Hi,
Please run sudo nvpmodel -m 2 and sudo jetson_clocks to get maximum throughput of CPU cores.
For dropping frames, you may try to get frame data in I420 in appsink:
[Gstreamer] nvvidconv, BGR as INPUT - #4 by DaneLLL
And if you don’t want to process the buffer, can skip calling
cv2.cvtColor(img, cv2.COLOR_YUV2BGR_I420);
It should save some CPU resource by not to converting I420 to BGR for each frame.