5+MSE: DASH-‐JS (dash.itec.aau.at), dash.js (DASH-‐IF, v1.1.2), YouTube • … Real-‐World Environments …
– DASH-‐JS, dash.js hosted at ITEC/AAU (~ 10Gbit/s) – YouTube hosted at Google data centers – Content: Tears of Steel @ 144p (250 kbit/s), 240p (380 kbit/s), 360p (740 kbit/
s), 480p (1308 kbit/s), and 720p (2300 kbit/s); segment size: 2s – Users access content over the open Internet
• … Crowdsourcing – Campaign at Microworker plaVorm (others also possible: Mechanical Turk,
social networks) limited to Europe, USA/Canada, India – Screening Techniques: Browser fingerprin+ng, s+mulus presenta+on +me,
QoE ra+ngs and pre-‐ques+onnaire
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Results: QoE
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Results: Media Throughput
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Results: Start-‐Up Time
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Results: Number of Switches
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Results: Number of Stalls
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Results: Summary • DASH-‐JS
– High start-‐up +me – Low number of stalls – Good throughput, QoE
• dash.js – Low start-‐up +me – High # stalls – Low throughput – Low QoE
• YouTube – Low start-‐up +me – Low number of stalls – Best throughput, QoE
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Conclusions • QoE evalua+on of DASH-‐like systems in real-‐world environments
using crowdsourcing – Detailed methodology described in the paper – Results indicate that the delivered representa+on bitrate (media
throughput) and the number of stalls are the main influence factors on the QoE
– Results confirmed by previous evalua+ons but within controlled environments
– Evidence about QoE aspects of DASH-‐enabled Web clients within real-‐world environments
– Feasibility of using crowdsourcing for subjec+ve quality assessments • Future work
– Comprehensive evalua+on of various adapta+on logics (both objec+ve and subjec+ve) and
– the impact of dedicated delivery infrastructures aiming to improve DASH-‐based services
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Thank you for your a"en+on
... ques+ons, comments, etc. are welcome …
Priv.-‐Doz. Dipl.-‐Ing. Dr. Chris+an Timmerer Associate Professor
Klagenfurt University, Department of Informa+on Technology (ITEC) Universitätsstrasse 65-‐67, A-‐9020 Klagenfurt, AUSTRIA
[email protected]‐klu.ac.at h"p://research.+mmerer.com/
Tel: +43/463/2700 3621 Fax: +43/463/2700 3699 © Copyright: Chris>an Timmerer
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BACKUP SLIDES
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End-‐to-‐End DASH System Aspects • (Distributed) dataset
– Full movie length in high quality
– Various bitrate, resolu+ons, segment lengths (2-‐15s), (sub-‐)segments
– Distributed: ini+al 3 sites, now 9 in Europe, USA, Taiwan
• DASH encoder – Encoding + Mul+plexing +
MPD genera+on – Fully configurable using a
configura+on file – Enables batch processing – x264/ffmpeg + GPAC MP4Box
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S. Lederer, C. Müller, C. Timmerer, “Dynamic Adap+ve Streaming over HTTP Dataset”, In Proceedings of the ACM Conference on Mul+media Systems 2012, Chapel Hill, North Carolina, February 2012. // S. Lederer, C. Mueller, C. Timmerer, C. Concolato, J. Le Feuvre, K. Fliegel, “Distributed DASH Dataset”, In Proceedings of the ACM Conference on Mul+media Systems 2013, Oslo, Norway, 2013.
End-‐to-‐End DASH System Aspects • Playback
– VLC plugin (first implementa+on) – DASH-‐JS (HTML5 + MSE) – libdash / qtsampleplayer
• MPD valida+on – XML schema valida+on – Xlink resolver & processing – Addi+onal valida+on rules
(Schematron) • Experimental
– DASH over Content-‐Centric Networks (CCN)
– VLC + libdash
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C. Müller and C. Timmerer, “A VLC Media Player Plugin enabling Dynamic Adap+ve Streaming over HTTP”, In Proceedings of the ACM Mul+media 2011, Sco"sdale, Arizona, November 2011. // B. Rainer, S. Lederer, C. Müller, C. Timmerer, “A Seamless Web Integra+on of Adap+ve HTTP Streaming”, In Proceedings of the 20th European Signal Processing Conference 2012, Bucharest, Romania, August 2012.
h"p://records.sigmm.ndlab.net/2013/04/open-‐source-‐column-‐dynamic-‐adap+ve-‐streaming-‐over-‐h"p-‐toolset/