command: add ambient-light property

make it observable to make it usable as a replacement for --gamma-auto.

DOCS/man/input.rst

@@ -2849,6 +2849,9 @@ Property list
 ``focused``
     Whether the window has focus. Might not be supported by all VOs.
 
+``ambient-light``
+    Ambient lighting condition in lux. (macOS only)
+
 ``display-names``
     Names of the displays that the mpv window covers. On X11, these
     are the xrandr names (LVDS1, HDMI1, DP1, VGA1, etc.). On Windows, these

player/command.c

@@ -2778,6 +2778,18 @@ static void update_hidpi_window_scale(struct MPContext *mpctx, bool hidpi_scale)
     vo_control(vo, VOCTRL_SET_UNFS_WINDOW_SIZE, s);
 }
 
+static int mp_property_ambient_light(void *ctx, struct m_property *prop,
+                                     int action, void *arg)
+{
+    MPContext *mpctx = ctx;
+    struct vo *vo = mpctx->video_out;
+    double lux;
+    if (!vo || vo_control(vo, VOCTRL_GET_AMBIENT_LUX, &lux) < 1)
+        return M_PROPERTY_UNAVAILABLE;
+
+    return m_property_double_ro(action, arg, lux);
+}
+
 static int mp_property_focused(void *ctx, struct m_property *prop,
                                      int action, void *arg)
 {
@@ -4373,6 +4385,7 @@ static const struct m_property mp_properties_base[] = {
     {"estimated-display-fps", mp_property_estimated_display_fps},
     {"vsync-jitter", mp_property_vsync_jitter},
     {"display-hidpi-scale", mp_property_hidpi_scale},
+    {"ambient-light", mp_property_ambient_light},
 
     {"working-directory", mp_property_cwd},
 
@@ -4460,6 +4473,7 @@ static const char *const *const mp_event_property_change[] = {
       "display-height"),
     E(MP_EVENT_WIN_STATE2, "display-hidpi-scale"),
     E(MP_EVENT_FOCUS, "focused"),
+    E(MP_EVENT_AMBIENT_LIGHTING_CHANGED, "ambient-light"),
     E(MP_EVENT_CHANGE_PLAYLIST, "playlist", "playlist-pos", "playlist-pos-1",
       "playlist-count", "playlist/count", "playlist-current-pos",
       "playlist-playing-pos"),

player/command.h

@@ -101,6 +101,7 @@ enum {
     MP_EVENT_WIN_STATE,
     MP_EVENT_WIN_STATE2,
     MP_EVENT_FOCUS,
+    MP_EVENT_AMBIENT_LIGHTING_CHANGED,
     MP_EVENT_CHANGE_PLAYLIST,
     MP_EVENT_CORE_IDLE,
     MP_EVENT_DURATION_UPDATE,

player/playloop.c

@@ -859,6 +859,8 @@ static void handle_vo_events(struct MPContext *mpctx)
         mp_notify(mpctx, MP_EVENT_WIN_STATE2, NULL);
     if (events & VO_EVENT_FOCUS)
         mp_notify(mpctx, MP_EVENT_FOCUS, NULL);
+    if (events & VO_EVENT_AMBIENT_LIGHTING_CHANGED)
+        mp_notify(mpctx, MP_EVENT_AMBIENT_LIGHTING_CHANGED, NULL);
 }
 
 static void handle_sstep(struct MPContext *mpctx)

video/out/vo.h

@@ -54,7 +54,7 @@ enum {
 
     // Set of events the player core may be interested in.
     VO_EVENTS_USER = VO_EVENT_RESIZE | VO_EVENT_WIN_STATE | VO_EVENT_DPI |
-                     VO_EVENT_INITIAL_UNBLOCK | VO_EVENT_FOCUS,
+                     VO_EVENT_INITIAL_UNBLOCK | VO_EVENT_FOCUS | VO_EVENT_AMBIENT_LIGHTING_CHANGED,
 };
 
 enum mp_voctrl {