[Opalvoip-user] Restrict devices before opening OPAL?

[jeremy a. <jer...@gm...>]

I use a small snippet of code to open the OPAL device in a SIP voice
application

  OpalHandle hOPAL;

  unsigned version;

  version = OPAL_C_API_VERSION;

  if ((hOPAL = OpalInitialise(&version, OPAL_PREFIX_SIP " TraceLevel=4")) == NULL)

  {

    fputs("Could not initialise OPAL\n", stderr);

    return false;   

  }

However the OPAL instance wants to open a V4L2 device and fails since I
don't have one.

Can I prevent the OPAL instance from trying to open a V4L device and
instead open an ALSA device?

What calls prior to the OplaInitialise are required? Or is using the
wrapper functions not suitable for this and I should use low level
calls? Or does it require compile time switches? In all cases is there a
link or tutorial I can use?

I did searches on the error message phrase and not found much of use
other than similar messages from apps using OPAL. I also looked through
the doxygen documentation but it's a bit obscure about this. I also
installed a 4VL device and got it to work O.K. but my target application
won't have V4L.

Any advice appreciated.