How to trim out black frames with ffmpeg on windows?
Here's a way to do it with the blackdetect and trim filters.

First, a better way to get the blackdetect output is via ffprobe because it is capable of writing structured data such as XML, JSON or one key=value per line. 

You do this using metadata injection:

ffprobe -f lavfi -i "movie=/path/to/input.mp4,blackdetect[out0]" -show_entries tags=lavfi.black_start,lavfi.black_end -of default=nw=1 -v quiet
TAG:lavfi.black_start=0
TAG:lavfi.black_end=5.42208
TAG:lavfi.black_start=73.4067


As you can see it returns the start and end time of each black section. You use the returned info to trim the segments between each end and the next start:

ffmpeg -i /path/to/input.mp4 -filter_complex "[0:v]trim=start=5.42208:end=73.4067,setpts=PTS-STARTPTS[v1];[0:a]atrim=start=5.42208:end=73.4067,asetpts=PTS-STARTPTS[a1]" -map [v1] -map [a1] output.mp4

You can chain multiple trim filters in the same command. See this answer for a detailed example.

To automate this in Windows you can install and use PowerShell or another scripting language of your choice (PHP, Python etc).