When in A2DP sink role and remote end switches codec, BlueZ nowadays
appears sometimes emit first SetConfiguration (creating new transport),
and then ClearConfiguration (removing old transport).
Handle this case: emit profiles_changed event always when transports
come/go.
Redefine profiles_changed() to take bitmask of profiles whose connection
status changed, so we don't need to emit two remove+add events.
Now that BlueZ supports delay reporting in A2DP sink role, implement
that.
Report value that gives the total latency between packet reception and
audio rendering.
Also make Latency parameter in media-source to be not just a dummy
value.
A new 'broadcasting' state is to be added in BlueZ. It is
functionally similar to 'pending', but for the Broadcast scenario.
Until now, on Broadcast sink side, the transports associated with a
scanned source would automatically be switched to pending. PipeWire
then acquired any transport that was pending.
This is to be changed, transports will now remain in 'idle' state
until the user calls transport.select on them from bluetoothctl.
This changes the state to 'broadcasting'. PipeWire will then acquire
these selected transports.
This way, the user can select to which sink he wishes to sync.
Kernel-provided MTU does not work for USB controllers and the correct
packet size to send can be known currently only from RX. So we are
waiting for RX to get it.
The known problem is USB-specific, we shouldn't need the workaround for
other transport types.
Don't wait for POLLIN for non-USB controllers on connect, but ready
things on POLLOUT as usual.
For non-USB controllers, pick some sensible packet sizes to use
initially, before we switch to same size as for RX.
BlueZ API as BAP Server gives us the ISO interval, instead of the SDU
interval, in the MediaTransport.QoS.Interval property. They are not
necessarily the same. What we need is the SDU interval.
The SDU interval is the interval between packets the encoder outputs, so
it is determined by the codec configuration, and for LC3 is equal to the
frame duration.
Add codec method get_interval() that returns the correct interval, and
use it in iso-io.
HFP 1.9 adds LC3 as a possible codec in addition to CVSD & mSBC.
E.g. Pixel Buds Pro latest firmware supports it.
Add the RFCOMM side and codec selection for it.
Don't have separate input route for A2DP and HFP, as it is generally not
necessary.
When in A2DP mode when there's also HFP possible, emit the input route
in SPA_PARAM_Route, even though there is no corresponding input node
emitted.
The host may then emit a loopback microphone node, and switch profiles
according to its status. Having the input route available at all times
allows to retain changes to volume settings made when there is no real
input node.
Make supported codec checks to use profiles, not "is-a-sink" flag, to
determine which codecs can be used.
Fixes bluez5-device checking only source profiles, even when the local
device is only a sink.
Once Pipewire is started it will try to register a BAP broadcast source media endpoint on UUID 00001852-0000-1000-8000-00805f9b34fb if the media codec that supports BAP and the adapter indicates LE Audio is supported.
When the endpoint is detected (over DBus) by Pipewire and it has a broadcast sink UUID, a new device will be created with the address 00:00:00:00:00:00. This device will be our simulated remote device. This is done because a broadcast source emitting device does not need any connection to start transmitting the audio. This device is set as connected.
When the SetConfiguration DBus method is called and the spa_bt_transport structure with the profile BAP broadcast source is created we switch the device from the one read from DBus to the one created by us. This is done because in BlueZ, when the transport is created, at the Device property, BlueZ sets the adapter as the device that the transport is connected to. Here the device will have the newly created SPA_BT_PROFILE_BAP_BROADCAST_SINK profile connected.
Added code that allows to create a node in the graph for a device connected to the SPA_BT_PROFILE_BAP_BROADCAST_SINK profile.
The transport set volume call may take a long time or never complete, so
make them async to not block main loop.
Also reduce log level to info for the failed volume setting, as this is
something the user can do nothing about.
Do BAP audio location selection properly in SelectProperties, now that
BlueZ provides the supported locations there. Remove a previous
workaround.
The audio location in SelectProperties determines the audio channel
allocation, which determines the channel positions.
For ISO server sockets, the QOS struct from getsockopt contains values
with different meaning from ISO client socket. Get the values via DBus
instead, which is right in both cases.
If BAP codec configuration is mono channel with unspecified location,
set the channel position from transport location.
This in principle should be set in SelectProperties, but currently BlueZ
doesn't tell us that yet there, so we hack it up later on.
Add factored out helper for ISO socket I/O.
ISO sockets need synchronization of writes and audio position for
different stream fds in the same isochronous group, and it's easier to
separate out the part that coordinates it.
If transport goes into error state too often, fail instead of trying to
acquire it again.
This avoids getting into a tight acquire->fail->reacquire loop.
Change A2DP/BAP transport acquire and release to be async.
Since BlueZ acquiring ISO sockets blocks until all sockets in same CIG
are acquired, BAP transports must be acquired asynchronously.
Allow asynchronous changes in transport state in the sinks/sources.
Also allow transport acquire to be actually synchronous, in this case it
must set transport state during acquire call.
Separate driver start/stop from transport start/stop.
For BAP server audio sink, set buffering target so that we try to match
the target presentation delay. Also adjust requested node latency to be
smaller than the delay.
Also fix BAP transport presentation delay value parsing, and parse also
the other BAP transport properties. Of these, transport latency value
needs to be taken into account in the total sink latency.
BlueZ fails registering object managers containing A2DP endpoints if
controller is in LE-only mode.
Make the A2DP and BAP object managers separate, so that failure to
register one does not prevent registering the other.
Also rename some functions to indicate which ones deal with the legacy
BlueZ API.
AVDTP in principle allows 62 endpoints, but in practice it appears some
devices (Samsung Galaxy Buds2 Pro, Redmi Buds 3 Lite, probably others)
fail to connect A2DP when the number is somewhere above 24. A2DP
connection works when initiated from the Central, but not when the
device itself does it, so these devices are not fully broken. We should
reduce the number of registered A2DP endpoints to avoid running into
problems with such broken devices.
Some of our source codecs are the same actual codec with the same
configuration, and don't need separate source endpoints.
Allow codecs to not have a registered endpoint (fill_caps == NULL), and
tolerate codecs with the same endpoint name. In codec switch, keep
track separately which of the codecs with the same endpoint name the
local endpoint is currently associated with.
Multiple transport from the same device may share the same stream (CIS)
and group (CIG) but for different direction, e.g. a speaker and a
microphone. In this case they are linked.
In this case:
- On acquire, if another transport has already been acquired, the new
transport should not call Acquire or TryAcquire but re-use values from
the previously acquired transport,
- on release, the closing of transport fd and call to Release should be
done only for the last transport.
We can't determine which remote endpoint or device the
SelectConfiguration() call is associated with. For LE Audio BAP, as this
method is called only for the Initiator we set the whole instance as a
Central/Initiator.
This flag is unset on BAP media endpoint removal.
AVDTP (v1.3 Sec 5.3) has a limitation that a local SEP (on the same
adapter) can be connected to at most one remote SEP. Trying to do have
it connected to multiple remotes either fails or causes misbehavior
later on.
Skip SetConfigure the same local endpoint for multiple remote ones in
codec switch. BlueZ observes this restriction in SelectConfiguration,
so also it won't try to do invalid configurations.
In BlueZ 5.64, the SetConfiguration calls succeed, but subsequent
transport acquires will fail. (Likely already the SetConfiguration DBus
call should fail.)
This all has the consequence, with the current approach to the
codec=endpoint correspondence, that if multiple devices are connected to
the same adapter, they currently have to use different codecs.
Remove quantum limitation from a2dp-sink, and adjust how flushing is
done.
The "low-latency" A2DP codecs are not able to flush all data at once, so
for them flush based on a timeout, such that "excess samples" for each
quantum is bounded. We also limit excess samples for the other A2DP
codecs, based on some testing on flaky headset/adapter combinations (for
most cases, this does not appear to matter).
Leave decision of packet sizes to the codecs. Currently, we send packets
based on min_latency, but sendinf full packets might help with stutter
on some headset/adapter combinations. The slightly increased latency
hardly matters against the 100ms delays in BT headsets.
Bump codec API version.
Codec probe connections can trigger bad behavior from oFono if done when
device is busy (e.g. at connect), and they might be done at the same
time as A2DP transport is acquired which cannot work.
Also, oFono will not reply to DBus Acquire, if device does not complete
codec negotiation correctly. This is most likely to happen just after
device connect, when it is busy with other stuff (eg A2DP).
Remove codec probe connections altogether: instead, we guess mSBC if
mSBC is enabled and otherwise CVSD. If the guess turns out to be wrong,
which is unlikely (almost all devices have mSBC), we recreate the
transport with correct codec (from main loop, must not be done in
*_acquire because that can destroy nodes + unload the spa libs while
we're being called from there).
To avoid oFono DBus hangs at startup, add delay before marking the
profile connected, enforcing a time difference to A2DP operations.
When acting as SCO AG / A2DP sink, the remote end should decide when to
close the connection. This does not work currently properly, because
stopping sources/sinks releases the transport, which causes it to go
idle, and which then destroys dynamic nodes. The sources/sinks should
not cause the transport to be released.
Implement keepalive flag for spa_bt_transport, such that
spa_bt_transport_release does not actually release the transport when
the refcount reaches zero. Set the flag for dynamic nodes when the
transport becomes pending (remote end connects) and unset the flag when
idle (remote end disconnected, or dynamic node removed).
Using a probe connection to determine adapter msbc capability causes
problems on some adapters (ff8c3d2, 84bc0490a5, 717004334b,
pipewire#2030) and seems to be a bad idea.
Go back to probing for transparent msbc transport capability via HCI
commands. bluetooth/hci.h may be deprecated later, but for now it's
better to go back to using it. (In practice, adapters not supporting
esco appear to be fairly rare; kernel commit in 2013 refers to "older
devices", so if we can't use HCI, assume the adapter supports the
necessary modes.)
A2DP profile may disappear if several SetConfiguration events occur too
rapidly. Rate limit these calls when switching codecs.
This resolves failures if e.g. the session manager attempts to set the
profile immediately after the device is created, which previously might
cause a failure.
Some devices (Bose Mini Soundlink II, Air 1 Plus, ...) don't enable
AVRCP volume control, or fail to enable it before a hardware button is
pressed. However, these devices appear to enable it, if an AVRCP player
is present.
As a workaround, register a dummy AVRCP player for each adapter. It only
displays the current transport acquisition state as playing/stopped, but
just its presence appears to be enough to make devices behave.
Multiple AVRCP players interfere with each other, as BlueZ uses the one
registered earliest as the default player. So add also a config option
for disabling this. (It's not common to have mpris-proxy etc. running,
so defaulting to true should be OK.)
See pipewire#1157
