Nvv4l2decoder enable-frame-type-reporting get value in code

Hi all:
when I run pipeline with …! v4l2decoder enable-frame-type-reporting=1 ! …, I can see the Frame, Frame Type and nActiveRefFrames information on the terminal. How can I get these values in C code after g_object_set(nvv4l2decoder, "enable-frame-type-reporting", 1, NULL)? Like g_object_get or g_ signal_connect ?

Thanks,
Ernan