c - ALSA: How can I find a device in the device list and still I get "No such file or directory" when opening it?

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

在您尝试打开脉冲设备之前，pulseaudio 是否在加载 alsa 仿真插件的情况下运行？如果我了解 asoundrc 文件的工作原理，您可以从配置文件（这是创建脉冲设备的方式）创建虚拟 alsa 设备，无论该虚拟设备的后端是否正在运行，该设备都将存在。