From 02e4d92cbf781a5d3c19b34d81f2fee812acd6bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Wed, 22 Nov 2017 10:42:37 +0200
Subject: [PATCH] decklinkvideosink: Wait until scheduled playback is actually
 stopped before continuing

Otherwise we might "start" again, just to get finally stopped and then
getting errors all over the place.

https://bugzilla.gnome.org/show_bug.cgi?id=790114
---
 sys/decklink/gstdecklink.cpp          |  4 ++++
 sys/decklink/gstdecklink.h            |  4 +++-
 sys/decklink/gstdecklinkvideosink.cpp | 22 +++++++++++++++++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/sys/decklink/gstdecklink.cpp b/sys/decklink/gstdecklink.cpp
index 85498c9b13..d7d9e503ed 100644
--- a/sys/decklink/gstdecklink.cpp
+++ b/sys/decklink/gstdecklink.cpp
@@ -1152,6 +1152,10 @@ init_devices (gpointer data)
   i = 0;
   ret = iterator->Next (&decklink);
   while (ret == S_OK) {
+    g_mutex_init (&devices[i].input.lock);
+    g_mutex_init (&devices[i].output.lock);
+    g_cond_init (&devices[i].output.cond);
+
     ret = decklink->QueryInterface (IID_IDeckLinkInput,
         (void **) &devices[i].input.input);
     if (ret != S_OK) {
diff --git a/sys/decklink/gstdecklink.h b/sys/decklink/gstdecklink.h
index 29809716eb..af98a03246 100644
--- a/sys/decklink/gstdecklink.h
+++ b/sys/decklink/gstdecklink.h
@@ -215,10 +215,12 @@ struct _GstDecklinkOutput {
   GstClock *clock;
   GstClockTime clock_start_time, clock_last_time, clock_epoch;
   GstClockTimeDiff clock_offset;
-  gboolean started, clock_restart;
+  gboolean started;
+  gboolean clock_restart;
 
   /* Everything below protected by mutex */
   GMutex lock;
+  GCond cond;
 
   /* Set by the video source */
   /* Configured mode or NULL */
diff --git a/sys/decklink/gstdecklinkvideosink.cpp b/sys/decklink/gstdecklinkvideosink.cpp
index 9096c5fcdf..ac61637ba8 100644
--- a/sys/decklink/gstdecklinkvideosink.cpp
+++ b/sys/decklink/gstdecklinkvideosink.cpp
@@ -100,6 +100,12 @@ public:
   {
     GST_LOG_OBJECT (m_sink, "Scheduled playback stopped");
 
+    if (m_sink->output) {
+      g_mutex_lock (&m_sink->output->lock);
+      g_cond_signal (&m_sink->output->cond);
+      g_mutex_unlock (&m_sink->output->lock);
+    }
+
     return S_OK;
   }
 
@@ -900,6 +906,12 @@ gst_decklink_video_sink_start_scheduled_playback (GstElement * element)
         gst_object_unref (clock);
         return;
       }
+
+      // Wait until scheduled playback actually stopped
+      do {
+        g_cond_wait (&self->output->cond, &self->output->lock);
+        self->output->output->IsScheduledPlaybackRunning (&active);
+      } while (active);
     }
 
     GST_DEBUG_OBJECT (self,
@@ -976,16 +988,24 @@ gst_decklink_video_sink_stop_scheduled_playback (GstDecklinkVideoSink * self)
 
   g_mutex_lock (&self->output->lock);
   self->output->started = FALSE;
-  g_mutex_unlock (&self->output->lock);
   res = self->output->output->StopScheduledPlayback (start_time, 0, GST_SECOND);
   if (res != S_OK) {
     GST_ELEMENT_ERROR (self, STREAM, FAILED,
         (NULL), ("Failed to stop scheduled playback: 0x%08lx", (unsigned long)
             res));
     ret = GST_STATE_CHANGE_FAILURE;
+  } else {
+    bool active = false;
+
+    // Wait until scheduled playback actually stopped
+    do {
+        g_cond_wait (&self->output->cond, &self->output->lock);
+        self->output->output->IsScheduledPlaybackRunning (&active);
+    } while (active);
   }
   self->internal_base_time = GST_CLOCK_TIME_NONE;
   self->external_base_time = GST_CLOCK_TIME_NONE;
+  g_mutex_unlock (&self->output->lock);
 
   return ret;
 }