WASAPI Max Output Channels = 0, but Input Channels = 2

[glowysourworm]

// WASAPI Device
PaHostApiIndex wasapiIndex = Pa_HostApiTypeIdToHostApiIndex(PaHostApiTypeId::paWASAPI);
PaDeviceIndex outputDeviceIndex;

for (PaDeviceIndex index = 0; index < Pa_GetDeviceCount(); index++)
{
	const PaDeviceInfo* device = Pa_GetDeviceInfo(index);

	if (device->hostApi == wasapiIndex)
	{
		outputDeviceIndex = index;
	}
}

The resulting device info will have the output channels set as input channels.

[RossBencina]

Your report is not clear. Are you saying that an input-only device is reporting non-zero output channels? Could you extend your code example to show which fields are inconsistent: what you got and what you expected please? maybe some printfs with the device name and input and output channels, and show the program output.. Does it happen with all devices? Your code will operate for all WASAPI devices?

[dmitrykos]

@glowysourworm please use PaWasapi_GetDeviceRole WASAPI API and tell the device role of the device in your test if you're absolutely sure that found device is wrong.

Your example is also not correct, so it can't demonstrate/reproduce your issue. Try this corrected version:

PaHostApiIndex wasapiIndex = Pa_HostApiTypeIdToHostApiIndex(PaHostApiTypeId::paWASAPI);
PaDeviceIndex outputDeviceIndex = -1;

for (PaDeviceIndex index = 0, index_max = Pa_GetDeviceCount(); index < index_max; index++)
{
    const PaDeviceInfo* device = Pa_GetDeviceInfo(index);

    if (device->hostApi == wasapiIndex)
    {
        // Output device has maxOutputChannels!=0, once found, break the searching loop
        if (device->maxOutputChannels != 0)
        {
            outputDeviceIndex = index;
            break;
        }
    }
}

If you can't reproduce the reported problem, please notify too so that issue could be closed.

[glowysourworm]

@dmitrykos I think you might've been correct. But, I've since gotten proper output; and can't remember how I had that bug. There are approx 12 devices that I'm getting on my machine; but they're somehow duplicates of the same (actual 3). So, using input / output channels to see which one is the speaker was the correct answer.

I do have one more question if you could direct me to the proper resource.

There seems to be a "slight bandwidth issue" reproducing a simple sine wave output. I'm not sure whether it's the host API, or my use of the parameters in the initialization. I've tried pretty much everything to eliminate it. The sine wave output should be perfectly clear; but it is not. I'm hearing slight harmonic distortion for higher ranges - using typical 44100 sampling rate and the proper device settings from the API.

I'm using MME, and WASAPI. Please let me know where people have had similar problems. (MME isn't working either)

[dmitrykos]

There seems to be a "slight bandwidth issue" reproducing a simple sine wave output. I'm not sure whether it's the host API, or my use of the parameters in the initialization.

It is definitely not a PA's issue if you experience both issues with different backends. Check the output sample format and the data format you are supplying, maybe that is a cause of sample format conversion, or use WASAPI Exclusive mode to avoid any format conversion.

Your question is outside the topic of this issue, so I am closing it.