If one stream has a logo, you can use ROI (region of interest) to have objective metrics calculated correctly.
Click the ROI checkbox, specify ROI values and choose normal or inverse type of the analyzed area. The result will be shown either for a certain area or without a determined area (depending on a chosen type: normal or inverse).
You can do the same thing manually. For that, clear the checkbox “Start quality estimation after closing this dialog” when creating a new task and click OK. Then, use the ROI tool and launch estimation via the Play button.