From c9596c9b82245434cfc07fa70cfc9115ba62ad74 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Mon, 4 Apr 2016 22:21:30 +0300
Subject: decklinkaudiosrc: Don't crash when receiving video frames but no
 audio

And mark these events as disconts to reset time tracking in the audio source.

https://bugzilla.gnome.org/show_bug.cgi?id=747633
---
 sys/decklink/gstdecklink.cpp         | 13 +++++++++----
 sys/decklink/gstdecklink.h           |  3 ++-
 sys/decklink/gstdecklinkaudiosrc.cpp |  7 +++++--
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/sys/decklink/gstdecklink.cpp b/sys/decklink/gstdecklink.cpp
index 8a2f10144..6d68a9a8a 100644
--- a/sys/decklink/gstdecklink.cpp
+++ b/sys/decklink/gstdecklink.cpp
@@ -479,7 +479,7 @@ public:
         IDeckLinkVideoInputFrame * frame, GstDecklinkModeEnum mode,
         GstClockTime capture_time, GstClockTime capture_duration) = NULL;
     void (*got_audio_packet) (GstElement * videosrc,
-        IDeckLinkAudioInputPacket * packet, GstClockTime capture_time) = NULL;
+        IDeckLinkAudioInputPacket * packet, GstClockTime capture_time, gboolean discont) = NULL;
     GstDecklinkModeEnum mode;
     BMDTimeValue capture_time, capture_duration;
     HRESULT res;
@@ -526,9 +526,13 @@ public:
     }
 
 no_video_frame:
-
-    if (audio_packet && got_audio_packet && audiosrc) {
-      m_input->got_audio_packet (audiosrc, audio_packet, capture_time);
+    if (got_audio_packet && audiosrc && audio_packet) {
+      m_input->got_audio_packet (audiosrc, audio_packet, capture_time, m_input->audio_discont);
+      m_input->audio_discont = FALSE;
+    } else {
+      m_input->audio_discont = TRUE;
+      if (!audio_packet)
+        GST_DEBUG ("Received no audio packet at %" GST_TIME_FORMAT, GST_TIME_ARGS (capture_time));
     }
 
     gst_object_replace ((GstObject **) & videosrc, NULL);
@@ -779,6 +783,7 @@ gst_decklink_acquire_nth_input (gint n, GstElement * src, gboolean is_audio)
   g_mutex_lock (&input->lock);
   if (is_audio && !input->audiosrc) {
     input->audiosrc = GST_ELEMENT_CAST (gst_object_ref (src));
+    input->audio_discont = TRUE;
     g_mutex_unlock (&input->lock);
     return input;
   } else if (!input->videosrc) {
diff --git a/sys/decklink/gstdecklink.h b/sys/decklink/gstdecklink.h
index 353769faa..418023dca 100644
--- a/sys/decklink/gstdecklink.h
+++ b/sys/decklink/gstdecklink.h
@@ -174,10 +174,11 @@ struct _GstDecklinkInput {
   const GstDecklinkMode *mode;
 
   /* Set by the audio source */
-  void (*got_audio_packet) (GstElement *videosrc, IDeckLinkAudioInputPacket * packet, GstClockTime capture_time);
+  void (*got_audio_packet) (GstElement *videosrc, IDeckLinkAudioInputPacket * packet, GstClockTime capture_time, gboolean discont);
 
   GstElement *audiosrc;
   gboolean audio_enabled;
+  gboolean audio_discont;
   GstElement *videosrc;
   gboolean video_enabled;
   void (*start_streams) (GstElement *videosrc);
diff --git a/sys/decklink/gstdecklinkaudiosrc.cpp b/sys/decklink/gstdecklinkaudiosrc.cpp
index 1171ff368..6360c2a72 100644
--- a/sys/decklink/gstdecklinkaudiosrc.cpp
+++ b/sys/decklink/gstdecklinkaudiosrc.cpp
@@ -57,6 +57,7 @@ typedef struct
 {
   IDeckLinkAudioInputPacket *packet;
   GstClockTime capture_time;
+  gboolean discont;
 } CapturePacket;
 
 static void
@@ -411,7 +412,7 @@ gst_decklink_audio_src_get_caps (GstBaseSrc * bsrc, GstCaps * filter)
 
 static void
 gst_decklink_audio_src_got_packet (GstElement * element,
-    IDeckLinkAudioInputPacket * packet, GstClockTime capture_time)
+    IDeckLinkAudioInputPacket * packet, GstClockTime capture_time, gboolean discont)
 {
   GstDecklinkAudioSrc *self = GST_DECKLINK_AUDIO_SRC_CAST (element);
   GstDecklinkVideoSrc *videosrc = NULL;
@@ -447,6 +448,7 @@ gst_decklink_audio_src_got_packet (GstElement * element,
     p = (CapturePacket *) g_malloc0 (sizeof (CapturePacket));
     p->packet = packet;
     p->capture_time = capture_time;
+    p->discont = discont;
     packet->AddRef ();
     g_queue_push_tail (&self->current_packets, p);
     g_cond_signal (&self->cond);
@@ -501,6 +503,7 @@ gst_decklink_audio_src_create (GstPushSrc * bsrc, GstBuffer ** buffer)
   ap->input->AddRef ();
 
   timestamp = p->capture_time;
+  discont = p->discont;
 
   // Jitter and discontinuity handling, based on audiobasesrc
   start_time = timestamp;
@@ -515,7 +518,7 @@ gst_decklink_audio_src_create (GstPushSrc * bsrc, GstBuffer ** buffer)
 
   duration = end_time - start_time;
 
-  if (self->next_offset == (guint64) - 1) {
+  if (discont || self->next_offset == (guint64) - 1) {
     discont = TRUE;
   } else {
     guint64 diff, max_sample_diff;
-- 
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