[asterisk-dev] move monitor from one channel to another

[Klaus Darilion]

David Backeberg wrote:
> On Fri, Mar 12, 2010 at 12:41 PM, Klaus Darilion
> <klaus.mailinglists at pernau.at> wrote:
>> Hi!
>>
>> For debugging purposes I monitor bridged fax calls. This is a problem if
>> the incoming channel changes to T.38 (I use the FaxGateway application
>> from bugtracker to make T.38-gatewaying). In this case I want to move
>> the monitor from the incoming channel to the outgoing channel and swap
>> directions, e.g:
>>
>>  outchannel->monitor = inchannel->monitor;
>>  inchannel->monitor = NULL;
>>  temp = outchannel->monitor->read_stream;
>>  outchannel->monitor->read_stream = outchannel->monitor->write_stream;
>>  outchannel->monitor->write_stream = temp;
>>
>> Would this work? Do I have to apply any locks or is it safe inside by
>> bridge-application?
> 
> Ummm, maybe I just don't understand T.38, but I think you are mistaken.
> The reason you're not getting a recording with T.38 is because it goes
> out-of-band, and is no longer audio.

Hi David!

If both channels, incoming and outgoing, are using T.38 then you are 
correct. Then the fax transmission through Asterisk is purely digital.

In my case I use Asterisk in T.38 gateway [1] mode. There is the 
FaxGateway application which bridges between a T.38 and a non-T.38 
channel. On the non-T.38 channel there is still audio available. Thus, 
if the monitor is attached to the non-T.38 channel everything work fine, 
but, as you mentioned, if the monitor is attached to the T.38 channel 
then there are no more voice frames to record.

Therefore I want to move the monitor from the T.38 channel to the 
non-T.38 channel.

regards
klaus


[1] https://issues.asterisk.org/view.php?id=13405