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

BlueALSA v4.2.0                                   January 2024                              ORG.BLUEALSA.PCM1(7)