Revert "switch from gstream to opencv; map to COM5;"

This reverts commit 98bba994b82215251c57ab2ebf68f3a58b43dcd9.
Revert "Revert "switch from gstream to opencv; map to COM5;""

This reverts commit 07490e536ace0e07bb0665bfad46bac93398f47b.
ignore mp4 file;