When change preprocess gpu-id，it cannot detect any thing,but the program can run normally

[fanzh]

@jiangyuzhe1992

after the preprocess ,shouldnot it be 4 frames in one batch_meta?

yes, should be 4.

@jiangyuzhe1992

it has no objs.

need to narrow down this issue, please refer to dump_infer_input_to_file.patch.txt in DeepStream SDK FAQ - #9 by mchi to dump the input data before inference, by this method, we can know if preprocess plugin can give right tensor data.