Playing music with Pyglet and Tkinter in Python

Question

I wanted to create a simple gui with a play and stop button to play an mp3 file in python. I created a very simple gui using Tkinter that consists of 2 buttons (stop and play).

I created a function that does the following:

def playsound () :
    sound = pyglet.media.load('music.mp3')
    sound.play()
    pyglet.app.run()

I added that function as a command to the button play. I also made a different function to stop music:

def stopsound ():
    pyglet.app.exit

I added this function as a command to the second button. But the problem is that when I hit play, python and the gui freeze. I can try to close the window but it does not close, and the stop button is not responsive. I understand that this is because the pyglet.app.run() is executing till the song is over but how exactly do I prevent this? I want the gui to stop the music when I click on the button. Any ideas on where I can find a solution to this?

score 4 · Answer 1 · edited Oct 03 '12 at 05:04

You are mixing two UI libraries together - that is not intrinsically bad, but there are some problems. Notably, both of them need a main loop of their own to process their events. TKinter uses it to communicate with the desktop and user-generated events, and in this case, pyglet uses it to play your music.

Each of these loops prevents a normal "top down" program flow, as we are used to when we learn non-GUI programming, and the program should proceed basically with callbacks from the main loops. In this case, in the middle of a Tkinter callback, you put the pyglet mainloop (calling pyglet.app.run) in motion, and the control never returns to the Tkinter library.

Sometimes loops of different libraries can coexist on the same process, with no conflicts -- but of course you will be either running one of them or the other. If so, it may be possible to run each library's mainloop in a different Python thread.

If they can not exist together, you will have to deal with each library in a different process.

So, one way to make the music player to start in another thread could be:

from threading import Thread

def real_playsound () :
    sound = pyglet.media.load('music.mp3')
    sound.play()
    pyglet.app.run()

def playsound():
    global player_thread
    player_thread = Thread(target=real_playsound)
    player_thread.start()

If Tkinter and pyglet can coexist, that should be enough to get your music to start. To be able to control it, however, you will need to implement a couple more things. My suggestion is to have a callback on the pyglet thread that is called by pyglet every second or so -- this callback checks the state of some global variables, and based on them chooses to stop the music, change the file being played, and so on.

Hi ok I have a better understanding. How exactly do I do a callback on the pyglet. From my basic understanding what you were suggesting is have a global variable that is set to some value whenever some button is pressed. If the stop button is pressed, then the value gets changed and the pyglet instance needs to stop. I understand how that would be implemented but how would you make sure the pyglet thread checks to see if this global variable is the correct value or not each second or so? — Paul, Apr 24 '12 at 00:23
this doesn't work as pyglet is the thread unsafiest program on earth. Any attempt to use pyglet from a thread on a Mac will crash with error `Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSWindow drag regions should only be invalidated on the Main Thread!'` — Jason Nichols, Jul 16 '19 at 21:29

score 1 · Answer 2 · answered Feb 06 '13 at 17:32

I would do something like:

import pyglet
from pyglet.gl import *

class main (pyglet.window.Window):
    def __init__ (self):
        super(main, self).__init__(800, 600, fullscreen = False)
        self.button_texture = pyglet.image.load('button.png')
        self.button = pyglet.sprite.Sprite(self.button_texture)

        self.sound = pyglet.media.load('music.mp3')
        self.sound.play()

        self.alive = 1

    def on_draw(self):
        self.render()

    def on_close(self):
        self.alive = 0

    def on_mouse_press(self, x, y, button, modifiers):
        if x > self.button.x and x < (self.button.x + self.button_texture.width):
            if y > self.button.y and y < (self.button.y + self.button_texture.height):
                self.alive = 0

    def on_key_press(self, symbol, modifiers):
        if symbol == 65307: # [ESC]
            self.alive = 0

    def render(self):
        self.clear()
        self.button.draw()
        self.flip()

    def run(self):
        while self.alive == 1:
            self.render()

            # -----------> This is key <----------
            # This is what replaces pyglet.app.run()
            # but is required for the GUI to not freeze
            #
            event = self.dispatch_events()


x = main()
x.run()

score 1 · Answer 3 · answered Mar 05 '16 at 22:40

This solution is the easiest one:

import pyglet
foo=pyglet.media.load("/data/Me/Music/Goo Goo Dolls/[1998] Dizzy Up The Girl/11 - Iris.mp3")
foo.play()

def exiter(dt):
    pyglet.app.exit()
print "Song length is: %f" % foo.duration
# foo.duration is the song length
pyglet.clock.schedule_once(exiter, foo.duration)

pyglet.app.run()

source: http://ubuntuforums.org/showthread.php?t=1651906

score 0 · Answer 4 · answered Apr 23 '12 at 15:28

0

There is a media player implementation in the pyglet documentation:

http://www.pyglet.org/doc/programming_guide/playing_sounds_and_music.html

The script you should look at is media_player.py

Hopefully this will get you started

answered Apr 23 '12 at 15:28

Peter Bennett

633
5
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Playing music with Pyglet and Tkinter in Python

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