Add new 'proxy' element to stream data between pipelines

This keep-it-simple plugin is useful when you want to pipe arbitrary
data to a different pipeline within the same process. Some advantages
over appsink/appsrc, the inter elements, etc:

* Ease of use. Buffers, events, and caps are transmitted as-is without
  copying or serialization.
* Enables zerocopy (especially DMABUF) transparently without any
  special-casing.
* Enables usage with sinks or elements that are unreliable and may
  throw errors and need re-initialization, such as a network sink, a
  USB device sink (v4l2), etc.
* Transmits arbitrary data, not just audio/video/subs
* Can easily implement 1 producer pipeline -> N dynamic consumer
  pipelines within a single process when combined with the `tee`
  element.

All queries, events, buffers, and buffer lists are proxied. State
changes, clocks, and base times for the two pipelines are independent
since the upstream and downstreams continue to be different pipelines.

https://bugzilla.gnome.org/show_bug.cgi?id=788200

1 files changed, 56 insertions, 0 deletions

diff --git a/gst/proxy/gstproxysrc.h b/gst/proxy/gstproxysrc.h
new file mode 100644
index 000000000..cc8577fc2
--- /dev/null
+++ b/gst/proxy/gstproxysrc.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2015 Centricular Ltd.
+ *   Author: Sebastian Dröge <sebastian@centricular.com>
+ *   Author: Nirbheek Chauhan <nirbheek@centricular.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_PROXY_SRC_H__
+#define __GST_PROXY_SRC_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_PROXY_SRC            (gst_proxy_src_get_type())
+#define GST_PROXY_SRC(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_PROXY_SRC, GstProxySrc))
+#define GST_IS_PROXY_SRC(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_PROXY_SRC))
+#define GST_PROXY_SRC_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass) , GST_TYPE_PROXY_SRC, GstProxySrcClass))
+#define GST_IS_PROXY_SRC_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) , GST_TYPE_PROXY_SRC))
+#define GST_PROXY_SRC_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj) , GST_TYPE_PROXY_SRC, GstProxySrcClass))
+
+typedef struct _GstProxySrc GstProxySrc;
+typedef struct _GstProxySrcClass GstProxySrcClass;
+typedef struct _GstProxySrcPrivate GstProxySrcPrivate;
+
+struct _GstProxySrc {
+  GstBin parent;
+
+  /* < private > */
+  GstProxySrcPrivate *priv;
+  gpointer  _gst_reserved[GST_PADDING];
+};
+
+struct _GstProxySrcClass {
+  GstBinClass parent_class;
+};
+
+GType gst_proxy_src_get_type(void);
+
+G_END_DECLS
+
+#endif /* __GST_PROXY_SRC_H__ */