Re: [Linphone-developers] Linphone iOS Interfering with iOS Music

[Gautier Pelloux-Prayer]

Hi list,

We continued on a private thread because Qian had issue answering the mailing 
list, but I'll update status here too (answer inlined).

Cheers,

Gautier Pelloux-Prayer
Software Engineer @ Belledonne Communications

> On 05 Jan 2016, at 16:13, Gautier Pelloux-Prayer <address@hidden> wrote:
> 
> Hi,
> 
> Thanks for these detailed bug reports. See my answers inlined.
> 
> Cheers,
> 
> Gautier Pelloux-Prayer
> Software Engineer @ Belledonne Communications
> 
>> On 04 Jan 2016, at 10:40, Qian Li <address@hidden> wrote:
>> 
>> Dear Linphone developers,
>> 
>> I found some issues with Linphone iOS, which related to iOS system music 
>> playback.
>> 
>> 1. Fresh open Linphone will stop the music playback. This issue exists for a 
>> very long time. I suspect starting liblinphone will somehow acquire the 
>> audio session and stop the iOS music playback, which is not necessary and 
>> can be delayed until there’s a call.
> Yes, you are right. I will give it a look for the next release.
It is now fixed in master, will be available in next release comming in the 
next days/weeks now.
>> 
>> 2. When switching Linphone from background to foreground, the current music 
>> playback quality will drop, and back to normal when Linphone goes to 
>> background. Step to replicate:
>> - Open Linphone.
>> - Make a outgoing call.
>> - Hangup.
>> - Open iOS Music app and play some music.
>> - Switch back to Linphone. The music will be paused for half a second, and 
>> then resume with a bad quality.
>> - Press Home and make Linphone to background. The music quality becomes 
>> normal again.
I was finally able to reproduce the bug on iOS8 using PCMA audio codec for the 
call. Now that I can reproduce the issue, I will try to fix it but do not have 
time for it right now - it will probably not be in next release except if I can 
find an easy fix and/or anyone suggest a patch for it in time.

>> 
>> This issue only happens after making the call. There are something worth 
>> mention based on the output of the log:
>> 
>> When switching Linphone to foreground:
>> 
>> 2016-01-04 17:34:19.158 linphone[1208:546918] I configuring resampler output 
>> to rate=[8000], nchannels=[1]
>> 2016-01-04 17:34:19.158 linphone[1208:548171] I Priority used: 47
>> 2016-01-04 17:34:19.159 linphone[1208:548171] I Ring MSTicker priority set 
>> to SCHED_RR and value (47)
>> 2016-01-04 17:34:19.158 linphone[1208:546918] I ms_filter_link: 
>> MSFilePlayer:0x1513967b0,0-->MSDtmfGen:0x1513969b0,0
>> 2016-01-04 17:34:19.159 linphone[1208:546918] I ms_filter_link: 
>> MSDtmfGen:0x1513969b0,0-->MSResample:0x151396e10,0
>> 2016-01-04 17:34:19.161 linphone[1208:546918] I ms_filter_link: 
>> MSResample:0x151396e10,0-->MSAQWrite:0x151396a50,0
>> 2016-01-04 17:34:19.161 linphone[1208:546918] I Initializing speex resampler 
>> in mode [voip] 
>> 2016-01-04 17:34:19.383 linphone[1208:546918] I AQ: Configuring audio 
>> session for playback
>> 
>> When switching Linphone to background:
>> 
>> 2016-01-04 17:35:48.867 linphone[1208:546918] I ms_filter_unlink: 
>> MSFilePlayer:0x14ef98cd0,0-->MSDtmfGen:0x14ef98d90,0
>> 2016-01-04 17:35:48.867 linphone[1208:546918] I ms_filter_unlink: 
>> MSDtmfGen:0x14ef98d90,0-->MSResample:0x14ef99f70,0
>> 2016-01-04 17:35:48.867 linphone[1208:546918] I ms_filter_unlink: 
>> MSResample:0x14ef99f70,0-->MSAQWrite:0x14ef98e80,0
>> 2016-01-04 17:35:48.871 linphone[1208:549053] I Ring MSTicker thread exiting
>> 
>> Based on the log, Linphone set the output sampling rate to 8000, which I 
>> suspect is the cause the the music quality drop. This only happens after a 
>> call is made, so I also suspect that when the call is connected, Linphone 
>> sets the sampling rate to 8000 for call, and when the call ends, it is not 
>> completely cleared or released so the app still think it is in the call.
>> 
>> Any feedback on possible work around is appreciated.
> 
> Thanks for sharing your detailled analysis. It makes sense, however I could 
> not reproduce your error yet with latest Linphone version released on the 
> market (2.4.3), so could you:
> 
> - confirm me that you are also running version 2.4.3?
> - provide me device(s) model and iOS version(s) affected by this bug? I only 
> tested on 6s running 9.2 yet.
> 
> I'll check more in depth this issue in any case to ensure that it's really 
> fixed. 
> 
>> 
>> Looking forward to hearing from you.
>> 
>> Best Regards,
>> Li
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> 
> 
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