From 506afa54dfcb1dc3378e4394b306bbf01ee9ef83 Mon Sep 17 00:00:00 2001
From: Thibault Saunier <tsaunier@gnome.org>
Date: Fri, 20 Feb 2015 17:50:48 +0100
Subject: [PATCH] basetransform: Add a method to let subclasses cleanly update
 srcpad caps

API:
    gst_base_transform_update_src

https://bugzilla.gnome.org/show_bug.cgi?id=734424
---
 docs/libs/gstreamer-libs-sections.txt |  1 +
 libs/gst/base/gstbasetransform.c      | 30 +++++++++++++++++++++++++++
 libs/gst/base/gstbasetransform.h      |  2 ++
 3 files changed, 33 insertions(+)

diff --git a/docs/libs/gstreamer-libs-sections.txt b/docs/libs/gstreamer-libs-sections.txt
index 86355fb8f7..f1db3a0975 100644
--- a/docs/libs/gstreamer-libs-sections.txt
+++ b/docs/libs/gstreamer-libs-sections.txt
@@ -361,6 +361,7 @@ gst_base_transform_get_allocator
 gst_base_transform_get_buffer_pool
 gst_base_transform_reconfigure_sink
 gst_base_transform_reconfigure_src
+gst_base_transform_update_src
 
 GST_BASE_TRANSFORM_SINK_NAME
 GST_BASE_TRANSFORM_SRC_NAME
diff --git a/libs/gst/base/gstbasetransform.c b/libs/gst/base/gstbasetransform.c
index 073d08c774..13badd92cd 100644
--- a/libs/gst/base/gstbasetransform.c
+++ b/libs/gst/base/gstbasetransform.c
@@ -2786,3 +2786,33 @@ gst_base_transform_get_allocator (GstBaseTransform * trans,
   if (params)
     *params = trans->priv->params;
 }
+
+/**
+ * gst_base_transform_update_src_caps:
+ * @trans: a #GstBaseTransform
+ * @updated_caps: An updated version of the srcpad caps to be pushed
+ * downstream
+ *
+ * Updates the srcpad caps and send the caps downstream. This function
+ * can be used by subclasses when they have already negotiated their caps
+ * but found a change in them (or computed new informations). This way,
+ * they can notify downstream about that change without loosing any
+ * buffer.
+ *
+ * Returns: %TRUE if the caps could be send downstream %FALSE otherwise
+ */
+gboolean
+gst_base_transform_update_src_caps (GstBaseTransform * trans,
+    GstCaps * updated_caps)
+{
+  g_return_val_if_fail (GST_IS_BASE_TRANSFORM (trans), FALSE);
+
+  if (gst_pad_push_event (GST_BASE_TRANSFORM_SRC_PAD (trans),
+          gst_event_new_caps (updated_caps))) {
+    gst_pad_mark_reconfigure (trans->srcpad);
+
+    return TRUE;
+  }
+
+  return FALSE;
+}
diff --git a/libs/gst/base/gstbasetransform.h b/libs/gst/base/gstbasetransform.h
index 3043a6294c..0eec6e992d 100644
--- a/libs/gst/base/gstbasetransform.h
+++ b/libs/gst/base/gstbasetransform.h
@@ -293,6 +293,8 @@ void            gst_base_transform_get_allocator    (GstBaseTransform *trans,
 
 void		gst_base_transform_reconfigure_sink (GstBaseTransform *trans);
 void		gst_base_transform_reconfigure_src  (GstBaseTransform *trans);
+gboolean gst_base_transform_update_src_caps (GstBaseTransform *trans,
+                                             GstCaps *updated_caps);
 G_END_DECLS
 
 #endif /* __GST_BASE_TRANSFORM_H__ */
-- 
2.34.1