dvd, bd: don't unnecessarily block on demuxer/stream all the time

This was completely breaking any low-level caching. Change it so that at
least demuxer caching will work.

Do this by using the metadata cache mechanism to funnel through the menu
commands.

For some incomprehensible reason, I had to reorder the events (which
affects their delivery priority), or they would be ignored. Probably
some crap about the event state being cleared before it could be
delivered. I don't give a shit.

All this code sucks. It would probably be better to let discnav.c access
the menu event "queue" directly, and to synchronize access with a mutex,
instead of going through all the caching layers, making things
complicated and slow.

3 files changed, 21 insertions, 0 deletions

diff --git a/demux/demux.c b/demux/demux.c
index 95d35034eb..af7277941e 100644
--- a/demux/demux.c
+++ b/demux/demux.c
@@ -125,6 +125,7 @@ struct demux_internal {
     // Cached state.
     bool force_cache_update;
     double time_length;
+    struct mp_nav_event *nav_event;
     struct mp_tags *stream_metadata;
     int64_t stream_size;
     int64_t stream_cache_size;
@@ -229,6 +230,7 @@ void free_demuxer(demuxer_t *demuxer)
         ds_flush(demuxer->streams[n]->ds);
     pthread_mutex_destroy(&in->lock);
     pthread_cond_destroy(&in->wakeup);
+    talloc_free(in->nav_event);
     talloc_free(demuxer);
 }
 
@@ -1135,10 +1137,17 @@ static void update_cache(struct demux_internal *in)
     int64_t stream_cache_size = -1;
     int64_t stream_cache_fill = -1;
     int stream_cache_idle = -1;
+    struct mp_nav_event *nav_event = NULL;
+
+    pthread_mutex_lock(&in->lock);
+    bool need_nav_event = !in->nav_event;;
+    pthread_mutex_unlock(&in->lock);
 
     if (demuxer->desc->control) {
         demuxer->desc->control(demuxer, DEMUXER_CTRL_GET_TIME_LENGTH,
                                &time_length);
+        if (need_nav_event)
+            demuxer->desc->control(demuxer, DEMUXER_CTRL_GET_NAV_EVENT, &nav_event);
     }
 
     stream_control(stream, STREAM_CTRL_GET_METADATA, &stream_metadata);
@@ -1158,6 +1167,7 @@ static void update_cache(struct demux_internal *in)
         in->stream_metadata = talloc_steal(in, stream_metadata);
         in->d_buffer->events |= DEMUX_EVENT_METADATA;
     }
+    in->nav_event = nav_event ? nav_event : in->nav_event;
     pthread_mutex_unlock(&in->lock);
 }
 
@@ -1248,6 +1258,13 @@ static int cached_demux_control(struct demux_internal *in, int cmd, void *arg)
             r->ts_duration = 0;
         return DEMUXER_CTRL_OK;
     }
+    case DEMUXER_CTRL_GET_NAV_EVENT:
+        if (!in->nav_event)
+            return DEMUXER_CTRL_NOTIMPL;
+        *(struct mp_nav_event **)arg = in->nav_event;
+        in->nav_event = NULL;
+        return DEMUXER_CTRL_OK;
+
     }
     return DEMUXER_CTRL_DONTKNOW;
 }
diff --git a/demux/demux.h b/demux/demux.h
index 7892718027..39bfee7fea 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -55,6 +55,7 @@ enum demux_ctrl {
     DEMUXER_CTRL_IDENTIFY_PROGRAM,
     DEMUXER_CTRL_STREAM_CTRL,
     DEMUXER_CTRL_GET_READER_STATE,
+    DEMUXER_CTRL_GET_NAV_EVENT,
 };
 
 struct demux_ctrl_reader_state {
diff --git a/demux/demux_disc.c b/demux/demux_disc.c
index e92198f0af..751b81281f 100644
--- a/demux/demux_disc.c
+++ b/demux/demux_disc.c
@@ -349,6 +349,9 @@ static int d_control(demuxer_t *demuxer, int cmd, void *arg)
     case DEMUXER_CTRL_SWITCHED_TRACKS:
         reselect_streams(demuxer);
         return DEMUXER_CTRL_OK;
+    case DEMUXER_CTRL_GET_NAV_EVENT:
+        return stream_control(demuxer->stream, STREAM_CTRL_GET_NAV_EVENT, arg)
+               == STREAM_OK ? DEMUXER_CTRL_OK : DEMUXER_CTRL_DONTKNOW;
     }
     return demux_control(p->slave, cmd, arg);
 }