Python Change Master/Application Volume

Question

How do I change it?

I'm looking for something like:

SetMasterVolume(0.5)
SetAppVolume('FooBar',0.5)

I tried using ctypes.windll.winmm, but I can't find much documentation on how to use it.

Thanks in advance.

Answer 1

I'd hope after 5 years this is no longer a problem for you, but I've just had to do the same thing. It's possible using the PyCaw library.

Simple proof of concept, based on PyCaw's examples

from __future__ import print_function
from pycaw.pycaw import AudioUtilities, ISimpleAudioVolume


def main():
    sessions = AudioUtilities.GetAllSessions()
    for session in sessions:
        volume = session._ctl.QueryInterface(ISimpleAudioVolume)
        if session.Process and session.Process.name() == "vlc.exe":
            print("volume.GetMasterVolume(): %s" % volume.GetMasterVolume())
            volume.SetMasterVolume(0.6, None)


if __name__ == "__main__":
    main()

Answer 2

First import subprocess import subprocess

Then to get the master volume

def get_master_volume(self):
    proc = subprocess.Popen('/usr/bin/amixer sget Master', shell=True, stdout=subprocess.PIPE)
    amixer_stdout = proc.communicate()[0].split('\n')[4]
    proc.wait()

    find_start = amixer_stdout.find('[') + 1
    find_end = amixer_stdout.find('%]', find_start)

    return float(amixer_stdout[find_start:find_end])

And to set the Master volume

def set_master_volume(self, widget):
    val = self.volume
    val = float(int(val))
    proc = subprocess.Popen('/usr/bin/amixer sset Master ' + str(val) + '%', shell=True, stdout=subprocess.PIPE)
    proc.wait()

Answer 3

So instead of editing my old answer I'm adding a new post to allow others who use self to use my old code and anyone who's not, to use my new code.

def get_master_volume():
    proc = subprocess.Popen('/usr/bin/amixer sget Master', shell=True, stdout=subprocess.PIPE)
    amixer_stdout = proc.communicate()[0].split('\n')[4]
    proc.wait()

    find_start = amixer_stdout.find('[') + 1
    find_end = amixer_stdout.find('%]', find_start)

    return float(amixer_stdout[find_start:find_end])

def set_master_volume(volume):
    val = float(int(volume))

    proc = subprocess.Popen('/usr/bin/amixer sset Master ' + str(val) + '%', shell=True, stdout=subprocess.PIPE)
    proc.wait()

Answer 4

I ripped this from here and modified it to use functions only.

import time
import ctypes

# Import the SendInput object
SendInput = ctypes.windll.user32.SendInput

# C struct redefinitions
PUL = ctypes.POINTER(ctypes.c_ulong)

class KeyBoardInput(ctypes.Structure):
    _fields_ = [
        ("wVk", ctypes.c_ushort),
        ("wScan", ctypes.c_ushort),
        ("dwFlags", ctypes.c_ulong),
        ("time", ctypes.c_ulong),
        ("dwExtraInfo", PUL)
    ]

class HardwareInput(ctypes.Structure):
    _fields_ = [
        ("uMsg", ctypes.c_ulong),
        ("wParamL", ctypes.c_short),
        ("wParamH", ctypes.c_ushort)
    ]

class MouseInput(ctypes.Structure):
    _fields_ = [
        ("dx", ctypes.c_long),
        ("dy", ctypes.c_long),
        ("mouseData", ctypes.c_ulong),
        ("dwFlags", ctypes.c_ulong),
        ("time",ctypes.c_ulong),
        ("dwExtraInfo", PUL)
    ]

class Input_I(ctypes.Union):
    _fields_ = [
        ("ki", KeyBoardInput),
        ("mi", MouseInput),
        ("hi", HardwareInput)
    ]

class Input(ctypes.Structure):
    _fields_ = [
        ("type", ctypes.c_ulong),
        ("ii", Input_I)
    ]

VK_VOLUME_MUTE = 0xAD
VK_VOLUME_DOWN = 0xAE
VK_VOLUME_UP = 0xAF

def key_down(keyCode):
    extra = ctypes.c_ulong(0)
    ii_ = Input_I()
    ii_.ki = KeyBoardInput(keyCode, 0x48, 0, 0, ctypes.pointer(extra))
    x = Input( ctypes.c_ulong(1), ii_ )
    SendInput(1, ctypes.pointer(x), ctypes.sizeof(x))


def key_up(keyCode):
    extra = ctypes.c_ulong(0)
    ii_ = Input_I()
    ii_.ki = KeyBoardInput(keyCode, 0x48, 0x0002, 0, ctypes.pointer(extra))
    x = Input(ctypes.c_ulong(1), ii_)
    SendInput(1, ctypes.pointer(x), ctypes.sizeof(x))


def key(key_code, length = 0):    
    key_down(key_code)
    time.sleep(length)
    key_up(key_code)


def volume_up():
    key(VK_VOLUME_UP)


def volume_down():
    key(VK_VOLUME_DOWN)

def set_volume(int):
    for _ in range(0, 50):
        volume_down()
    for _ in range(int / 2):
        volume_up()