to build a custom player

[zimbot]

I was wondering about trying to make a custom player.

here is my need
I wish to play a video and ...hit a button...a keyboard button of a button on the gui

and write the filename and current frame number to a txt file.

what I hope to accomplish: I have many many videos that need to have the 1st few seconds trimmed off

So I was day dreaming of a vlc player where I could play the video and build a txt file that I could then build many ffmpeg commands.
as in: ffmpeg -ss <tothat frame number> -i <inThatFile> etc.

my current work around is to do snaps
after changing the Simple Preferences > video > prefix as $N-$T-

I then get pngs with a name of
fileName-hh_mm_sec-yyy-mm-dd-timeofDay.png

so I parse those making use of just fileName & hh_mm_sec

but the temporal resolution is only to the second

so -- my question is

is there an addon that exists?
is there currently a way ? a way that I do not know?

or can I build a custom vlc player that could do all that?
and If I try to build it .... i wonder how hard.
meaning : if someone who already programs VLC thinks it is easy or hard...
and how might one start?

Thanks