Another audio observation

One more observation before I am done for the night. The following call
works fine:

output_device=SDL_OpenAudio(&wave.spec, NULL);

It returns 0, and starts playing audio. However, the following call returns
2 and plays nothing:

output_device=SDL_OpenAudioDevice(NULL, 0, &wave.spec, NULL,

Could this be related to the fact that I can’t enumerate devices, so that it
isn’t able to find something for the NULL device name?

Kind regards,

Philip Bennefall
P.S. I am trying to create a loopback program where the input from the
microphone goes into another device’s playback buffer. I started with the
loopwave example as an initial test.