Hi,
I am a Ubuntu and audio newbie and I am trying to fix an audio problem on 
Ubuntu 14.04 LTS that affects some tests I am working on.I would like to know 
how to disable the HFP support of pulseaudio.
ProblemI am trying to get some legacy tests to work on Ubuntu 14.04 LTS, they 
already work on Ubuntu 12.04 LTS. I have managed to get all but one test 
passing.
The test is a HFP audio test, it sends an audio file over bluetooth, captures 
it and dumps it to file using hcidump (--audio), and then tests the frequency 
peaks.
Looking at the output file (converted to .wav by adding a RIFF header) we can 
see an additional channel embedded into the signal that has no frequency and 
resulting in twice the duration, hence the test fails as peaks are missing. 
Being a HFP file this should have only one channel (mono) as it did on Ubuntu 
12.04 LTS.
After a process of elimination we found that pulseaudio is to blame, i.e. we 
uninstalled pulseaudio and the failing test passes.It seems to us that 
pulseaudio is overriding the HFP support provided by oFono and this is causing 
the problem. I understand HFP support is a new feature introduced in pulseaudio 
rel 3?
Looking in the config files and comparing them to 12.04 we also noticed a 
change to the jackdbus config line in the /etc/pulse/default.pa 
file;load-module module-jackdbus-detect channels=2
Removing the channels=2 and retesting resulted in the test sometimes passing, 
i.e. the sample HFP was as expected, no additional channel, however at other 
times it would include the additional channel, so this is not a stable fix. 
Looking at the release notes there seem to be several pulseaudio and jack 
fixes, so this could be the culprit but I am unsure how to get around this 
problem.
We have also tried to downgrade pulseaudio to the 12.04 LTS version, but this 
introduces a whole new set of problems, i.e. compatibility issues.I have found 
some information here but how do I set these attribute values for 
module-bluetooth-discover? I know the module is used in pulseaudio's 
default.pa.http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/Modules/#index6h2
I found some more information here that talks about sco_sink and sco_source but 
I'm not sure it helps; 
http://lists.freedesktop.org/archives/pulseaudio-discuss/2011-June/010297.html
HFP moved to oFono from BlueZ, not sure which version this is talking about 
though; //www.bluez.org/profiles/
oFono can be found here; //01.org/ofono
ConfigurationUbuntu 12.04
------------
$ dpkg --status ofono | grep '^Version:'
Version: 1.9-1ubuntu1

$ dpkg --status bluez-hcidump | grep '^Version:'
Version: 2.2-1

$ dpkg --status bluez | grep '^Version:'
Version: 4.98-2ubuntu7.2

$ dpkg --status pulseaudio | grep '^Version:'
Version: 1:1.1-0ubuntu15.4

$ dpkg --status libpulse0 | grep '^Version:'
Version: 1:1.1-0ubuntu15.4


Ubuntu 14.04
------------
$ dpkg --status ofono | grep '^Version:'
Version: 1.12.bzr6858+14.04.20140318-0ubuntu1

$ dpkg --status bluez-hcidump | grep '^Version:'
Version: 2.5-1

$ dpkg --status bluez | grep '^Version:'
Version: 4.101-0ubuntu13.1

$ dpkg --status pulseaudio | grep '^Version:'
Version: 1:4.0-0ubuntu11.1

$ dpkg --status libpulse0 | grep '^Version:'
Version: 1:4.0-0ubuntu11.1
I have also posted the question 
here;http://askubuntu.com/questions/629008/how-to-disable-hfp-support-of-pulseaudio-on-ubuntu-14-04-lts


                                          
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