videodecoder: add getter for QoS proportion and earliest_time

Add a getter for the QoS proportion and earliest_time to help
subclasses do better estimations based on the proportion.

API: gst_video_decoder_get_qos_info()

https://bugzilla.gnome.org/show_bug.cgi?id=687991

docs/libs/gst-plugins-base-libs-sections.txt

@@ -2253,6 +2253,7 @@ gst_video_decoder_get_max_decode_time
 gst_video_decoder_get_max_errors
 gst_video_decoder_get_oldest_frame
 gst_video_decoder_get_packetized
+gst_video_decoder_get_qos_info
 gst_video_decoder_have_frame
 gst_video_decoder_get_latency
 gst_video_decoder_set_latency

gst-libs/gst/video/gstvideodecoder.c

@@ -3158,6 +3158,34 @@ gst_video_decoder_get_max_decode_time (GstVideoDecoder *
   return deadline;
 }
 
+/**
+ * gst_video_decoder_get_qos_info:
+ * @decoder: a #GstVideoDecoder
+ * @proportion: (out) (allow-none): address of variable in which to store the
+ *     current QoS proportion, or %NULL
+ * @earliest_time: (out) (allow-none): address of variable in which to store the
+ *     QoS earliest_time, or %NULL
+ *
+ * Returns: TRUE on success
+ *
+ * Since: 1.0.3
+ */
+gboolean
+gst_video_decoder_get_qos_info (GstVideoDecoder * decoder, gdouble * proportion,
+    GstClockTime * earliest_time)
+{
+  g_return_val_if_fail (GST_IS_VIDEO_DECODER (decoder), FALSE);
+
+  GST_OBJECT_LOCK (decoder);
+  if (proportion != NULL)
+    *proportion = decoder->priv->proportion;
+  if (earliest_time != NULL)
+    *earliest_time = decoder->priv->earliest_time;
+  GST_OBJECT_UNLOCK (decoder);
+
+  return TRUE;
+}
+
 GstFlowReturn
 _gst_video_decoder_error (GstVideoDecoder * dec, gint weight,
     GQuark domain, gint code, gchar * txt, gchar * dbg, const gchar * file,

gst-libs/gst/video/gstvideodecoder.h

@@ -353,6 +353,10 @@ gboolean         gst_video_decoder_negotiate           (GstVideoDecoder * decode
 GstClockTimeDiff gst_video_decoder_get_max_decode_time (GstVideoDecoder *decoder,
 							GstVideoCodecFrame *frame);
 
+gboolean         gst_video_decoder_get_qos_info (GstVideoDecoder * decoder,
+                                                 gdouble *proportion,
+                                                 GstClockTime *earliest_time);
+
 GstFlowReturn    gst_video_decoder_finish_frame (GstVideoDecoder *decoder,
 						 GstVideoCodecFrame *frame);
 

win32/common/libgstvideo.def

@@ -88,6 +88,7 @@ EXPORTS
 	gst_video_decoder_get_oldest_frame
 	gst_video_decoder_get_output_state
 	gst_video_decoder_get_packetized
+	gst_video_decoder_get_qos_info
 	gst_video_decoder_get_type
 	gst_video_decoder_have_frame
 	gst_video_decoder_merge_tags