Gil Hadas wrote:
> But I couldn't compile it , I don't have the declaration of
> PaAsioStreamInfo

first of all you need pa_asio.h for PaAsioStreamInfo

> any Idea if it the channel selector can help me and how?

In my experience with asio under portaudio i found channelselector quite
helpful:
here's the way i use them:

PaStreamParameters  InputParameters;
PaStreamParameters  OutputParameters;
PaAsioStreamInfo    AsioInputInfo;
PaAsioStreamInfo    AsioOutputInfo;
int                 iNumDevices;
int                 iMaxAsioInputChannels;
int                 iMaxAsioOutputChannels;
int                 iNumOfInputChannels;
int                 iNumOfOutputChannels;
int                 *piOutputChannelSelector;
int                 *piInputChannelSelector;
const PaDeviceInfo  *DeviceInfo;

iNumDevices = Pa_GetDeviceCount();


for(int i = 0; i < iNumDevices ; i++) // it is not useful for you, but
with that you can check if compiled everything in the right way
{
DeviceInfo = Pa_GetDeviceInfo(i);
iMaxAsioInputChannels = DeviceInfo->maxInputChannels;
iMaxAsioOutputChannels = DeviceInfo->maxOutputChannels;
}

piOutputChannelSelector = new int[iMaxAsioOutputChannels];
piInputChannelSelector = new int[iMaxAsioInputChannels];

//here's the important part:

piOutputChannelSelector[0] = 4; // that maps asio virtual channel to 0,
also if yours is 5
piOutputChannelSelector[1] = 5; // that maps asio virtual channel to 1,
also if yours is 6

piInputChannelSelector[0] = 2;
piInputChannelSelector[1] = 3;

// if you want to use a direct selection, you need to maps
piOutputChannelSelector & piInputChannelSelector like that:
// for (int i = 0; i < iMaxAsioInputChannels ; i++)
//  piInputChannelSelector[i] = i;
//
// for (int i = 0; i < iMaxAsioOutputChannels ; i++)
//  piOutputChannelSelector [i] = i;
//
// Then in the callback you'll have to route in the right way all your
channels, also the one you are actually not using
// Hence i prefer to map just the channel i use at the beginning of the
channelSelector array


//Input
AsioInputInfo.size                = sizeof(PaAsioStreamInfo);
AsioInputInfo.hostApiType         = paASIO;
AsioInputInfo.flags               = paAsioUseChannelSelectors;
AsioInputInfo.version             = 1;
AsioInputInfo.channelSelectors    = piInputChannelSelector;
InputParameters.channelCount      = iNumOfInputChannels; //for you it's 2
InputParameters.device            = Pa_GetDefaultOutputDevice();
InputParameters.sampleFormat      = paFloat32;
InputParameters.suggestedLatency   = Pa_GetDeviceInfo(
InputParameters.device )->defaultLowInputLatency;
InputParameters.hostApiSpecificStreamInfo = &AsioInputInfo;
//Output
AsioOutputInfo.size                = sizeof(PaAsioStreamInfo);
AsioOutputInfo.hostApiType         = paASIO;
AsioOutputInfo.flags               = paAsioUseChannelSelectors;
AsioOutputInfo.version             = 1;
AsioOutputInfo.channelSelectors    = piOutputChannelSelector;
OutputParameters.channelCount      = iNumOfOutputChannels;
OutputParameters.device            = Pa_GetDefaultOutputDevice();
OutputParameters.sampleFormat      = paFloat32;
OutputParameters.suggestedLatency  =
Pa_GetDeviceInfo(OutputParameters.device)->defaultLowOutputLatency;
OutputParameters.hostApiSpecificStreamInfo = &AsioOutputInfo;

--

Cristian Marletta

Hello Gil,

       I'm afraid there is no PortAudio interface to retrieve this
information, nor is there an interface for selecting specific
channels, although there have been discussions of the latter. If you
wanted to submit a patch to add this functionality, I would gladly
look it over and apply it if it looks good.

       bjorn

On Apr 1, 2007, at 11:07 AM, Gil Hadas wrote:

> Hi,
> I am creating an interface in my application in which the user can
> choose the I/O channels of the sound device.
> In windows, using ASIO only, I am looping over all the available
> input channels of a device and call PaAsio_GetInputChannelName()
> that  retrieves the name of the selected channel.
> When trying to implement the Mac OSX equivalent logic, using core
> audio, I did not find any call that retrieves the channels name.
> Is this supported in PortAudio?
> I found that when using Core Audio, it appears that the following
> call should be done: AudioDeviceGetProperty(... ,
> kAudioDevicePropertyChannelName,...)
> However, I did not find such a call in PortAudio sources.
> How is it recommended to proceed from here?
>
> Thanks,
> Gil
> _______________________________________________
> Portaudio mailing list
> Portaudio <at> techweb.rfa.org
> http://techweb.rfa.org/mailman/listinfo/portaudio

-----------------------------
Bjorn Roche
XO Wave
Digital Audio Production and Post-Production Software
http://www.xowave.com
http://blog.bjornroche.com
http://myspace.com/xowave

Hi,

try the following patch posted to the mailing list:

"Subject: [Portaudio] [patch] pkg-config in pacpp configure (was
portaudio cpp bindings - compilation question)

I have made a patch which use pkg-config to detect compilation and
linking parameters instead of linking directly to libportaudio.la."

http://techweb.rfa.org/pipermail/portaudio/2006-November/006237.html

Mikael