[opendev] The Background Music Box

cyperghost

Some code snippets ;)

BGM_PATH="/home/pi/BGM"
SONGLOOP=$(ps aux | grep "$BGM_PLAYER" | grep -o "$BGM_PATH" | wc -l)

This counts all songs that are currently in loop. So we can show the number of tracks till mpg123 finishes (except you use the -Z parameter this will cycle endless through your songs).

Annother question...
What behaviour is more natural? If I use PLAYLIST-button then the selected song will be send to Playlist array. If I now go to SELECT-button the marked song will be also send to Playlist array and mpg123 starts the tracklist.

Or is is better to use the SELECT-button without adding a song to playlist array and just start playing (except if no other song is holded into playlist?) Maybe should rename the button to PLAY then ;)

cyperghost

Some more code snipptes....

How to detect current song playing?

Method using lsof
This tool is so versatile and should be part of the standard image. It detects every opened file or opened network connection (security reasons). So to detect the current song running a useful code snippet with lsof-usage can be

songname=$(lsof -c $BGM_PLAYER -F | grep "$BGM_PATH")
songname="${songname##*/}"

Method is using pgrep aux command
This tool is a process monitoring tool that is also very versatile. It show the state of process and the whole command structure. Together with a simple mp3 player like mpg123 it's possible to show all truncated filenames as "playlist". So a working code snippet is...

songname=$(ps aux | grep mpg123 | grep -o -E "$BGM_PATH.*")
songname="${songname#*$BGM_PATH/}"
songname="${songname%% /*}"

Which method is better? For comfort reasons Method 1 is more versatile because this will always work with every music player. Remember? lsof shows file access of processes whereas Method 2 shows just the whole command line ;)

In the case of the Raspberry I would prefer Method2 becasue lsof is not installed by default :(

More to come ;)

cyperghost

Annother crippling lines of code

so take a swift look, I put the playlist entries in a ARRAY named farray.
I asked the question of how I could make better navgation through the items.
You know you put song1.mp3 and song2.mp3 into a Playlist by select the dedicated button. Now you stay on song2.mp3 and press play. The usually this song would also be put into Playlist now. Not good? Yes I think so!

So we will look to the codeline

[[ ${#farray[@]} -eq 0 || "${farray[-1]}" != "$BGM_PATH/$file" ]] && farray+=("$BGM_PATH/$file")

Inside the bash test command [[ .... ]]
I have two conditions

If

the array is empty (that makes the # in front of the array)
OR
The last entry of the array HAS NOT the same name of the current selected file

THEN
add the file to the array and start playing your music ;)

I just want you to show how, to count entries in arrays and the crazy thing (-1) read the latest array position (very usefull and also new to me)

more to come ;)

cyperghost

Added restart if musicplayer is not available.
We try to start the Player with Shuffle mode.
I will release script code soon ;)

! [[ -d $BGM_PATH ]] && dialog_error "Directory $BGM_PATH not found! Exit!" && exit

if [[ $PLAYER_INSTANCE -eq 0 ]]; then
    dialog_yesno "$BGM_PLAYER not running!\nShould I try to start it using shuffle mode?\n\nShuffle command: $PLAYER_SHUFFLE
    [[ $? -eq 0 ]] || exit
    $PLAYER_SHUFFLE &
    exit
fi

cyperghost

Finished

All improvements made here in this topic are merged to the final code
Sadly noone made suggestions ;)
So luckily I'm finished now - SCRUM run in 2 weeks
So Team, PO, SM in one person with 3 sprints ;)

Superman550

am i missing a step because when i try to launch the script all i get is "error expect 5 tokens to launch menu but only 4 available"

i am running 4.4 on a raspberry pi 3 b+

cyperghost

@Superman550 Then your array for mp3 files is empty. Place your mp3 files directly to /home/pi/BGM not in subfolders. Our can you tell me how your mp3 files are arranged? They need a mp3 file externsion as well.

PS: If there are subfolders you can try to change line 76 -maxdepth 1, to 2 or completly remove this argument. You see sadly I got no response for this as I coded so I wasn't aware of different setups ;)

EDIT: Tried with -maxdepth 2 and yes I can now acess subfolders within playlists. So this could be a possible solution. I do not change the code as long there are some responses.

Superman550

@cyperghost i did have the files in the BGM folder and i only did one to test the script out and i did have the music player script installed but when i did disabled the music player from running at start up your script worked again

ketaketish

Loving the script!
1 question: I notice when I select a song, once that song is over mpg123 stops by default.
How would I go about, or is it possible to modify the command so that once the selected song is over, it returns to shuffle mode on its own without the need to re-enter the script?

Thanks for your work!

cyperghost

@ketaketish Thank you

I notice when I select a song, once that song is over mpg123 stops by default.

Yes that's a behaviour I'm aware of. But see my BGM tracks have a length of more then 60 min per track. If you want to continue music then you need a second call to mpg123 inside the script. But this is not good coding because the second will check every x seconds if the current session of mpg123 is still running or you can use wait command.

I think it is not a great deal to restart the player in shuffle mode if you want to select a new track. Everything else is not clean coding imho. The best solution would be a player inside ES ;)

ketaketish

@cyperghost Thank you for your response!
I must admit, I have not listened to your tracks... I kind of immediately added my own :S
60min tracks would definitely be less of a nuance compared to my 2mins tracks haha.

That explanation makes perfect sense. I am not as well-versed so I was more curious if it were possible but I do see that making a check every X seconds is a waste of resources.

Keep up the good work! :)

ketaketish

@cyperghost Just had a thought (if its a no then all good):

Would there be a way to analyse the selected mp3 file for its duration? Then output that into say "Length", then use "wait $Length" before returning to shuffle?

I love learning this stuff and have been doing most of it so far through these forums and "Trial and Error" and have learned all the Linux I know so far through it. So I do appreciate your explanations :)

cyperghost

@ketaketish about mp3 lenght... There are surly tools available that can analyse track length.

Easiest approch would be a small script like this

#!/bin/bash
while pidof mpg123 > /dev/nul; do
     sleep 10
done
mpg123 -q -Z /path/to/mp3files/*.mp3

Then you send this script to background alongside with the script. You add a line between 101 and 102 like
/path/to/script/above/shuffle.sh &

It's a dirty hack but will work

EDIT: Improved the dirty hack a bit

cyperghost

@ketaketish Even if this is a very old topic. I've added the length of mp3 files (for current song only)
There is a package mp3info - it's very capable in getting info of tracks ;)

The whole script is improved alot.
Please install the tools lsof and mp3info before with sudo apt install lsof mp3info
The script will run without these but it will look more nice with the tools installed.

Default player is mpg123
Please change the player inside the script or install with sudo apt install mpg123
mpg123 is the smallest mp3 I know for Debian .... it's very relyable and small in footprint and won't hurt your system setup!

Changes:

Code Cleanup
Show length of current played song in mm:ss
use realpath for path resolving
use /dev/null hack to use mpg123 with Raspbian stretch (=RetroPie 4.5.1)

cyperghost

It's possible to see tracklength of current selected track...

Ugly hack!! removed!!!

and add --item-help to your dialog config, then you can see tracklength of selected mp3 title ;) Maybe somebody can improve the coding .... I did it just in a swift way.

cyperghost

So this is an updated version of the music player with additional info to selected mp3 file. See bottom line ....

Get it from here

majikill

i understand that this topic is old. but a different bgm player is no longer woking properly. That and im having way more fun setting it up and having bgm work the way it should. That being said its kind of a shame this project didnt go far, i aim to change that. Is is possible to set a different volume level for mpg123 than master setting of ES? to keep the music at a tollerable level i cant hear the games. id have to set the volume the moment i get out of a game and that can be a hassle. so im hoping there is a script or something i can use to remedy this

mitu

@majikill said in [opendev] The Background Music Box:

That being said its kind of a shame this project didnt go far, i aim to change that. Is is possible to set a different volume level for mpg123 than master setting of ES.

You can, by defining a new ALSA device, with it's own volume - https://alsa.opensrc.org/How_to_use_softvol_to_control_the_master_volume.

Basically, you add in $HOME/.asoundrc

pcm.mp3 {
    type            softvol
    slave.pcm       "default"
    control.name    "Softmaster"
    control.card    0
}

then you instruct the audio application to use the mp3 ALSA device. When you open alsamixer to se the volume, you'll have 2 mixer elements, one of them called "Softmaster", and you can set the volume individually.

cyperghost

@mitu @majikill The method for volume change can be kept quite simpler. mpg123 -f switch scales volume level.

So please feel free to improve

32768 -- Volume 100%
29491  --Volume 90%
...
16284 -- Volume 50%
...
0 -- Mute

majikill

@cyperghost where would i apply these changes exactly? unless i make the changes to any instance mpg123 starts?