I had a mentee that wanted to show her students how she formed the words she was saying. This is how I responded.
The way I see it, you two options:
1) Low Tech: Get a wired webcam and move it closer to your face to get the mouth shapes.
2) Editing, Screenpal lets you crop your webcam. I did it here: https://go.screenpal.com/watch/cZ1tYDV8YDt
- Record a video normally
- When editing, click on the webcam and then the pin with an "O" on it. You should see options to both resize and crop your webcam video.
- First make the webcam larger.
- Then, crop to show your mouth.
- At the end of the clip that requires mouthshapes, do the opposite.
If it helps, I could try to make a video of me using screenpal, but I need to download another screen recorder to do that.