Still not sure why the things I was trying from command-line didn't work, but this seems to be getting the job done pretty reliably:

autostart.sh:

(vcgencmd force_audio hdmi 1 >/dev/null 2>&1; sleep 8; mpg123 -Z /home/pi/RetroPie/bgm/*.mp3 >/dev/null 2>&1) & #bgm emulationstation #auto

.bashrc (excerpt):

[[ $(tty) == "/dev/tty1" ]] && (vcgencmd force_audio hdmi 0 >/dev/null 2>&1; pkill mpg123) #bgm # RETROPIE PROFILE START

...this seems to work as intended, even though I couldn't get it to work on command-line for whatever reason. With this setup the audio channel opens in time for the music to begin, and closes again when I quit to console.

In autostart.sh, I put vcgencmd before the sleep command because when I did the other way, sometimes it would open up in time for the music but other times it wouldn't. This way it opens up and "hums" for a few seconds before the music starts, but it always starts from the first instant, so an acceptable compromise.

In .bashrc, the original guide said to put the command inside the RETROPIE PROFILE section but that whole section gets rewritten if you update bashwelcometweak; putting it outside the section preserves it even when the welcome tweak is updated.

Issue 1 can be easily solved by using the Audio menu in RetroPie and choosing your default output (Analog Jack/HDMI).

For #2 - The Headphone value can also be chosen in the EmulationStation settings, since it has been updated in June 2020 following the RPI OS changes.

@weirdh I already put console=tty3 some days ago, but it doesn't really hide the console, it just leaves a black screen instead of text.
Actually, I don't really see the console when I run my scripts, I see a black screen. But since, I had console=tty3 I deduced that there would normally be console text instead of a black screen.
It will be difficult to completely hide that console/black screen, maybe it's not even possible.
Anyway, with the icons and detailed names in my scripts, it looks a lot better and 2 or 3 seconds of black screen isn't that bad I guess xD
Thanks!

@windg That's a really good list there. Thanks for that! :)

@mitu said in Redream playing BGM from ES:

I don't know, but you can run ps -ef while steamlink is started and see the process name that it uses, so you can add it to the emulator list.

thanks got it!

@bluestang
Great, glad it's working.
I removed the vc4 workaround stuff since it's not needed, and changed the init_delay to use seconds rather than milliseconds, since it's totally more useful with seconds (if people use video splashscreens).

The installer script was also updated to have a brand new file/directory selector for the initial song and music directory options, making them actually usable without having to pull out the keyboard.
Change Music Dir
Also fixed an issue with spaces in file paths and fixed some smaller niggling things (stopping used to spit out "Terminated blah blah...").

The only thing I'm planning at the moment is to maybe dynamically come up with some nice volume step values based off of fade_duration and max_volume to make just that little more "user-friendly" and remove that config option.

Its is the best method.

That's ok mitu. I would be willing to run a .bat file in the background if need be. I tried doing it myself and I was successful getting music to load up before the main screen finishes loading up on EmulationStation, as well as when you exit out of a game and go back to the menu. The problem I'm having is getting just one splashscreen to randomly load up/play before the loading screen and stopping/closing the media player that displays it.

The code for my splashtest.bat is the following:

@ECHO OFF

REM Your splashscreens file path:
start "" --play and exit "C:\Program Files (x86)\VLC\vlc.exe" -L "C:\Users\Username\Music\Playlists\Splashscreens.wpl"

REM Kill your media player:
C:\Program Files (x86)\VLC\vlc.exe /F

REM Run the frontend (EmulationStation example):
start "" "C:\Program Files (x86)\EmulationStation\emulationstation.exe"

REM Run the media player (WMPlayer example):
start "" "C:\Program Files (x86)\Windows Media Player\wmplayer.exe" -L "C:\Users\Username\Music\Playlists\EmulationStation.wpl"

If anyone here has ideas on any mistakes you can see or a better way of executing this, please let me know. A big thank you goes out to those who can provide these answers :-D.

@mitu success - I'm now in. Thank you so much for your help - much appreciated and sorry for my daft questions

@mitu said in BGM in Ubuntu Desktop 18.04:

@dbrown1986 said in BGM in Ubuntu Desktop 18.04:

I think Ubuntu wouldn't allow it since it was a 'hidden' folder.

First time I hear this kind of - obviously wrong - explanation. Check the permissions on the folder and make sure your $USER owns the folder where the scripts are saved. You don't need to use sudo to edit something that's in your home folder.

Could also been something I mucked up; since I installed using net-inst, I checked the permissions and they looked fine.

@thestarglider My pleasure mate, I'm glad I could help :)

@mitu ok, i think i get it now. im using this as a crash course in writing scripts, so im sorry if i dont understand how this should work. but this is a huge help, thank you.

@cyperghost I have a working scriptmodule that installs mpg123 and sets up the background music automatically. May I have your blessing to include a modified version of this volume fade script (with credit) in the distribution?

@prog-amateur I would also like to know the steps taken to add BGM to RetroPie. This would be a great feature to be added

@Cascote
Solved: The issue lies on the Sample rate of the Mp3 file. It seems that Pygame is not able to correctly play anything that's not on 44100Hz Rate, so I Resampled the mp3s that were not on that rate using Audacity

@legacy said in Modified Background Music Script with added overlays!:

I click a game, the video loading screen kicks in and the music fades out.
Black screen appears to load the game, but the music kicks in for 1 second and fades out, then the game loads.
is there a fix for this. Thank you

I know, I know, you have probably solved this or not interested on it anymore, but for whomever needs it, I had this issue too, I solved it by adding the following lines at the end of the runcommands scripts:
runcommand-onend.sh

pkill -CONT python

runcommand-onstart.sh

sleep 1 pkill -STOP python

Thank you @zerojay ! This is tremendous. Very easy to install, and after a minor issue with the vgm directory permissions, was able to get everything up and running....kind of.

Few issues below. Any help would be much appreciated.
*Update Recreating the autostart.sh file fixed issues 1 and 2.

Both the playmusic.sh and generatem3u.sh scripts are running without issue, but music will not start automatically after boot. I can start it by running the playmusic.sh script from the command line (or via ssh), but it only plays through HDMI port. I don't see anyplace in the vgmplay config file to point it to the Headphone output on RPI4. The playlist does not loop. Playback terminates after reaching the last item in the m3u file.