[pulseaudio-discuss] Bluetooth ports

[Arun Raghavan]

On Fri, 2012-11-23 at 08:31 +0100, David Henningsson wrote:
> On 11/23/2012 05:24 AM, Arun Raghavan wrote:
> > David,
> >
> > On Thu, 2012-11-22 at 16:55 +0100, David Henningsson wrote:
> > [...]
> >> ...now, I'm testing PulseAudio 2.99.2 and things do not show up as I
> >> expect them to. In PulseAudio 2.x, there were no bluetooth ports at all,
> >> in 2.99, "pactl list-cards" looks like this [1]. I don't know if it's a
> >> bug, or if it is for a reason, but at least it's an unhappy surprise for me.
> >>
> >> In short; if it's the same physical output on the device, it's *the same
> >> port*. Just like my USB headset has one port in each direction, so
> >> should my bluetooth headset. I e, there should not be one "hsp-output"
> >> and one "a2dp-output" ports, because they go to the same headset, they
> >> should share the same port, preferrably called "Headset" or something
> >> similar.
> >
> > A case could be made that they are not the same output -- A2DP is a
> > high-quality audio path, HSP is a speech-only path.
> 
> It is still inconsistent with how we deal with ALSA cards. On my USB 
> headset, I can use both "Analog stereo" and "Analog mono", analog stereo 
> is the high-quality audio path. But both share the same port. (And I'd 
> like to keep it that way, especially now that we've built a GUI that 
> builds on this premise.)

The way I was looking at it is the same physical jack used for S/PDIF
vs. analog out. The physical port is the same, logically these are
different paths. Since this is an analogy, the validity of either over
the other is somewhat subjective. :-)

> >> To point out the practical problem for end users is that in GNOME sound
> >> settings, it now looks like you're having two different headsets. :-(
> >
> > I don't think this is such a bad thing. Having separate ports actually
> > makes the UI cleaner in some sense. With PA 2.1, I can go to the new
> > GNOME sound settings panel, choose my BT headset in the Input tab, and
> > select the A2DP profile. This makes no sense, since A2DP and input on
> > the headset are mutually exclusive. On my box, this crashes g-c-c.
> 
> The way I want it to work would be that on the output tab, you can 
> choose between "A2DP", "HSP" and "Off" for the profile combobox, and 
> between "HSP" and "Off" on the input tab. Switching from HSP to A2DP on 
> the output tab automatically switches from HSP to Off on the input tab.

The new port-centric UI heavily deemphasises the role of profiles from
users' perspectives. Afaict, having an "except for Bluetooth" case there
makes things inconsistent.

-- Arun

p.s.: In either case, for our next release, I hope to have the automatic
profile switching merged in, so the number of cases where the user needs
to fidget with these settings should hopefully be lower.