In fact, the answer lies in your own QQ settings, which is purely what QQ Tencent Help Center should and has the obligation to answer. You Ke
Look for it on their website first, and there is no answer, so that users' questions are flying all over the internet. It's irresponsible! !
Open QQ- System Settings-Friends and Chat-Voice and Video-Video Settings-Please select your video device.
This is the problem. You may have many options, but your current QQ video is a black screen, which is definitely the default choice for QQ.
So, what camera are you using now? Once plugged in, it will be displayed in the drop-down list. Choose the right one, and the problem will be solved immediately!