[Openal] Could not find capture device

Mon May 22 09:00:34 PDT 2006

Hi,

I think the problem is that you are requesting the ALC_EXT_CAPTURE
extension before selecting (opening) an OpenAL playback device.   If you
open either the "Generic Hardware" or "Generic Software" playback devices
first, and then request the capture extension everything should work ok.

We will need to investigate further into this issue - it maybe that we need
to change the behaviour of the OpenAL Router with respect to Capture
Devices.

Dan

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             <X.Shi at surrey.ac.                                             
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                                       [Openal] Could not find capture     
             05/20/2006 02:51          device                              
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Dan,

Thanks for your reply. I think I should list my test more clearly.

1. In my case, the following line gives me all the available (output)
device, namely the SB Audigy 2, the Generic Hardware and Generic Software.
        char *devList = (char *)alcGetString(NULL, ALC_DEVICE_SPECIFIER);

2. The following line of code returns FLASE.
        isAlcExtensionPresent(NULL, "ALC_EXT_CAPTURE");

    I understood this line should return TRUE if any capture extension is
supported. My question is whether it should return True if the Generic
Hardware is existed.

3. The following line of code also returns False:
      alcCaptureOpenDevice("Generic Hardware", FREQ, FMT, BUFSIZE);

      where the FREQ is 44100, FMT is AL_FORMAT_MONO16.

4. The open output device is OK with following line:
       alcOpenDevice("Generic Hardware");

I have another machine with a SoundMax Integrated Digital Audio card and
installed the OpenAL 1.1 WinSDK. If I query the output device, it lists
Generic Hardware and Generic Software. However, the results for step 2, 3
and 4 are the same as above. It seems that it just cannot get the capture
device. I really don't understand where the problem could be.

I appreciate your help.

Thanks.

Xiyu

--------------------------------------------------------------------------------------------------------

Hi,

Which OpenAL device are you using (i.e what are you passing to the
alcOpenDevice() function call) ?

The "Generic Software" and "Generic Hardware" devices include support for
all the OpenAL 1.1 features including ALC_EXT_CAPTURE.  However, the
current 'native' OpenAL device, called something like "SB Audigy 2 [XXXX]"
(where XXXX is the base address of the card) does not include OpenAL 1.1
support, and more specifically it does not include support for the
ALC_EXT_CAPTURE.    These features are planned, and will be available in
the near future.

For the time being, you will need to use the "Generic Hardware" device in
order to get hardware accelerated 3D audio with audio capture support (and
any other OpenAL 1.1 features).

Dan

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             <X.Shi at surrey.ac.

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                                                                   Subject
                                       [Openal] Could not find capture
             05/19/2006 08:03          device
             AM

I have installed the OpenAL 1.1 for Windows and try to record sound from
Mic. Although I can enumerate all the output devices, I am not able to find
any capture device. The following line of code always return false.

    alcIsExtensionPresent(audioDevice, "ALC_EXT_capture")

The sound card is a Creative SB Audigy 2. I checked the microphone and
sound card work properly with other applications.

What could be the reason of no capture device with OpenAL 1.1? Is there
anything related to the card?

Thanks.

Xiyu Shi_______________________________________________
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