A plugin to add an alpha channel to I420 video. Can optionally do chroma keying.

Original commit message from CVS:
* configure.ac:
* gst/alpha/Makefile.am:
* gst/alpha/gstalpha.c: (gst_alpha_method_get_type),
(gst_alpha_get_type), (gst_alpha_base_init),
(gst_alpha_class_init), (gst_alpha_init), (gst_alpha_set_property),
(gst_alpha_get_property), (gst_alpha_sink_link), (gst_alpha_add),
(gst_alpha_chroma_key), (gst_alpha_chain),
(gst_alpha_change_state), (plugin_init):
A plugin to add an alpha channel to I420 video. Can optionally do
chroma keying.
* gst/multipart/Makefile.am:
* gst/multipart/multipart.c: (plugin_init):
* gst/multipart/multipartdemux.c: (gst_multipart_demux_base_init),
(gst_multipart_demux_class_init), (gst_multipart_demux_init),
(gst_multipart_demux_finalize), (gst_multipart_demux_handle_event),
(gst_multipart_find_pad_by_mime), (gst_multipart_demux_chain),
(gst_multipart_demux_change_state),
(gst_multipart_demux_plugin_init):
* gst/multipart/multipartmux.c: (gst_multipart_mux_get_type),
(gst_multipart_mux_base_init), (gst_multipart_mux_class_init),
(gst_multipart_mux_get_sink_event_masks), (gst_multipart_mux_init),
(gst_multipart_mux_sinkconnect), (gst_multipart_mux_pad_link),
(gst_multipart_mux_pad_unlink),
(gst_multipart_mux_request_new_pad),
(gst_multipart_mux_handle_src_event),
(gst_multipart_mux_next_buffer), (gst_multipart_mux_compare_pads),
(gst_multipart_mux_queue_pads), (gst_multipart_mux_loop),
(gst_multipart_mux_get_property), (gst_multipart_mux_set_property),
(gst_multipart_mux_change_state), (gst_multipart_mux_plugin_init):
A Multipart demuxer/muxer. Not sure if it violates specs. Used to
send multipart jpeg images to a browser.
* gst/videobox/Makefile.am:
* gst/videobox/README:
* gst/videobox/gstvideobox.c: (gst_video_box_fill_get_type),
(gst_video_box_get_type), (gst_video_box_base_init),
(gst_video_box_class_init), (gst_video_box_init),
(gst_video_box_set_property), (gst_video_box_get_property),
(gst_video_box_sink_link), (gst_video_box_i420),
(gst_video_box_ayuv), (gst_video_box_chain),
(gst_video_box_change_state), (plugin_init):
Crops or adds borders around an image. can do alpha channel
borders as well.
* gst/videomixer/Makefile.am:
* gst/videomixer/README:
* gst/videomixer/videomixer.c: (gst_videomixer_pad_get_type),
(gst_videomixer_pad_base_init), (gst_videomixer_pad_class_init),
(gst_videomixer_pad_get_sink_event_masks),
(gst_videomixer_pad_get_property),
(gst_videomixer_pad_set_property),
(gst_videomixer_pad_sinkconnect), (gst_videomixer_pad_link),
(gst_videomixer_pad_unlink), (gst_videomixer_pad_init),
(gst_video_mixer_background_get_type), (gst_videomixer_get_type),
(gst_videomixer_base_init), (gst_videomixer_class_init),
(gst_videomixer_init), (gst_videomixer_request_new_pad),
(gst_videomixer_handle_src_event),
(gst_videomixer_blend_ayuv_i420), (gst_videomixer_fill_checker),
(gst_videomixer_fill_color), (gst_videomixer_fill_queues),
(gst_videomixer_blend_buffers), (gst_videomixer_update_queues),
(gst_videomixer_loop), (gst_videomixer_get_property),
(gst_videomixer_set_property), (gst_videomixer_change_state),
(plugin_init):
Generic video mixer plugin, can handle multiple inputs all with
different framerates and video sizes. Is fully alpha channel
aware.

12 files changed, 3503 insertions, 0 deletions

diff --git a/gst/alpha/Makefile.am b/gst/alpha/Makefile.am
new file mode 100644
index 00000000..cd908f9d
--- /dev/null
+++ b/gst/alpha/Makefile.am
@@ -0,0 +1,9 @@
+
+plugin_LTLIBRARIES = libgstalpha.la
+
+libgstalpha_la_SOURCES = gstalpha.c
+libgstalpha_la_CFLAGS = $(GST_CFLAGS)
+libgstalpha_la_LIBADD =
+libgstalpha_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
+noinst_HEADERS = 
diff --git a/gst/alpha/gstalpha.c b/gst/alpha/gstalpha.c
new file mode 100644
index 00000000..ece724e9
--- /dev/null
+++ b/gst/alpha/gstalpha.c
@@ -0,0 +1,558 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#include <string.h>
+
+#define GST_TYPE_ALPHA \
+  (gst_alpha_get_type())
+#define GST_ALPHA(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_ALPHA,GstAlpha))
+#define GST_ALPHA_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ALPHA,GstAlphaClass))
+#define GST_IS_ALPHA(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_ALPHA))
+#define GST_IS_ALPHA_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_ALPHA))
+
+typedef struct _GstAlpha GstAlpha;
+typedef struct _GstAlphaClass GstAlphaClass;
+
+typedef enum
+{
+  ALPHA_METHOD_ADD,
+  ALPHA_METHOD_GREEN,
+  ALPHA_METHOD_BLUE,
+}
+GstAlphaMethod;
+
+#define DEFAULT_METHOD ALPHA_METHOD_ADD
+#define DEFAULT_ALPHA 1.0
+#define DEFAULT_TARGET_CR 116
+#define DEFAULT_TARGET_CB 116
+
+struct _GstAlpha
+{
+  GstElement element;
+
+  /* pads */
+  GstPad *sinkpad;
+  GstPad *srcpad;
+
+  /* caps */
+  gint in_width, in_height;
+  gint out_width, out_height;
+
+  gdouble alpha;
+
+  guint target_cr, target_cb;
+
+  GstAlphaMethod method;
+};
+
+struct _GstAlphaClass
+{
+  GstElementClass parent_class;
+};
+
+/* elementfactory information */
+static GstElementDetails gst_alpha_details =
+GST_ELEMENT_DETAILS ("alpha filter",
+    "Filter/Effect/Video",
+    "Adds an alpha channel to video",
+    "Wim Taymans <wim@fluendo.com>");
+
+
+/* Alpha signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  ARG_0,
+  ARG_METHOD,
+  ARG_ALPHA,
+  ARG_TARGET_CR,
+  ARG_TARGET_CB,
+  /* FILL ME */
+};
+
+static GstStaticPadTemplate gst_alpha_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("AYUV"))
+    );
+
+static GstStaticPadTemplate gst_alpha_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
+    );
+
+
+static void gst_alpha_base_init (gpointer g_class);
+static void gst_alpha_class_init (GstAlphaClass * klass);
+static void gst_alpha_init (GstAlpha * alpha);
+
+static void gst_alpha_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_alpha_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+static GstPadLinkReturn
+gst_alpha_sink_link (GstPad * pad, const GstCaps * caps);
+static void gst_alpha_chain (GstPad * pad, GstData * _data);
+
+static GstElementStateReturn gst_alpha_change_state (GstElement * element);
+
+
+static GstElementClass *parent_class = NULL;
+
+#define GST_TYPE_ALPHA_METHOD (gst_alpha_method_get_type())
+static GType
+gst_alpha_method_get_type (void)
+{
+  static GType alpha_method_type = 0;
+  static GEnumValue alpha_method[] = {
+    {ALPHA_METHOD_ADD, "0", "Add alpha channel"},
+    {ALPHA_METHOD_GREEN, "1", "Chroma Key green"},
+    {ALPHA_METHOD_BLUE, "2", "Chroma Key blue"},
+    {0, NULL, NULL},
+  };
+
+  if (!alpha_method_type) {
+    alpha_method_type = g_enum_register_static ("GstAlphaMethod", alpha_method);
+  }
+  return alpha_method_type;
+}
+
+/* static guint gst_alpha_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_alpha_get_type (void)
+{
+  static GType alpha_type = 0;
+
+  if (!alpha_type) {
+    static const GTypeInfo alpha_info = {
+      sizeof (GstAlphaClass),
+      gst_alpha_base_init,
+      NULL,
+      (GClassInitFunc) gst_alpha_class_init,
+      NULL,
+      NULL,
+      sizeof (GstAlpha),
+      0,
+      (GInstanceInitFunc) gst_alpha_init,
+    };
+
+    alpha_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstAlpha", &alpha_info, 0);
+  }
+  return alpha_type;
+}
+
+static void
+gst_alpha_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details (element_class, &gst_alpha_details);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_alpha_sink_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_alpha_src_template));
+}
+static void
+gst_alpha_class_init (GstAlphaClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_METHOD,
+      g_param_spec_enum ("method", "Method",
+          "How the alpha channels should be created", GST_TYPE_ALPHA_METHOD,
+          DEFAULT_METHOD, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_ALPHA,
+      g_param_spec_double ("alpha", "Alpha", "The value for the alpha channel",
+          0.0, 1.0, DEFAULT_ALPHA, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_CR,
+      g_param_spec_uint ("target_cr", "Target Red", "The Red Chroma target", 0,
+          255, 116, (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TARGET_CB,
+      g_param_spec_uint ("target_cb", "Target Blue", "The Blue Chroma target",
+          0, 255, 116, (GParamFlags) G_PARAM_READWRITE));
+
+  gobject_class->set_property = gst_alpha_set_property;
+  gobject_class->get_property = gst_alpha_get_property;
+
+  gstelement_class->change_state = gst_alpha_change_state;
+}
+
+static void
+gst_alpha_init (GstAlpha * alpha)
+{
+  /* create the sink and src pads */
+  alpha->sinkpad =
+      gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_alpha_sink_template), "sink");
+  gst_element_add_pad (GST_ELEMENT (alpha), alpha->sinkpad);
+  gst_pad_set_chain_function (alpha->sinkpad, gst_alpha_chain);
+  gst_pad_set_link_function (alpha->sinkpad, gst_alpha_sink_link);
+
+  alpha->srcpad =
+      gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_alpha_src_template), "src");
+  gst_element_add_pad (GST_ELEMENT (alpha), alpha->srcpad);
+
+  alpha->alpha = DEFAULT_ALPHA;
+  alpha->method = DEFAULT_METHOD;
+  alpha->target_cr = DEFAULT_TARGET_CR;
+  alpha->target_cb = DEFAULT_TARGET_CB;
+
+  GST_FLAG_SET (alpha, GST_ELEMENT_EVENT_AWARE);
+}
+
+/* do we need this function? */
+static void
+gst_alpha_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstAlpha *alpha;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_ALPHA (object));
+
+  alpha = GST_ALPHA (object);
+
+  switch (prop_id) {
+    case ARG_METHOD:
+      alpha->method = g_value_get_enum (value);
+      break;
+    case ARG_ALPHA:
+      alpha->alpha = g_value_get_double (value);
+      break;
+    case ARG_TARGET_CB:
+      alpha->target_cb = g_value_get_uint (value);
+      break;
+    case ARG_TARGET_CR:
+      alpha->target_cr = g_value_get_uint (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+static void
+gst_alpha_get_property (GObject * object, guint prop_id, GValue * value,
+    GParamSpec * pspec)
+{
+  GstAlpha *alpha;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_ALPHA (object));
+
+  alpha = GST_ALPHA (object);
+
+  switch (prop_id) {
+    case ARG_METHOD:
+      g_value_set_enum (value, alpha->method);
+      break;
+    case ARG_ALPHA:
+      g_value_set_double (value, alpha->alpha);
+      break;
+    case ARG_TARGET_CR:
+      g_value_set_uint (value, alpha->target_cr);
+      break;
+    case ARG_TARGET_CB:
+      g_value_set_uint (value, alpha->target_cb);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstPadLinkReturn
+gst_alpha_sink_link (GstPad * pad, const GstCaps * caps)
+{
+  GstAlpha *alpha;
+  GstStructure *structure;
+  gboolean ret;
+
+  alpha = GST_ALPHA (gst_pad_get_parent (pad));
+  structure = gst_caps_get_structure (caps, 0);
+
+  ret = gst_structure_get_int (structure, "width", &alpha->in_width);
+  ret &= gst_structure_get_int (structure, "height", &alpha->in_height);
+
+  return GST_PAD_LINK_OK;
+}
+
+/*
+static int yuv_colors_Y[] = {  16, 150,  29 };
+static int yuv_colors_U[] = { 128,  46, 255 };
+static int yuv_colors_V[] = { 128,  21, 107 };
+*/
+
+static void
+gst_alpha_add (guint8 * src, guint8 * dest, gint width, gint height,
+    gdouble alpha)
+{
+  gint b_alpha = (gint) (alpha * 255);
+  guint8 *srcY;
+  guint8 *srcU;
+  guint8 *srcV;
+  gint size;
+  gint half_width = width / 2;
+  gint i, j;
+
+  size = width * height;
+
+  srcY = src;
+  srcU = srcY + size;
+  srcV = srcU + size / 4;
+
+  for (i = 0; i < height; i++) {
+    for (j = 0; j < width / 2; j++) {
+      *dest++ = b_alpha;
+      *dest++ = *srcY++;
+      *dest++ = *srcU;
+      *dest++ = *srcV;
+      *dest++ = b_alpha;
+      *dest++ = *srcY++;
+      *dest++ = *srcU++;
+      *dest++ = *srcV++;
+    }
+    if (i % 2 == 0) {
+      srcU -= half_width;
+      srcV -= half_width;
+    }
+  }
+}
+
+static void
+gst_alpha_chroma_key (gchar * src, gchar * dest, gint width, gint height,
+    gboolean soft, gint target_u, gint target_v, gfloat edge_factor,
+    gdouble alpha)
+{
+  gint b_alpha;
+  gint f_alpha = (gint) (alpha * 255);
+  guint8 *srcY1, *srcY2, *srcU, *srcV;
+  guint8 *dest1, *dest2;
+  gint i, j;
+  gint x, z, u, v;
+  gint size;
+
+  size = width * height;
+
+  srcY1 = src;
+  srcY2 = src + width;
+  srcU = srcY1 + size;
+  srcV = srcU + size / 4;
+
+  dest1 = dest;
+  dest2 = dest + width * 4;
+
+  for (i = 0; i < height / 2; i++) {
+    for (j = 0; j < width / 2; j++) {
+      u = *srcU++;
+      v = *srcV++;
+
+      x = target_u - u;
+      z = target_v - v;
+
+      // only filter if in top left square
+      if ((x > 0) && (z > 0)) {
+        // only calculate lot of stuff if we'll use soft edges
+        if (soft) {
+          gint ds = (x > z) ? z : x;
+
+          gfloat df = (gfloat) (ds) / edge_factor;
+
+          if (df > 1.0)
+            df = 1.0;
+
+          // suppress foreground
+          if (x > z) {
+            u += z;
+            v += z;
+          } else {
+            u += x;
+            v += x;
+          }
+          b_alpha = (int) (f_alpha * (1.0 - df));
+        } else {
+          // kill color and alpha
+          b_alpha = 0;
+        }
+      } else {
+        // do nothing;
+        b_alpha = f_alpha;
+      }
+
+      *dest1++ = b_alpha;
+      *dest1++ = *srcY1++;
+      *dest1++ = u;
+      *dest1++ = v;
+      *dest1++ = b_alpha;
+      *dest1++ = *srcY1++;
+      *dest1++ = u;
+      *dest1++ = v;
+      *dest2++ = b_alpha;
+      *dest2++ = *srcY2++;
+      *dest2++ = u;
+      *dest2++ = v;
+      *dest2++ = b_alpha;
+      *dest2++ = *srcY2++;
+      *dest2++ = u;
+      *dest2++ = v;
+    }
+    dest1 += width * 4;
+    dest2 += width * 4;
+    srcY1 += width;
+    srcY2 += width;
+  }
+}
+
+static void
+gst_alpha_chain (GstPad * pad, GstData * _data)
+{
+  GstBuffer *buffer;
+  GstAlpha *alpha;
+  GstBuffer *outbuf;
+  gint new_width, new_height;
+
+  alpha = GST_ALPHA (gst_pad_get_parent (pad));
+
+  if (GST_IS_EVENT (_data)) {
+    GstEvent *event = GST_EVENT (_data);
+
+    switch (GST_EVENT_TYPE (event)) {
+      default:
+        gst_pad_event_default (pad, event);
+        break;
+    }
+    return;
+  }
+
+  buffer = GST_BUFFER (_data);
+
+  new_width = alpha->in_width;
+  new_height = alpha->in_height;
+
+  if (new_width != alpha->out_width ||
+      new_height != alpha->out_height || !GST_PAD_CAPS (alpha->srcpad)) {
+    GstCaps *newcaps;
+
+    newcaps = gst_caps_copy (gst_pad_get_negotiated_caps (alpha->sinkpad));
+    gst_caps_set_simple (newcaps,
+        "format", GST_TYPE_FOURCC, GST_STR_FOURCC ("AYUV"),
+        "width", G_TYPE_INT, new_width, "height", G_TYPE_INT, new_height, NULL);
+
+    if (!gst_pad_try_set_caps (alpha->srcpad, newcaps)) {
+      GST_ELEMENT_ERROR (alpha, CORE, NEGOTIATION, (NULL), (NULL));
+      return;
+    }
+
+    alpha->out_width = new_width;
+    alpha->out_height = new_height;
+  }
+
+  outbuf = gst_buffer_new_and_alloc (new_width * new_height * 4);
+  GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
+  GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
+
+  switch (alpha->method) {
+    case ALPHA_METHOD_ADD:
+      gst_alpha_add (GST_BUFFER_DATA (buffer),
+          GST_BUFFER_DATA (outbuf), new_width, new_height, alpha->alpha);
+      break;
+    case ALPHA_METHOD_GREEN:
+      gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
+          GST_BUFFER_DATA (outbuf),
+          new_width, new_height,
+          TRUE, alpha->target_cr, alpha->target_cb, 1.0, alpha->alpha);
+      break;
+    case ALPHA_METHOD_BLUE:
+      gst_alpha_chroma_key (GST_BUFFER_DATA (buffer),
+          GST_BUFFER_DATA (outbuf),
+          new_width, new_height, TRUE, 100, 100, 1.0, alpha->alpha);
+      break;
+  }
+
+  gst_buffer_unref (buffer);
+
+  gst_pad_push (alpha->srcpad, GST_DATA (outbuf));
+}
+
+static GstElementStateReturn
+gst_alpha_change_state (GstElement * element)
+{
+  GstAlpha *alpha;
+
+  alpha = GST_ALPHA (element);
+
+  switch (GST_STATE_TRANSITION (element)) {
+    case GST_STATE_NULL_TO_READY:
+      break;
+    case GST_STATE_READY_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_PLAYING:
+      break;
+    case GST_STATE_PLAYING_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_READY:
+      break;
+    case GST_STATE_READY_TO_NULL:
+      break;
+  }
+
+  parent_class->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "alpha", GST_RANK_NONE, GST_TYPE_ALPHA);
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "alpha",
+    "resizes a video by adding borders or cropping",
+    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)
diff --git a/gst/multipart/Makefile.am b/gst/multipart/Makefile.am
new file mode 100644
index 00000000..45632eff
--- /dev/null
+++ b/gst/multipart/Makefile.am
@@ -0,0 +1,9 @@
+plugindir = $(libdir)/gstreamer-@GST_MAJORMINOR@
+
+plugin_LTLIBRARIES = libmultipart.la
+
+libmultipart_la_SOURCES = multipart.c multipartdemux.c multipartmux.c
+libmultipart_la_CFLAGS = $(GST_CFLAGS)
+libmultipart_la_LIBADD = 
+libmultipart_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
diff --git a/gst/multipart/multipart.c b/gst/multipart/multipart.c
new file mode 100644
index 00000000..802653fb
--- /dev/null
+++ b/gst/multipart/multipart.c
@@ -0,0 +1,44 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+extern gboolean gst_multipart_demux_plugin_init (GstPlugin * plugin);
+extern gboolean gst_multipart_mux_plugin_init (GstPlugin * plugin);
+
+GST_DEBUG_CATEGORY (vorbisdec_debug);
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  gst_multipart_demux_plugin_init (plugin);
+  gst_multipart_mux_plugin_init (plugin);
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "multipart",
+    "multipart stream manipulation",
+    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)
diff --git a/gst/multipart/multipartdemux.c b/gst/multipart/multipartdemux.c
new file mode 100644
index 00000000..6406df27
--- /dev/null
+++ b/gst/multipart/multipartdemux.c
@@ -0,0 +1,374 @@
+/* GStreamer
+ * Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
+ *
+ * gstmultipartdemux.c: multipart stream demuxer
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+
+#include <string.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_multipart_demux_debug);
+#define GST_CAT_DEFAULT gst_multipart_demux_debug
+
+#define GST_TYPE_MULTIPART_DEMUX (gst_multipart_demux_get_type())
+#define GST_MULTIPART_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_MULTIPART_DEMUX, GstMultipartDemux))
+#define GST_MULTIPART_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_MULTIPART_DEMUX, GstMultipartDemux))
+#define GST_IS_MULTIPART_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_MULTIPART_DEMUX))
+#define GST_IS_MULTIPART_DEMUX_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_MULTIPART_DEMUX))
+
+#define MAX_LINE_LEN 500
+
+typedef struct _GstMultipartDemux GstMultipartDemux;
+typedef struct _GstMultipartDemuxClass GstMultipartDemuxClass;
+
+static gchar *toFind = "--ThisRandomString\nContent-type: ";    //image/jpeg\n\n";
+static gint toFindLen;
+
+/* all information needed for one multipart stream */
+typedef struct
+{
+  GstPad *pad;                  /* reference for this pad is held by element we belong to */
+
+  gchar *mime;
+
+  guint64 offset;               /* end offset of last buffer */
+  guint64 known_offset;         /* last known offset */
+
+  guint flags;
+}
+GstMultipartPad;
+
+struct _GstMultipartDemux
+{
+  GstElement element;
+
+  /* pad */
+  GstPad *sinkpad;
+
+  GSList *srcpads;
+  gint numpads;
+
+  gchar *parsing_mime;
+  gchar *buffer;
+  gint maxlen;
+  gint bufsize;
+  gint scanpos;
+  gint lastpos;
+};
+
+struct _GstMultipartDemuxClass
+{
+  GstElementClass parent_class;
+};
+
+/* elementfactory information */
+static GstElementDetails gst_multipart_demux_details =
+GST_ELEMENT_DETAILS ("multipart demuxer",
+    "Codec/Demuxer",
+    "demux multipart streams",
+    "Wim Taymans <wim@fluendo.com>");
+
+
+/* signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  ARG_0,
+  /* FILL ME */
+};
+
+static GstStaticPadTemplate multipart_demux_src_template_factory =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_SOMETIMES,
+    GST_STATIC_CAPS_ANY);
+
+static GstStaticPadTemplate multipart_demux_sink_template_factory =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("multipart/x-mixed-replace")
+    );
+
+
+static void gst_multipart_demux_finalize (GObject * object);
+
+static void gst_multipart_demux_chain (GstPad * pad, GstData * buffer);
+
+static GstElementStateReturn gst_multipart_demux_change_state (GstElement *
+    element);
+
+
+GST_BOILERPLATE (GstMultipartDemux, gst_multipart_demux, GstElement,
+    GST_TYPE_ELEMENT)
+
+     static void gst_multipart_demux_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details (element_class, &gst_multipart_demux_details);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&multipart_demux_sink_template_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&multipart_demux_src_template_factory));
+
+  toFindLen = strlen (toFind);
+}
+
+static void
+gst_multipart_demux_class_init (GstMultipartDemuxClass * klass)
+{
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (klass);
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gstelement_class->change_state = gst_multipart_demux_change_state;
+
+  gobject_class->finalize = gst_multipart_demux_finalize;
+}
+
+static void
+gst_multipart_demux_init (GstMultipartDemux * multipart)
+{
+  /* create the sink pad */
+  multipart->sinkpad =
+      gst_pad_new_from_template (gst_static_pad_template_get
+      (&multipart_demux_sink_template_factory), "sink");
+  gst_element_add_pad (GST_ELEMENT (multipart), multipart->sinkpad);
+  gst_pad_set_chain_function (multipart->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_multipart_demux_chain));
+
+  GST_FLAG_SET (multipart, GST_ELEMENT_EVENT_AWARE);
+
+  multipart->maxlen = 4096;
+  multipart->buffer = g_malloc (multipart->maxlen);
+  multipart->parsing_mime = NULL;
+  multipart->numpads = 0;
+  multipart->scanpos = 0;
+  multipart->lastpos = 0;
+}
+
+static void
+gst_multipart_demux_finalize (GObject * object)
+{
+  GstMultipartDemux *multipart;
+
+  multipart = GST_MULTIPART_DEMUX (object);
+}
+
+static void
+gst_multipart_demux_handle_event (GstPad * pad, GstEvent * event)
+{
+  //GstMultipartDemux *multipart = GST_MULTIPART_DEMUX (gst_pad_get_parent (pad));
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_DISCONTINUOUS:
+    case GST_EVENT_EOS:
+    default:
+      gst_pad_event_default (pad, event);
+      break;
+  }
+  return;
+}
+
+static GstMultipartPad *
+gst_multipart_find_pad_by_mime (GstMultipartDemux * demux, gchar * mime)
+{
+  GSList *walk;
+
+  walk = demux->srcpads;
+  while (walk) {
+    GstMultipartPad *pad = (GstMultipartPad *) walk->data;
+
+    if (!strcmp (pad->mime, mime)) {
+      return pad;
+    }
+
+    walk = walk->next;
+  }
+  // pad not found, create it
+  {
+    GstPad *pad;
+    GstMultipartPad *mppad;
+    gchar *name;
+    GstCaps *caps;
+
+    mppad = g_new0 (GstMultipartPad, 1);
+
+    name = g_strdup_printf ("src_%d", demux->numpads);
+    pad = gst_pad_new_from_template (gst_static_pad_template_get
+        (&multipart_demux_src_template_factory), name);
+    g_free (name);
+    caps = gst_caps_from_string (mime);
+    gst_pad_use_explicit_caps (pad);
+    gst_pad_set_explicit_caps (pad, caps);
+
+    mppad->pad = pad;
+    mppad->mime = g_strdup (mime);
+
+    demux->srcpads = g_slist_prepend (demux->srcpads, mppad);
+    demux->numpads++;
+
+    gst_element_add_pad (GST_ELEMENT (demux), pad);
+
+    return mppad;
+  }
+}
+
+static void
+gst_multipart_demux_chain (GstPad * pad, GstData * buffer)
+{
+  GstMultipartDemux *multipart;
+  gint size;
+  gchar *data;
+  gint matchpos;
+
+  /* handle events */
+  if (GST_IS_EVENT (buffer)) {
+    gst_multipart_demux_handle_event (pad, GST_EVENT (buffer));
+    return;
+  }
+
+  multipart = GST_MULTIPART_DEMUX (gst_pad_get_parent (pad));
+
+  data = GST_BUFFER_DATA (buffer);
+  size = GST_BUFFER_SIZE (buffer);
+
+  // first make sure our buffer is long enough
+  if (multipart->bufsize + size > multipart->maxlen) {
+    gint newsize = (multipart->bufsize + size) * 2;
+
+    multipart->buffer = g_realloc (multipart->buffer, newsize);
+    multipart->maxlen = newsize;
+  }
+  // copy bytes into the buffer
+  memcpy (multipart->buffer + multipart->bufsize, data, size);
+  multipart->bufsize += size;
+
+  // find \n
+  while (multipart->scanpos < multipart->bufsize) {
+    if (multipart->buffer[multipart->scanpos] == '\n') {
+
+    }
+    multipart->scanpos++;
+  }
+
+  // then scan for the boundary
+  for (matchpos = 0;
+      multipart->scanpos + toFindLen + MAX_LINE_LEN - matchpos <
+      multipart->bufsize; multipart->scanpos++) {
+    if (multipart->buffer[multipart->scanpos] == toFind[matchpos]) {
+      matchpos++;
+      if (matchpos == toFindLen) {
+        int datalen;
+        int i, start;
+        gchar *mime_type;
+
+        multipart->scanpos++;
+
+        start = multipart->scanpos;
+        // find \n
+        for (i = 0; i < MAX_LINE_LEN; i++) {
+          if (multipart->buffer[multipart->scanpos] == '\n')
+            break;
+          multipart->scanpos++;
+          matchpos++;
+        }
+        mime_type =
+            g_strndup (multipart->buffer + start, multipart->scanpos - start);
+        multipart->scanpos += 2;
+        matchpos += 3;
+
+        datalen = multipart->scanpos - matchpos;
+        if (datalen > 0 && multipart->parsing_mime) {
+          GstBuffer *outbuf;
+          GstMultipartPad *srcpad;
+
+          srcpad =
+              gst_multipart_find_pad_by_mime (multipart,
+              multipart->parsing_mime);
+          if (srcpad != NULL) {
+            outbuf = gst_buffer_new_and_alloc (datalen);
+
+            memcpy (GST_BUFFER_DATA (outbuf), multipart->buffer, datalen);
+            GST_BUFFER_TIMESTAMP (outbuf) = 0;
+            gst_pad_push (srcpad->pad, GST_DATA (outbuf));
+          }
+        }
+        // move rest downward
+        multipart->bufsize -= multipart->scanpos;
+        memcpy (multipart->buffer, multipart->buffer + multipart->scanpos,
+            multipart->bufsize);
+
+        multipart->parsing_mime = mime_type;
+        multipart->scanpos = 0;
+      }
+    } else {
+      matchpos = 0;
+    }
+  }
+
+  gst_buffer_unref (buffer);
+}
+
+static GstElementStateReturn
+gst_multipart_demux_change_state (GstElement * element)
+{
+  GstMultipartDemux *multipart;
+
+  multipart = GST_MULTIPART_DEMUX (element);
+
+  switch (GST_STATE_TRANSITION (element)) {
+    case GST_STATE_NULL_TO_READY:
+      break;
+    case GST_STATE_READY_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_PLAYING:
+      break;
+    case GST_STATE_PLAYING_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_READY:
+      break;
+    case GST_STATE_READY_TO_NULL:
+      break;
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+
+  return parent_class->change_state (element);
+}
+
+gboolean
+gst_multipart_demux_plugin_init (GstPlugin * plugin)
+{
+  GST_DEBUG_CATEGORY_INIT (gst_multipart_demux_debug,
+      "multipartdemux", 0, "multipart demuxer");
+
+  return gst_element_register (plugin, "multipartdemux", GST_RANK_PRIMARY,
+      GST_TYPE_MULTIPART_DEMUX);
+}
diff --git a/gst/multipart/multipartmux.c b/gst/multipart/multipartmux.c
new file mode 100644
index 00000000..d4d96bc6
--- /dev/null
+++ b/gst/multipart/multipartmux.c
@@ -0,0 +1,593 @@
+/* multipart muxer plugin for GStreamer
+ * Copyright (C) 2004 Wim Taymans <wim@fluendo.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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <string.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_multipart_mux_debug);
+#define GST_CAT_DEFAULT gst_multipart_mux_debug
+
+#define GST_TYPE_MULTIPART_MUX (gst_multipart_mux_get_type())
+#define GST_MULTIPART_MUX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_MULTIPART_MUX, GstMultipartMux))
+#define GST_MULTIPART_MUX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_MULTIPART_MUX, GstMultipartMux))
+#define GST_IS_MULTIPART_MUX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_MULTIPART_MUX))
+#define GST_IS_MULTIPART_MUX_CLASS(obj) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_MULTIPART_MUX))
+
+typedef struct _GstMultipartMux GstMultipartMux;
+typedef struct _GstMultipartMuxClass GstMultipartMuxClass;
+
+/* all information needed for one multipart stream */
+typedef struct
+{
+  GstPad *pad;                  /* reference for this pad is held by element we belong to */
+
+  GstBuffer *buffer;            /* the queued buffer for this pad */
+
+  gboolean eos;
+  const gchar *mimetype;
+
+  guint state;                  /* state of the pad */
+}
+GstMultipartPad;
+
+struct _GstMultipartMux
+{
+  GstElement element;
+
+  /* pad */
+  GstPad *srcpad;
+
+  /* sinkpads, a GSList of GstMultipartPads */
+  GSList *sinkpads;
+  gint numpads;
+
+  /* the pad we are currently pulling from to fill a page */
+  GstMultipartPad *pulling;
+
+  /* next timestamp for the page */
+  GstClockTime next_ts;
+
+  /* offset in stream */
+  guint64 offset;
+};
+
+typedef enum
+{
+  GST_MULTIPART_FLAG_BOS = GST_ELEMENT_FLAG_LAST,
+  GST_MULTIPART_FLAG_EOS
+}
+GstMultipartFlag;
+
+struct _GstMultipartMuxClass
+{
+  GstElementClass parent_class;
+};
+
+/* elementfactory information */
+static GstElementDetails gst_multipart_mux_details =
+GST_ELEMENT_DETAILS ("multipart muxer",
+    "Codec/Muxer",
+    "mux multipart streams",
+    "Wim Taymans <wim@fluendo.com>");
+
+/* MultipartMux signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  ARG_0,
+};
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("multipart/x-mixed-replace")
+    );
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink_%d",
+    GST_PAD_SINK,
+    GST_PAD_REQUEST,
+    GST_STATIC_CAPS_ANY         /* we can take anything, really */
+    );
+
+static void gst_multipart_mux_base_init (gpointer g_class);
+static void gst_multipart_mux_class_init (GstMultipartMuxClass * klass);
+static void gst_multipart_mux_init (GstMultipartMux * multipart_mux);
+
+static void gst_multipart_mux_loop (GstElement * element);
+static gboolean gst_multipart_mux_handle_src_event (GstPad * pad,
+    GstEvent * event);
+static GstPad *gst_multipart_mux_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * name);
+static void gst_multipart_mux_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_multipart_mux_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+static GstElementStateReturn gst_multipart_mux_change_state (GstElement *
+    element);
+
+static GstElementClass *parent_class = NULL;
+
+/*static guint gst_multipart_mux_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_multipart_mux_get_type (void)
+{
+  static GType multipart_mux_type = 0;
+
+  if (!multipart_mux_type) {
+    static const GTypeInfo multipart_mux_info = {
+      sizeof (GstMultipartMuxClass),
+      gst_multipart_mux_base_init,
+      NULL,
+      (GClassInitFunc) gst_multipart_mux_class_init,
+      NULL,
+      NULL,
+      sizeof (GstMultipartMux),
+      0,
+      (GInstanceInitFunc) gst_multipart_mux_init,
+    };
+
+    multipart_mux_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstMultipartMux",
+        &multipart_mux_info, 0);
+  }
+  return multipart_mux_type;
+}
+
+static void
+gst_multipart_mux_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_factory));
+
+  gst_element_class_set_details (element_class, &gst_multipart_mux_details);
+}
+
+static void
+gst_multipart_mux_class_init (GstMultipartMuxClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+
+  gstelement_class->request_new_pad = gst_multipart_mux_request_new_pad;
+
+  gstelement_class->change_state = gst_multipart_mux_change_state;
+
+  gstelement_class->get_property = gst_multipart_mux_get_property;
+  gstelement_class->set_property = gst_multipart_mux_set_property;
+}
+
+static const GstEventMask *
+gst_multipart_mux_get_sink_event_masks (GstPad * pad)
+{
+  static const GstEventMask gst_multipart_mux_sink_event_masks[] = {
+    {GST_EVENT_EOS, 0},
+    {0,}
+  };
+
+  return gst_multipart_mux_sink_event_masks;
+}
+
+static void
+gst_multipart_mux_init (GstMultipartMux * multipart_mux)
+{
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (multipart_mux);
+
+  multipart_mux->srcpad =
+      gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
+          "src"), "src");
+  gst_pad_set_event_function (multipart_mux->srcpad,
+      gst_multipart_mux_handle_src_event);
+  gst_element_add_pad (GST_ELEMENT (multipart_mux), multipart_mux->srcpad);
+
+  GST_FLAG_SET (GST_ELEMENT (multipart_mux), GST_ELEMENT_EVENT_AWARE);
+  GST_FLAG_SET (GST_ELEMENT (multipart_mux), GST_MULTIPART_FLAG_BOS);
+
+  multipart_mux->sinkpads = NULL;
+  multipart_mux->pulling = NULL;
+
+  gst_element_set_loop_function (GST_ELEMENT (multipart_mux),
+      gst_multipart_mux_loop);
+}
+
+static GstPadLinkReturn
+gst_multipart_mux_sinkconnect (GstPad * pad, const GstCaps * vscaps)
+{
+  GstMultipartMux *multipart_mux;
+  GstMultipartPad *mppad;
+  GstStructure *structure;
+
+  multipart_mux = GST_MULTIPART_MUX (gst_pad_get_parent (pad));
+
+  mppad = (GstMultipartPad *) gst_pad_get_element_private (pad);
+
+  GST_DEBUG ("multipart_mux: sinkconnect triggered on %s",
+      gst_pad_get_name (pad));
+
+  structure = gst_caps_get_structure (vscaps, 0);
+  mppad->mimetype = gst_structure_get_name (structure);
+
+  return GST_PAD_LINK_OK;
+}
+
+static void
+gst_multipart_mux_pad_link (GstPad * pad, GstPad * peer, gpointer data)
+{
+  //GstMultipartMux *multipart_mux = GST_MULTIPART_MUX (data);
+  const gchar *padname = gst_pad_get_name (pad);
+
+  GST_DEBUG ("pad '%s' connected", padname);
+}
+
+static void
+gst_multipart_mux_pad_unlink (GstPad * pad, GstPad * peer, gpointer data)
+{
+  //GstMultipartMux *multipart_mux = GST_MULTIPART_MUX (data);
+  const gchar *padname = gst_pad_get_name (pad);
+
+  GST_DEBUG ("pad '%s' unlinked", padname);
+}
+
+static GstPad *
+gst_multipart_mux_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * req_name)
+{
+  GstMultipartMux *multipart_mux;
+  GstPad *newpad;
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
+
+  g_return_val_if_fail (templ != NULL, NULL);
+
+  if (templ->direction != GST_PAD_SINK) {
+    g_warning ("multipart_mux: request pad that is not a SINK pad\n");
+    return NULL;
+  }
+
+  g_return_val_if_fail (GST_IS_MULTIPART_MUX (element), NULL);
+
+  multipart_mux = GST_MULTIPART_MUX (element);
+
+  if (templ == gst_element_class_get_pad_template (klass, "sink_%d")) {
+    gchar *name;
+
+    /* create new pad with the name */
+    name = g_strdup_printf ("sink_%02d", multipart_mux->numpads);
+    newpad = gst_pad_new_from_template (templ, name);
+    g_free (name);
+
+    /* construct our own wrapper data structure for the pad to
+     * keep track of its status */
+    {
+      GstMultipartPad *multipartpad = g_new0 (GstMultipartPad, 1);
+
+      multipartpad->pad = newpad;
+      multipartpad->eos = FALSE;
+
+      /* save a pointer to our data in the pad */
+      gst_pad_set_element_private (newpad, multipartpad);
+      /* store our data for the pad */
+      multipart_mux->sinkpads =
+          g_slist_prepend (multipart_mux->sinkpads, multipartpad);
+      multipart_mux->numpads++;
+    }
+  } else {
+    g_warning ("multipart_mux: this is not our template!\n");
+    return NULL;
+  }
+
+  g_signal_connect (newpad, "linked",
+      G_CALLBACK (gst_multipart_mux_pad_link), (gpointer) multipart_mux);
+  g_signal_connect (newpad, "unlinked",
+      G_CALLBACK (gst_multipart_mux_pad_unlink), (gpointer) multipart_mux);
+
+  /* setup some pad functions */
+  gst_pad_set_link_function (newpad, gst_multipart_mux_sinkconnect);
+  gst_pad_set_event_mask_function (newpad,
+      gst_multipart_mux_get_sink_event_masks);
+  /* dd the pad to the element */
+  gst_element_add_pad (element, newpad);
+
+  return newpad;
+}
+
+/* handle events */
+static gboolean
+gst_multipart_mux_handle_src_event (GstPad * pad, GstEvent * event)
+{
+  GstMultipartMux *multipart_mux;
+  GstEventType type;
+
+  multipart_mux = GST_MULTIPART_MUX (gst_pad_get_parent (pad));
+
+  type = event ? GST_EVENT_TYPE (event) : GST_EVENT_UNKNOWN;
+
+  switch (type) {
+    case GST_EVENT_SEEK:
+      /* disable seeking for now */
+      return FALSE;
+    default:
+      break;
+  }
+
+  return gst_pad_event_default (pad, event);
+}
+
+static GstBuffer *
+gst_multipart_mux_next_buffer (GstMultipartPad * pad)
+{
+  GstData *data = NULL;
+
+  while (data == NULL) {
+    GST_LOG ("muxer: pulling %s:%s\n", GST_DEBUG_PAD_NAME (pad->pad));
+    data = gst_pad_pull (pad->pad);
+    /* if it's an event, handle it */
+    if (GST_IS_EVENT (data)) {
+      GstEventType type;
+      GstMultipartMux *multipart_mux;
+      GstEvent *event = GST_EVENT (data);
+
+      multipart_mux = GST_MULTIPART_MUX (gst_pad_get_parent (pad->pad));
+      type = event ? GST_EVENT_TYPE (event) : GST_EVENT_UNKNOWN;
+
+      switch (type) {
+        case GST_EVENT_EOS:
+          return NULL;
+        default:
+          gst_pad_event_default (pad->pad, event);
+          break;
+      }
+      data = NULL;
+    }
+  }
+  return GST_BUFFER (data);
+}
+
+/*
+ * Given two pads, compare the buffers queued on it and return 0 if they have
+ * an equal priority, 1 if the new pad is better, -1 if the old pad is better 
+ */
+static gint
+gst_multipart_mux_compare_pads (GstMultipartMux * multipart_mux,
+    GstMultipartPad * old, GstMultipartPad * new)
+{
+  guint64 oldtime, newtime;
+
+  /* if the old pad doesn't contain anything or is even NULL, return 
+   * the new pad as best candidate and vice versa */
+  if (old == NULL || old->buffer == NULL)
+    return 1;
+  if (new == NULL || new->buffer == NULL)
+    return -1;
+
+  /* no timestamp on old buffer, it must go first */
+  oldtime = GST_BUFFER_TIMESTAMP (old->buffer);
+  if (oldtime == GST_CLOCK_TIME_NONE)
+    return -1;
+
+  /* no timestamp on new buffer, it must go first */
+  newtime = GST_BUFFER_TIMESTAMP (new->buffer);
+  if (newtime == GST_CLOCK_TIME_NONE)
+    return 1;
+
+  /* old buffer has higher timestamp, new one should go first */
+  if (newtime < oldtime)
+    return 1;
+  /* new buffer has higher timestamp, old one should go first */
+  else if (newtime > oldtime)
+    return -1;
+
+  /* same priority if all of the above failed */
+  return 0;
+}
+
+/* make sure a buffer is queued on all pads, returns a pointer to an multipartpad
+ * that holds the best buffer or NULL when no pad was usable */
+static GstMultipartPad *
+gst_multipart_mux_queue_pads (GstMultipartMux * multipart_mux)
+{
+  GstMultipartPad *bestpad = NULL;
+  GSList *walk;
+
+  /* try to make sure we have a buffer from each usable pad first */
+  walk = multipart_mux->sinkpads;
+  while (walk) {
+    GstMultipartPad *pad = (GstMultipartPad *) walk->data;
+
+    walk = walk->next;
+
+    /* try to get a new buffer for this pad if needed and possible */
+    if (pad->buffer == NULL && GST_PAD_IS_USABLE (pad->pad)) {
+      pad->buffer = gst_multipart_mux_next_buffer (pad);
+      /* no next buffer, try another pad */
+      if (pad->buffer == NULL)
+        continue;
+    }
+
+    /* skip unusable pads */
+    if (!GST_PAD_IS_USABLE (pad->pad))
+      continue;
+
+    /* we should have a buffer now, see if it is the best pad to
+     * pull on */
+    if (pad->buffer != NULL) {
+      if (gst_multipart_mux_compare_pads (multipart_mux, bestpad, pad) > 0) {
+        bestpad = pad;
+      }
+    }
+  }
+  return bestpad;
+}
+
+/* basic idea:
+ *
+ * 1) find a pad to pull on, this is done by pulling on all pads and
+ *    looking at the buffers to decide which one should be muxed first.
+ * 2) push buffer on best pad, go to 1
+ */
+static void
+gst_multipart_mux_loop (GstElement * element)
+{
+  GstMultipartMux *mux;
+
+  mux = GST_MULTIPART_MUX (element);
+
+  /* if we don't know which pad to pull on, find one */
+  if (mux->pulling == NULL) {
+    mux->pulling = gst_multipart_mux_queue_pads (mux);
+    /* remember timestamp of first buffer for this new pad */
+    if (mux->pulling != NULL) {
+      mux->next_ts = GST_BUFFER_TIMESTAMP (mux->pulling->buffer);
+    } else {
+      /* no pad to pull on, send EOS */
+      if (GST_PAD_IS_USABLE (mux->srcpad))
+        gst_pad_push (mux->srcpad, GST_DATA (gst_event_new (GST_EVENT_EOS)));
+      gst_element_set_eos (element);
+      return;
+    }
+  }
+
+  /* we are pulling from a pad, continue to do so until a page
+   * has been filled and pushed */
+  if (mux->pulling != NULL) {
+    GstBuffer *buf, *tmpbuf;
+    GstMultipartPad *pad = mux->pulling;
+    GstBuffer *newbuf;
+    gchar *header;
+    gint headerlen;
+
+    /* now see if we have a buffer */
+    buf = pad->buffer;
+    if (buf == NULL) {
+      /* no buffer, get one */
+      buf = gst_multipart_mux_next_buffer (pad);
+      /* data exhausted on this pad (EOS) */
+      if (buf == NULL) {
+        /* stop pulling from the pad */
+        mux->pulling = NULL;
+        return;
+      }
+    }
+
+    /* read ahead one more buffer to find EOS */
+    tmpbuf = gst_multipart_mux_next_buffer (pad);
+    /* data exhausted on this pad */
+    if (tmpbuf == NULL) {
+      /* stop pulling from the pad */
+      mux->pulling = NULL;
+    }
+
+    header = g_strdup_printf ("\n--ThisRandomString\nContent-type: %s\n\n",
+        pad->mimetype);
+    headerlen = strlen (header);
+    newbuf =
+        gst_pad_alloc_buffer (mux->srcpad, GST_BUFFER_OFFSET_NONE, headerlen);
+    GST_BUFFER_DATA (newbuf) = header;
+    GST_BUFFER_SIZE (newbuf) = headerlen;
+    GST_BUFFER_TIMESTAMP (newbuf) = GST_BUFFER_TIMESTAMP (buf);
+    gst_pad_push (mux->srcpad, GST_DATA (newbuf));
+    gst_pad_push (mux->srcpad, GST_DATA (buf));
+
+    /* store new readahead buffer */
+    pad->buffer = tmpbuf;
+
+    /* we're done pulling on this pad, make sure to choose a new 
+     * pad for pulling in the next iteration */
+    mux->pulling = NULL;
+  }
+}
+
+static void
+gst_multipart_mux_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_multipart_mux_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstElementStateReturn
+gst_multipart_mux_change_state (GstElement * element)
+{
+  GstMultipartMux *multipart_mux;
+  gint transition = GST_STATE_TRANSITION (element);
+
+  g_return_val_if_fail (GST_IS_MULTIPART_MUX (element), GST_STATE_FAILURE);
+
+  multipart_mux = GST_MULTIPART_MUX (element);
+
+  switch (transition) {
+    case GST_STATE_NULL_TO_READY:
+    case GST_STATE_READY_TO_PAUSED:
+      multipart_mux->next_ts = 0;
+      multipart_mux->offset = 0;
+      multipart_mux->pulling = NULL;
+      break;
+    case GST_STATE_PAUSED_TO_PLAYING:
+    case GST_STATE_PLAYING_TO_PAUSED:
+    case GST_STATE_PAUSED_TO_READY:
+    case GST_STATE_READY_TO_NULL:
+      break;
+  }
+
+  if (GST_ELEMENT_CLASS (parent_class)->change_state)
+    return GST_ELEMENT_CLASS (parent_class)->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}
+
+gboolean
+gst_multipart_mux_plugin_init (GstPlugin * plugin)
+{
+  GST_DEBUG_CATEGORY_INIT (gst_multipart_mux_debug, "multipartmux", 0,
+      "multipart muxer");
+
+  return gst_element_register (plugin, "multipartmux", GST_RANK_PRIMARY,
+      GST_TYPE_MULTIPART_MUX);
+}
diff --git a/gst/videobox/Makefile.am b/gst/videobox/Makefile.am
new file mode 100644
index 00000000..37da9aae
--- /dev/null
+++ b/gst/videobox/Makefile.am
@@ -0,0 +1,9 @@
+
+plugin_LTLIBRARIES = libgstvideobox.la
+
+libgstvideobox_la_SOURCES = gstvideobox.c
+libgstvideobox_la_CFLAGS = $(GST_CFLAGS)
+libgstvideobox_la_LIBADD =
+libgstvideobox_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
+noinst_HEADERS = 
diff --git a/gst/videobox/README b/gst/videobox/README
new file mode 100644
index 00000000..e71da590
--- /dev/null
+++ b/gst/videobox/README
@@ -0,0 +1,21 @@
+Videobox
+--------
+
+This plugin crops or enlarges the image. It takes 4 values as input, a
+top, bottom, left and right offset. Positive values will crop that much
+pixels from the respective border of the image, negative values will add
+that much pixels. When pixels are added, you can specify their color. 
+Some predefined colors are usable with an enum property.
+
+The plugin is alpha channel aware and will try to negotiate with a format
+that supports alpha channels first. When alpha channel is active two
+other properties, alpha and border_alpha can be used to set the alpha
+values of the inner picture and the border respectively. an alpha value of
+0.0 means total transparency, 1.0 is opaque.
+
+The videobox plugin has many uses such as doing a mosaic of pictures, 
+letterboxing video, cutting out pieces of video, picture in picture, etc..
+
+TODO
+
+- add enum to specify common aspect ratios/sizes and add borders/crop
diff --git a/gst/videobox/gstvideobox.c b/gst/videobox/gstvideobox.c
new file mode 100644
index 00000000..c1d9c3ba
--- /dev/null
+++ b/gst/videobox/gstvideobox.c
@@ -0,0 +1,734 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ *
+ * 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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+#include <string.h>
+
+#define GST_TYPE_VIDEO_BOX \
+  (gst_video_box_get_type())
+#define GST_VIDEO_BOX(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_BOX,GstVideoBox))
+#define GST_VIDEO_BOX_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_BOX,GstVideoBoxClass))
+#define GST_IS_VIDEO_BOX(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_BOX))
+#define GST_IS_VIDEO_BOX_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_BOX))
+
+typedef struct _GstVideoBox GstVideoBox;
+typedef struct _GstVideoBoxClass GstVideoBoxClass;
+
+typedef enum
+{
+  VIDEO_BOX_FILL_BLACK,
+  VIDEO_BOX_FILL_GREEN,
+  VIDEO_BOX_FILL_BLUE,
+}
+GstVideoBoxFill;
+
+struct _GstVideoBox
+{
+  GstElement element;
+
+  /* pads */
+  GstPad *sinkpad;
+  GstPad *srcpad;
+
+  /* caps */
+  gint in_width, in_height;
+  gint out_width, out_height;
+
+  gint box_left, box_right, box_top, box_bottom;
+
+  gint border_left, border_right, border_top, border_bottom;
+  gint crop_left, crop_right, crop_top, crop_bottom;
+
+  gboolean use_alpha;
+  gdouble alpha;
+  gdouble border_alpha;
+
+  GstVideoBoxFill fill_type;
+};
+
+struct _GstVideoBoxClass
+{
+  GstElementClass parent_class;
+};
+
+/* elementfactory information */
+static GstElementDetails gst_video_box_details =
+GST_ELEMENT_DETAILS ("video box filter",
+    "Filter/Effect/Video",
+    "Resizes a video by adding borders or cropping",
+    "Wim Taymans <wim@fluendo.com>");
+
+
+/* VideoBox signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+#define DEFAULT_LEFT      0
+#define DEFAULT_RIGHT     0
+#define DEFAULT_TOP       0
+#define DEFAULT_BOTTOM    0
+#define DEFAULT_FILL_TYPE VIDEO_BOX_FILL_BLACK
+#define DEFAULT_ALPHA     1.0
+#define DEFAULT_BORDER_ALPHA 1.0
+
+enum
+{
+  ARG_0,
+  ARG_LEFT,
+  ARG_RIGHT,
+  ARG_TOP,
+  ARG_BOTTOM,
+  ARG_FILL_TYPE,
+  ARG_ALPHA,
+  ARG_BORDER_ALPHA,
+  /* FILL ME */
+};
+
+static GstStaticPadTemplate gst_video_box_src_template =
+GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("{ I420, AYUV }"))
+    );
+
+static GstStaticPadTemplate gst_video_box_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS (GST_VIDEO_CAPS_YUV ("I420"))
+    );
+
+
+static void gst_video_box_base_init (gpointer g_class);
+static void gst_video_box_class_init (GstVideoBoxClass * klass);
+static void gst_video_box_init (GstVideoBox * video_box);
+
+static void gst_video_box_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_video_box_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+static GstPadLinkReturn
+gst_video_box_sink_link (GstPad * pad, const GstCaps * caps);
+static void gst_video_box_chain (GstPad * pad, GstData * _data);
+
+static GstElementStateReturn gst_video_box_change_state (GstElement * element);
+
+
+static GstElementClass *parent_class = NULL;
+
+#define GST_TYPE_VIDEO_BOX_FILL (gst_video_box_fill_get_type())
+static GType
+gst_video_box_fill_get_type (void)
+{
+  static GType video_box_fill_type = 0;
+  static GEnumValue video_box_fill[] = {
+    {VIDEO_BOX_FILL_BLACK, "0", "Black"},
+    {VIDEO_BOX_FILL_GREEN, "1", "Colorkey green"},
+    {VIDEO_BOX_FILL_BLUE, "2", "Colorkey blue"},
+    {0, NULL, NULL},
+  };
+
+  if (!video_box_fill_type) {
+    video_box_fill_type =
+        g_enum_register_static ("GstVideoBoxFill", video_box_fill);
+  }
+  return video_box_fill_type;
+}
+
+/* static guint gst_video_box_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_video_box_get_type (void)
+{
+  static GType video_box_type = 0;
+
+  if (!video_box_type) {
+    static const GTypeInfo video_box_info = {
+      sizeof (GstVideoBoxClass),
+      gst_video_box_base_init,
+      NULL,
+      (GClassInitFunc) gst_video_box_class_init,
+      NULL,
+      NULL,
+      sizeof (GstVideoBox),
+      0,
+      (GInstanceInitFunc) gst_video_box_init,
+    };
+
+    video_box_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstVideoBox",
+        &video_box_info, 0);
+  }
+  return video_box_type;
+}
+
+static void
+gst_video_box_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details (element_class, &gst_video_box_details);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_video_box_sink_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&gst_video_box_src_template));
+}
+static void
+gst_video_box_class_init (GstVideoBoxClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FILL_TYPE,
+      g_param_spec_enum ("fill", "Fill", "How to fill the borders",
+          GST_TYPE_VIDEO_BOX_FILL, DEFAULT_FILL_TYPE,
+          (GParamFlags) G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LEFT,
+      g_param_spec_int ("left", "Left", "Pixels to box at left",
+          G_MININT, G_MAXINT, DEFAULT_LEFT, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_RIGHT,
+      g_param_spec_int ("right", "Right", "Pixels to box at right",
+          G_MININT, G_MAXINT, DEFAULT_RIGHT, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_TOP,
+      g_param_spec_int ("top", "Top", "Pixels to box at top",
+          G_MININT, G_MAXINT, DEFAULT_TOP, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_BOTTOM,
+      g_param_spec_int ("bottom", "Bottom", "Pixels to box at bottom",
+          G_MININT, G_MAXINT, DEFAULT_BOTTOM, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_ALPHA,
+      g_param_spec_double ("alpha", "Alpha", "Alpha value picture",
+          0.0, 1.0, DEFAULT_ALPHA, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_BORDER_ALPHA,
+      g_param_spec_double ("border_alpha", "Border Alpha",
+          "Alpha value of the border", 0.0, 1.0, DEFAULT_BORDER_ALPHA,
+          G_PARAM_READWRITE));
+
+  gobject_class->set_property = gst_video_box_set_property;
+  gobject_class->get_property = gst_video_box_get_property;
+
+  gstelement_class->change_state = gst_video_box_change_state;
+}
+
+static void
+gst_video_box_init (GstVideoBox * video_box)
+{
+  /* create the sink and src pads */
+  video_box->sinkpad =
+      gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_video_box_sink_template), "sink");
+  gst_element_add_pad (GST_ELEMENT (video_box), video_box->sinkpad);
+  gst_pad_set_chain_function (video_box->sinkpad, gst_video_box_chain);
+  gst_pad_set_link_function (video_box->sinkpad, gst_video_box_sink_link);
+
+  video_box->srcpad =
+      gst_pad_new_from_template (gst_static_pad_template_get
+      (&gst_video_box_src_template), "src");
+  gst_element_add_pad (GST_ELEMENT (video_box), video_box->srcpad);
+
+  video_box->box_right = DEFAULT_RIGHT;
+  video_box->box_left = DEFAULT_LEFT;
+  video_box->box_top = DEFAULT_TOP;
+  video_box->box_bottom = DEFAULT_BOTTOM;
+  video_box->fill_type = DEFAULT_FILL_TYPE;
+  video_box->alpha = DEFAULT_ALPHA;
+  video_box->border_alpha = DEFAULT_BORDER_ALPHA;
+
+  GST_FLAG_SET (video_box, GST_ELEMENT_EVENT_AWARE);
+}
+
+/* do we need this function? */
+static void
+gst_video_box_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstVideoBox *video_box;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_VIDEO_BOX (object));
+
+  video_box = GST_VIDEO_BOX (object);
+
+  switch (prop_id) {
+    case ARG_LEFT:
+      video_box->box_left = g_value_get_int (value);
+      if (video_box->box_left < 0) {
+        video_box->border_left = -video_box->box_left;
+        video_box->crop_left = 0;
+      } else {
+        video_box->border_left = 0;
+        video_box->crop_left = video_box->box_left;
+      }
+      break;
+    case ARG_RIGHT:
+      video_box->box_right = g_value_get_int (value);
+      if (video_box->box_right < 0) {
+        video_box->border_right = -video_box->box_right;
+        video_box->crop_right = 0;
+      } else {
+        video_box->border_right = 0;
+        video_box->crop_right = video_box->box_right;
+      }
+      break;
+    case ARG_TOP:
+      video_box->box_top = g_value_get_int (value);
+      if (video_box->box_top < 0) {
+        video_box->border_top = -video_box->box_top;
+        video_box->crop_top = 0;
+      } else {
+        video_box->border_top = 0;
+        video_box->crop_top = video_box->box_top;
+      }
+      break;
+    case ARG_BOTTOM:
+      video_box->box_bottom = g_value_get_int (value);
+      if (video_box->box_bottom < 0) {
+        video_box->border_bottom = -video_box->box_bottom;
+        video_box->crop_bottom = 0;
+      } else {
+        video_box->border_bottom = 0;
+        video_box->crop_bottom = video_box->box_bottom;
+      }
+      break;
+    case ARG_FILL_TYPE:
+      video_box->fill_type = g_value_get_enum (value);
+      break;
+    case ARG_ALPHA:
+      video_box->alpha = g_value_get_double (value);
+      break;
+    case ARG_BORDER_ALPHA:
+      video_box->border_alpha = g_value_get_double (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+static void
+gst_video_box_get_property (GObject * object, guint prop_id, GValue * value,
+    GParamSpec * pspec)
+{
+  GstVideoBox *video_box;
+
+  /* it's not null if we got it, but it might not be ours */
+  g_return_if_fail (GST_IS_VIDEO_BOX (object));
+
+  video_box = GST_VIDEO_BOX (object);
+
+  switch (prop_id) {
+    case ARG_LEFT:
+      g_value_set_int (value, video_box->box_left);
+      break;
+    case ARG_RIGHT:
+      g_value_set_int (value, video_box->box_right);
+      break;
+    case ARG_TOP:
+      g_value_set_int (value, video_box->box_top);
+      break;
+    case ARG_BOTTOM:
+      g_value_set_int (value, video_box->box_bottom);
+      break;
+    case ARG_FILL_TYPE:
+      g_value_set_enum (value, video_box->fill_type);
+      break;
+    case ARG_ALPHA:
+      g_value_set_double (value, video_box->alpha);
+      break;
+    case ARG_BORDER_ALPHA:
+      g_value_set_double (value, video_box->border_alpha);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstPadLinkReturn
+gst_video_box_sink_link (GstPad * pad, const GstCaps * caps)
+{
+  GstVideoBox *video_box;
+  GstStructure *structure;
+  gboolean ret;
+
+  video_box = GST_VIDEO_BOX (gst_pad_get_parent (pad));
+  structure = gst_caps_get_structure (caps, 0);
+
+  ret = gst_structure_get_int (structure, "width", &video_box->in_width);
+  ret &= gst_structure_get_int (structure, "height", &video_box->in_height);
+
+  return GST_PAD_LINK_OK;
+}
+
+#define GST_VIDEO_I420_Y_OFFSET(width,height) (0)
+#define GST_VIDEO_I420_U_OFFSET(width,height) ((width)*(height))
+#define GST_VIDEO_I420_V_OFFSET(width,height) ((width)*(height) + ((width/2)*(height/2)))
+
+#define GST_VIDEO_I420_Y_ROWSTRIDE(width) (width)
+#define GST_VIDEO_I420_U_ROWSTRIDE(width) ((width)/2)
+#define GST_VIDEO_I420_V_ROWSTRIDE(width) ((width)/2)
+
+static int yuv_colors_Y[] = { 16, 150, 29 };
+static int yuv_colors_U[] = { 128, 46, 255 };
+static int yuv_colors_V[] = { 128, 21, 107 };
+
+static void
+gst_video_box_i420 (GstVideoBox * video_box, guint8 * src, guint8 * dest)
+{
+  guint8 *srcY, *srcU, *srcV;
+  guint8 *destY, *destU, *destV;
+  gint crop_width, crop_height;
+  gint out_width, out_height;
+  gint src_stride;
+  gint br, bl, bt, bb;
+  gint j;
+  gint color1, color2;
+
+  br = video_box->border_right;
+  bl = video_box->border_left;
+  bt = video_box->border_top;
+  bb = video_box->border_bottom;
+
+  out_width = video_box->out_width;
+  out_height = video_box->out_height;
+
+  destY = dest + GST_VIDEO_I420_Y_OFFSET (out_width, out_height);
+
+  srcY =
+      src + GST_VIDEO_I420_Y_OFFSET (video_box->in_width, video_box->in_height);
+  src_stride = GST_VIDEO_I420_Y_ROWSTRIDE (video_box->in_width);
+
+  crop_width =
+      video_box->in_width - (video_box->crop_left + video_box->crop_right);
+  crop_height =
+      video_box->in_height - (video_box->crop_top + video_box->crop_bottom);
+
+  srcY += src_stride * video_box->crop_top + video_box->crop_left;
+
+  color1 = yuv_colors_Y[video_box->fill_type];
+
+  /* copy Y plane first */
+  for (j = 0; j < bt; j++) {
+    memset (destY, color1, out_width);
+    destY += out_width;
+  }
+  for (j = 0; j < crop_height; j++) {
+    memset (destY, color1, bl);
+    destY += bl;
+    memcpy (destY, srcY, crop_width);
+    destY += crop_width;
+    memset (destY, color1, br);
+    destY += br;
+    srcY += src_stride;
+  }
+  for (j = 0; j < bb; j++) {
+    memset (destY, color1, out_width);
+    destY += out_width;
+  }
+
+  src_stride = GST_VIDEO_I420_U_ROWSTRIDE (video_box->in_width);
+
+  destU = dest + GST_VIDEO_I420_U_OFFSET (out_width, out_height);
+  destV = dest + GST_VIDEO_I420_V_OFFSET (out_width, out_height);
+
+  crop_width /= 2;
+  crop_height /= 2;
+  out_width /= 2;
+  out_height /= 2;
+  bb /= 2;
+  bt /= 2;
+  br /= 2;
+  bl /= 2;
+
+  srcU =
+      src + GST_VIDEO_I420_U_OFFSET (video_box->in_width, video_box->in_height);
+  srcV =
+      src + GST_VIDEO_I420_V_OFFSET (video_box->in_width, video_box->in_height);
+  srcU += src_stride * (video_box->crop_top / 2) + (video_box->crop_left / 2);
+  srcV += src_stride * (video_box->crop_top / 2) + (video_box->crop_left / 2);
+
+  color1 = yuv_colors_U[video_box->fill_type];
+  color2 = yuv_colors_V[video_box->fill_type];
+
+  for (j = 0; j < bt; j++) {
+    memset (destU, color1, out_width);
+    memset (destV, color2, out_width);
+    destU += out_width;
+    destV += out_width;
+  }
+  for (j = 0; j < crop_height; j++) {
+    memset (destU, color1, bl);
+    destU += bl;
+    /* copy U plane */
+    memcpy (destU, srcU, crop_width);
+    destU += crop_width;
+    memset (destU, color1, br);
+    destU += br;
+    srcU += src_stride;
+
+    memset (destV, color2, bl);
+    destV += bl;
+    /* copy V plane */
+    memcpy (destV, srcV, crop_width);
+    destV += crop_width;
+    memset (destV, color2, br);
+    destV += br;
+    srcV += src_stride;
+  }
+  for (j = 0; j < bb; j++) {
+    memset (destU, color1, out_width);
+    memset (destV, color2, out_width);
+    destU += out_width;
+    destV += out_width;
+  }
+}
+
+static void
+gst_video_box_ayuv (GstVideoBox * video_box, guint8 * src, guint8 * dest)
+{
+  guint8 *srcY, *srcU, *srcV;
+  gint crop_width, crop_width2, crop_height;
+  gint out_width, out_height;
+  gint src_stride, src_stride2;
+  gint br, bl, bt, bb;
+  gint colorY, colorU, colorV;
+  gint i, j;
+  guint8 b_alpha = (guint8) (video_box->border_alpha * 255);
+  guint8 i_alpha = (guint8) (video_box->alpha * 255);
+  guint32 *destp = (guint32 *) dest;
+  guint32 ayuv;
+
+  br = video_box->border_right;
+  bl = video_box->border_left;
+  bt = video_box->border_top;
+  bb = video_box->border_bottom;
+
+  out_width = video_box->out_width;
+  out_height = video_box->out_height;
+
+  src_stride = GST_VIDEO_I420_Y_ROWSTRIDE (video_box->in_width);
+  src_stride2 = src_stride / 2;
+
+  crop_width =
+      video_box->in_width - (video_box->crop_left + video_box->crop_right);
+  crop_width2 = crop_width / 2;
+  crop_height =
+      video_box->in_height - (video_box->crop_top + video_box->crop_bottom);
+
+  srcY =
+      src + GST_VIDEO_I420_Y_OFFSET (video_box->in_width, video_box->in_height);
+  srcY += src_stride * video_box->crop_top + video_box->crop_left;
+  srcU =
+      src + GST_VIDEO_I420_U_OFFSET (video_box->in_width, video_box->in_height);
+  srcU += src_stride2 * (video_box->crop_top / 2) + (video_box->crop_left / 2);
+  srcV =
+      src + GST_VIDEO_I420_V_OFFSET (video_box->in_width, video_box->in_height);
+  srcV += src_stride2 * (video_box->crop_top / 2) + (video_box->crop_left / 2);
+
+  colorY = yuv_colors_Y[video_box->fill_type];
+  colorU = yuv_colors_U[video_box->fill_type];
+  colorV = yuv_colors_V[video_box->fill_type];
+
+  ayuv =
+      GUINT32_FROM_BE ((b_alpha << 24) | (colorY << 16) | (colorU << 8) |
+      colorV);
+
+  /* top border */
+  for (i = 0; i < bt; i++) {
+    for (j = 0; j < out_width; j++) {
+      *destp++ = ayuv;
+    }
+  }
+  for (i = 0; i < crop_height; i++) {
+    /* left border */
+    for (j = 0; j < bl; j++) {
+      *destp++ = ayuv;
+    }
+    dest = (guint8 *) destp;
+    /* center */
+    for (j = 0; j < crop_width2; j++) {
+      *dest++ = i_alpha;
+      *dest++ = *srcY++;
+      *dest++ = *srcU;
+      *dest++ = *srcV;
+      *dest++ = i_alpha;
+      *dest++ = *srcY++;
+      *dest++ = *srcU++;
+      *dest++ = *srcV++;
+    }
+    if (i % 2 == 0) {
+      srcU -= crop_width2;
+      srcV -= crop_width2;
+    } else {
+      srcU += src_stride2 - crop_width2;
+      srcV += src_stride2 - crop_width2;
+    }
+    srcY += src_stride - crop_width;
+
+    destp = (guint32 *) dest;
+    /* right border */
+    for (j = 0; j < br; j++) {
+      *destp++ = ayuv;
+    }
+  }
+  /* bottom border */
+  for (i = 0; i < bb; i++) {
+    for (j = 0; j < out_width; j++) {
+      *destp++ = ayuv;
+    }
+  }
+}
+
+static void
+gst_video_box_chain (GstPad * pad, GstData * _data)
+{
+  GstBuffer *buffer;
+  GstVideoBox *video_box;
+  GstBuffer *outbuf;
+  gint new_width, new_height;
+
+  video_box = GST_VIDEO_BOX (gst_pad_get_parent (pad));
+
+  if (GST_IS_EVENT (_data)) {
+    GstEvent *event = GST_EVENT (_data);
+
+    switch (GST_EVENT_TYPE (event)) {
+      default:
+        gst_pad_event_default (pad, event);
+        break;
+    }
+    return;
+  }
+
+  buffer = GST_BUFFER (_data);
+
+  new_width =
+      video_box->in_width - (video_box->box_left + video_box->box_right);
+  new_height =
+      video_box->in_height - (video_box->box_top + video_box->box_bottom);
+
+  if (new_width != video_box->out_width ||
+      new_height != video_box->out_height ||
+      !GST_PAD_CAPS (video_box->srcpad)) {
+    GstCaps *newcaps;
+
+    newcaps = gst_caps_copy (gst_pad_get_negotiated_caps (video_box->sinkpad));
+
+    video_box->use_alpha = TRUE;
+
+    /* try AYUV first */
+    gst_caps_set_simple (newcaps,
+        "format", GST_TYPE_FOURCC, GST_STR_FOURCC ("AYUV"),
+        "width", G_TYPE_INT, new_width, "height", G_TYPE_INT, new_height, NULL);
+
+    if (GST_PAD_LINK_FAILED (gst_pad_try_set_caps (video_box->srcpad, newcaps))) {
+      video_box->use_alpha = FALSE;
+      newcaps =
+          gst_caps_copy (gst_pad_get_negotiated_caps (video_box->sinkpad));
+      gst_caps_set_simple (newcaps, "format", GST_TYPE_FOURCC,
+          GST_STR_FOURCC ("I420"), "width", G_TYPE_INT, new_width, "height",
+          G_TYPE_INT, new_height, NULL);
+
+      if (GST_PAD_LINK_FAILED (gst_pad_try_set_caps (video_box->srcpad,
+                  newcaps))) {
+        GST_ELEMENT_ERROR (video_box, CORE, NEGOTIATION, (NULL), (NULL));
+        return;
+      }
+    }
+
+    video_box->out_width = new_width;
+    video_box->out_height = new_height;
+  }
+
+  if (video_box->use_alpha) {
+    outbuf = gst_buffer_new_and_alloc (new_width * new_height * 4);
+
+    gst_video_box_ayuv (video_box,
+        GST_BUFFER_DATA (buffer), GST_BUFFER_DATA (outbuf));
+  } else {
+    outbuf = gst_buffer_new_and_alloc ((new_width * new_height * 3) / 2);
+
+    gst_video_box_i420 (video_box,
+        GST_BUFFER_DATA (buffer), GST_BUFFER_DATA (outbuf));
+  }
+  GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (buffer);
+  GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (buffer);
+
+
+  gst_buffer_unref (buffer);
+
+  gst_pad_push (video_box->srcpad, GST_DATA (outbuf));
+}
+
+static GstElementStateReturn
+gst_video_box_change_state (GstElement * element)
+{
+  GstVideoBox *video_box;
+
+  video_box = GST_VIDEO_BOX (element);
+
+  switch (GST_STATE_TRANSITION (element)) {
+    case GST_STATE_NULL_TO_READY:
+      break;
+    case GST_STATE_READY_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_PLAYING:
+      break;
+    case GST_STATE_PLAYING_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_READY:
+      break;
+    case GST_STATE_READY_TO_NULL:
+      break;
+  }
+
+  parent_class->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "videobox", GST_RANK_NONE,
+      GST_TYPE_VIDEO_BOX);
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "videobox",
+    "resizes a video by adding borders or cropping",
+    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)
diff --git a/gst/videomixer/Makefile.am b/gst/videomixer/Makefile.am
new file mode 100644
index 00000000..ab5f423a
--- /dev/null
+++ b/gst/videomixer/Makefile.am
@@ -0,0 +1,9 @@
+plugindir = $(libdir)/gstreamer-@GST_MAJORMINOR@
+
+plugin_LTLIBRARIES = libvideomixer.la
+
+libvideomixer_la_SOURCES = videomixer.c
+libvideomixer_la_CFLAGS = $(GST_CFLAGS)
+libvideomixer_la_LIBADD = 
+libvideomixer_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
diff --git a/gst/videomixer/README b/gst/videomixer/README
new file mode 100644
index 00000000..6794a481
--- /dev/null
+++ b/gst/videomixer/README
@@ -0,0 +1,27 @@
+Video Mixer
+-----------
+
+A generice video mixer, it blends the ayuv buffers from all pads onto 
+a new buffer. The new buffer has by default a checkerboard pattern but
+its color can be changed with a property.
+The mixer can mix streams with different framerates and video sizes. It
+uses the duration value of the buffer to schedule the rendering of the
+buffers. For streams with a different resoltion than the final output
+resolution one can specify the position of the top left corner where this
+image should be placed with the pad properties xpos and ypos.
+The overall alpha value of a stream can also be specified with a pad
+property.
+By default, the streams are blended in the order that the pads were 
+requested from the element. This can be overridden by changing the 
+zorder pad property of the stream, a stream with lower zorder gets
+drawn first.
+
+
+TODO
+----
+
+- really implement zorder
+- take I420 yuv as well
+- output AYUV if possible.
+- implement different blend modes, some code is already done
+- use filter caps on srcpad to decide on the final output size
diff --git a/gst/videomixer/videomixer.c b/gst/videomixer/videomixer.c
new file mode 100644
index 00000000..5211ba1a
--- /dev/null
+++ b/gst/videomixer/videomixer.c
@@ -0,0 +1,1116 @@
+/* Generic video mixer plugin
+ * Copyright (C) 2004 Wim Taymans <wim@fluendo.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., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <string.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_videomixer_debug);
+#define GST_CAT_DEFAULT gst_videomixer_debug
+
+#define GST_TYPE_VIDEO_MIXER_PAD (gst_videomixer_pad_get_type())
+#define GST_VIDEO_MIXER_PAD(obj) \
+	(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_MIXER_PAD, GstVideoMixerPad))
+#define GST_VIDEO_MIXER_PAD_CLASS(klass) \
+	(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_MIXER_PAD, GstVideoMixerPadiClass))
+#define GST_IS_VIDEO_MIXER_PAD(obj) \
+	(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_MIXER_PAD))
+#define GST_IS_VIDEO_MIXER_PAD_CLASS(obj) \
+	(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_MIXER_PAD))
+
+typedef struct _GstVideoMixerPad GstVideoMixerPad;
+typedef struct _GstVideoMixerPadClass GstVideoMixerPadClass;
+
+static void gst_videomixer_pad_base_init (gpointer g_class);
+static void gst_videomixer_pad_class_init (GstVideoMixerPadClass * klass);
+static void gst_videomixer_pad_init (GstVideoMixerPad * mixerpad);
+
+static void gst_videomixer_pad_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+static void gst_videomixer_pad_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+
+#define DEFAULT_PAD_ZORDER 0
+#define DEFAULT_PAD_XPOS   0
+#define DEFAULT_PAD_YPOS   0
+#define DEFAULT_PAD_ALPHA  1.0
+enum
+{
+  ARG_PAD_0,
+  ARG_PAD_ZORDER,
+  ARG_PAD_XPOS,
+  ARG_PAD_YPOS,
+  ARG_PAD_ALPHA,
+};
+
+/* all information needed for one video stream */
+struct _GstVideoMixerPad
+{
+  GstRealPad parent;            /* subclass the pad */
+
+  GstBuffer *buffer;            /* the queued buffer for this pad */
+  gboolean eos;
+
+  gint64 queued;
+
+  guint in_width, in_height;
+  gdouble in_framerate;
+
+  gint xpos, ypos;
+  guint zorder;
+  gint blend_mode;
+  gdouble alpha;
+};
+
+struct _GstVideoMixerPadClass
+{
+  GstRealPadClass parent_class;
+};
+
+GType
+gst_videomixer_pad_get_type (void)
+{
+  static GType videomixer_pad_type = 0;
+
+  if (!videomixer_pad_type) {
+    static const GTypeInfo videomixer_pad_info = {
+      sizeof (GstVideoMixerPadClass),
+      gst_videomixer_pad_base_init,
+      NULL,
+      (GClassInitFunc) gst_videomixer_pad_class_init,
+      NULL,
+      NULL,
+      sizeof (GstVideoMixerPad),
+      0,
+      (GInstanceInitFunc) gst_videomixer_pad_init,
+    };
+
+    videomixer_pad_type =
+        g_type_register_static (GST_TYPE_REAL_PAD,
+        "GstVideoMixerPad", &videomixer_pad_info, 0);
+  }
+  return videomixer_pad_type;
+}
+
+static void
+gst_videomixer_pad_base_init (gpointer g_class)
+{
+}
+
+static void
+gst_videomixer_pad_class_init (GstVideoMixerPadClass * klass)
+{
+  GObjectClass *gobject_class;
+
+  gobject_class = (GObjectClass *) klass;
+
+  gobject_class->set_property =
+      GST_DEBUG_FUNCPTR (gst_videomixer_pad_set_property);
+  gobject_class->get_property =
+      GST_DEBUG_FUNCPTR (gst_videomixer_pad_get_property);
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PAD_ZORDER,
+      g_param_spec_uint ("zorder", "Z-Order", "Z Order of the picture",
+          0, 10000, DEFAULT_PAD_ZORDER, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PAD_XPOS,
+      g_param_spec_int ("xpos", "X Position", "X Position of the picture",
+          G_MININT, G_MAXINT, DEFAULT_PAD_XPOS, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PAD_YPOS,
+      g_param_spec_int ("ypos", "Y Position", "Y Position of the picture",
+          G_MININT, G_MAXINT, DEFAULT_PAD_YPOS, G_PARAM_READWRITE));
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_PAD_ALPHA,
+      g_param_spec_double ("alpha", "Alpha", "Alpha of the picture",
+          0.0, 1.0, DEFAULT_PAD_ALPHA, G_PARAM_READWRITE));
+}
+
+static const GstEventMask *
+gst_videomixer_pad_get_sink_event_masks (GstPad * pad)
+{
+  static const GstEventMask gst_videomixer_sink_event_masks[] = {
+    {GST_EVENT_EOS, 0},
+    {0,}
+  };
+
+  return gst_videomixer_sink_event_masks;
+}
+
+static void
+gst_videomixer_pad_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstVideoMixerPad *pad;
+
+  g_return_if_fail (GST_IS_VIDEO_MIXER_PAD (object));
+
+  pad = GST_VIDEO_MIXER_PAD (object);
+
+  switch (prop_id) {
+    case ARG_PAD_ZORDER:
+      g_value_set_uint (value, pad->zorder);
+      break;
+    case ARG_PAD_XPOS:
+      g_value_set_int (value, pad->xpos);
+      break;
+    case ARG_PAD_YPOS:
+      g_value_set_int (value, pad->ypos);
+      break;
+    case ARG_PAD_ALPHA:
+      g_value_set_double (value, pad->alpha);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_videomixer_pad_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstVideoMixerPad *pad;
+
+  g_return_if_fail (GST_IS_PAD (object));
+
+  pad = GST_VIDEO_MIXER_PAD (object);
+
+  switch (prop_id) {
+    case ARG_PAD_ZORDER:
+      pad->zorder = g_value_get_uint (value);
+      break;
+    case ARG_PAD_XPOS:
+      pad->xpos = g_value_get_int (value);
+      break;
+    case ARG_PAD_YPOS:
+      pad->ypos = g_value_get_int (value);
+      break;
+    case ARG_PAD_ALPHA:
+      pad->alpha = g_value_get_double (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+#define GST_TYPE_VIDEO_MIXER (gst_videomixer_get_type())
+#define GST_VIDEO_MIXER(obj) \
+	(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_VIDEO_MIXER, GstVideoMixer))
+#define GST_VIDEO_MIXER_CLASS(klass) \
+	(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_VIDEO_MIXER, GstVideoMixerClass))
+#define GST_IS_VIDEO_MIXER(obj) \
+	(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_VIDEO_MIXER))
+#define GST_IS_VIDEO_MIXER_CLASS(obj) \
+	(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_VIDEO_MIXER))
+
+typedef struct _GstVideoMixer GstVideoMixer;
+typedef struct _GstVideoMixerClass GstVideoMixerClass;
+
+GType gst_videomixer_get_type (void);
+
+typedef enum
+{
+  VIDEO_MIXER_BACKGROUND_CHECKER,
+  VIDEO_MIXER_BACKGROUND_BLACK,
+  VIDEO_MIXER_BACKGROUND_WHITE,
+}
+GstVideoMixerBackground;
+
+struct _GstVideoMixer
+{
+  GstElement element;
+
+  /* pad */
+  GstPad *srcpad;
+
+  /* sinkpads, a GSList of GstVideoMixerPads */
+  GSList *sinkpads;
+  gint numpads;
+
+  /* the master pad */
+  GstVideoMixerPad *master;
+
+  gint in_width, in_height;
+  gint out_width, out_height;
+
+  GstVideoMixerBackground background;
+
+  gdouble in_framerate;
+};
+
+struct _GstVideoMixerClass
+{
+  GstElementClass parent_class;
+};
+
+static GstPadLinkReturn
+gst_videomixer_pad_sinkconnect (GstPad * pad, const GstCaps * vscaps)
+{
+  GstVideoMixer *mix;
+  GstVideoMixerPad *mixpad;
+  GstStructure *structure;
+
+  mix = GST_VIDEO_MIXER (gst_pad_get_parent (pad));
+  mixpad = GST_VIDEO_MIXER_PAD (pad);
+
+  GST_DEBUG ("videomixer: sinkconnect triggered on %s", gst_pad_get_name (pad));
+
+  structure = gst_caps_get_structure (vscaps, 0);
+
+  gst_structure_get_int (structure, "width", &mixpad->in_width);
+  gst_structure_get_int (structure, "height", &mixpad->in_height);
+  gst_structure_get_double (structure, "framerate", &mixpad->in_framerate);
+
+  mixpad->xpos = 0;
+  mixpad->ypos = 0;
+
+  mix->in_width = MAX (mix->in_width, mixpad->in_width);
+  mix->in_height = MAX (mix->in_height, mixpad->in_height);
+  mix->in_framerate = mixpad->in_framerate;
+
+  return GST_PAD_LINK_OK;
+}
+
+static void
+gst_videomixer_pad_link (GstPad * pad, GstPad * peer, gpointer data)
+{
+  //GstVideoMixer *videomixer = GST_VIDEO_MIXER (data);
+  const gchar *padname = gst_pad_get_name (pad);
+
+  GST_DEBUG ("pad '%s' connected", padname);
+}
+
+static void
+gst_videomixer_pad_unlink (GstPad * pad, GstPad * peer, gpointer data)
+{
+  //GstVideoMixer *videomixer = GST_VIDEO_MIXER (data);
+  const gchar *padname = gst_pad_get_name (pad);
+
+  GST_DEBUG ("pad '%s' unlinked", padname);
+}
+
+static void
+gst_videomixer_pad_init (GstVideoMixerPad * mixerpad)
+{
+  g_signal_connect (mixerpad, "linked",
+      G_CALLBACK (gst_videomixer_pad_link), (gpointer) mixerpad);
+  g_signal_connect (mixerpad, "unlinked",
+      G_CALLBACK (gst_videomixer_pad_unlink), (gpointer) mixerpad);
+
+  /* setup some pad functions */
+  gst_pad_set_link_function (GST_PAD (mixerpad),
+      gst_videomixer_pad_sinkconnect);
+  gst_pad_set_event_mask_function (GST_PAD (mixerpad),
+      gst_videomixer_pad_get_sink_event_masks);
+
+  mixerpad->zorder = DEFAULT_PAD_ZORDER;
+  mixerpad->xpos = DEFAULT_PAD_XPOS;
+  mixerpad->ypos = DEFAULT_PAD_YPOS;
+  mixerpad->alpha = DEFAULT_PAD_ALPHA;
+}
+
+
+
+/* elementfactory information */
+static GstElementDetails gst_videomixer_details =
+GST_ELEMENT_DETAILS ("video mixer",
+    "Filter/Editor/Video",
+    "Mix multiple video streams",
+    "Wim Taymans <wim@fluendo.com>");
+
+/* VideoMixer signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+#define DEFAULT_BACKGROUND VIDEO_MIXER_BACKGROUND_CHECKER
+enum
+{
+  ARG_0,
+  ARG_BACKGROUND,
+};
+
+#define GST_TYPE_VIDEO_MIXER_BACKGROUND (gst_video_mixer_background_get_type())
+static GType
+gst_video_mixer_background_get_type (void)
+{
+  static GType video_mixer_background_type = 0;
+  static GEnumValue video_mixer_background[] = {
+    {VIDEO_MIXER_BACKGROUND_CHECKER, "0", "Checker pattern"},
+    {VIDEO_MIXER_BACKGROUND_BLACK, "1", "Black"},
+    {VIDEO_MIXER_BACKGROUND_WHITE, "2", "White"},
+    {0, NULL, NULL},
+  };
+
+  if (!video_mixer_background_type) {
+    video_mixer_background_type =
+        g_enum_register_static ("GstVideoMixerBackground",
+        video_mixer_background);
+  }
+  return video_mixer_background_type;
+}
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("video/x-raw-yuv,"
+        "format = (fourcc) I420,"
+        "width = (int) [ 16, 4096 ],"
+        "height = (int) [ 16, 4096 ]," "framerate = (double) [ 0, max ]")
+    );
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink_%d",
+    GST_PAD_SINK,
+    GST_PAD_REQUEST,
+    GST_STATIC_CAPS ("video/x-raw-yuv,"
+        "format = (fourcc) AYUV,"
+        "width = (int) [ 16, 4096 ],"
+        "height = (int) [ 16, 4096 ]," "framerate = (double) [ 0, max ]")
+    );
+
+static void gst_videomixer_base_init (gpointer g_class);
+static void gst_videomixer_class_init (GstVideoMixerClass * klass);
+static void gst_videomixer_init (GstVideoMixer * videomixer);
+
+static void gst_videomixer_loop (GstElement * element);
+static gboolean gst_videomixer_handle_src_event (GstPad * pad,
+    GstEvent * event);
+static GstPad *gst_videomixer_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * name);
+static void gst_videomixer_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_videomixer_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+static GstElementStateReturn gst_videomixer_change_state (GstElement * element);
+
+static GstElementClass *parent_class = NULL;
+
+/*static guint gst_videomixer_signals[LAST_SIGNAL] = { 0 }; */
+
+GType
+gst_videomixer_get_type (void)
+{
+  static GType videomixer_type = 0;
+
+  if (!videomixer_type) {
+    static const GTypeInfo videomixer_info = {
+      sizeof (GstVideoMixerClass),
+      gst_videomixer_base_init,
+      NULL,
+      (GClassInitFunc) gst_videomixer_class_init,
+      NULL,
+      NULL,
+      sizeof (GstVideoMixer),
+      0,
+      (GInstanceInitFunc) gst_videomixer_init,
+    };
+
+    videomixer_type =
+        g_type_register_static (GST_TYPE_ELEMENT, "GstVideoMixer",
+        &videomixer_info, 0);
+  }
+  return videomixer_type;
+}
+
+static void
+gst_videomixer_base_init (gpointer g_class)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_factory));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_factory));
+
+  gst_element_class_set_details (element_class, &gst_videomixer_details);
+}
+
+static void
+gst_videomixer_class_init (GstVideoMixerClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstElementClass *gstelement_class;
+
+  gobject_class = (GObjectClass *) klass;
+  gstelement_class = (GstElementClass *) klass;
+
+  parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
+
+  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_BACKGROUND,
+      g_param_spec_enum ("background", "Background", "Background type",
+          GST_TYPE_VIDEO_MIXER_BACKGROUND,
+          DEFAULT_BACKGROUND, G_PARAM_READWRITE));
+
+  gstelement_class->request_new_pad = gst_videomixer_request_new_pad;
+
+  gstelement_class->change_state = gst_videomixer_change_state;
+
+  gstelement_class->get_property = gst_videomixer_get_property;
+  gstelement_class->set_property = gst_videomixer_set_property;
+}
+
+static void
+gst_videomixer_init (GstVideoMixer * mix)
+{
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (mix);
+
+  mix->srcpad =
+      gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
+          "src"), "src");
+  gst_pad_set_event_function (mix->srcpad, gst_videomixer_handle_src_event);
+  gst_element_add_pad (GST_ELEMENT (mix), mix->srcpad);
+
+  GST_FLAG_SET (GST_ELEMENT (mix), GST_ELEMENT_EVENT_AWARE);
+
+  mix->sinkpads = NULL;
+  mix->background = DEFAULT_BACKGROUND;
+  mix->in_width = 0;
+  mix->in_height = 0;
+  mix->out_width = 0;
+  mix->out_height = 0;
+
+  gst_element_set_loop_function (GST_ELEMENT (mix), gst_videomixer_loop);
+}
+
+static GstPad *
+gst_videomixer_request_new_pad (GstElement * element,
+    GstPadTemplate * templ, const gchar * req_name)
+{
+  GstVideoMixer *mix;
+  GstPad *newpad;
+  GstElementClass *klass = GST_ELEMENT_GET_CLASS (element);
+
+  g_return_val_if_fail (templ != NULL, NULL);
+
+  if (templ->direction != GST_PAD_SINK) {
+    g_warning ("videomixer: request pad that is not a SINK pad\n");
+    return NULL;
+  }
+
+  g_return_val_if_fail (GST_IS_VIDEO_MIXER (element), NULL);
+
+  mix = GST_VIDEO_MIXER (element);
+
+  if (templ == gst_element_class_get_pad_template (klass, "sink_%d")) {
+    gchar *name;
+    GstVideoMixerPad *mixpad;
+
+    /* create new pad with the name */
+    name = g_strdup_printf ("sink_%02d", mix->numpads);
+    newpad =
+        gst_pad_custom_new_from_template (GST_TYPE_VIDEO_MIXER_PAD, templ,
+        name);
+    g_free (name);
+
+    mixpad = GST_VIDEO_MIXER_PAD (newpad);
+
+    mixpad->zorder = mix->numpads;
+    mix->numpads++;
+    if (mix->numpads == 1) {
+      mix->master = mixpad;
+    }
+    mix->sinkpads = g_slist_append (mix->sinkpads, newpad);
+  } else {
+    g_warning ("videomixer: this is not our template!\n");
+    return NULL;
+  }
+
+  /* dd the pad to the element */
+  gst_element_add_pad (element, newpad);
+
+  return newpad;
+}
+
+/* handle events */
+static gboolean
+gst_videomixer_handle_src_event (GstPad * pad, GstEvent * event)
+{
+  GstVideoMixer *mix;
+  GstEventType type;
+
+  mix = GST_VIDEO_MIXER (gst_pad_get_parent (pad));
+
+  type = event ? GST_EVENT_TYPE (event) : GST_EVENT_UNKNOWN;
+
+  switch (type) {
+    case GST_EVENT_SEEK:
+      /* disable seeking for now */
+      return FALSE;
+    default:
+      break;
+  }
+
+  return gst_pad_event_default (pad, event);
+}
+
+#define BLEND_NORMAL(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	Y = ((Y1*(255-alpha))+(Y2*alpha))>>8;		\
+	U = ((U1*(255-alpha))+(U2*alpha))>>8;		\
+	V = ((V1*(255-alpha))+(V2*alpha))>>8;
+
+#define BLEND_ADD(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  		\
+	Y = Y1+((Y2*alpha)>>8);					\
+	U = U1+(((127*(255-alpha)+(U2*alpha)))>>8)-127;		\
+	V = V1+(((127*(255-alpha)+(V2*alpha)))>>8)-127;		\
+        if (Y>255) {						\
+	  gint mult = MAX (0, 288-Y);				\
+	  U = ((U*mult) + (127*(32-mult)))>>5;			\
+	  V = ((V*mult) + (127*(32-mult)))>>5;			\
+	  Y = 255;						\
+	}							\
+	U = MIN (U,255)						\
+	V = MIN (V,255)
+
+#define BLEND_SUBTRACT(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  		\
+	Y = Y1-((Y2*alpha)>>8);					\
+	U = U1+(((127*(255-alpha)+(U2*alpha)))>>8)-127;		\
+	V = V1+(((127*(255-alpha)+(V2*alpha)))>>8)-127;		\
+        if (Y<0) {						\
+	  gint mult = MIN (32, -Y);				\
+	  U = ((U*(32-mult)) + (127*mult))>>5;			\
+	  V = ((V*(32-mult)) + (127*mult))>>5;			\
+	  Y = 0;						\
+	}
+
+#define BLEND_DARKEN(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	if (Y1 < Y2) {					\
+	  Y = Y1; U = U1; V = V1;			\
+	}						\
+	else {						\
+	  Y = ((Y1*(255-alpha))+(Y2*alpha))>>8;		\
+	  U = ((U1*(255-alpha))+(U2*alpha))>>8;		\
+	  V = ((V1*(255-alpha))+(V2*alpha))>>8;		\
+	}
+
+#define BLEND_LIGHTEN(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	if (Y1 > Y2) {					\
+	  Y = Y1; U = U1; V = V1;			\
+	}						\
+	else {						\
+	  Y = ((Y1*(255-alpha))+(Y2*alpha))>>8;		\
+	  U = ((U1*(255-alpha))+(U2*alpha))>>8;		\
+	  V = ((V1*(255-alpha))+(V2*alpha))>>8;		\
+	}
+
+#define BLEND_MULTIPLY(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  			\
+	Y = (Y1*(256*(255-alpha) +(Y2*alpha)))>>16;			\
+	U = ((U1*(255-alpha)*256)+(alpha*(U1*Y2+128*(256-Y2))))>>16;	\
+	V = ((V1*(255-alpha)*256)+(alpha*(V1*Y2+128*(256-Y2))))>>16;
+
+#define BLEND_DIFFERENCE(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	Y = ABS((gint)Y1-(gint)Y2)+127;				\
+	U = ABS((gint)U1-(gint)U2)+127;				\
+	V = ABS((gint)V1-(gint)V2)+127;				\
+	Y = ((Y*alpha)+(Y1*(255-alpha)))>>8;			\
+	U = ((U*alpha)+(U1*(255-alpha)))>>8;			\
+	V = ((V*alpha)+(V1*(255-alpha)))>>8;			\
+        if (Y>255) {						\
+	  gint mult = MAX (0, 288-Y);				\
+	  U = ((U*mult) + (127*(32-mult)))>>5;			\
+	  V = ((V*mult) + (127*(32-mult)))>>5;			\
+	  Y = 255;						\
+	} else if (Y<0) {					\
+	  gint mult = MIN (32, -Y);				\
+	  U = ((U*(32-mult)) + (127*mult))>>5;			\
+	  V = ((V*(32-mult)) + (127*mult))>>5;			\
+	  Y = 0;						\
+	}							\
+        U = CLAMP(U, 0, 255);					\
+        V = CLAMP(V, 0, 255);
+
+#define BLEND_EXCLUSION(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	Y = ((gint)(Y1^0xff)*Y2+(gint)(Y2^0xff)*Y1)>>8;		\
+	U = ((gint)(U1^0xff)*Y2+(gint)(Y2^0xff)*U1)>>8;		\
+	V = ((gint)(V1^0xff)*Y2+(gint)(Y2^0xff)*V1)>>8;		\
+	Y = ((Y*alpha)+(Y1*(255-alpha)))>>8;			\
+	U = ((U*alpha)+(U1*(255-alpha)))>>8;			\
+	V = ((V*alpha)+(V1*(255-alpha)))>>8;			\
+        if (Y>255) {						\
+	  gint mult = MAX (0, 288-Y);				\
+	  U = ((U*mult) + (127*(32-mult)))>>5;			\
+	  V = ((V*mult) + (127*(32-mult)))>>5;			\
+	  Y = 255;						\
+	} else if (Y<0) {					\
+	  gint mult = MIN (32, -Y);				\
+	  U = ((U*(32-mult)) + (127*mult))>>5;			\
+	  V = ((V*(32-mult)) + (127*mult))>>5;			\
+	  Y = 0;						\
+	}							\
+        U = CLAMP(U, 0, 255);					\
+        V = CLAMP(V, 0, 255);
+
+#define BLEND_SOFTLIGHT(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	Y = (gint)Y1+(gint)Y2 - 127;				\
+	U = (gint)U1+(gint)U2 - 127;				\
+	V = (gint)V1+(gint)V2 - 127;				\
+	Y = ((Y*alpha)+(Y1*(255-alpha)))>>8;			\
+	U = ((U*alpha)+(U1*(255-alpha)))>>8;			\
+	V = ((V*alpha)+(V1*(255-alpha)))>>8;			\
+        if (Y>255) {						\
+	  gint mult = MAX (0, 288-Y);				\
+	  U = ((U*mult) + (127*(32-mult)))>>5;			\
+	  V = ((V*mult) + (127*(32-mult)))>>5;			\
+	  Y = 255;						\
+	} else if (Y<0) {					\
+	  gint mult = MIN (32, -Y);				\
+	  U = ((U*(32-mult)) + (127*mult))>>5;			\
+	  V = ((V*(32-mult)) + (127*mult))>>5;			\
+	  Y = 0;						\
+	}							\
+
+#define BLEND_HARDLIGHT(Y1,U1,V1,Y2,U2,V2,alpha,Y,U,V)  	\
+	Y = (gint)Y1+(gint)Y2*2 - 255;				\
+	U = (gint)U1+(gint)U2 - 127;				\
+	V = (gint)V1+(gint)V2 - 127;				\
+	Y = ((Y*alpha)+(Y1*(255-alpha)))>>8;			\
+	U = ((U*alpha)+(U1*(255-alpha)))>>8;			\
+	V = ((V*alpha)+(V1*(255-alpha)))>>8;			\
+        if (Y>255) {						\
+	  gint mult = MAX (0, 288-Y);				\
+	  U = ((U*mult) + (127*(32-mult)))>>5;			\
+	  V = ((V*mult) + (127*(32-mult)))>>5;			\
+	  Y = 255;						\
+	} else if (Y<0) {					\
+	  gint mult = MIN (32, -Y);				\
+	  U = ((U*(32-mult)) + (127*mult))>>5;			\
+	  V = ((V*(32-mult)) + (127*mult))>>5;			\
+	  Y = 0;						\
+	}							\
+
+#define BLEND_MODE BLEND_NORMAL
+#if 0
+#define BLEND_MODE BLEND_ADD
+#define BLEND_MODE BLEND_SUBTRACT
+#define BLEND_MODE BLEND_DARKEN
+#define BLEND_MODE BLEND_LIGHTEN
+#define BLEND_MODE BLEND_MULTIPLY
+#define BLEND_MODE BLEND_DIFFERENCE
+#define BLEND_MODE BLEND_EXCLUSION
+#define BLEND_MODE BLEND_SOFTLIGHT
+#define BLEND_MODE BLEND_HARDLIGHT
+#endif
+
+/* note that this function does packing conversion and blending at the
+ * same time */
+static void
+gst_videomixer_blend_ayuv_i420 (guint8 * src, gint xpos, gint ypos,
+    gint src_width, gint src_height, gdouble src_alpha,
+    guint8 * dest, gint dest_width, gint dest_height)
+{
+  gint dest_size;
+  gint alpha, b_alpha;
+  guint8 *destY1, *destY2, *destU, *destV;
+  gint accumU;
+  gint accumV;
+  gint i, j;
+  gint src_stride;
+  gint src_add, destY_add, destC_add;
+  guint8 *src1, *src2;
+  gint Y, U, V;
+
+  src_stride = src_width * 4;
+  dest_size = dest_width * dest_height;
+
+  b_alpha = (gint) (src_alpha * 255);
+
+  /* adjust src pointers for negative sizes */
+  if (xpos < 0) {
+    src += -xpos * 4;
+    src_width -= -xpos;
+    xpos = 0;
+  }
+  if (ypos < 0) {
+    src += -ypos * src_stride;
+    src_height -= -ypos;
+    ypos = 0;
+  }
+  /* adjust width/height if the src is bigger than dest */
+  if (xpos + src_width > dest_width) {
+    src_width = dest_width - xpos;
+  }
+  if (ypos + src_height > dest_height) {
+    src_height = dest_height - ypos;
+  }
+
+  src_add = 2 * src_stride - (4 * src_width);
+  destY_add = 2 * dest_width - (src_width);
+  destC_add = dest_width / 2 - (src_width / 2);
+
+  destY1 = dest + xpos + (ypos * dest_width);
+  destY2 = destY1 + dest_width;
+  destU = dest + dest_size + xpos / 2 + (ypos / 2 * dest_width / 2);
+  destV = destU + dest_size / 4;
+
+  src1 = src;
+  src2 = src + src_stride;
+
+  /* we convert a square of 2x2 samples to generate 4 Luma and 2 chroma samples */
+  for (i = 0; i < src_height / 2; i++) {
+    for (j = 0; j < src_width / 2; j++) {
+      alpha = (src1[0] * b_alpha) >> 8;
+      BLEND_MODE (destY1[0], destU[0], destV[0], src1[1], src1[2], src1[3],
+          alpha, Y, U, V);
+      destY1[0] = Y;
+      accumU = U;
+      accumV = V;
+      alpha = (src1[4] * b_alpha) >> 8;
+      BLEND_MODE (destY1[1], destU[0], destV[0], src1[5], src1[6], src1[7],
+          alpha, Y, U, V);
+      destY1[1] = Y;
+      accumU += U;
+      accumV += V;
+      alpha = (src2[0] * b_alpha) >> 8;
+      BLEND_MODE (destY2[0], destU[0], destV[0], src2[1], src2[2], src2[3],
+          alpha, Y, U, V);
+      destY2[0] = Y;
+      accumU += U;
+      accumV += V;
+      alpha = (src2[4] * b_alpha) >> 8;
+      BLEND_MODE (destY2[1], destU[0], destV[0], src2[5], src2[6], src2[7],
+          alpha, Y, U, V);
+      destY2[1] = Y;
+      accumU += U;
+      accumV += V;
+
+      /* take the average of the 4 chroma samples to get the final value */
+      destU[0] = accumU / 4;
+      destV[0] = accumV / 4;
+
+      src1 += 8;
+      src2 += 8;
+      destY1 += 2;
+      destY2 += 2;
+      destU += 1;
+      destV += 1;
+    }
+    src1 += src_add;
+    src2 += src_add;
+    destY1 += destY_add;
+    destY2 += destY_add;
+    destU += destC_add;
+    destV += destC_add;
+  }
+}
+
+#undef BLEND_MODE
+
+/* fill a buffer with a checkerboard pattern */
+static void
+gst_videomixer_fill_checker (guint8 * dest, gint width, gint height)
+{
+  gint size = width * height;
+  gint i, j;
+  static int tab[] = { 80, 160, 80, 160 };
+
+  for (i = 0; i < height; i++) {
+    for (j = 0; j < width; j++) {
+      *dest++ = tab[((i & 0x8) >> 3) + ((j & 0x8) >> 3)];
+    }
+  }
+  memset (dest, 128, size / 2);
+}
+
+static void
+gst_videomixer_fill_color (guint8 * dest, gint width, gint height,
+    gint colY, gint colU, gint colV)
+{
+  gint size = width * height;
+
+  memset (dest, colY, size);
+  memset (dest + size, colU, size / 4);
+  memset (dest + size + size / 4, colV, size / 4);
+}
+
+/* try to get a buffer on all pads. As long as the queued value is
+ * negative, we skip buffers */
+static gboolean
+gst_videomixer_fill_queues (GstVideoMixer * mix)
+{
+  GSList *walk;
+  gboolean eos = TRUE;
+
+  /* loop over all pads and fill it with a buffer */
+  walk = mix->sinkpads;
+  while (walk) {
+    GstVideoMixerPad *pad = GST_VIDEO_MIXER_PAD (walk->data);
+
+    walk = g_slist_next (walk);
+
+    GST_DEBUG ("looking at pad %s", gst_pad_get_name (GST_PAD (pad)));
+
+    /* don't care about eos pads */
+    if (pad->eos) {
+      GST_DEBUG ("pad %s in eos, skipping", gst_pad_get_name (GST_PAD (pad)));
+      continue;
+    }
+
+    GST_DEBUG ("pad %s: buffer %p, queued %lld  ",
+        gst_pad_get_name (GST_PAD (pad)), pad->buffer, pad->queued);
+
+    /* this pad is in need of a new buffer */
+    if (pad->buffer == NULL) {
+      GstData *data;
+      GstBuffer *buffer;
+
+      /* as long as not enough buffers have been queued */
+      while (pad->queued <= 0 && !pad->eos) {
+        data = gst_pad_pull (GST_PAD (pad));
+        if (GST_IS_EVENT (data)) {
+          GstEvent *event = GST_EVENT (data);
+
+          switch (GST_EVENT_TYPE (event)) {
+            case GST_EVENT_EOS:
+              GST_DEBUG ("videomixer: EOS on pad %s",
+                  gst_pad_get_name (GST_PAD (pad)));
+              /* mark pad eos */
+              pad->eos = TRUE;
+              gst_event_unref (event);
+              break;
+            default:
+              gst_pad_event_default (GST_PAD (pad), GST_EVENT (data));
+          }
+        } else {
+          guint64 duration;
+
+          buffer = GST_BUFFER (data);
+          duration = GST_BUFFER_DURATION (buffer);
+          /* no duration on the buffer, use the framerate */
+          if (duration == -1)
+            duration = GST_SECOND / pad->in_framerate;
+          pad->queued += duration;
+          /* this buffer will need to be mixed */
+          if (pad->queued > 0) {
+            pad->buffer = buffer;
+          } else {
+            /* skip buffer, it's too old */
+            gst_buffer_unref (buffer);
+          }
+        }
+        GST_DEBUG ("pad %s: in loop, buffer %p, queued %lld  ",
+            gst_pad_get_name (GST_PAD (pad)), pad->buffer, pad->queued);
+      }
+    }
+    if (pad->buffer != NULL) {
+      /* got a buffer somewhere so were not eos */
+      eos = FALSE;
+    }
+  }
+  return eos;
+}
+
+/* blend all buffers present on the pads */
+static void
+gst_videomixer_blend_buffers (GstVideoMixer * mix, GstBuffer * outbuf)
+{
+  GSList *walk;
+
+  walk = mix->sinkpads;
+  while (walk) {
+    GstVideoMixerPad *pad = GST_VIDEO_MIXER_PAD (walk->data);
+
+    walk = g_slist_next (walk);
+
+    if (pad->buffer != NULL) {
+      gst_videomixer_blend_ayuv_i420 (GST_BUFFER_DATA (pad->buffer),
+          pad->xpos, pad->ypos,
+          pad->in_width, pad->in_height,
+          pad->alpha,
+          GST_BUFFER_DATA (outbuf), mix->out_width, mix->out_height);
+    }
+  }
+}
+
+/* remove buffers from the queue that were expired in the
+ * interval of the master, we also prepare the queued value
+ * in the pad so that we can skip and fill buffers later on */
+static void
+gst_videomixer_update_queues (GstVideoMixer * mix)
+{
+  GSList *walk;
+  guint64 interval;
+
+  interval = mix->master->queued;
+  if (interval <= 0) {
+    interval = GST_SECOND / mix->in_framerate;
+  }
+
+  walk = mix->sinkpads;
+  while (walk) {
+    GstVideoMixerPad *pad = GST_VIDEO_MIXER_PAD (walk->data);
+
+    walk = g_slist_next (walk);
+
+    if (pad->buffer != NULL) {
+      pad->queued -= interval;
+      GST_DEBUG ("queued now %s %lld", gst_pad_get_name (GST_PAD (pad)),
+          pad->queued);
+      if (pad->queued <= 0) {
+        gst_buffer_unref (pad->buffer);
+        pad->buffer = NULL;
+      }
+    }
+  }
+}
+
+/*
+ * The basic idea is to get a buffer on all pads and mix them together.
+ * Based on the framerate, buffers are removed from the queues to make room
+ * for a new buffer. 
+ */
+static void
+gst_videomixer_loop (GstElement * element)
+{
+  GstVideoMixer *mix;
+  GstBuffer *outbuf;
+  gint outsize;
+  gint new_width, new_height;
+  gboolean eos;
+
+  mix = GST_VIDEO_MIXER (element);
+
+  eos = gst_videomixer_fill_queues (mix);
+  if (eos) {
+    gst_pad_push (mix->srcpad, GST_DATA (gst_event_new (GST_EVENT_EOS)));
+    gst_element_set_eos (GST_ELEMENT (mix));
+    return;
+  }
+
+  new_width = mix->in_width;
+  new_height = mix->in_height;
+
+  if (new_width != mix->out_width ||
+      new_height != mix->out_height || !GST_PAD_CAPS (mix->srcpad)) {
+    GstCaps *newcaps;
+
+    newcaps =
+        gst_caps_copy (gst_pad_get_negotiated_caps (GST_PAD (mix->master)));
+    gst_caps_set_simple (newcaps, "format", GST_TYPE_FOURCC,
+        GST_STR_FOURCC ("I420"), "width", G_TYPE_INT, new_width, "height",
+        G_TYPE_INT, new_height, NULL);
+
+    if (!gst_pad_try_set_caps (mix->srcpad, newcaps)) {
+      GST_ELEMENT_ERROR (mix, CORE, NEGOTIATION, (NULL), (NULL));
+      return;
+    }
+
+    mix->out_width = new_width;
+    mix->out_height = new_height;
+  }
+
+  outsize = 3 * (mix->out_width * mix->out_height) / 2;
+  outbuf = gst_pad_alloc_buffer (mix->srcpad, GST_BUFFER_OFFSET_NONE, outsize);
+  switch (mix->background) {
+    case VIDEO_MIXER_BACKGROUND_CHECKER:
+      gst_videomixer_fill_checker (GST_BUFFER_DATA (outbuf),
+          new_width, new_height);
+      break;
+    case VIDEO_MIXER_BACKGROUND_BLACK:
+      gst_videomixer_fill_color (GST_BUFFER_DATA (outbuf),
+          new_width, new_height, 16, 128, 128);
+      break;
+    case VIDEO_MIXER_BACKGROUND_WHITE:
+      gst_videomixer_fill_color (GST_BUFFER_DATA (outbuf),
+          new_width, new_height, 240, 128, 128);
+      break;
+  }
+
+  gst_videomixer_blend_buffers (mix, outbuf);
+
+  gst_videomixer_update_queues (mix);
+
+  gst_pad_push (mix->srcpad, GST_DATA (outbuf));
+}
+
+static void
+gst_videomixer_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec)
+{
+  GstVideoMixer *mix = GST_VIDEO_MIXER (object);
+
+  switch (prop_id) {
+    case ARG_BACKGROUND:
+      g_value_set_enum (value, mix->background);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_videomixer_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec)
+{
+  GstVideoMixer *mix = GST_VIDEO_MIXER (object);
+
+  switch (prop_id) {
+    case ARG_BACKGROUND:
+      mix->background = g_value_get_enum (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstElementStateReturn
+gst_videomixer_change_state (GstElement * element)
+{
+  GstVideoMixer *mix;
+  gint transition = GST_STATE_TRANSITION (element);
+
+  g_return_val_if_fail (GST_IS_VIDEO_MIXER (element), GST_STATE_FAILURE);
+
+  mix = GST_VIDEO_MIXER (element);
+
+  switch (transition) {
+    case GST_STATE_NULL_TO_READY:
+    case GST_STATE_READY_TO_PAUSED:
+      break;
+    case GST_STATE_PAUSED_TO_PLAYING:
+    case GST_STATE_PLAYING_TO_PAUSED:
+    case GST_STATE_PAUSED_TO_READY:
+    case GST_STATE_READY_TO_NULL:
+      break;
+  }
+
+  if (GST_ELEMENT_CLASS (parent_class)->change_state)
+    return GST_ELEMENT_CLASS (parent_class)->change_state (element);
+
+  return GST_STATE_SUCCESS;
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  GST_DEBUG_CATEGORY_INIT (gst_videomixer_debug, "videomixer", 0,
+      "video mixer");
+
+  return gst_element_register (plugin, "videomixer", GST_RANK_PRIMARY,
+      GST_TYPE_VIDEO_MIXER);
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "videomixer",
+    "Video mixer", plugin_init, VERSION, GST_LICENSE, GST_PACKAGE, GST_ORIGIN)