ubuntu-phone team mailing list archive

[Stefano Verzegnassi <stefano92.100@xxxxxxxxx>]

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 wrote a mail here, since I'm not sure for which packages I should fill 
a bug report.

Cheers,
Stefano.


[1] - 
http://bazaar.launchpad.net/~verzegnassi-stefano/+junk/recorder-test/files
[2] - http://qt-project.org/doc/qt-5/qaudiorecorder.html
[3]
{
    "policy_version": 1.2,
"template": "unconfined",
    "policy_groups": []
}