Playing a video on Raspberry Pi OS startup - linux

Question

I need to run a script to play a video when I turn on my Raspberry Pi 4. I'm using crontab to run my script which opens a video with mpv.
When I run the script normally, it works fine and the video is being played.
The problem is, when i boot the raspberry, the script automatically runs but mpv doesn't .
here is my script:
#!/bin/bash
VIDEOPATH="/home/pi/Desktop/my-movie.mkv"
SERVICE="mpv"
while true; do
echo "playing "+$VIDEOPATH
$SERVICE --fs --start=00:00:00 $VIDEOPATH
done
I added this line to crontab:
#reboot /home/pi/Desktop/my-script.sh
I'm totally stuck in this. Any help saves my life!

Answer 1

The most practical solution I found to run GUI programs on startup is using Autostart.
I created a .desktop file at /etc/xdg/autostart directory:
sudo nano /etc/xdg/autostart/display.desktop
when display would be a custom name for my script.
I added following lines the display.desktop :
[Desktop Entry]
Name=Play a video
Exec=mpv --fs --start=00:00:00 path-to-my-video
Saved the file and reboot the Pi.
sudo reboot
As soon as my Pi boots up, my GUI program automatically start as well.

Answer 2

Please update your script:
#!/bin/bash
source ~/.bash_profile
VIDEOPATH="/home/pi/Desktop/my-movie.mkv"
SERVICE="mpv"
while true; do
echo "playing "+$VIDEOPATH
$SERVICE --fs --start=00:00:00 $VIDEOPATH
done