This looks promising: ComChap
This gives you the option to cut or just add chapters. I only tested on a .mp4 file. Later I will try with mpeg2 files from Channels DVR.
Also, I had to apply fix from this Issue #24 to get it to work on MacOS.
I used command: comchap --keep-edl --keep-meta input.mp4 output.mp4
That way I keep some of the files for analysis. Also, if you have input.edl file, comskip won't try to process the input file it will just chapter mark the file.