Clearing media list for vlc media_list_player won't allow to restart media player

Question

I'm working on a Raspberry Pi 4B and I'm creating a music player to replace the inside of a jukebox. I'm trying to feed music to VLC using key combinations. In this case, selecting 'A1' will go to the USB stick mounted as '/media/usb1' to the 'A1' folder, add any media found to a playlist being played by a media_list_player. This works as designed.

My problem comes in when I'm trying to clear the media list to start over. I need to use the same media_list_player name, but once I create a new media list I can't restart the player.

Here is my snippet of code:

#!/usr/bin/env python3
#
import os, sys, csv, vlc, time, serial, configparser, termios, tty, subprocess
#
# Get Defaults
#
SoundBeforeSong = None
SoundAfterSong = None
TrackDelay = None
PlayHistory = None
USBDrive =  "/media/usb1/"
#
# Get keyboard input
#
def getch():  # getchar(), getc(stdin)  #PYCHOK flake
    fd = sys.stdin.fileno()
    old = termios.tcgetattr(fd)
    try:
        tty.setraw(fd)
        ch = sys.stdin.read(1)
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, old)
    return ch
#
# Adding to playlist - Returns directory contents and adds to playlist
#
def addplaylist(track):
    list = None
    if os.path.isdir(os.path.join(USBDrive, track)):
        files = [f for f in os.listdir(os.path.join(USBDrive, track)) if os.path.isfile(os.path.join(USBDrive, track, f))]
        for f in files:
            if list is None:
                if SoundBeforeSong:
                    list = SoundBeforeSong + ";" + os.path.join(USBDrive, track, f)
                else:
                    list = os.path.join(USBDrive, track, f)
                if SoundAfterSong:
                    list = list + ";" + SoundAfterSong  
            else:
                if SoundBeforeSong:
                    list = list + ";" + SoundBeforeSong + ";" + os.path.join(USBDrive, track, f)
                else:
                    list = list + ";" + os.path.join(USBDrive, track, f)
                if SoundAfterSong:
                    list = list + ";" + SoundAfterSong
    else:
        print ("Error(3) - Selection folder not present")
    if list is None:
        print ("Error(4) - Selection has no media")
    else:
        if ";" in list:
            list = list.split(";")
            for song in list:
                media_list.add_media(song)
        else:
            media_list.add_media(list)
        print("add media play")
        if not media_player.is_playing():
            media_player.play() 
    return
#
# Define keyboard actions
#
def Jukebox():
    global Action, Bluetooth
    Sel_char = None
    while True:
        key = getch()
        try:
            Sel_char = int(key)
        except:
            try:
                Sel_char = key.upper()
            except:
                Sel_char = None
        if Sel_char == "Z":
            return False
        elif Sel_char == "W":
            if not media_player.is_playing():
                media_player.play()
            if media_player.is_playing():   
                media_player.stop()
                media_list = player.media_list_new()  # creating a new media list
                media_player.set_media_list(media_list)  # setting media list to the media player
        elif type(Sel_char) == str:
            Action = Sel_char
        elif type(Sel_char) == int:
            Action = Action + str(Sel_char)
            addplaylist(Action)
        else:
            pass
#
# Setting Up Media Player
#
# creating Instance class object
player = vlc.Instance('--no-xlib --quiet ') # no-xlib for linux and quiet don't complain
media_player = vlc.MediaListPlayer()  # creating a media player object
media_list = player.media_list_new()  # creating a new media list
media_player.set_media_list(media_list)  # setting media list to the media player
new = player.media_player_new()  # new media player instance
media_player.set_media_player(new)  # setting media player to it
media_events = new.event_manager()  # setting event handler
#
# Read keyboard input
#
print("Ready...")
Jukebox()
#
# Program is shutting down
#
sys.exit()

For me, I hit 'A1' and music starts as expected. I hit 'W' and it stops as expected. behind the curtains, I'm also clearing the media list by creating a new blank one. Hitting 'W' again does nothing as I cleared the list, so that makes sense. I hit 'A1' and expect to hear music again, but I don't. I see "add media play", but no sound. How can I restart the media list player? Or probably the more appropriate question is, how do I clear the media list (by creating new or removing media from the list) and allow the media player to be used using the same reference?

score 0 · Answer 1 · edited Sep 07 '21 at 19:05

If your looking to clear the playlist for vlc python player programmatically then this worked for me using raspbian buster os, python3.7 in a .py program.

import subprocess
import time
import vlc

subprocess.call('vlc -d', shell=True)
time.sleep(.5)

def clearlist():
    check_list = subprocess.check_output("sudo pgrep -u pi vlc | cut -d' ' -f1", shell=True)
    time.sleep(.25)
    subprocess.run('sudo kill %d' % round(float(check_list.decode('ascii'))), shell=True)
    time.sleep(3)
    subprocess.call('vlc -d', shell=True)
    time.sleep(.5)
    subprocess.call('playerctl volume 0.5', shell=True)

it's just easier to kill the player and restart it with a blank playlist

Clearing media list for vlc media_list_player won't allow to restart media player

1 Answers1