hints: Added SDL_HINT_AUDIO_ENFORCE_MINIMUM_SPEC.

Fixes #14426.

include/SDL3/SDL_hints.h

@@ -493,6 +493,36 @@ extern "C" {
  */
 #define SDL_HINT_AUDIO_DUMMY_TIMESCALE "SDL_AUDIO_DUMMY_TIMESCALE"
 
+/**
+ * A variable controlling whether SDL enforces a minimum audio device spec.
+ *
+ * By default, SDL will require devices to be opened at a minimum spec
+ * (at time of writing: 44100Hz, stereo, Sint16 format), so if something
+ * lower quality tries to open the device first, it doesn't ruin audio
+ * for the next thing that opens a device. For example, if a VoIP library
+ * wants Uint8, 8000Hz, mono output, it doesn't force the entire game to
+ * this state simply because it got there first.
+ *
+ * However, an app that knows it will definitely be the only thing opening
+ * a device, and wants to open it at a lower spec, might be able to avoid
+ * some otherwise-unnecessary conversions by bypassing this minimum
+ * requirement.
+ *
+ * Note that even without the minimum enforcement, the system might choose a
+ * different format/channels/frequency than requested by the app; this hint
+ * just removes SDL's minimum policy.
+ *
+ * The variable can be set to the following values:
+ *
+ * - "0": Audio device mimimum formats _are not_ enforced.
+ * - "1": Audio device minimum formats _are_ enforced. (default)
+ *
+ * This hint should be set before an audio device is opened.
+ *
+ * \since This hint is available since SDL 3.4.0.
+ */
+#define SDL_HINT_AUDIO_ENFORCE_MINIMUM_SPEC "SDL_AUDIO_ENFORCE_MINIMUM_SPEC"
+
 /**
  * A variable controlling the default audio format.
  *