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Viewer Intelligence™ to Deliver The Ultimate Viewing Experience™
Video Quality-of-Experience Assessment
Zhou WangSSIMWAVE INC & University of Waterloo
QUALITY-OF-EXPERIENCE ASSESSMENT IN VIDEO DISTRIBUTION
Content Processing & Encoding
Trans-coding
Packaging and
Caching
TVsource
Trans port
Network
Tablet
Cellphone
Head-End Media Data CenterConsumer Devices
Edge Server
...
§ How do we ensure end users’ quality-of-experience (QoE)?
§ How do we ensure content producers’ creative intent is faithfully delivered to users?
§ How do we save resource/cost without sacrificing user QoE?
QUALITY-OF-EXPERIENCE ASSESSMENT IN VIDEO DISTRIBUTION
Quality-of-Serve (QoS)
bitratepackage dropnetwork delay
integrity checks……
initial bufferingstalling duration
stalling frequency……
Quality-of-Experience (QoE)
seeing like humans
QoS metrics
True QoEmetric
“Pseudo” QoE metrics
QUALITY-OF-EXPERIENCE ASSESSMENT IN VIDEO DISTRIBUTION
Content Processing & Encoding
Trans-coding
Packaging and
Caching
TVsource
Trans port
Network
Tablet
Cellphone
Head-End Media Data CenterConsumer Devices
Edge Server
...
QUALITY-OF-EXPERIENCE ASSESSMENT IN VIDEO DISTRIBUTION
Content Processing & Encoding
Trans-coding
Packaging and
Caching
TVsource
Trans port
Network
Tablet
Cellphone
Head-End Media Data CenterConsumer Devices
Edge Server
...
QoE Probe
DESIRED PROPERTIES OF QOE METRICS
§ High accuracy, high speed
§ Easy-to-understand, easy-to-use
§ High precision (fine granularity)
§ Consistent scoring across content, resolution, dynamic range, viewing device/condition
§ Spatial alignment, temporal alignment
§ Versatile: full-reference, no-reference, degraded-reference
§ End-to-end: consistent scoring between server and client
SSIMPLUS – HIGH ACCURACY
Well aligned with MOSCorrelation > 0.97
Only metric achieving 0.9 average correlation with MOS
SSIMPLUS – HIGH SPEED
SSIMPLUS – EASY-TO-UNDERSTAND, EASY-TO-USE
quality meter
Large-scale deployment, running 24/7
SSIMPLUS – HIGH PRECISION (FINE GRANULARITY)
test video frame pixel-precision quality map
SSIMPLUS – CONSISTENT SCORING
crossuser device
crossdynamic range
crossvideo content
cross resolution/ frame rate
SSIMPLUS – HIGH VERSATILITY
For source- Single-ended no-reference (NR)
quality assessment
For test- Double-ended full-reference (FR)
perceptual fidelity assessment
- Degraded-reference (DR) absolute quality assessment
SSIMPLUS – END-TO-END CONSISTENT QUALITY MONITORING
MEASURE END-TO-END
CROSS-RESOLUTION QUALITY ASSESSMENT
The ideal convex hull structure for rate-quality envelopSource: https://medium.com/netflix-techblog/per-title-encode-optimization-7e99442b62a2
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0 500 1000 1500 2000 2500 3000 3500 4000
234p 360p 432p 720p 1080p
PSNR fails to produce meaningful convex hull structure
CROSS-RESOLUTION QUALITY ASSESSMENT: PSNR
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0 500 1000 1500 2000 2500 3000 3500 4000
234p 360p 432p 720p 1080p
VMAF fails to produce convex hull structure
CROSS-RESOLUTION QUALITY ASSESSMENT: VMAF
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0 500 1000 1500 2000 2500 3000 3500 4000
360p 432p 576p 720p 1080p
SSIMPLUS creates ideal convex hull structure
CROSS-RESOLUTION QUALITY ASSESSMENT: SSIMPLUS
SUMMARY
Features PSNR VMAF SSIMPLUSHigh accuracy X √? √
High speed √ X √
Ease-of-understanding, ease-of-use √ X √
High precision (fine granularity) √ X √
Consistency across spatial resolution X X √
Consistency across frame rate X X √
Consistency across dynamic range X X √
Consistency across viewer device/condition X X √
Spatial alignment/temporal alignment X X √
Full-reference √ √ √
No-reference/degraded-reference X X √
End-to-end consistency X X √
SUMMARY
§ High accuracy, high speed
§ Easy-to-understand, easy-to-use
§ High precision (fine granularity)
§ Consistent scoring across content, resolution, dynamic range, viewing device/condition
§ Spatial alignment, temporal alignment
§ Versatile: full-reference, no-reference, degraded-reference
§ End-to-end: consistent scoring between server and client
SSIMPLUS: the only metric that satisfies all conditions