audio/out: make draining a separate operation

Until now, this was always conflated with uninit. This was ugly, and
also many AOs emulated this manually (or just ignored it). Make draining
an explicit operation, so AOs which support it can provide it, and for
all others generic code will emulate it.

For ao_wasapi, we keep it simple and basically disable the internal
draining implementation (maybe it should be restored later).

Tested on Linux only.

1 files changed, 8 insertions, 2 deletions

diff --git a/audio/out/ao_null.c b/audio/out/ao_null.c
index a6b40fdb76..6fff65dcd9 100644
--- a/audio/out/ao_null.c
+++ b/audio/out/ao_null.c
@@ -98,10 +98,15 @@ static int init(struct ao *ao)
 }
 
 // close audio device
-static void uninit(struct ao *ao, bool cut_audio)
+static void uninit(struct ao *ao)
+{
+}
+
+static void wait_drain(struct ao *ao)
 {
     struct priv *priv = ao->priv;
-    if (!cut_audio && !priv->paused)
+    drain(ao);
+    if (!priv->paused)
         mp_sleep_us(1000000.0 * priv->buffered / ao->samplerate / priv->speed);
 }
 
@@ -185,6 +190,7 @@ const struct ao_driver audio_out_null = {
     .get_delay = get_delay,
     .pause     = pause,
     .resume    = resume,
+    .drain     = wait_drain,
     .priv_size = sizeof(struct priv),
     .priv_defaults = &(const struct priv) {
         .bufferlen = 0.2,