videodecoder: add option to use default pad accept-caps handling

Add gst_video_decoder_set_use_default_pad_acceptcaps() to allow
subclasses to make videodecoder use the default pad acceptcaps
handling instead of resorting to the caps query that is, usually,
less efficient and unecessary

API: gst_video_decoder_set_use_default_pad_acceptcaps

3 files changed, 50 insertions, 16 deletions

diff --git a/gst-libs/gst/video/gstvideodecoder.c b/gst-libs/gst/video/gstvideodecoder.c
index c680722a9..99dd4ee0f 100644
--- a/gst-libs/gst/video/gstvideodecoder.c
+++ b/gst-libs/gst/video/gstvideodecoder.c
@@ -421,6 +421,9 @@ struct _GstVideoDecoderPrivate
 
   GstTagList *tags;
   gboolean tags_changed;
+
+  /* flags */
+  gboolean use_default_pad_acceptcaps;
 };
 
 static GstElementClass *parent_class = NULL;
@@ -1862,28 +1865,34 @@ gst_video_decoder_sink_query_default (GstVideoDecoder * decoder,
       break;
     }
     case GST_QUERY_ACCEPT_CAPS:{
-      GstCaps *caps;
-      GstCaps *allowed_caps;
-      GstCaps *template_caps;
-      gboolean accept;
+      if (decoder->priv->use_default_pad_acceptcaps) {
+        res =
+            gst_pad_query_default (GST_VIDEO_DECODER_SINK_PAD (decoder),
+            GST_OBJECT_CAST (decoder), query);
+      } else {
+        GstCaps *caps;
+        GstCaps *allowed_caps;
+        GstCaps *template_caps;
+        gboolean accept;
 
-      gst_query_parse_accept_caps (query, &caps);
+        gst_query_parse_accept_caps (query, &caps);
 
-      template_caps = gst_pad_get_pad_template_caps (pad);
-      accept = gst_caps_is_subset (caps, template_caps);
-      gst_caps_unref (template_caps);
+        template_caps = gst_pad_get_pad_template_caps (pad);
+        accept = gst_caps_is_subset (caps, template_caps);
+        gst_caps_unref (template_caps);
 
-      if (accept) {
-        allowed_caps = gst_pad_query_caps (GST_VIDEO_DECODER_SINK_PAD (decoder),
-            caps);
+        if (accept) {
+          allowed_caps =
+              gst_pad_query_caps (GST_VIDEO_DECODER_SINK_PAD (decoder), caps);
 
-        accept = gst_caps_can_intersect (caps, allowed_caps);
+          accept = gst_caps_can_intersect (caps, allowed_caps);
 
-        gst_caps_unref (allowed_caps);
-      }
+          gst_caps_unref (allowed_caps);
+        }
 
-      gst_query_set_accept_caps_result (query, accept);
-      res = TRUE;
+        gst_query_set_accept_caps_result (query, accept);
+        res = TRUE;
+      }
       break;
     }
     default:
@@ -4293,3 +4302,24 @@ gst_video_decoder_get_allocator (GstVideoDecoder * decoder,
   if (params)
     *params = decoder->priv->params;
 }
+
+/**
+ * gst_video_decoder_set_use_default_pad_acceptcaps:
+ * @decoder: a #GstVideoDecoder
+ * @use: if the default pad accept-caps query handling should be used
+ *
+ * Lets #GstVideoDecoder sub-classes decide if they want the sink pad
+ * to use the default pad query handler to reply to accept-caps queries.
+ *
+ * By setting this to true it is possible to further customize the default
+ * handler with %GST_PAD_SET_ACCEPT_INTERSECT and
+ * %GST_PAD_SET_ACCEPT_TEMPLATE
+ *
+ * Since: 1.6
+ */
+void
+gst_video_decoder_set_use_default_pad_acceptcaps (GstVideoDecoder * decoder,
+    gboolean use)
+{
+  decoder->priv->use_default_pad_acceptcaps = use;
+}
diff --git a/gst-libs/gst/video/gstvideodecoder.h b/gst-libs/gst/video/gstvideodecoder.h
index 779048e06..9497255b1 100644
--- a/gst-libs/gst/video/gstvideodecoder.h
+++ b/gst-libs/gst/video/gstvideodecoder.h
@@ -427,6 +427,9 @@ GstCaps *        gst_video_decoder_proxy_getcaps (GstVideoDecoder * decoder,
 gboolean         gst_video_decoder_sink_query_default (GstVideoDecoder * decoder,
                                                        GstQuery * query);
 
+void             gst_video_decoder_set_use_default_pad_acceptcaps (GstVideoDecoder * decoder,
+                                                                   gboolean use);
+
 
 G_END_DECLS
 
diff --git a/win32/common/libgstvideo.def b/win32/common/libgstvideo.def
index ef5d6501b..65ee98458 100644
--- a/win32/common/libgstvideo.def
+++ b/win32/common/libgstvideo.def
@@ -129,6 +129,7 @@ EXPORTS
 	gst_video_decoder_set_needs_format
 	gst_video_decoder_set_output_state
 	gst_video_decoder_set_packetized
+	gst_video_decoder_set_use_default_pad_acceptcaps
 	gst_video_decoder_sink_query_default
 	gst_video_dither_flags_get_type
 	gst_video_dither_free