macOS audio utility
- Automatically pauses your music player when other audio starts playing and unpauses it afterwards
- Per-application volume, boost quiet apps
- Record system audio
- No restart required to install
- Runs entirely in userspace
Version 0.1.0, first release. Probably very buggy. Not very polished or well tested.
Requires OS X 10.10+. Might work on 10.9, but I haven’t tried it. Currently unable to build in Xcode 6.
Background Music can pause your music player app when other audio starts playing and unpause it afterwards. The idea is that when I’m listening to music and pause it to watch a video or something I always forget to unpause it afterwards. So this keeps me from wearing headphones for hours listening to nothing.
So far iTunes, Spotify, VLC, VOX, Decibel and Hermes are supported. Adding support for a new music player should only take a few minutes1 – see BGMMusicPlayer.h. If you don’t know how to program, or just don’t feel like it, create an issue and I’ll try to add it for you.
Background Music has a volume slider for each app running on the system. I mostly use this to boost quiet apps above their normal maximum volume.
Recording system audio
With Background Music running, open QuickTime Player and go
File > New Audio Recording... (or movie/screen). Then
click the arrow next to the record button that looks like
⌄ and select
Background Music Device as the input device.
You should be able to record system audio and a microphone together by creating an aggregate
device that combines your input device (usually Built-in Input) with
Background Music Device. You can create the aggregate device using the Audio MIDI Setup utility from
No binaries yet (working on it) but building should take less than a minute.
|⚠️||Unfortunately, it won't build if you don't have Xcode installed because xcodebuild doesn't work on its own anymore. If you don't mind a 4GB download, you can get Xcode here.|
If you’re comfortable with it, you can just paste the following at a Terminal prompt.
(set -eo pipefail; URL='https://github.com/kyleneideck/BackgroundMusic/archive/master.tar.gz'; \ cd $(mktemp -d); echo Downloading $URL to $(pwd); curl -qfL# $URL | gzcat - | tar x && \ /bin/bash BackgroundMusic-master/build_and_install.sh -w && rm -rf BackgroundMusic-master)
Otherwise, to build and install:
- Clone or download the project.
- If the project is in a zip, unzip it.
Terminal.appand change directory to the directory containing the project.
- Run the following the command:
The script restarts the system audio process (coreaudiod) at the end of the installation, so you might want to pause any apps playing audio.
Additional detailed installation instructions can be found on the Wiki.
- Run the
uninstall.shscript to remove Background Music from your system.
- Go to the Sound section in System Preferences and change your default output device at least once. (If you only have
one device now, either use
Audio MIDI Setup.appto create a temporary aggregate device, restart any audio apps that have stopped working or just restart your system.)
Try following the instructions in
uninstall.sh fails. (You might
consider submitting a bug report, too.)
If Background Music crashes and system audio stops working, open the Sound panel in System Preferences and change your system’s default output device to something other than Background Music Device. If it already is, it might help to change the default device and then change it back again. Failing that, you might have to uninstall.
- VLC automatically pauses iTunes/Spotify when it starts playing something, but that stops Background Music from
unpausing your music afterwards. To workaround it, open VLC’s preferences, click
Show All, go
Control external music playersto either
Pause and resume iTunes/Spotify.
Similarly, Skype pauses iTunes during calls. If you want to disable that, uncheck
Pause iTunes during calls on the
General tab of Skype’s preferences.
- Plugging in or unplugging headphones when Background Music isn’t running can silence system audio. To fix it, go to
the Sound section in System Preferences, click the Output tab and change your default output device to something other
than Background Music Device. Alternatively, you may Option+Click on the Sound icon in the menu bar to select a
different output device.
This happens when macOS remembers that Background Music Device was your default audio device the last time you last
used (or didn’t use) headphones.
- A recent Chrome bug can stop Chrome from switching to
Background Music Device after you open Background Music. Chrome’s audio will still play, but Background Music won’t be
aware of it.
- Some apps play notification sounds that are only just long enough to trigger an auto-pause. The only workaround right
now is to increase the
kPauseDelayNSec constant in BGMAutoPauseMusic.mm.
That will make your music overlap the other audio for longer, though, so you don’t want to increase it too much. See
#5 for details.
- Plenty more. Some are in listed in TODO.md.
- Core Audio User-Space Driver Examples The sample code from Apple that BGMDriver is based on.
- Soundflower - “MacOS system extension that allows applications to pass audio to other applications.”
- WavTap - “globally capture whatever your mac is playing—-as simply as a screenshot”
- llaudio - “An old piece of work to reverse engineer the Mac OSX user/kernel audio interface. Shows how to read audio straight out of the kernel as you would on Darwin (where most the OSX goodness is missing)”
- mute.fm, GitHub (Windows) - Auto-pause music
- Jack OS X - “A Jack audio connection kit implementation for Mac OS X”
- PulseAudio OS X - “PulseAudio for Mac OS X”
- Sound Pusher - “Virtual audio device, real-time encoder and SPDIF forwarder for Mac OS X”
- Zirkonium - “An infrastructure and application for multi-channel sound spatialization on MacOS X.”
- Audio Hijack - “Capture Audio From Anywhere on Your Mac”
- Sound Siphon, Sound Control - System/app audio recording, per-app volumes, system audio equaliser
- SoundBunny - “Control application volume independently.”
- Boom 2 - “The Best Volume Booster & Equalizer For Mac”
- eqMac - “System-wide Audio Equalizer for Mac OSX”
Background Music includes code from:
- Core Audio User-Space Driver Examples, original license, Copyright © 2013 Apple Inc. All Rights Reserved.
- Core Audio Utility Classes, original license, Copyright © 2014 Apple Inc. All Rights Reserved.
 However, if the music player doesn’t support AppleScript, or doesn’t support the events Background
Music needs (
pause), it can take significantly more effort to add. (And in some
cases would require changes to the music player itself.) ↩