NAME

       org.bluealsa.PCM1 - Bluetooth Audio PCM D-Bus API

SYNOPSIS

       Service
              org.bluealsa[.unique ID]

       Interface
              org.bluealsa.PCM1

       Object path
              [variable prefix]/{hci0,...}/dev_XX_XX_XX_XX_XX_XX/[type]/[mode]

DESCRIPTION

       This page describes the D-Bus PCM interface of the bluealsa(8) service.  The PCM interface
       gives access to individual PCM objects created by this service.

   Methods
       fd, fd Open()
              Open BlueALSA PCM stream. This method returns two  file  descriptors,  respectively
              PCM stream PIPE and PCM controller SEQPACKET socket.

              Controller socket commands: "Drain", "Drop", "Pause", "Resume"

              Possible Errors:

                 dbus.Error.InvalidArguments
                 dbus.Error.NotSupported
                 dbus.Error.Failed

       array{string, dict} GetCodecs()
              Return the array of additional PCM codecs. Client can switch to one of these codecs
              with the SelectCodec() D-Bus method call.

       void SelectCodec(string codec, dict props)
              Select PCM codec. This call shall be made  before  PCM  stream  opening  for  given
              transport  type,  otherwise  the  ongoing stream (or PCM counterpart: sink, source)
              will be terminated.

              For  A2DP  codecs,  client  can  override  built-in  logic  for   selecting   codec
              configuration by providing the configuration blob via the "Configuration" property.
              Provided configuration must be valid for given codec in  respect  to  BlueALSA  and
              peer  device  capabilities.  Otherwise,  the  call  will  fail.   It is possible to
              override this validation by setting the "NonConformant" property to true.

              Possible Errors:

                 dbus.Error.InvalidArguments
                 dbus.Error.NotSupported
                 dbus.Error.Failed

       void SetDelayAdjustment(string codec, int16 adjustment)
              Set an arbitrary adjustment (+/-) to the reported Delay in 1/10 of millisecond  for
              a  specific codec. This adjustment is applied to the Delay property when that codec
              is selected, and can be used to compensate for devices that do not report  accurate
              Delay values.

              Possible Errors:

                 dbus.Error.InvalidArguments

       array{string, int16} GetDelayAdjustments()
              Return  the array of currently set delay adjustments. Each entry of the array gives
              the name of a codec and the adjustment  that  the  PCM  will  apply  to  the  Delay
              property when that codec is selected.

   Properties
       object Device [readonly]
              BlueZ device object path.

       uint32 Sequence [readonly]
              This  property  indicates  the  sequence in which devices connected. The larger the
              value, the later the device was connected.

       string Transport [readonly]
              Underlying Bluetooth transport type.

              Possible values:

                 "A2DP-sink"
                 "A2DP-source"
                 "HFP-AG"
                 "HFP-HF"
                 "HSP-AG"
                 "HSP-HS"

       string Mode [readonly]
              PCM stream operation mode (direction).

              Possible values:

                 "sink"
                 "source"

       boolean Running [readonly]
              This property is true when the Bluetooth transport for this  PCM  is  acquired  and
              able to transfer audio samples.

       uint16 Format [readonly]
              Stream  format  identifier. The highest two bits of the 16-bit identifier determine
              the signedness and the endianness. Next 6 bits determine the physical  width  of  a
              sample in bytes. The lowest 8 bits are used to store the actual sample bit-width.

              Examples:

                 0x4210 - unsigned 16-bit 2 bytes big-endian
                 0x8418 - signed 24-bit 4 bytes little-endian

       byte Channels [readonly]
              Number of audio channels.

       uint32 Sampling [readonly]
              Sampling frequency.

       string Codec [readonly]
              Bluetooth  transport codec. This property is available only when transport codec is
              selected.

       array{byte} CodecConfiguration [readonly]
              Optional. Bluetooth transport codec configuration blob. This property is  available
              only for transports which support codec configuration (e.g. A2DP).

       uint16 Delay [readonly]
              Approximate PCM delay in 1/10 of millisecond.

       int16 DelayAdjustment [readonly]
              An  adjustment  (+/-)  included within the reported Delay in 1/10 of millisecond to
              compensate for devices that do not report accurate delay values.

       boolean SoftVolume [readwrite]
              This property determines whether BlueALSA will make volume  control  internally  or
              will  delegate  this  task  to  BlueALSA  PCM  client or connected Bluetooth device
              respectively for PCM sink or PCM source.

       uint16 Volume [readwrite]
              This property holds volume (loudness) value and  mute  information  for  channel  1
              (left)  and 2 (right). Data for channel 1 is stored in the upper byte, channel 2 is
              stored in the lower byte. The highest bit of both bytes determines whether  channel
              is muted.

              Possible values:

                 A2DP: 0-127
                 SCO:  0-15

COPYRIGHT

       Copyright (c) 2016-2023 Arkadiusz Bokowy.

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

SEE ALSO

       bluealsa-cli(1), bluealsa-plugins(5), bluealsa(8)

       Project web site
              https://github.com/arkq/bluez-alsa