[AG-TECH] Is possible modify AudioService to Select an audio device?

Christoph Willing c.willing at uq.edu.au
Wed Jun 2 08:27:37 CDT 2010


Have a look at:

It explains how to switch between different devices in rat (actually,  
ALSA to OSS). Its not quite the same as your case, but it may be  
similar enough that you can apply the technique described there to  
your own situation. Some steps in the procedure may seem so trivial  
that you want to bypass them - however its important to follow each  
step precisely.


On 02/06/2010, at 8:39 PM, Jesus Cea Oliva wrote:

> Hi Jason, thanks for your help ;). I didn't know that I can save  
> preferences with RAT, but I try to save the preferences with RAT  
> without success. I execute localy RAT (without Access Grid), change  
> some preferences and click "Quit" button, closing RAT application.  
> But, when I execute again RAT, the preferences doesn't change.
> On Access Grid, I add an AudioService, Rat executes, and I change  
> some preferences (like audio device). I click "Quit" button (so, Rat  
> closes) and "Go" to enter again on a Venue, but RAT preferences  
> doesn't change.
> I don't know if I'm doing something bad :S.
> Regards!
> El dia 02 jun 2010 01:41, Jason Bell <j.bell at cqu.edu.au> escribió:
> Jesus
> I think being able to select the Audio device within Rat would be  
> useful.  (I will let the developers comment on this one)…
> But, there is a work around…  If you select the device in rat that  
> you want, and click on the “Quit” button on rat (which will close  
> the application down), it will actually save the device you selected  
> and will use this device for now on.  Therefore, if you change the  
> device or any preference settings, by manually “Quiting” rat, these  
> changes will be saved.
> I hope this helps.
> Cheers,
> Jason.
> From: ag-tech-bounces at lists.mcs.anl.gov [mailto:ag-tech-bounces at lists.mcs.anl.gov 
> ] On Behalf Of Jesus Cea Oliva
> Sent: Wednesday, 2 June 2010 02:01 AM
> To: ag-tech at mcs.anl.gov
> Subject: [AG-TECH] Is possible modify AudioService to Select an  
> audio device?
> Hi, list. Today, I found a interesting "need". We have installed a  
> Access Grid client on a normal machine where the audio is a external  
> multifunctional microphone (concretly, a Yamaha PJP-25EUR: http://www.gizmos.es/1828/audio-portatil/yamaha-pjp-25ur-microfono-multidireccional/) 
> , this has a speaker and a set of microphones and, usualy, it is  
> used for Meetings Venues, etc.
> Audio on Access Grid, works fine, but, I have to modify RAT to  
> select the audio device (in audio tab), because, by default, the  
> audio device selected is the sound card. On audio tab, I can select  
> the default audio device to use on RAT... so, I think that is  
> interesting add an aditional option to AudioService to select the  
> audio device prefered.
> I already modify the AudioService code tu add a new option, adding  
> to the end of __init__ function the next lines:
> self.audioDevice = OptionSetParameter( "Audio device:",  
> audioDefault, self.listAudio)
> self.configuration.append(self.audioDevice)
> Where, self.listAudio is a list where I want to store the differents  
> audio devices that has the system. And here is my doubt, how can I  
> obtain the audio devices installed on my system, like RAT show me? I  
> thought to modify RAT to permit storage the configuration, or see  
> the code to see how RAT does it, but I think that RAT is a compiled  
> program (C or C++), right? I saw the "aplay -L" and "aplay -l"  
> commands, but I don't know if with this commands I can do something  
> (I don't, for example, if RAT detect the audio names that this  
> commands show me).
> I know that I can modify the .RATdefault file to permanently save  
> the configuration.  But I think that I'm going to see this in the  
> future and I thought that is interesting save the config with  
> AudioService like Gains, etc. I add this lines too on  
> AudioService.py on WriteRatDefaults function:
> ratDefaults["*audioDevice"] = str(self.audioDevice.value )
> To save, the selected audio in AudioService window, to  
> the .RATdefault file.
> Sorry, as usual, for my bad English.
> Thanks and Regards!

Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland

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