command: add audio-device property

Meant for changing the --audio-device at runtime.

DOCS/man/input.rst

@@ -1395,6 +1395,19 @@ Property list
     human readable free form text. The description is an empty string if none
     was received.
 
+``audio-device`` (RW)
+    Set the audio device. This directly reads/writes the ``--audio-device``
+    option, but on write accesses, the audio output will be scheduled for
+    reloading.
+
+    Writing this property while no audio output is active will not automatically
+    enable audio. (This is also true in the case when audio was disabled due to
+    reinitialization failure after a previous write access to ``audio-device``.)
+
+    This property also doesn't tell you which audio device is actually in use.
+
+    How these details are handled may change in the future.
+
 ``options/<name>`` (RW)
     Read-only access to value of option ``--<name>``. Most options can be
     changed at runtime by writing to this property. Note that many options

player/command.c

@@ -1466,6 +1466,16 @@ static void reload_audio_output(struct MPContext *mpctx)
     reinit_audio_chain(mpctx);
 }
 
+static int mp_property_audio_device(void *ctx, struct m_property *prop,
+                                    int action, void *arg)
+{
+    struct MPContext *mpctx = ctx;
+    int r = mp_property_generic_option(mpctx, prop, action, arg);
+    if (action == M_PROPERTY_SET)
+        reload_audio_output(mpctx);
+    return r;
+}
+
 static int mp_property_audio_devices(void *ctx, struct m_property *prop,
                                      int action, void *arg)
 {
@@ -3049,6 +3059,7 @@ static const struct m_property mp_properties[] = {
     {"aid", mp_property_audio},
     {"balance", mp_property_balance},
     {"volume-restore-data", mp_property_volrestore},
+    {"audio-device", mp_property_audio_device},
     {"audio-device-list", mp_property_audio_devices},
 
     // Video