Thank you for creating the issue.
Do you want to deal with the frames outside recv()?
Though I’m not sure if it’s related to the issue, anyway, New Component: streamlit-webrtc, a new way to deal with real-time media streams - #23 by whitphx may help.
As you said, recv() is running in a different thread and cannot access global objects from inside recv.
Instead, you can pass values through processor instance’s attributes like the example above as they can be accessed both from recv() and the main thread.