Support for higher quality bluetooth A2DP audio codecs in sailfishos

poetaster · 23 June 2026 11:15

Just waiting for you to report your findings EDIT: you mean this build from @attah Release test1 · attah/sailfish-pulseaudio · GitHub just to keep the info in proximity…
SIGH, EDIT, Edit: I’m not a good testing candidate since I don’t have any bluetooth headphones.

nephros · 23 June 2026 13:59

zhasha:

It works

And for everyone else who wants to give this a go, you need
ssu ar gst-bluetooth https://repo.sailfishos.org/obs/home:/nephros:/devel:/gst-bluetooth/sailfish_latest_aarch64/
pkcon refresh
pkcon update gstreamer1.0-plugins-bad
Attah’s build of pulseaudio with gstreamer-bluez5 enabled, however all you need from the rpm is /usr/lib64/pulse-17.0/modules/libbluez5-util.so
Edit, somehow managed to forget to link it: Release test1 · attah/sailfish-pulseaudio · GitHub

EDIT: Unfortunately the below doesn’t quite work as planned…

You should now be able to install a package called pulseaudio-gst-bt from the gst-bluetooth repo directly. It packages only that one .so file, and places it in /opt/pulse-17.0/modules/libbluez5-util.so. I.e. you don’t need to install the attah package.
(Changes to attah’s branch visible here.)

With this installed you should be able to load the .so from /opt - either by adding --dl-search-path argument to the PA daemon, or setting the env var LTDL_LIBRARY_PATH.

Note that the PA systemd unit references an environment file at /etc/sysconfig/pulseaudio, so you can put LTDL_LIBRARY_PATH in there without editing any files belonging to a package.

AlexSailfish · 24 June 2026 20:58

It works for music (softlinked to .so in /usr/lib64/pulse-17.0/modules/ after renaming the original file) the Path Setting did not work.

pactl send-message /card/bluez_card.XXXXXXXXXXXX/bluez get-codec
“ldac_hq”

but during a call, it still changes to

“CVSD”

So at least a partial victory

zhasha · 25 June 2026 09:03

mSBC is disabled in /etc/pulse/default_sailfish.pa. You can reenable it but mSBC audio isn’t working (at least during phone calls). I’m looking into it.

zhasha · 25 June 2026 15:59

Okay, I got mSBC working. When pulseaudio-modules-droid-jb2q (the version used on my Xperia 10 II) routes the Bluetooth audio, it does so by setting the BT_SCO=on in the HIDL audio HAL. This causes the HAL to tell ALSA and then finally the kernel btfm driver that the sample rate is 8k, which causes a very low volume garbled mess.

github.com/mer-hybris/pulseaudio-modules-droid-jb2q

src/common/droid-util.c

master


      
          
          pa_assert(s);
          pa_assert(s->output);
          pa_assert(s->module);
          pa_assert(s->module->output_mutex);
          
          output = s->output;
          
          pa_mutex_lock(s->module->output_mutex);
          
          if (output->flags & AUDIO_OUTPUT_FLAG_PRIMARY || pa_droid_hw_primary_output_stream(s->module) == NULL) {
              int set_bt_sco = -1;
          
              parameters = pa_sprintf_malloc("%s=%u;", AUDIO_PARAMETER_STREAM_ROUTING, device);
          
              /* Set BT_SCO parameter for Bluetooth voice/voip call routes. */
              if (device != output->device &&
                  (device | output->device) & (AUDIO_DEVICE_OUT_BLUETOOTH_SCO |
                                               AUDIO_DEVICE_OUT_BLUETOOTH_SCO_HEADSET |
                                               AUDIO_DEVICE_OUT_BLUETOOTH_SCO_CARKIT)) {

All we need to do is activate the wideband audio in the audio HAL, by setting bt_wbs=on here as well. I tested this by changing enable_msbc=false to true in /etc/pulse/default_sailfish.pa and then manually switching my Bluetooth headset to HFP and setting up the droid source/sinks, then injecting the command using pulseaudio-modules-droid-hidl’s DBus interface:

pactl set-card-profile bluez_card.70_BF_92_D8_DF_0F handsfree_head_unit
pactl set-sink-port sink.primary_output output-sco_headset
pactl set-source-port source.droid input-bluetooth_sco_headset
dbus-send --print-reply --type=method_call --address='unix:path=/run/user/100000/pulse/dbus-socket' --dest=org.SailfishOS.AudioSystemPassthrough /org/sailfishos/audiosystempassthrough org.SailfishOS.AudioSystemPassthrough.set_parameters string:bt_wbs=on

Doing this, then either recording using parecord or staring a call, the headset is now in a functional mSBC mode. You’ll see a line like this in your syslog (note the rates:16000):

kernel: btfm_slim_enable_ch: channel define - rates:16000, baser:1, ratem:4

What we need now, is to figure out how to selectively activate bt_wbs=on/off in pulseaudio-modules-droid[-jb2q] based on whether or not the HFP is going into mSBC or CVSD mode. If anyone is knowledgeable about PulseAudio internals I am all ears.

kan_ibal · 29 August 2026 10:38

Sadly there is regression in this regard in SFOS 5.2.
After connecting always the best quality is selected(552kbps) and it gets me a lot of distortion (most likely bt receiver issue). Then I have to choose standard quality “sbc” but every reconnect it goes back to “sbc_xq_552”. At the moment bt is barely usable for me.

Workaround for the time being:
Requirements:
Situations and bluetoothctl
devel-su pkcon install bluez-tools

then a new rule should be created in Situtation:
When: BT device
What: Command:

pactl send-message /card/bluez_card.XX_XX_XX_XX_XX_XX/bluez switch-codec sbc
bluetoothctl disconnect XX:XX:XX:XX:XX:XX
bluetoothctl connect XX:XX:XX:XX:XX:XX

where XX… are device address
and in Command settings(gear at left bottom) set 1000ms delay