audio/out: make EOF handling properly event-based

With --gapless-audio=no, changing from one file to the next apparently
made it hang, until the player was woken up by unrelated events like
input. The reason was that the AO doesn't notify the player of EOF
properly. the played was querying ao_eof_reached(), and then just went
to sleep, without anything waking it up.

Make it event-based: the AO wakes up the playloop if the EOF state
changes.

We could have fixed this in a simpler way by synchronously draining the
AO in these cases. But I think proper event handling is preferable.

Fixes: #1069
CC: @mpv-player/stable (perhaps)

1 files changed, 2 insertions, 0 deletions

diff --git a/audio/out/internal.h b/audio/out/internal.h
index 4ee7f00f8a..e43b81a5ca 100644
--- a/audio/out/internal.h
+++ b/audio/out/internal.h
@@ -132,6 +132,8 @@ struct ao_driver {
     float (*get_delay)(struct ao *ao);
     // push based: block until all queued audio is played (optional)
     void (*drain)(struct ao *ao);
+    // Optional. Return true if audio has stopped in any way.
+    bool (*get_eof)(struct ao *ao);
     // Wait until the audio buffer needs to be refilled. The lock is the
     // internal mutex usually protecting the internal AO state (and used to
     // protect driver calls), and must be temporarily unlocked while waiting.