[alsa-devel] How to tell user level hardware not support a certain format in a certain sample rate

[Richard Zhao]

Hi,

runtime->hw.rates and runtime->hw.formats indicate the rate and
formats hardware can support, so the user level plugins can
auto-convert the audio data. But hardware may not support a certain
combin of sample rate and format, and will cause hw_parm fail. In such
case, plugin auto-convert will not work.
How can I let userlevel know the failure conbin, so let auto-convert work?

Thanks
Richard