Reduce video call quality in messaging apps while using mobile data

I see that most of the messaging apps that support video calls set the video quality automatically. WhatsApp, imo, Skype are the most famous examples. That is bad actually... I have a high-speed data connection. So the apps increase video quality to the best level. What is the result? Some hundred megabytes of data transfer during some 10 minutes and that means more money to pay. I don't want that. I prefer medium quality. What is the solution then? Any tweaks for the apps? Any other alternative messaging app?