TECHNICAL
Four Methods for Measuring Video Quality The customer experience is where video quality problems come to the fore, and it’s not unusual for customers to try to ferret out the problem. For example, if their Netflix video keeps freezing or tiling, they might launch their Apple TV, HBO Max or Hulu app to see whether those are also having problems. If so, they might deduce that their home network or their ISP is the problem. “For a consumer—and sometimes for the services themselves— it’s really hard to pinpoint exactly where the problem rests,” Sappington says. So when a customer reports a problem, the provider needs to be able to determine from where it’s originating. Figure 1 below shows all of the primary points where artifacts can be introduced. This section discusses the four primary options that streaming providers, their network operator partners and endpoint vendors have for measuring video quality: 1. Measure packets 2. Compare frames 3. Use an algorithm to compare pixels 4. View pixels like a human
For example, packet drops and delays have a bigger impact on the QoE of live streams such as sports than they do with on-demand content such as movies. Also, virtually all vMVPD and SVOD content is encrypted. That rules out deep packet inspection (DPI), which is the only way to understand how much those drops and delays are undermining QoE. The bottom line is that although measuring packets provides some useful insights, it’s a coarse analysis that needs to be used in conjunction with other methods, such as signal strength, to get a fuller picture of the customer’s QoE. For example, the packets might be delivered without a hitch, only to be mishandled by the endpoint’s hardware or software. “You may not necessarily figure out what they see,” Sappington says. “The processing and display of the video may be messed up.”
But if you’re the customer of an vMVPD or SVOD, the right answer could be C—as in churn. With no contracts and several streaming providers to choose from, it’s free and easy to switch when your current service keeps freezing, tiling and buffering like internet video circa 1996. As the streaming IP video market matures, so do customer expectations about the quality of experience (QoE) they get from those services. Those expectations are set partly by their experiences with linear and on-demand services from traditional cable, satellite and telco TV providers. They’re also set by how much they pay for a streaming service and how often they use it.
Typical Problems with Video
Video impairments fall within one of three categories:
Network Impairments n Freezing n Buffering n Packet loss Encoding Impairments n Blockiness n Blurriness n Scaling Camera Impairments n Noise n Focus
Compare Frames
Comparing frames involves capturing video at the customer endpoint and then comparing it with a pristine reference. The approach makes it easy to spot problems that viewers would notice. Examples include delayed or missing frames, stalls and freezes, as well as audio and video that are out of sync. But this method requires unencoded video and the ability to mark the frames, both of which are impractical with vMVPD and SVOD services.
Measure Packets
This approach analyses the delivery of the data that makes up the video stream. The value of its insights varies by content type.
Artifacts can be introduced at many points along the video distribution and reproduction chain at the capture, during encoding, while traversing the network, and during the decode and display.
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SEPTEMBER 2025 Volume 47 No.3
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