player: force refresh seek when changing audio filters

Unfortunately I see no better solution.

The refresh seek is skipped if the amount of buffered audio is not
overly huge.

Unfortunately softvol af_volume insertion still can cause this issue,
because it's outside of the normal dynamic filter chain changing code.

Move the video refresh call to reinit_video_filters() to make it more
uniform along with the audio code.

player/audio.c

@@ -147,8 +147,23 @@ int reinit_audio_filters(struct MPContext *mpctx)
     if (!ao_c)
         return 0;
 
+    double delay = 0;
+    if (ao_c->af->initialized > 0)
+        delay = af_calc_delay(ao_c->af);
+
     af_uninit(ao_c->af);
-    return recreate_audio_filters(mpctx) < 0 ? -1 : 1;
+    if (recreate_audio_filters(mpctx) < 0)
+        return -1;
+
+    // Only force refresh if the amount of dropped buffered data is going to
+    // cause "issues" for the A/V sync logic.
+    if (mpctx->audio_status == STATUS_PLAYING &&
+        mpctx->playback_pts != MP_NOPTS_VALUE && delay > 0.2)
+    {
+        queue_seek(mpctx, MPSEEK_ABSOLUTE, mpctx->playback_pts,
+                   MPSEEK_EXACT, true);
+    }
+    return 1;
 }
 
 // Call this if opts->playback_speed or mpctx->speed_factor_* change.

player/command.c

@@ -4044,9 +4044,6 @@ static int set_filters(struct MPContext *mpctx, enum stream_type mediatype,
         reinit_filters(mpctx, mediatype);
     }
 
-    if (mediatype == STREAM_VIDEO)
-        mp_force_video_refresh(mpctx);
-
     return success ? 0 : -1;
 }
 

player/video.c

@@ -226,6 +226,8 @@ int reinit_video_filters(struct MPContext *mpctx)
     if (need_reconfig)
         filter_reconfig(vo_c);
 
+    mp_force_video_refresh(mpctx);
+
     mp_notify(mpctx, MPV_EVENT_VIDEO_RECONFIG, NULL);
 
     return vo_c->vf->initialized;