FFMPEG: how to add 1 frame to the end of an mpeg file (creating time-lapse on the fly)?

Question

bash

Hello.
We have a camera. The script pulls a JPG snapshot from it every 30 seconds. I would like to add it to the end of the MPEG file so that time-lapse video with a given frame rate is gradually formed. The question is how to implement it?
* In principle, at the moment the above script puts snapshots in folders (folder name dd_mm_yyyy) with a name in the hh_mm_ss.jpg format and it would be possible to collect video from these files once a day. But the catch is that I can only do this with files like *000001*.jpg, *0000002*.jpg, etc., but I don’t want to save pictures in this format.
Tried the command avconv -i '%*.jpg' -r 30 -q:v 2 timelapse.mp4but it doesn't work.
In general, it seems to be a working option to abandon the storage of a bunch of jpegs and switch to recording ready-made time-lapses on the fly. But I don't understand how to do it. I used to use motion, which can do it myself, but the camera has changed, now only rtsp (mjpeg can’t) and motion choked, I had to take frames directly (

Answer 1

So far I googled this and it works
www.munz.li/2008/07/23/time-lapse-convert-single-j...
But this is mencoder, not ffmpeg)

Answer 2

quietly with yourself .. in the above, you need to add more -vf scaleso that the process does not crash in the middle for reasons that are not entirely clear to me