From 85ef4166a2ab6e871e3efde779d7fd65a3103dc6 Mon Sep 17 00:00:00 2001
From: Vivia Nikolaidou <vivia@ahiru.eu>
Date: Thu, 17 Nov 2016 18:23:04 +0200
Subject: [PATCH] decklinkvideosrc: Issue "no signal" warnings

When a frame is found to not have an associated input source (cable
unplugged, wrong mode selected), an element warning will be issued. When
the next frame in the stream is found to have an input source selected
(e.g. cable replugged), an element info will be issued.

https://bugzilla.gnome.org/show_bug.cgi?id=774629
---
 sys/decklink/gstdecklinkvideosrc.cpp | 18 ++++++++++++++++++
 sys/decklink/gstdecklinkvideosrc.h   |  1 +
 2 files changed, 19 insertions(+)

diff --git a/sys/decklink/gstdecklinkvideosrc.cpp b/sys/decklink/gstdecklinkvideosrc.cpp
index 0e8103406d..059487d129 100644
--- a/sys/decklink/gstdecklinkvideosrc.cpp
+++ b/sys/decklink/gstdecklinkvideosrc.cpp
@@ -203,6 +203,7 @@ gst_decklink_video_src_init (GstDecklinkVideoSrc * self)
   self->buffer_size = DEFAULT_BUFFER_SIZE;
   self->video_format = GST_DECKLINK_VIDEO_FORMAT_AUTO;
   self->timecode_format = bmdTimecodeRP188Any;
+  self->no_signal = FALSE;
 
   gst_base_src_set_live (GST_BASE_SRC (self), TRUE);
   gst_base_src_set_format (GST_BASE_SRC (self), GST_FORMAT_TIME);
@@ -579,6 +580,7 @@ gst_decklink_video_src_create (GstPushSrc * bsrc, GstBuffer ** buffer)
   CaptureFrame *f;
   GstCaps *caps;
   gboolean caps_changed = FALSE;
+  BMDFrameFlags flags;
 
   g_mutex_lock (&self->lock);
   while (g_queue_is_empty (&self->current_frames) && !self->flushing) {
@@ -655,6 +657,21 @@ gst_decklink_video_src_create (GstPushSrc * bsrc, GstBuffer ** buffer)
   vf->input = self->input->input;
   vf->input->AddRef ();
 
+  flags = f->frame->GetFlags();
+  if (flags & bmdFrameHasNoInputSource) {
+    if (!self->no_signal) {
+      self->no_signal = TRUE;
+      GST_ELEMENT_WARNING (GST_ELEMENT (self), RESOURCE, READ, ("No signal"),
+          ("No input source was detected - video frames invalid"));
+    }
+  } else {
+    if (self->no_signal) {
+      self->no_signal = FALSE;
+      GST_ELEMENT_INFO (GST_ELEMENT (self), RESOURCE, READ, ("Signal found"),
+          ("Input source detected"));
+    }
+  }
+
   GST_BUFFER_TIMESTAMP (*buffer) = f->capture_time;
   GST_BUFFER_DURATION (*buffer) = f->capture_duration;
   gst_buffer_add_video_time_code_meta (*buffer, f->tc);
@@ -926,6 +943,7 @@ gst_decklink_video_src_change_state (GstElement * element,
       self->input->clock_epoch += self->input->clock_last_time;
       self->input->clock_last_time = 0;
       self->input->clock_offset = 0;
+      self->no_signal = FALSE;
       g_mutex_unlock (&self->input->lock);
 
       gst_decklink_video_src_stop (self);
diff --git a/sys/decklink/gstdecklinkvideosrc.h b/sys/decklink/gstdecklinkvideosrc.h
index b1e7351cce..8c7f38a42b 100644
--- a/sys/decklink/gstdecklinkvideosrc.h
+++ b/sys/decklink/gstdecklinkvideosrc.h
@@ -66,6 +66,7 @@ struct _GstDecklinkVideoSrc
   GMutex lock;
   gboolean flushing;
   GQueue current_frames;
+  gboolean no_signal;
 
   guint buffer_size;