Re: [Linphone-developers] Hold file audio only plays once for ZRTP

[Trevor Alpeter]

I've attached a patch that corrects the issue where the hold audio file
is only played once when a ZRTP-encrypted call is paused.

Thanks.

Trevor

On 1/6/16 3:18 PM, Trevor Alpeter wrote:
> Hello,
> 
> I have been working with liblinphone and noticed that that the audio
> file used for hold music is only played once whenever a call encrypted
> with ZRTP is put on hold. This results in the party who was put on hold
> hearing only silence after the first time the file is played.
> 
> After a bit of debugging, I found that the issue appears to be that the
> MS_FILE_PLAYER_LOOP command is not invoked on the MSFilePlayer filter
> used to actually play the file.
> 
> I found that the MS_FILE_PLAYER_LOOP command is used within the
> linphone_call_start_audio_stream() method on the MSFilePlayer referenced
> by call->audiostream->soundread (coreapi/linphonecall.c, line 3102 in my
> source). However, that MSFilePlayer does not appear to be used.
> 
> Rather, a separate MSFilePlayer is created in
> linphone_call_start_media_streams() via a call to
> audio_stream_open_remote_play() (coreapi/linphonecall.c, line 3451).
> That MSFilePlayer is subsequently started, but it is not given a loop
> value so it plays the file once and then goes into the paused state.
> 
> I've attempted to fix this in my source by adding a call to the
> MS_FILE_PLAYER_LOOP just before starting it (coreapi/linphonecall.c,
> line 3453). I used the same pause value that is used in
> linphone_call_start_audio_stream(). This fixes the issue in my local build.
> 
> However, this leaves me with a couple of questions:
> 
> First, is this the correct fix? I'm still trying to get my head wrapped
> around the source, and I want to make sure I'm doing this correctly.
> 
> Second, could you provide any insight into why multiple MSFilePlayer
> filters are being created? In my debugging I'm actually seeing three
> filters. However, only one of them is actually being started and used.
> I'm a bit confused about what is going on.
> 
> Any insight is appreciated.
> 
> Thanks in advance.
> 
> Trevor
>

0001-Hold-file-loops-for-ZRTP-calls.patch
Description: Text document