[pulseaudio-discuss] [PATCH] bluetooth: bluez4: For each bluetooth profile use different port names

[David Henningsson]

On 2014-09-25 14:08, Pali Rohár wrote:
> On Thursday 25 September 2014 13:27:04 David Henningsson wrote:
>> On 2014-09-25 02:25, Pali Rohár wrote:
>>> With this patch it is possible to configure different volume
>>> settings for a2dp and hsp profiles. It is usefull for
>>> bluetooth headsets which do not have normalized a2dp and
>>> hsp volume levels.
>>>
>>> Module module-device-restore uses port name as identifier,
>>> so if different profiles have different names
>>> module-device-restore can store volume settings for each
>>> profile.
>>
>> Hi Pali and thanks for the patch,
>>
>> I understand the problem here, but this is the wrong way to
>> fix it.
>>
>> First, ports is what unity- and gnome-control-center thinks
>> are most closely to physical devices. If you have two
>> different ports, they will appear like two different devices.
>>
>
> Bluetooth A2DP and HSP are different streams, so they are
> basically different devices.

 From a technical perspective, maybe. But from a user perspective, how 
many headsets do you hold in your hand? It's not one A2DP headset and 
another HSP headset - it is one headset, so it's one device.

We've been through that discussion before. [1]

> They are using different codec and
> have different quality. So I think that "port" name for these
> bluetooth transport should be different.
>
> In future I'm planning to add support for bidirectional a2dp
> streaming support (with two bluetooth transports) so here I need
> two ports for it. I did not see any bluetooth headset with a2dp
> microphone, but on linux bluez systems it is possible and it is
> *only* one way how to get high quality sink+source streaming
> between two machine (via bluetooth).
>
> And some another rare headsets support using both a2dp and hsp
> transports at same time. Pulseaudio does not support this
> configuration too, but maybe in future (if I have one) I will
> want to see support in PA too. And for this configuration is more
> ports support needed.
>
> In above both bluetooth possible configurations are bluetooth
> transports in use and thus should be visible as *different* sound
> sink/sources (as this is for sending different streams via
> bluetooth). So I think that using more ports (with different)
> names is good idea and if gnome-control-center shows different
> ports as different cards, I think this is correct.

As for your potential future scenarios, let's try to deal with them when 
they materialize.

For very rare scenarios, I'm less worried about having one device look 
like it's two, if that's the last resort. But I definitely don't want it 
for every bluetooth headset out there.

-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic

[1] 
http://lists.freedesktop.org/archives/pulseaudio-discuss/2012-November/015462.html