Thank you for your reply. I am using AVCaptureVideoDataOutput. To detect a tennis ball with YOLO, I believe I need to use AVCaptureVideoDataOutput, right?

@DTS Engineer I see. Thank you for the explanation. It seems very likely that the reason the FPS is dropping is due to using the YOLO model for object detection within captureOutput. However, due to the requirements of the app, I don't want to lower the FPS. As one idea, would it be possible to save the images obtained in captureOutput and then run YOLO detection on them later?