audio: Add Pipewire playback/capture sink

include/SDL_hints.h

@@ -1610,6 +1610,26 @@ extern "C" {
  */
 #define SDL_HINT_AUDIO_DEVICE_STREAM_NAME "SDL_AUDIO_DEVICE_STREAM_NAME"
 
+/**
+ *  \brief Specify an application role for an audio device.
+ *
+ * Some audio backends (such as Pipewire) allow you to describe the role of
+ * your audio stream. Among other things, this description might show up in
+ * a system control panel or software for displaying and manipulating media
+ * playback/capture graphs.
+ *
+ * This hints lets you transmit that information to the OS. The contents of
+ * this hint are used while opening an audio device. You should use a string
+ * that describes your what your program is playing (Game, Music, Movie,
+ * etc...).
+ *
+ * Setting this to "" or leaving it unset will have SDL use a reasonable
+ * default: "Game" or something similar.
+ *
+ * On targets where this is not supported, this hint does nothing.
+ */
+#define SDL_HINT_AUDIO_DEVICE_STREAM_ROLE "SDL_AUDIO_DEVICE_STREAM_ROLE"
+
 /**
  *  \brief Specify the behavior of Alt+Tab while the keyboard is grabbed.
  *