GitLab

The HFP protocol supports the ability to negotiate codecs if that is
supported by both AG and HF.  This patch adds advertising of codec
negotiation support and the ability to negotiate a codec change.  The
only currently supported extra codec (as of HF 1.7.1) is mSBC.  mSBC
requires that the transmission be done over an eSCO link with
Transparent Data.  The linux kernel ensures the former, but we have to
manually set the socket to transparent data.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Part-of: <!507>

Adding processing support for the mSBC codec is somewhat problematic,
because, although it is a SBC codec, the a2dp handling can't simply be
reused because the codec is used on an eSCO link with transparent
data, meaning the transmission unit has to be 48 bytes (fragmenting
the codec packets) and reassembly and boundary detection is required
to be done by the implementation.  Therefore we have to implement
separate render and push routines for msbc that do this fragmentation.

Fragmentation is done by emulating circular buffers.  The receive
(push) buffer is easy, since the mSBC packet size is 60, simply have a
buffer of this size in the sbc_info area where the fragments are
reassembled.  Once we have a full 60 bytes, decode and restart from
zero.  The send (render) buffer is more problematic, since the
transmit must be done from contiguous memory.  This means that the
buffer must be the lowest common multiple of the transmission unit and
the packet size.  This value is 240 since 240/48 == 5 and 240/60 == 4.
So the buffer pointers are reset at 240 which is a whole number of
both rendered packets and eSCO transmission units.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Part-of: <!507>

Change default backend from 'auto' to 'native' so that in the usual
install pulseaudio uses the native backend with HFP_HF handling.

set default to false unless the backend is the native one, in which
case the default becomes true.

Additionally set default value of enable_native_hfp_hf to false unless
the backend is the native one, in which case the default becomes
true. so that we only bind the HFP_HF end point in the native case
(leaving it free for ofono in the ofono backend or auto case)
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Part-of: <!491>

HFP 1.6 requires a stateful negotiation of AT commands.  The prior
version got away with initialising HFP simply by replying 'OK' to
every negotiation attempt.  This one actually tries to parse the state
and make sure the negotiation occurs correctly
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---

v4:

- Update for PA 11.0
- Finally sort out CIND negotiaton for complex headsets

v3:

- remove internal debugging
- added comment for t->config being not null for hfp
- removed unused returns from hfp_rfcomm_handle()
- remove rfcomm comment
- use pa_startswith
- simplify negotiation

Part-of: <!491>

When all headsets supported both HSP and HFP, life was good and we
only needed to implement HSP in the native backend.  Unfortunately
some headsets have started supporting HFP only.  Unfortuantely, we
can't simply switch to HFP only because that might break older HSP
only headsets meaning we need to support both HSP and HFP separately.

This patch separates them from a joint profile to being two separate
ones.  The older one retains the headset_head_unit name, meaning any
saved parameters will still select this (keeping us backward
compatible).  It also introduces a new headset_handsfree.

For headsets that support both HSP and HFP, the two profiles will
become separately visible and selectable.  This will only matter once
we start adding features to HFP that HSP can't support (like wideband
audio).

Signed-off-by: <James.Bottomley@HansenPartnership.com>

---
v6:

- merge profile switching fixes patch from Rodrigo Araujo

v5:

- rename option to enable_native_hfp_hf
- don't call profile_done for HFP_HF unless it was initialised

v3:

- Update for PA 11.0

v2:

- fold in review feedback
- add global disable option for not registering HFP

v3:

- change parameter to enable_profile_hfp
- update device_supports_profile to be aware of hfp/hsp exclusivity
- change parameter to enable_profile_hfp_hf

bluetooth: separate HSP and HFP (to me merged with this patch)

Hi.

First, just to say that your patches are going great. Finally I can use
the microphone of my HFP only headset (a version of a Bluedio T2+).

So far, I've only encontered one problem: the auto_switch option of
module_bluetooth_policy stops working. Dug through the code and I think
you missed a few spots were you have to hangle the new headset_handsfree
profile in module_bluetooth_policy.c

Applying the following after applying your v5 patches fixed the issue
for me, now when I start making a VOIP call the profile switches to
headset_handsfree and the mic works automatically, and when the call
finishes it reverts back to a2dp.

Thanks and best regards.

Part-of: <!491>

The PA_BLUETOOTH_PROFILE names should mirror the PA_BLUETOOTH_UUID
names using profile_function instead of randomly made up names.  Fix
this with the transformation:

PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT -> PA_BLUETOOTH_PROFILE_HSP_HS
PA_BLUETOOTH_PROFILE_HEADSET_AUDIO_GATEWAY -> PA_BLUETOOTH_PROFILE_HFP_AG
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

---

v4: update for PA 11.0

Part-of: <!491>