Ubuntu Manpage: bluealsa - Bluetooth Audio ALSA Backend

Provided by: bluez-alsa-utils_3.0.0-2_amd64

NAME

       bluealsa - Bluetooth Audio ALSA Backend

SYNOPSIS

       bluealsa [OPTION]...

DESCRIPTION

       bluealsa  is  a  Linux daemon to give applications access to Bluetooth audio streams using
       the Bluetooth A2DP, HFP and/or HSP profiles.  It provides a D-Bus API to applications, and
       can be used by ALSA applications via libasound plugins.

OPTIONS

-h, --help
Output a usage message and exit.

-V, --version
Output the version number and exit.

-B, --dbus=NAME
BlueALSA D-Bus service name suffix. Without this option, bluealsa registers itself
as an “org.bluealsa” D-Bus service. For more information see the EXAMPLE below.

-S, --syslog
Send output to system logger (syslogd(8)). By default, system output is sent to
stderr.

-i, --device=hciX
HCI device to use. Can be specified multiple times to select more than one HCI.
Because HCI numbering can change after a system reboot, this option also accepts
HCI MAC address for the hciX value, e.g: --device=00:11:22:33:44:55.

-p, --profile=NAME
Enable NAME Bluetooth profile. Without this option, bluealsa enables a2dp-source,
hfp-ag and hsp-ag. For the list of supported profiles see the PROFILES section
below.

--a2dp-force-mono
Force monophonic sound for A2DP profile.

--a2dp-force-audio-cd
Force 44.1 kHz sampling frequency for A2DP profile. Some bluetooth devices can
handle streams sampled at either 48kHz or 44.1kHz, in which case they normally
default to using 48kHz. With this option, bluealsa will request such a device uses
only 44.1 kHz sample rate.

--a2dp-keep-alive=SEC
Keep A2DP transport alive for SEC number of seconds after streaming was closed.
This option can be useful when playing short audio files in quick succession. It
will reduce the gap between playbacks caused by Bluetooth audio transport
acquisition.

--a2dp-volume
Enable native A2DP volume control. By default bluealsa will use its own internal
scaling algorithm to attenuate the volume. This option disables that internal
scaling and instead passes the volume change request to the A2DP device. This
feature can also be controlled during runtime via BlueALSA D-Bus API. Note that
this feature might not work with all Bluetooth headsets.

--sbc-quality=NB
Set SBC encoder quality, where NB can be one of:

• 0 - low audio quality (mono: 114 kbps, stereo: 213 kbps)

• 1 - medium audio quality (mono: 132 kbps, stereo: 237 kbps)

• 2 - high audio quality (mono: 198 kbps, stereo: 345 kbps) (default)

• 3 - SBC Dual Channel HD (SBC XQ) (452 kbps)

--mp3-quality=NB
Selects LAME encoder internal algorithm. The NB can be in the range from 0 to 9,
where 0 is the best quality but requires a lot of CPU power. Default value is 5.

--mp3-vbr-quality=NB
Specifies variable bit rate (VBR) quality, where NB can be in the range from 0 to
9. For best VBR quality use 0. Default value is 2 (hight quality VBR mode).

--aac-afterburner
Enables Fraunhofer AAC afterburner feature, which is a type of analysis by
synthesis algorithm. This feature increases the audio quality at the cost of
increased processing power and overall memory consumption.

--aac-latm-version=NB
Select LATM syntax version used for AAC audio transport. Default value is 1.

The NB can be one of:

• 0 - LATM syntax specified by ISO-IEC 14496-3 (2001), should work with all older
BT devices

• 1 - LATM syntax specified by ISO-IEC 14496-3 (2005), should work with newer BT
devices

--aac-vbr-mode=NB
Specifies AAC encoder variable bit rate (VBR) quality, or disables it. The NB can
be one of:

• 0 - disables variable bit rate mode and uses constant bit rate specified by the
A2DP AAC configuration

• 1 - lowest quality VBR mode (mono: 32 kbps, stereo: 40 kbps)

• 2 - low quality VBR mode (mono: 40 kbps, stereo: 64 kbps)

• 3 - medium quality VBR mode (mono: 56 kbps, stereo: 96 kbps)

• 4 - high quality VBR mode (mono: 72 kbps, stereo: 128 kbps) (default)

• 5 - highest quality VBR mode (mono: 112 kbps, 192 kbps)

--ldac-abr
Enables LDAC adaptive bit rate, which will dynamically adjust encoder quality based
on the connection stability.

--ldac-eqmid=NB
Specifies LDAC encoder quality, where NB can be one of:

• 0 - high quality (44.1 kHz: 909 kbps, 48 kHz: 990 kbps)

• 1 - standard quality (44.1 kHz: 606 kbps, 48 kHz: 660 kbps) (default)

• 2 - mobile quality (44.1 kHz: 303 kbps, 48 kHz: 330 kbps)

PROFILES

       BlueALSA provides support for Bluetooth Advanced Audio Distribution Profile (A2DP), Hands-
       Free  Profile  (HFP)  and  Headset Profile (HFP).  A2DP profile is dedicated for streaming
       music (i.e. stereo, 48 kHz or more sampling frequency), while  HFP  and  HSP  for  two-way
       voice  transmission  (mono,  8  kHz  or  16  kHz sampling frequency).  With A2DP, BlueALSA
       includes mandatory SBC codec and various optional codecs like AAC, aptX, and  other.   The
       full  list  of  available  optional codecs, which depends on selected compilation options,
       will be shown with bluealsa command-line help message.

       The list of profile NAMEs accepted by the --profile=NAME option:

       • a2dp-source - Advanced Audio Source (streaming audio to connected device)

       • a2dp-sink - Advanced Audio Sink (receiving audio from connected device)

       • hfp-ofono - Hands-Free handled by oFono

       • hfp-hf - Hands-Free

       • hfp-ag - Hands-Free Audio Gateway

       • hsp-hs - Headset

       • hsp-ag Headset Audio Gateway

       The hfp-ofono is available only when bluealsa was compiled with oFono  support.   Enabling
       HFP over oFono will automatically disable hfp-hf and hfp-ag.

FILES

       /etc/dbus-1/system.d/bluealsa.conf
              BlueALSA service D-Bus policy file.

EXAMPLE

       Emulate Bluetooth headset with A2DP and HFP support:

              bluealsa -p a2dp-sink -p hsp-hs

       On  systems  with more than one HCI device, it is possible to expose different profiles on
       different HCI devices.  A system with three HCI devices might (for example) use  hci0  for
       an  A2DP  sink service named “org.bluealsa.sink” and both hci1 and hci2 for an A2DP source
       service named “org.bluealsa.source”.  Such a setup might be created as follows:

              bluealsa -B sink -i hci0 -p a2dp-sink &
              bluealsa -B source -i hci1 -i hci2 -p a2dp-source &

       Setup like this will also require a change to the BlueALSA  D-Bus  configuration  file  in
       order  to  allow  connection  with  BlueALSA  services  with  suffixed  names.  Please add
       following lines to the BlueALSA D-Bus policy:

              ...
              <allow send_destination="org.bluealsa.sink" />
              <allow send_destination="org.bluealsa.source" />
              ...

COPYRIGHT

       Copyright (c) 2016-2020 Arkadiusz Bokowy.

       The bluez-alsa project is licensed under the terms of the MIT license.