mixer: restore volume with playback resume

Note that this is intentionally never done if the AO or softvolume is
different, or if the current volume control method is thought to control
system wide volume (such as ALSA) or otherwise user controllable (such
as PulseAudio). The intention is to keep things robust and to avoid
messing with the user's audio settings as far as possible, while still
providing the ability to resume volume if it makes sense.

4 files changed, 19 insertions, 2 deletions

diff --git a/mpvcore/command.c b/mpvcore/command.c
index dedac9dc10..ea71b9e082 100644
--- a/mpvcore/command.c
+++ b/mpvcore/command.c
@@ -804,6 +804,21 @@ static int mp_property_mute(m_option_t *prop, int action, void *arg,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
+static int mp_property_volrestore(m_option_t *prop, int action,
+                                   void *arg, MPContext *mpctx)
+{
+    switch (action) {
+    case M_PROPERTY_GET: {
+        char *s = mixer_get_volume_restore_data(&mpctx->mixer);
+        *(char **)arg = s;
+        return s ? M_PROPERTY_OK : M_PROPERTY_UNAVAILABLE;
+    }
+    case M_PROPERTY_SET:
+        return M_PROPERTY_NOT_IMPLEMENTED;
+    }
+    return mp_property_generic_option(prop, action, arg, mpctx);
+}
+
 /// Audio delay (RW)
 static int mp_property_audio_delay(m_option_t *prop, int action,
                                    void *arg, MPContext *mpctx)
@@ -1806,6 +1821,7 @@ static const m_option_t mp_properties[] = {
     M_OPTION_PROPERTY_CUSTOM("aid", mp_property_audio),
     { "balance", mp_property_balance, CONF_TYPE_FLOAT,
       M_OPT_RANGE, -1, 1, NULL },
+    M_OPTION_PROPERTY_CUSTOM("volume-restore-data", mp_property_volrestore),
 
     // Video
     M_OPTION_PROPERTY_CUSTOM("fullscreen", mp_property_fullscreen),
diff --git a/mpvcore/mplayer.c b/mpvcore/mplayer.c
index fafb88d022..00229364e6 100644
--- a/mpvcore/mplayer.c
+++ b/mpvcore/mplayer.c
@@ -809,8 +809,7 @@ static const char *backup_properties[] = {
     "speed",
     "edition",
     "pause",
-    //"volume",
-    //"mute",
+    "volume-restore-data",
     "audio-delay",
     //"balance",
     "fullscreen",
diff --git a/mpvcore/options.c b/mpvcore/options.c
index a09a28856f..e3b3137aed 100644
--- a/mpvcore/options.c
+++ b/mpvcore/options.c
@@ -565,6 +565,7 @@ const m_option_t mp_opts[] = {
                ({"auto", -1},
                 {"no", 0},
                 {"yes", 1}, {"", 1})),
+    OPT_STRING("volume-restore-data", mixer_restore_volume_data, 0),
     OPT_FLAG("gapless-audio", gapless_audio, 0),
 
     // set screen dimensions (when not detectable or virtual!=visible)
diff --git a/mpvcore/options.h b/mpvcore/options.h
index 67074de241..d425d0789b 100644
--- a/mpvcore/options.h
+++ b/mpvcore/options.h
@@ -51,6 +51,7 @@ typedef struct MPOpts {
     int softvol;
     float mixer_init_volume;
     int mixer_init_mute;
+    char *mixer_restore_volume_data;
     int volstep;
     float softvol_max;
     int gapless_audio;