mplayer: fix volume setting with --gapless-audio

Playing something with "mpv f1.mkv f2.mkv --gapless-audio --volume=20"
caused the volume to be reset when playing a new file. Normally, the
volume should not be reset (unless explicitly requested with per-file
options), and without either --gapless-audio or --volume it works as
expected.

The underlying problem is that volume was saved only when the AO was
uninitialized, and also the volume was always set when starting a file.
Fix this by saving the volume when playback ends, and when the audio
is reinitialized. To make sure the volume is never restored twice or
saved in the wrong situation, introduce INITIALIZED_VOL.

Also note that this volume saving and restoring only happens if the
--volume option is used. mixer.c does its own bookkeeping of volume.
The main reason for this is that the volume option could be reset by
per-file options (see manpage), and mixer.c doesn't know anything
about this stuff. This is probably dumb, and maybe some things could
be simplified. But for now this will work.

2 files changed, 26 insertions, 16 deletions

diff --git a/core/mp_core.h b/core/mp_core.h
index 3b693d1658..9e61c8ffa3 100644
--- a/core/mp_core.h
+++ b/core/mp_core.h
@@ -31,7 +31,7 @@
 
 #define INITIALIZED_VO      1
 #define INITIALIZED_AO      2
-
+#define INITIALIZED_VOL     4
 #define INITIALIZED_GETCH2  8
 #define INITIALIZED_SPUDEC  32
 #define INITIALIZED_STREAM  64
diff --git a/core/mplayer.c b/core/mplayer.c
index ad8441f476..684991127b 100644
--- a/core/mplayer.c
+++ b/core/mplayer.c
@@ -557,21 +557,27 @@ void uninit_player(struct MPContext *mpctx, unsigned int mask)
         vo_spudec = NULL;
     }
 
-    if (mask & INITIALIZED_AO) {
-        mpctx->initialized_flags &= ~INITIALIZED_AO;
+    if (mask & INITIALIZED_VOL) {
+        mpctx->initialized_flags &= ~INITIALIZED_VOL;
         if (mpctx->mixer.ao) {
             // Normally the mixer remembers volume, but do it even if the
-            // volume is set explicitly with --volume=...
+            // volume is set explicitly with --volume=... (so that the same
+            // volume is restored on reinit)
             if (opts->mixer_init_volume >= 0 && mpctx->mixer.user_set_volume)
                 mixer_getbothvolume(&mpctx->mixer, &opts->mixer_init_volume);
             if (opts->mixer_init_mute >= 0 && mpctx->mixer.user_set_mute)
                 opts->mixer_init_mute = mixer_getmute(&mpctx->mixer);
-            mixer_uninit(&mpctx->mixer);
         }
+    }
+
+    if (mask & INITIALIZED_AO) {
+        mpctx->initialized_flags &= ~INITIALIZED_AO;
+        if (mpctx->mixer.ao)
+            mixer_uninit(&mpctx->mixer);
+        mpctx->mixer.ao = NULL;
         if (mpctx->ao)
             ao_uninit(mpctx->ao, mpctx->stop_play != AT_END_OF_FILE);
         mpctx->ao = NULL;
-        mpctx->mixer.ao = NULL;
     }
 }
 
@@ -1693,7 +1699,7 @@ void reinit_audio_chain(struct MPContext *mpctx)
     struct ao *ao;
     init_demux_stream(mpctx, STREAM_AUDIO);
     if (!mpctx->sh_audio) {
-        uninit_player(mpctx, INITIALIZED_AO);
+        uninit_player(mpctx, INITIALIZED_VOL | INITIALIZED_AO);
         goto no_audio;
     }
     if (!(mpctx->initialized_flags & INITIALIZED_ACODEC)) {
@@ -1759,11 +1765,20 @@ void reinit_audio_chain(struct MPContext *mpctx)
     mpctx->mixer.softvol = opts->softvol;
     mpctx->mixer.softvol_max = opts->softvol_max;
     mixer_reinit(&mpctx->mixer, ao);
+    if (!(mpctx->initialized_flags & INITIALIZED_VOL)) {
+        if (opts->mixer_init_volume >= 0) {
+            mixer_setvolume(&mpctx->mixer, opts->mixer_init_volume,
+                            opts->mixer_init_volume);
+        }
+        if (opts->mixer_init_mute >= 0)
+            mixer_setmute(&mpctx->mixer, opts->mixer_init_mute);
+        mpctx->initialized_flags |= INITIALIZED_VOL;
+    }
     mpctx->syncing_audio = true;
     return;
 
 init_error:
-    uninit_player(mpctx, INITIALIZED_ACODEC | INITIALIZED_AO);
+    uninit_player(mpctx, INITIALIZED_ACODEC | INITIALIZED_AO | INITIALIZED_VOL);
     cleanup_demux_stream(mpctx, STREAM_AUDIO);
 no_audio:
     mpctx->current_track[STREAM_AUDIO] = NULL;
@@ -2165,7 +2180,7 @@ void mp_switch_track(struct MPContext *mpctx, enum stream_type type,
         uninit_player(mpctx, INITIALIZED_VCODEC |
                         (mpctx->opts.fixed_vo && track ? 0 : INITIALIZED_VO));
     } else if (type == STREAM_AUDIO) {
-        uninit_player(mpctx, INITIALIZED_AO | INITIALIZED_ACODEC);
+        uninit_player(mpctx, INITIALIZED_AO | INITIALIZED_ACODEC | INITIALIZED_VOL);
     } else if (type == STREAM_SUB) {
         uninit_player(mpctx, INITIALIZED_SUB);
     }
@@ -2405,7 +2420,7 @@ static int fill_audio_out_buffers(struct MPContext *mpctx, double endpts)
              * while displaying video, then doing the output format switch.
              */
             if (!mpctx->opts.gapless_audio)
-                uninit_player(mpctx, INITIALIZED_AO);
+                uninit_player(mpctx, INITIALIZED_AO | INITIALIZED_VOL);
             reinit_audio_chain(mpctx);
             return -1;
         } else if (res == ASYNC_PLAY_DONE)
@@ -2942,7 +2957,7 @@ static bool timeline_set_part(struct MPContext *mpctx, int i, bool force)
     enum stop_play_reason orig_stop_play = mpctx->stop_play;
     if (!mpctx->sh_video && mpctx->stop_play == KEEP_PLAYING)
         mpctx->stop_play = AT_END_OF_FILE;  // let audio uninit drain data
-    uninit_player(mpctx, INITIALIZED_VCODEC | (mpctx->opts.fixed_vo ? 0 : INITIALIZED_VO) | (mpctx->opts.gapless_audio ? 0 : INITIALIZED_AO) | INITIALIZED_ACODEC | INITIALIZED_SUB);
+    uninit_player(mpctx, INITIALIZED_VCODEC | (mpctx->opts.fixed_vo ? 0 : INITIALIZED_VO) | (mpctx->opts.gapless_audio ? 0 : INITIALIZED_AO) | INITIALIZED_VOL | INITIALIZED_ACODEC | INITIALIZED_SUB);
     mpctx->stop_play = orig_stop_play;
 
     mpctx->demuxer = n->source;
@@ -4404,11 +4419,6 @@ goto_enable_cache: ;
             mpctx->audio_delay += mpctx->sh_video->stream_delay;
     }
     if (mpctx->sh_audio) {
-        if (opts->mixer_init_volume >= 0)
-            mixer_setvolume(&mpctx->mixer, opts->mixer_init_volume,
-                            opts->mixer_init_volume);
-        if (opts->mixer_init_mute >= 0)
-            mixer_setmute(&mpctx->mixer, opts->mixer_init_mute);
         if (!opts->ignore_start)
             mpctx->audio_delay -= mpctx->sh_audio->stream_delay;
     }