Give error when using an invalid audio input with pipewire

include/sound.hpp

@@ -18,11 +18,19 @@
 #ifndef GPU_SCREEN_RECORDER_H
 #define GPU_SCREEN_RECORDER_H
 
+#include <vector>
+#include <string>
+
 typedef struct {
     void *handle;
     unsigned int frames;
 } SoundDevice;
 
+struct AudioInput {
+    std::string name;
+    std::string description;
+};
+
 /*
     Get a sound device by name, returning the device into the @device parameter.
     The device should be closed with @sound_device_close after it has been used
@@ -39,4 +47,6 @@ void sound_device_close(SoundDevice *device);
 */
 int sound_device_read_next_chunk(SoundDevice *device, void **buffer);
 
+std::vector<AudioInput> get_pulseaudio_inputs();
+
 #endif /* GPU_SCREEN_RECORDER_H */