This project is implemented for the Pex C++ programming challenge; see
<https://gist.github.com/ehmo/ece1b13a101b416c6b3c928ad11e1776>.

It is based on the file 0_hello_world.c from
<https://github.com/leandromoreira/ffmpeg-libav-tutorial>, which is Copyright
2017, Leandro Moreira and released under the BSD license; see LICENSE.

It was designed with and tested against FFmpeg v4.1.3.

To build, type:

    $ make

After building, it can be run with:

    $ ./analyze-keyframes <video file>

which will output a CSV file, frame-analysis.csv. By changing the constants
VerticalCellCount, HorizontalCellCount, FrameAnalysisCSVFile, or
OutputKeyframeImages in analyze-keyframes.cpp, you can modify the behavior of
the program.