Block 6. Streaming QoE

Streaming QoE metrics — startup time, rebuffering, bitrate, switching — predict whether a viewer stays. What the engagement research found, and why.

Rebuffering is the mid-stream spinner. Learn what the rebuffering ratio measures, how to compute it, and why a 1% stall costs about 5% of watch time.

Time to first frame is the wait before video plays. Learn what startup time measures, where the seconds go, and why a 2-second start loses viewers.

How adaptive streaming trades bitrate, rebuffering, and switching — and why a switchy stream loses to a stable one at the same average bitrate.

How player telemetry becomes QoE metrics: the CTA-2066 event taxonomy, CMCD/CMSD, the analytics stack, and where each player-side number lies.

Picture metrics score the encode; QoE scores the session. How VMAF and rebuffering combine into one experience score, and why optimizing one backfires.

No-reference video quality for live and UGC: which blind metrics work (NIQE, BRISQUE, UVQ, DOVER), how accurate they are, and how to deploy them.