How to export frames from a video with timecode in filenames (ffmpeg)?

[eliio]

Hi,
can anybody help me export a number of frames from a video at certain intervals (e.g. every 10 seconds) or set the overall amount of frames (e.g. 100 frames total). And (it's important for me) include the timecode in the filenames (e.g. out_0-00-00-000.jpg, out_0-00-10-000.jpg, etc.).
I've tried ffmpeg using:

ffmpeg -i file -frame_pts true out%d.jpg

from this post or

ffmpeg -i source -vf fps=1,select='not(mod(t,5))' -frame_pts 1 z%d.jpg

from this post.
But got similar results: just a numbered filelist, out_0000.jpg, out_0001.jpg, etc. Or slightly different numbered list, z0.jpg, z5.jpg, ... , z405.jpg (the last is close to seconds timecode but actually it's not accurate).
Is it possible to set something clear and simple like:

ffmpeg -i video.mp4 -frames -interval 10sec out_%timecode.jpg

or

ffmpeg -i video.mp4 -frames -number 100 out_%timecode.jpg

Or perhaps are there any other more specific tools with such capabilities?
I don't get why frame_pts doesn't work for me.