pulsevideo: add gstreamer elements

Add custom gstreamer elements to pad/depay
Add pv_init() to register new elements

src/gst/gsttmpfileallocator.h

@@ -0,0 +1,37 @@
+/* GStreamer
+ * Copyright (C) 2014 William Manley <will@williammanley.net>
+ *
+ * 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_TMPFILE_ALLOCATOR_H_
+#define _GST_TMPFILE_ALLOCATOR_H_
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_ALLOCATOR_TMPFILE "tmpfile"
+
+
+/* Allocator that allocates memory from a file stored on a tmpfs */
+GstAllocator* gst_tmpfile_allocator_new (void);
+
+gint           gst_tmpfile_memory_get_fd (GstMemory * mem);
+gboolean       gst_is_tmpfile_memory     (GstMemory * mem);
+
+G_END_DECLS
+#endif /* _GST_TMPFILE_ALLOCATOR_H_ */