decklinksrc: Sample the pipeline clock for the timestamps instead of coming up with...

If we just count the frames and calculate timestamps from that, all frames
will arrive late in the sink as we have a live source here. Instead take
the pipeline clock at capture time as reference.

diff --git a/sys/decklink/capture.cpp b/sys/decklink/capture.cpp
index e9c981b..1795af2 100644 (file)
--- a/sys/decklink/capture.cpp
+++ b/sys/decklink/capture.cpp
@@ -78,6 +78,8 @@ HRESULT
     videoFrame, IDeckLinkAudioInputPacket * audioFrame)
 {
   GstDecklinkSrc *decklinksrc;
+  GstClock *clock;
+  GstClockTime base_time, clock_time, capture_time;
   const char *timecodeString = NULL;
 
   g_return_val_if_fail (priv != NULL, S_OK);
@@ -109,9 +111,32 @@ HRESULT
     }
   }
 
-  GST_DEBUG_OBJECT (decklinksrc, "Frame received [%s] - %s - Size: %li bytes",
-      timecodeString != NULL ? timecodeString : "No timecode",
-      "Valid Frame", videoFrame->GetRowBytes () * videoFrame->GetHeight ());
+  GST_OBJECT_LOCK (decklinksrc);
+  if ((clock = GST_ELEMENT_CLOCK (decklinksrc))) {
+    base_time = GST_ELEMENT (decklinksrc)->base_time;
+    gst_object_ref (clock);
+  } else {
+    base_time = GST_CLOCK_TIME_NONE;
+  }
+  GST_OBJECT_UNLOCK (decklinksrc);
+  if (clock) {
+    clock_time = gst_clock_get_time (clock);
+    gst_object_unref (clock);
+  } else {
+    clock_time = GST_CLOCK_TIME_NONE;
+  }
+
+  if (base_time != GST_CLOCK_TIME_NONE) {
+    capture_time = clock_time - base_time;
+  } else {
+    capture_time = GST_CLOCK_TIME_NONE;
+  }
+
+  GST_DEBUG_OBJECT (decklinksrc,
+      "Frame received [%s] - %s - %" GST_TIME_FORMAT "Size: %li bytes",
+      timecodeString != NULL ? timecodeString : "No timecode", "Valid Frame",
+      GST_TIME_ARGS (capture_time),
+      videoFrame->GetRowBytes () * videoFrame->GetHeight ());
 
   if (timecodeString)
     FREE_COM_STRING (timecodeString);
@@ -130,6 +155,7 @@ HRESULT
     audioFrame->AddRef ();
     decklinksrc->audio_frame = audioFrame;
   }
+  decklinksrc->capture_time = capture_time;
 
   /* increment regardless whether frame was dropped or not */
   decklinksrc->frame_num++;

diff --git a/sys/decklink/gstdecklinksrc.cpp b/sys/decklink/gstdecklinksrc.cpp
index 939fb8b..f796f6c 100644 (file)
--- a/sys/decklink/gstdecklinksrc.cpp
+++ b/sys/decklink/gstdecklinksrc.cpp
@@ -756,6 +756,7 @@ gst_decklink_src_task (void *priv)
   GstFlowReturn video_flow, audio_flow, flow;
   const GstDecklinkMode *mode;
   gboolean discont = FALSE;
+  GstClockTime capture_time;
 
   GST_DEBUG_OBJECT (decklinksrc, "task");
 
@@ -766,6 +767,7 @@ gst_decklink_src_task (void *priv)
   }
   video_frame = decklinksrc->video_frame;
   audio_frame = decklinksrc->audio_frame;
+  capture_time = decklinksrc->capture_time;
   decklinksrc->video_frame = NULL;
   decklinksrc->audio_frame = NULL;
   g_mutex_unlock (&decklinksrc->mutex);
@@ -846,12 +848,9 @@ gst_decklink_src_task (void *priv)
     vf->input->AddRef ();
   }
 
-  GST_BUFFER_TIMESTAMP (buffer) =
-      gst_util_uint64_scale_int (decklinksrc->frame_num * GST_SECOND,
+  GST_BUFFER_TIMESTAMP (buffer) = capture_time;
+  GST_BUFFER_DURATION (buffer) = gst_util_uint64_scale_int (GST_SECOND,
       mode->fps_d, mode->fps_n);
-  GST_BUFFER_DURATION (buffer) =
-      gst_util_uint64_scale_int ((decklinksrc->frame_num + 1) * GST_SECOND,
-      mode->fps_d, mode->fps_n) - GST_BUFFER_TIMESTAMP (buffer);
   GST_BUFFER_OFFSET (buffer) = decklinksrc->frame_num;
   GST_BUFFER_OFFSET_END (buffer) = decklinksrc->frame_num;      /* FIXME: +1? */
 
@@ -873,9 +872,7 @@ gst_decklink_src_task (void *priv)
     audio_buffer = gst_buffer_new_and_alloc (n_samples * 2 * 2);
     gst_buffer_fill (audio_buffer, 0, data, n_samples * 2 * 2);
 
-    GST_BUFFER_TIMESTAMP (audio_buffer) =
-        gst_util_uint64_scale_int (decklinksrc->num_audio_samples * GST_SECOND,
-        1, 48000);
+    GST_BUFFER_TIMESTAMP (audio_buffer) = capture_time;
     /* FIXME: should be next_timestamp - timestamp for perfect stream */
     GST_BUFFER_DURATION (audio_buffer) =
         gst_util_uint64_scale_int (n_samples * GST_SECOND, 1, 48000);

diff --git a/sys/decklink/gstdecklinksrc.h b/sys/decklink/gstdecklinksrc.h
index eb7a252..5d8ae90 100644 (file)
--- a/sys/decklink/gstdecklinksrc.h
+++ b/sys/decklink/gstdecklinksrc.h
@@ -60,6 +60,7 @@ struct _GstDecklinkSrc
   int dropped_frames;
   int dropped_frames_old;
   gboolean stop;
+  GstClockTime capture_time;
   IDeckLinkVideoInputFrame *video_frame;
   IDeckLinkAudioInputPacket * audio_frame;