Now I have found a solution to replace the existing sound file : beep, beep by a new created file alarm-clock-elapsed.oga
(refer to ./gnome-clocks-45.0/data/sounds (respective sources))
What I did :
0.download the sources :
https://github.com/GNOME/gnome-clocks/tags and there use Tag 45 (the most you will need you will have preinstalled in Mate 24.04) and unzip it.
1. Generate a new alarm-clock-elapsed.oga and copy it to /gnome-clocks-45.0/data/sounds
I did cut with ffmpeg 9sec of the mp3 file
Increased the loudness of the file via Audacity (filter) and via ffmpeg generated the respective oga-file :
Code:
ffmpeg -ss 0 -t 9 -i '"Queen - Another One Bites the Dust.mp3" output.mp3
Read output.mp3 with Audacity to increase loudness => output.m4a
Code:
ffmpeg -i output.m4a -c:a libvorbis -b:a 256k alarm-clock-elapsed.oga
2 cd to the directory where you will find meson.build
The respective builddir will be created, if you get some error messages, use synaptic to install the respective packages.
And try again until no error.
3.
4. The binary gnome-clocks you will find in :
gnome-clocks-45.0/builddir/src
5. open caja as administrator. Open /usr/bin and rename the existing gnome-clocks to gnome-clocks_old and copy the new created binary to /usr/bin.
(It is necessary to have a preinstalled version of gnome-clocks)
How to install meson, ninja, an easy description you will find here :
https://github.com/vivictorg/vivictpp -> Building Ubuntu
Attached a screen-record with calling clocks + elapsed time + new sound