ubuntu-phone team mailing list archive

[Jamie Strandboge <jamie@xxxxxxxxxxxxx>]

On 09/14/2014 02:06 PM, Stefano Verzegnassi wrote:
> I recently wrote a small application[1] to spot an ancient issue I had using
> QAudioRecorder[2] on Ubuntu devices.
> 
> Specifically, it seems that applications are not able to access to any audio
> source available on the device, and for that reason QAudioRecorder::record() fails.
> 
> First of all, I've asked to some people that own an official supported device if
> they can reproduce the bug, and the answer was affirmative.
> 
> I then started some tests on my Nexus 5 (utopic-devel-proposed #185), on the
> i386-ubuntu-emulator (utopic-devel #206) and on my pc (Ubuntu 14.10).
> The test application I used is set to run under confinement, and use the
> following security policies: networking, audio and microphone.
> 
> In the first test I checked for some denials from apparmor (using 'dmesg | grep
> DEN'), but I found no denial.
> 
> Then I started to take a look to the available audio sources on emulator and my
> N5 and I've seen that only "default:" was available (on PC there are also
> 'pulseaudio:' and all the sources from ALSA).
> This is the first strange behaviour I found: after I took a look to the
> 'microphone' policy, I expected to find at least 'pulseaudio:' on my device.
> 
> After a comparison between the installed packages on my PC and my smartphone, I
> found that gstreamer0.10-pulseaudio was missing. I installed it on the device,
> and finally I got 'pulseaudio:' in the list of available sources.
> 
> I tried to start a recording, but QAudioRecorder still failed.
> I got this output on my console: "shm_open() failed: Permission denied"
> 
> I changed the apparmor profile[3], so that my app has been launched in a
> unconfined environment: I supposed that the shared memory was confined for
> security issue.
> 
> So finally I got QAudioRecorder working as expected.
> 
> It seems there are actually two issues:
> 1) gstreamer0.10-pulseaudio is not available on Ubuntu devices. I don't know the
> reasons for that, but it would seem to give problems to QAudioRecorder.
> 2) 'microphone' security policy is too strong, and does not allow QAudioRecorder
> to work properly.
> 

I'm not sure about the gstreamer0.10-pulseaudio portion, however you can file a
bug about the microphone policy not working here:
https://bugs.launchpad.net/ubuntu/+source/apparmor-easyprof-ubuntu/+filebug



-- 
Jamie Strandboge                 http://www.ubuntu.com/

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