ALSA：如何在设备列表中找到设备，但打开该设备时仍收到“无此文件或目录”？

Question

It seems I don't understand the ALSA architecture, even after reading most of the documentation on offer:

I list all the available ALSA devices using snd_device_name_hint() and snd_device_name_get_hint(). This lists, among others "pulse" under hwdep class so it looks like PulseAudio is available in my system. But when I try to open it with snd_pcm_open() (non-blocking mode and either in or out) I get "No such file or directory".

What gives? I can open other devices, for instance the in-built Intel chip works fine, why doesn't PulseAudio?

Answer 1

Is pulseaudio running with the alsa emulation plugin loaded before you try to open the pulse device? If I understand how asoundrc files work you can create virtual alsa devices from the config file (which is how a pulse device gets created) which will exist whether the backend for that virtual device is running or not.