What is a Mean Opinion Score or MOS?

Sep 12, 2019 12:35:27 PM

 

 

Mean opinion score (MOS) is a measurement of the quality of experience, commonly used in profiling the quality of audio and video content. HeadSpin’s AI engine continuously measures video mean opinion score of mobile application video during a performance session test. The following is a screenshot of Video Quality MOS on HeadSpin’s waterfall UI timeline highlighted with a red outline.

MOS Performance Metric in HeadSpin’s waterfall UI
mos_performance_metric_in_HeadSpins Waterfall UI

Performance Session Link:
https://ui-dev.headspin.io/sessions/de8d3768-c57d-11e9-bcde-f01898ea5299/waterfall

Video contents are incorporated in different types of mobile applications: live streaming sports and events, live streaming news, explanation video, cutscene in a game, introduction/walkthrough video, live communication video, video as a file etc. Poor video experience can negatively impact user’s overall experience. It is crucial for mobile developers and QA teams to understand how well their video performs on real devices in real network conditions.

HeadSpin’s AI Engine MOS

HeadSpin’s mean opinion score ranges from 0 to 4, with 0 being very poor and 4 being excellent as shown in the following list.

Score range:

  • 0 very poor
  • 1 poor
  • 2 fair
  • 3 good
  • 4 excellent


iPhone X Video Examples
MOS: 3.54 [Youtube video]


iphone-x-video-youtube-video-text-mos

Comments: Although the content of the Chinese character and QR character are not crystal clear, no visible blockiness can be observed.

MOS: 2 [NBA Video with blur and blockiness]
MOS- 2 [NBA Video with blur and blockiness]

Comments: Notice that the player on the video screen capture is blocky. The scoreboard on the video is blurry.

MOS Score: 0.57 [Youtube Video with severe blockiness]MOS Score- 0.57 [Youtube Video with severe blockiness]

Comments: Notice that the video is very blocky where the face of the person is indistinguishable.

Improve your video and delight your customers

With real networks on real devices, many factors can affect the delivery of video content through mobile applications. The following list includes some of these different factors:

  • The device and OS of the mobile application
  • Bandwidth, latency, jitter packet losses of the network
  • Misconfiguration of the content delivery network (CDN)
  • Mobile application client issue playing the video
  • Corrupted video download


Using HeadSpin’s platform video mean opinion score (MOS) and network performance capture, developers and QA teams can resolve issues and improve mobile video viewing experience, which ultimately leads to delighted customers.