How to use samples from deepstream sdk to point different video ?

Hi, I am trying to run all the samples in the deepstream sdk.

Sample code - nvDecInfer_detection
I was able to produce the expected result. Now, I am trying to point different video of same type and resolution. I see the only black color window. The sample code uses …/data/video/sample_720p.h264. The one which I am trying is also h264 and same resolution. What code change is required to work other type of videos.
The sample video which I am using is in the below link -