audio: move replaygain control to top-level options

af_volume is deprecated, and so are its replaygain sub-options. To make
it possible to use replaygain without deprecated options (and of course
to make it available at all after af_volume is dropped), reintroduce
them as top-level options.

This also means that they are easily changeable at runtime by using them
as properties. Change the "volume" property to use the new update
mechanism as well.

We don't actually bother sharing the implementation between new and
deprecated mechanisms, as the deprecated one will simply be deleted.

For the from_dB() functions, we mention anders' copyright, although I'm
not sure if a mere formula is copyrightable. This will have to be
determined later.

This whole change is mostly untested. Our distributed human CI will take
care of it.

1 files changed, 4 insertions, 4 deletions

diff --git a/player/command.c b/player/command.c
index 73081e89f9..ad871e34b3 100644
--- a/player/command.c
+++ b/player/command.c
@@ -1820,10 +1820,7 @@ static int mp_property_volume(void *ctx, struct m_property *prop,
         return M_PROPERTY_OK;
     }
 
-    int r = mp_property_generic_option(mpctx, prop, action, arg);
-    if (action == M_PROPERTY_SET)
-        audio_update_volume(mpctx);
-    return r;
+    return mp_property_generic_option(mpctx, prop, action, arg);
 }
 
 /// Mute (RW)
@@ -5798,6 +5795,9 @@ void mp_option_change_callback(void *ctx, struct m_config_option *co, int flags)
 
     if (flags & UPDATE_SCREENSAVER)
         update_screensaver_state(mpctx);
+
+    if (flags & UPDATE_VOL)
+        audio_update_volume(mpctx);
 }
 
 void mp_notify_property(struct MPContext *mpctx, const char *property)