A2DP Sink on Ubuntu Linux with bluez (streaming bluetooth stereo audio from smartphone to pc)

a2dp_sink_ubuntu_linux.md

Howto Enable and Use A2DP Sink on Ubuntu Linux with Bluez

1. Add Enable=Source to /etc/bluetooth/audio.conf right after [General].

2. Find address in form XX:XX:XX:XX:XX:XX of phone with hcitool scan.

3. Pair and trust smartphone with sudo bluez-simple-agent hci0 XX:XX:XX:XX:XX:XX and sudo bluez-test-device trusted XX:XX:XX:XX:XX:XX yes.

4. Create loopback in pulseaudio connection bluetooth a2dp source with alsa sink:

pactl load-module module-loopback \
source=bluez_source.XX_XX_XX_XX_XX_XX \
sink=alsa_output.pci-0000_00_1b.0.analog-stereo

You can find your own values for source and sink with pacmd list-sources and pacmd list-sinks.

@domenpuncer I've modified your python script to remove the loopback module when the device disconnects. If the module is kept loaded, it can cause some nasty feedback.

Gist is here: https://gist.github.com/dghodgson/8406352

Unfortunately I'm not very familiar with python, or dbus's python interface, so my solution is a bit of a hack. It just checks for a dbus message which consistently pops up when the device connects, and runs a shell command that removes all loopback modules for that device. Kind of ugly, but it seems to work reliably for me.

I updated the script with a fix for the issue where multiple loopback modules would get loaded with successive pausing/playing of an audio stream.

Is it possible to change the code in a way that will allow streaming audio from iPhone to Linux?

When I ran this code on Ubuntu 14.04, and connected an iPhone via bluetooth to the Ubuntu box, I got the following two lines:
{HandsfreeGateway.PropertyChanged} [/org/bluez/27095/hci0/dev_00_34_5E_22_F5_61] State = connecting
{HandsfreeGateway.PropertyChanged} [/org/bluez/27095/hci0/dev_00_34_5E_22_F5_61] State = disconnected

Thanks so mcuh for this script and thanks domenpuncer and Toasty27 for your improvements!
I wrote my own little Gist (https://gist.github.com/boulund/8949499e17493e1c00db) explaining all the steps I had to take to get it working on my Debian server (mainly for my own memory, should I ever need to redo it).

When I tried this, I found the following two sinks:

$ pacmd list-sinks | grep name:
name: <alsa_output.pci-0000_01_00.1.hdmi-stereo>
name: <alsa_output.pci-0000_00_1b.0.iec958-stereo>

However, both failed the same way:

$ pactl load-module module-loopback source=bluez_source.7C:6D:62:6B:85:68 sink=alsa_output.pci-0000_01_00.1.hdmi-stereo
Failure: Module initialization failed

What am I missing?

How would I pair automatically? Example - I want to run the system on a HTPC device, so it should pretend to be A2DP headphones and start playback from any phone which asks for connection.

I get Failure: Module initialization failed when running this on 16.10 unfortunately.

@csvan check your pactl list. alsa module name is changed.
In my case, I using sink=alsa_output.pci-0000_00_1f.4.analog-stereo.

pactl list | grep Name:
...
Name: alsa_output.pci-0000_00_1f.4.analog-stereo
...

Worked like a charm on my arch i3 box!! Thanks a lot for this!

Thanks a lot, also working on my zotac zbox with kaby lake processor and ubuntu 16.04 LTS :)

It did not work with me on raspberry pi

If this is for Streaming Audio from Ubuntu -> pulse -> bluetooth -> Phone?
Then it not work on Ubuntu 17.04:
pactl load-module module-loopback source=bluez_source.10_2F_6B_6E_14_06 sink=alsa_output.pci-0000_00_1f.3.analog-stereo
Failure: Module initialization failed

What does " pacmd list-sources | grep name: " produce?

Does your bluez source have .a2dp_source on the end of the name? I think there's a typo in the original post although things may have changed since then. My machine gives:

test@test:~$ pacmd list-sources | grep name:
        name: <alsa_output.pci-0000_00_05.0.analog-stereo.monitor>
        name: <alsa_input.pci-0000_00_05.0.analog-stereo>
        name: <bluez_source.94_7B_E7_XX_XX_XX.a2dp_source>

So I need

pactl load-module module-loopback source=bluez_source.94_7B_E7_XX_XX_XX.a2dp_source sink=alsa_output.pci-0000_00_05.0.analog-stereo

I'm not getting output but at least the loopback loads without error.

Edit: This worked for me:
https://gist.github.com/oleq/24e09112b07464acbda1#gistcomment-2175574