QQ International offers high quality video and voice calls to all users – for free. When using a smartphone client you won’t need to setup input and output hardware settings since they’re all incorporated in your device. However if you use QQ International for Windows you might want to change these settings and optimize them for the best possible experience.
Go to Settings, then General and Audio and Video as below:
From this menu you can adjust all your hardware settings. When you customize your audio/video settings you should be able to hear your voice and see the picture of yourself if a microphone and webcam (or just a webcam) are correctly installed. If not please double check your system drivers.
To enhance your video call experience you can choose to prioritize speed over quality or vice versa, try to save bandwidth by using additional compression and so on.