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A Quest for an Internet Video Quality-of-Experience Metric. Athula Balachandran , Vyas Sekar , Aditya Akella , Srinivasan Seshan , Ion Stoica , Hui Zhang. Internet Video is taking off. Improve Users’ Quality of Experience. Video Quality Metrics: The State of the Art. Subjective Scores
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A Quest for an Internet Video Quality-of-Experience Metric AthulaBalachandran, VyasSekar, AdityaAkella, SrinivasanSeshan, Ion Stoica, Hui Zhang
Internet Video is taking off Improve Users’ Quality of Experience
Video Quality Metrics: The State of the Art Subjective Scores (e.g., Mean Opinion Score) Objective Score (e.g., Peak Signal to Noise Ratio)
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate
Problem 1: New Effects, New Metrics PLAYER STATES Joining Playing Buffering Playing EVENTS Buffer filled up Buffer filled up Buffer empty Switch bitrate Join Time Buffering Ratio Rate of buffering Rate of switching Average bitrate
Problem 2: Opinion Scores Engagement Opinion Scores - Not representative of “in the wild” experience - Combinatorial explosion of parameters Engagement as replacement for opinion score. (e.g., Play time, customer return rate)
Internet Video QoE Subjective Scores MOS Objective Scores PSNR
Internet Video QoE Subjective Scores MOS Engagement (e.g., Fraction of video viewed) Objective Scores PSNR
Internet Video QoE Subjective Scores MOS Engagement (e.g., Fraction of video viewed) Objective Scores PSNR Join Time, Avg. bitrate, …?
Internet Video QoE Subjective Scores MOS Engagement (e.g., Fraction of video viewed) Objective Scores PSNR Join Time, Avg. bitrate, …? f(Join Time, Avg. bitrate, …)
Internet Video QoE Subjective Scores MOS Engagement (e.g., Fraction of video viewed) Objective Scores PSNR Join Time, Avg. bitrate, …? f(Join Time, Avg. bitrate, …)
Outline • Need for a unified QoE • What makes this hard? • Our proposed approach
Challenge: Complex Engagement-to-metric Relationships Engagement Quality Metric
Challenge: Complex Engagement-to-metric Relationships [Dobrian et al. Sigcomm 2011] Engagement Engagement Non-monotonic Average bitrate Quality Metric
Challenge: Complex Engagement-to-metric Relationships [Dobrian et al. Sigcomm 2011] Engagement Engagement Non-monotonic Average bitrate Engagement Quality Metric Threshold Rate of switching
Challenge: Complex Metric Interdependencies Join Time Bitrate Rate of switching Rate of buffering Buffering Ratio
Challenge: Complex Metric Interdependencies Join Time Bitrate Rate of switching Rate of buffering Buffering Ratio
Challenge: Complex Metric Interdependencies Join Time Bitrate Rate of switching Rate of buffering Buffering Ratio
Challenge: Complex Metric Interdependencies Join Time Avg. bitrate Rate of switching Rate of buffering Buffering Ratio
Need to learn these complex engagement-to-metric relationships and metric-to-metric dependencies
Casting as a Learning Problem Need to learn these complex engagement-to-metric relationships and metric-to-metric dependencies Engagement Quality Metrics MACHINE LEARNING QoE Model
Impact of the ML algorithm • Classify engagement into uniform classes • Accuracy = # of accurate predictions/ # of cases ML algorithm must be expressive enough to handle the complex relationships and interdependencies
Challenge: Confounding Factors Live and VOD sessions experience similar quality
Challenge: Confounding Factors However, user viewing behavior is very different
Challenge: Confounding Factors Devices Connectivity User Interest Need systematic approach to identify and handle confounding factors
Domain-specific Refinement Engagement Quality Metrics MACHINE LEARNING QoE Model
Domain-specific Refinement Engagement Confounding Factors Quality Metrics MACHINE LEARNING QoE Model
Improved prediction accuracy Refined ML models can handle confounding factors
Concluding Remarks • Internet Video needs unified quantitative QoE • What makes this hard? • Complex engagement-to-metric relationships • Complex metric-to-metric interdependencies • Confounding factors (e.g., genre, device) • Promising start • Machine learning + domain-specific refinements • Open Challenges • Coverage over confounding factors • System Design