Pyds.get_nvds_buf_surface() does not work for IP Camera!

Hi there

I am trying to capture the output of an IP camera by pyds.get_nvds_buf_surface() in deepstream_test_3.py in deepstream 5 python examples. But when I run the code, the following error occurred:

Traceback (most recent call last):
File “test3_IPCamera.py”, line 2115, in tiler_src_pad_buffer_probe
n_frame = pyds.get_nvds_buf_surface(hash(gst_buffer), frame_meta.batch_id)
RuntimeError: get_nvds_buf_Surface: Currently we only support RGBA color Format

I would appreciate it if you guide me what should I do to use correctly the pyds.get_nvds_buf_surface() for IP camera.
I used the method for USB camera and it works well.

Many thanks in advance
Roya