''python scripts/convert_seqs.py'' not working for me

[MichelSMartins]

michel@michel-Lenovo-IdeaPad-Y510P:~/Desktop/caltech-pedestrian-dataset-converter-master$ python scripts/convert_seqs.py
GStreamer Plugin: Embedded video playback halted; module typefind reported: Could not determine type of stream.
OpenCV Error: Unspecified error (GStreamer: unable to start pipeline
) in cvCaptureFromCAM_GStreamer, file /home/michel/opencv-2.4.13/modules/highgui/src/cap_gstreamer.cpp, line 816
Traceback (most recent call last):
File "scripts/convert_seqs.py", line 19, in
cap = cv.VideoCapture(fn)
cv2.error: /home/michel/opencv-2.4.13/modules/highgui/src/cap_gstreamer.cpp:816: error: (-2) GStreamer: unable to start pipeline
in function cvCaptureFromCAM_GStreamer

[ezfn]

I have exactly the same problem.