[Stk] RtWvOut and audio device on linux

[Gary Scavone]

Hi Enrico,

It appears that it found a device but that it does not support only 1  
channel.  That is weird, because RtAudio is supposed to automatically  
compensate for devices that have a minimum number of channels greater  
than that requested by the user.  In any event, you may try changing  
the number of channels parameter to RtWvOut to 2 or more.

You can also download the RtAudio distribution, compile the "info"  
program in the "tests" directory and see what it reports for your  
system.

Regards,

--gary

On 30-Jun-07, at 1:36 PM, Enrico Costanza wrote:

> Hi Steve,
>
> thanks a lot for your reply.
> I tried to set the sample rate to 48000, both using  
> Stk::setSampleRate() and using the argument in the RtDuplex  
> constructor, but nothing changed. What else could I try?
>
>> Also, when you run mplayer to play a 44100 Hz mp3 or wav file,  
>> check the audio path.
> How do I do this?
>
> Thanks,
> Enrico
>
> Stephen Sinclair wrote:
>> Hi Enrico,
>>
>> I don't know if this is the problem, but sometimes I have had  
>> trouble with ALSA if I haven't set my sample rate to 48000.   I  
>> don't know why exactly, but it doesn't seem to handle the wrong  
>> sample rate.  Probably because ALSA is a hardware driver and isn't  
>> supposed to provide software resampling.  Anyways, give it a try.
>>
>> Also, when you run mplayer to play a 44100 Hz mp3 or wav file,  
>> check the audio path.  I often notice that it sticks a 44100- 
>> >48000 resampling section in the audio pipeline, so this is  
>> probably the reason.  It would of course be nice to handle this a  
>> little smoother, maybe by throwing an exception.
>>
>> Steve
>>
>>
>> Enrico Costanza wrote:
>>> Dear All,
>>>
>>> I am trying to use the stk on kubuntu 7.04, and I am experiencing  
>>> problems with the real-time classes.
>>> Here is a simple test program trying to allocate RtWvOut with the  
>>> default parameters, and its output.
>>>
>>> ---
>>> #include <RtWvOut.h>
>>>
>>> using std::cout;
>>> using std::endl;
>>>
>>> int main(){
>>>    RtWvOut * test = NULL;
>>>    cout << "about to alloc" << endl;
>>>    test = new RtWvOut(  );
>>>    cout << "allocated" << endl;
>>>    delete test;
>>>    cout << "de-allocated" << endl;
>>>      return 0;
>>> }
>>> ---
>>> This is what I get:
>>> ---
>>> about to alloc
>>>
>>> RtApi: no devices found for given stream parameters:
>>>    RtApiAlsa: channels (1) not supported by device  
>>> (hw:I82801CAICH3,0).
>>>    RtApiAlsa: pcm device (hw:I82801CAICH3,1) won't open: No such  
>>> file or directory.
>>>    RtApiAlsa: pcm device (hw:U0x4710x329,0) won't open: No such  
>>> file or directory.
>>>
>>>
>>> terminate called after throwing an instance of 'StkError'
>>> Aborted (core dumped)
>>> ---
>>>
>>> At the same time, audio seems to work fine on my machine.  For  
>>> example I can play wave files with aplay.
>>> Am I doing something obviously stupid?
>>>
>>> Any suggestions and pointers are welcome.
>>>
>>> Thank you in advance.
>>>
>>> Enrico
>>>
>>> _______________________________________________
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>>> http://ccrma-mail.stanford.edu/mailman/listinfo/stk
>>
>> _______________________________________________
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>
>
> -- 
> Enrico Costanza
> Assistant-doctorant
> Media and Design Laboratory
> Ecole Polytechnique Fédérale de Lausanne
>
> http://web.media.mit.edu/~enrico
>
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