[pulseaudio-discuss] Multiple Bluetooth sources

[Pali Rohár]

On Wednesday 27 July 2016 09:15:44 Arun Raghavan wrote:
> On Tue, 26 Jul 2016, at 03:42 PM, Philippe Latulippe wrote:
> > Hello!
> > 
> > I would like to connect many Bluetooth sources (devices that emit
> > audio over bluetooth) and listen to them simultaneously. I am using
> > Pulseaudio 5.0 and BlueZ 5.23.
> > 
> > I managed to connect a single device and listen to it using the
> > loopback module. But when I try to connect a second device, it
> > immediately disconnects.
> > 
> > Using hcidump, I can see that it all goes wrong with this packet, sent
> > by the device receiving audio:
> > 
> > < ACL data: handle 62 flags 0x00 dlen 10
> >     L2CAP(d): cid 0x0042 len 6 [psm 25]
> >       AVDTP(s): Discover rsp: transaction 0 nsp 0x00
> >         ACP SEID 1 - Audio Source
> >         ACP SEID 2 - Audio Sink (InUse)
> > 
> > Notice how the sink is marked as InUse. After seeing this, the source
> > ends the Bluetooth connection.
> > 
> > It would seem that a BlueZ sink can only be used by one device. Is
> > Pulseaudio supposed to register multiple endpoints with BlueZ, one for
> > each device? Or is this an issue with BlueZ?
> 
> My understanding is that this is broadly a limitation of how most (but
> not all) Bluetooth devices work. You can't send  multiple A2DP streams
> at the same time.
> 
> Depending on how many streams you're sending, you might even end up
> hitting bandwidth restrictions quite quickly -- just something to keep
> in mind.

You can perfectly create A2DP "server" on linux machine. That will
accept both Audio Sink & Source... I have tested it more times (between
linux and linux machines) and that work fine.

-- 
Pali Rohár
pali.rohar at gmail.com