Question about the input data.

[Gatsby23]

Sorry for bothering you. But when I run the code on my mac. It always shows:

in.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.
               main.cpp:705   Discarding a bad frame.

It seems the video input didn't get the video ? But I just install opencv from the 3rdparty through build.sh. Everything shows the it build success. So I don't know how to solve this problem, could you please give me some advice?