Add APE tag demuxer (#325649).

Original commit message from CVS:
* configure.ac:
* docs/plugins/Makefile.am:
* docs/plugins/gst-plugins-good-plugins-docs.sgml:
* docs/plugins/gst-plugins-good-plugins-sections.txt:
* docs/plugins/gst-plugins-good-plugins.hierarchy:
* docs/plugins/inspect/plugin-apetag.xml:
* gst/apetag/Makefile.am:
* gst/apetag/gstapedemux.c:
* gst/apetag/gstapedemux.h:
* gst/apetag/gsttagdemux.c:
* gst/apetag/gsttagdemux.h:
Add APE tag demuxer (#325649).

5 files changed, 1867 insertions, 0 deletions

diff --git a/gst/apetag/Makefile.am b/gst/apetag/Makefile.am
new file mode 100644
index 00000000..d249a84e
--- /dev/null
+++ b/gst/apetag/Makefile.am
@@ -0,0 +1,11 @@
+plugin_LTLIBRARIES = libgstapetag.la
+
+libgstapetag_la_SOURCES = gstapedemux.c gsttagdemux.c
+libgstapetag_la_CFLAGS = \
+	-I$(top_srcdir)/gst-libs \
+	$(GST_CFLAGS)
+libgstapetag_la_LIBADD = \
+	$(GST_LIBS)
+libgstapetag_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
+
+noinst_HEADERS = gstapedemux.h gsttagdemux.h
diff --git a/gst/apetag/gstapedemux.c b/gst/apetag/gstapedemux.c
new file mode 100644
index 00000000..37e92245
--- /dev/null
+++ b/gst/apetag/gstapedemux.c
@@ -0,0 +1,356 @@
+/* GStreamer APEv1/2 tag reader
+ * Copyright (C) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:element-apedemux
+ * @short_description: reads tag information from APE tag data blocks and
+ * outputs them as GStreamer tag messages and events.
+ *
+ * <refsect2>
+ * <para>
+ * apedemux accepts data streams with APE tags at the start or at the end
+ * (or both). The mime type of the data between the tag blocks is detected
+ * using typefind functions, and the appropriate output mime type set on
+ * outgoing buffers. 
+ * </para>
+ * <para>
+ * The element is only able to read APE tags at the end of a stream from
+ * a seekable stream, ie. when get_range mode is supported by the upstream
+ * elements. If get_range operation is available, apedemux makes it available
+ * downstream. This means that elements which require get_range mode, such as
+ * wavparse or musepackdec, can operate on files containing APE tag
+ * information.
+ * </para>
+ * <title>Example launch line</title>
+ * <para>
+ * <programlisting>
+ * gst-launch -t filesrc location=file.mpc ! apedemux ! fakesink
+ * </programlisting>
+ * This pipeline should read any available APE tag information and output it.
+ * The contents of the file inside the APE tag regions should be detected, and
+ * the appropriate mime type set on buffers produced from apedemux.
+ * </para>
+ * </refsect2>
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/gst-i18n-plugin.h>
+
+#include "gstapedemux.h"
+
+#include <string.h>
+
+#define APE_VERSION_MAJOR(ver)  ((ver)/1000)
+
+GST_DEBUG_CATEGORY (apedemux_debug);
+#define GST_CAT_DEFAULT (apedemux_debug)
+
+static GstElementDetails gst_ape_demux_details =
+GST_ELEMENT_DETAILS ("APE tag demuxer",
+    "Codec/Demuxer/Metadata",
+    "Read and output APE tags while demuxing the contents",
+    "Ronald Bultje <rbultje@ronald.bitfreak.net>, "
+    "Tim-Philipp Müller <tim centricular net>");
+
+static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("application/x-apetag")
+    );
+
+static gboolean gst_ape_demux_identify_tag (GstTagDemux * demux,
+    GstBuffer * buffer, gboolean start_tag, guint * tag_size);
+static GstTagDemuxResult gst_ape_demux_parse_tag (GstTagDemux * demux,
+    GstBuffer * buffer, gboolean start_tag, guint * tag_size,
+    GstTagList ** tags);
+
+GST_BOILERPLATE (GstApeDemux, gst_ape_demux, GstTagDemux, GST_TYPE_TAG_DEMUX)
+
+     static void gst_ape_demux_base_init (gpointer klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_factory));
+
+  gst_element_class_set_details (element_class, &gst_ape_demux_details);
+
+  GST_DEBUG_CATEGORY_INIT (apedemux_debug, "apedemux", 0,
+      "GStreamer APE tag demuxer");
+}
+
+static void
+gst_ape_demux_class_init (GstApeDemuxClass * klass)
+{
+  GstTagDemuxClass *tagdemux_class;
+
+  tagdemux_class = GST_TAG_DEMUX_CLASS (klass);
+
+  tagdemux_class->identify_tag = GST_DEBUG_FUNCPTR (gst_ape_demux_identify_tag);
+  tagdemux_class->parse_tag = GST_DEBUG_FUNCPTR (gst_ape_demux_parse_tag);
+}
+
+static void
+gst_ape_demux_init (GstApeDemux * apedemux, GstApeDemuxClass * gclass)
+{
+  GstTagDemux *tagdemux = GST_TAG_DEMUX (apedemux);
+
+  tagdemux->min_start_size = 32;
+  tagdemux->min_end_size = 32;
+
+  tagdemux->prefer_start_tag = TRUE;
+}
+
+static const struct _GstApeDemuxTagTableEntry
+{
+  const gchar *ape_tag;
+  const gchar *gst_tag;
+} tag_table[] = {
+  {
+  "replaygain_track_gain", GST_TAG_TRACK_GAIN}, {
+  "replaygain_track_peak", GST_TAG_TRACK_PEAK}, {
+  "replaygain_album_gain", GST_TAG_ALBUM_GAIN}, {
+  "replaygain_album_peak", GST_TAG_ALBUM_PEAK}, {
+  "title", GST_TAG_TITLE}, {
+  "artist", GST_TAG_ARTIST}, {
+  "album", GST_TAG_ALBUM}, {
+  "comment", GST_TAG_COMMENT}, {
+  "comments", GST_TAG_COMMENT}, {
+  "copyright", GST_TAG_COPYRIGHT}, {
+  "genre", GST_TAG_GENRE}, {
+  "isrc", GST_TAG_ISRC}, {
+  "track", GST_TAG_TRACK_NUMBER}, {
+  "year", GST_TAG_DATE}
+};
+
+static gboolean
+ape_demux_get_gst_tag_from_tag (const gchar * ape_tag,
+    const gchar ** gst_tag, GType * gst_tag_type)
+{
+  gint i;
+
+  for (i = 0; i < G_N_ELEMENTS (tag_table); ++i) {
+    if (g_ascii_strcasecmp (tag_table[i].ape_tag, ape_tag) == 0) {
+      *gst_tag = tag_table[i].gst_tag;
+      *gst_tag_type = gst_tag_get_type (tag_table[i].gst_tag);
+      return TRUE;
+    }
+  }
+
+  GST_WARNING ("Could not map APE tag '%s' to a GStreamer tag", ape_tag);
+  return FALSE;
+}
+
+static GstTagList *
+ape_demux_parse_tags (const guint8 * data, gint size)
+{
+  GstTagList *taglist = gst_tag_list_new ();
+  gboolean have_tag = FALSE;
+
+  GST_LOG ("Reading tags from chunk of size %u bytes", size);
+
+  /* get rid of header/footer */
+  if (size >= 32 && memcmp (data, "APETAGEX", 8) == 0) {
+    data += 32;
+    size -= 32;
+  }
+  if (size > 32 && memcmp (data + size - 32, "APETAGEX", 8) == 0) {
+    size -= 32;
+  }
+
+  /* read actual tags - at least 10 bytes for tag header */
+  while (size >= 10) {
+    guint len, n = 8;
+    gchar *tag, *val;
+    const gchar *gst_tag;
+    GType gst_tag_type;
+
+    /* find tag type and size */
+    len = GST_READ_UINT32_LE (data);
+    while (n < size && data[n] != 0x0)
+      n++;
+    if (n == size)
+      break;
+    g_assert (data[n] == 0x0);
+    n++;
+    if (size - n < len)
+      break;
+
+    /* read */
+    tag = g_strndup ((gchar *) data + 8, n - 9);
+    val = g_strndup ((gchar *) data + n, len);
+
+    if (ape_demux_get_gst_tag_from_tag (tag, &gst_tag, &gst_tag_type)) {
+      GValue v = { 0, };
+
+      switch (gst_tag_type) {
+        case G_TYPE_INT:
+          g_value_init (&v, G_TYPE_INT);
+          g_value_set_int (&v, atoi (val));
+          break;
+        case G_TYPE_UINT:
+          g_value_init (&v, G_TYPE_UINT);
+          g_value_set_uint (&v, (guint) atof (val));    /* hmmm */
+          break;
+        case G_TYPE_STRING:
+          g_value_init (&v, G_TYPE_STRING);
+          g_value_set_string (&v, val);
+          break;
+        case G_TYPE_DOUBLE:
+          g_value_init (&v, G_TYPE_DOUBLE);
+          g_value_set_double (&v, atof (val));
+          break;
+        default:{
+          if (gst_tag_type == GST_TYPE_DATE) {
+            GDate *date = g_date_new_dmy (1, 1, atoi (val));
+
+            g_value_init (&v, GST_TYPE_DATE);
+            gst_value_set_date (&v, date);
+            g_date_free (date);
+          } else {
+            GST_WARNING ("Unhandled tag type '%s' for tag '%s'",
+                g_type_name (gst_tag_type), gst_tag);
+          }
+          break;
+        }
+      }
+      if (G_VALUE_TYPE (&v) != 0) {
+        gst_tag_list_add_values (taglist, GST_TAG_MERGE_APPEND,
+            gst_tag, &v, NULL);
+        g_value_unset (&v);
+        have_tag = TRUE;
+      }
+    }
+    GST_DEBUG ("Read tag %s: %s", tag, val);
+    g_free (tag);
+    g_free (val);
+
+    /* move data pointer */
+    size -= len + n;
+    data += len + n;
+  }
+
+  GST_DEBUG ("Taglist: %" GST_PTR_FORMAT, taglist);
+  return taglist;
+}
+
+static gboolean
+gst_ape_demux_identify_tag (GstTagDemux * demux, GstBuffer * buffer,
+    gboolean start_tag, guint * tag_size)
+{
+  if (memcmp (GST_BUFFER_DATA (buffer), "APETAGEX", 8) != 0) {
+    GST_DEBUG_OBJECT (demux, "No APETAGEX marker at %s - not an APE file",
+        (start_tag) ? "start" : "end");
+    return FALSE;
+  }
+
+  *tag_size = GST_READ_UINT32_LE (GST_BUFFER_DATA (buffer) + 12);
+
+  /* size is without header, so add 32 to account for that */
+  *tag_size += 32;
+
+  return TRUE;
+}
+
+static GstTagDemuxResult
+gst_ape_demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
+    gboolean start_tag, guint * tag_size, GstTagList ** tags)
+{
+  const guint8 *data;
+  const guint8 *footer;
+  gboolean have_header;
+  gboolean end_tag = !start_tag;
+  guint version, footer_size;
+
+  GST_LOG_OBJECT (demux, "Parsing buffer of size %u", GST_BUFFER_SIZE (buffer));
+
+  data = GST_BUFFER_DATA (buffer);
+  footer = GST_BUFFER_DATA (buffer) + GST_BUFFER_SIZE (buffer) - 32;
+
+  GST_LOG_OBJECT (demux, "Checking for footer at offset 0x%04x",
+      (guint) (footer - data));
+  if (footer > data && memcmp (footer, "APETAGEX", 8) == 0) {
+    GST_DEBUG_OBJECT (demux, "Found footer");
+    footer_size = 32;
+  } else {
+    GST_DEBUG_OBJECT (demux, "No footer");
+    footer_size = 0;
+  }
+
+  /* APE tags at the end must have a footer */
+  if (end_tag && footer_size == 0) {
+    GST_WARNING_OBJECT (demux, "Tag at end of file without footer!");
+    return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
+  }
+
+  /* don't trust the header/footer flags, better detect them ourselves */
+  have_header = (memcmp (data, "APETAGEX", 8) == 0);
+
+  if (start_tag && !have_header) {
+    GST_DEBUG_OBJECT (demux, "Tag at beginning of file without header!");
+    return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
+  }
+
+  if (end_tag && !have_header) {
+    GST_DEBUG_OBJECT (demux, "Tag at end of file has no header (APEv1)");
+    *tag_size -= 32;            /* adjust tag size */
+  }
+
+  if (have_header) {
+    version = GST_READ_UINT32_LE (data + 8);
+  } else {
+    version = GST_READ_UINT32_LE (footer + 8);
+  }
+
+  /* skip header */
+  if (have_header) {
+    data += 32;
+  }
+
+  GST_DEBUG_OBJECT (demux, "APE tag with version %u, size %u at offset 0x%08"
+      G_GINT64_MODIFIER "x", version, *tag_size,
+      GST_BUFFER_OFFSET (buffer) + ((have_header) ? 0 : 32));
+
+  if (APE_VERSION_MAJOR (version) != 1 && APE_VERSION_MAJOR (version) != 2) {
+    GST_WARNING ("APE tag is version %u.%03u, but decoder only supports "
+        "v1 or v2. Ignoring.", APE_VERSION_MAJOR (version), version % 1000);
+    return GST_TAG_DEMUX_RESULT_OK;
+  }
+
+  *tags = ape_demux_parse_tags (data, *tag_size - footer_size);
+
+  return GST_TAG_DEMUX_RESULT_OK;
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  return gst_element_register (plugin, "apedemux",
+      GST_RANK_PRIMARY, GST_TYPE_APE_DEMUX);
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "apetag",
+    "APEv1/2 tag reader",
+    plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)
diff --git a/gst/apetag/gstapedemux.h b/gst/apetag/gstapedemux.h
new file mode 100644
index 00000000..93f390a9
--- /dev/null
+++ b/gst/apetag/gstapedemux.h
@@ -0,0 +1,51 @@
+/* GStreamer APEv1/2 tag reader
+ * Copyright (C) 2004 Ronald Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GST_APE_DEMUX_H__
+#define __GST_APE_DEMUX_H__
+
+#include <gst/tag/gsttagdemux.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_APE_DEMUX             (gst_ape_demux_get_type())
+#define GST_APE_DEMUX(obj)             (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_APE_DEMUX,GstApeDemux))
+#define GST_APE_DEMUX_CLASS(klass)     (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_APE_DEMUX,GstApeDemuxClass))
+#define GST_IS_APE_DEMUX(obj)          (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_APE_DEMUX))
+#define GST_IS_APE_DEMUX_CLASS(klass)  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_APE_DEMUX))
+
+typedef struct _GstApeDemux      GstApeDemux;
+typedef struct _GstApeDemuxClass GstApeDemuxClass;
+
+struct _GstApeDemux
+{
+  GstTagDemux tagdemux;
+};
+
+struct _GstApeDemuxClass 
+{
+  GstTagDemuxClass parent_class;
+};
+
+GType gst_ape_demux_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_APE_DEMUX_H__ */
diff --git a/gst/apetag/gsttagdemux.c b/gst/apetag/gsttagdemux.c
new file mode 100644
index 00000000..9bb43c88
--- /dev/null
+++ b/gst/apetag/gsttagdemux.c
@@ -0,0 +1,1344 @@
+/* GStreamer Base Class for Tag Demuxing
+ * Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
+ * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:gsttagdemux
+ * @see_also: GstApeDemux
+ * @short_description: Base class for demuxing tags that are in chunks
+ *                     directly at the beginning or at the end of a file
+ * 
+ * <refsect2>
+ * <para>
+ * Provides a base class for demuxing tags at the beginning or end of a
+ * stream and handles things like typefinding, querying, seeking, and
+ * different modes of operation (chain-based, pull_range-based, and providing
+ * downstream elements with random access if upstream supports that). The tag
+ * is stripped from the output, and all offsets are adjusted for the tag
+ * sizes, so that to the downstream element the stream will appear as if
+ * there was no tag at all. Also, once the tag has been parsed, GstTagDemux
+ * will try to determine the media type of the resulting stream and add a
+ * source pad with the appropriate caps in order to facilitate auto-plugging.
+ * </para>
+ * <title>Deriving from GstTagDemux</title>
+ * <para>
+ * Subclasses have to do four things:
+ * <itemizedlist>
+ *  <listitem><para>
+ *  In their base init function, they must add a pad template for the sink
+ *  pad to the element class, describing the media type they can parse in
+ *  the caps of the pad template.
+ *  </para></listitem>
+ *  <listitem><para>
+ *  In their class init function, they must override
+ *  GST_TAG_DEMUX_CLASS(demux_klass)->identify_tag with their own identify
+ *  function.
+ *  </para></listitem>
+ *  <listitem><para>
+ *  In their class init function, they must override
+ *  GST_TAG_DEMUX_CLASS(demux_klass)->parse_tag with their own parse
+ *  function.
+ *  </para></listitem>
+ *  <listitem><para>
+ *  In their instance init function, they must set
+ *  GST_TAG_DEMUX(demux)->min_start_size and/or 
+ *  GST_TAG_DEMUX(demux)->min_end_size to the minimum size required for the
+ *  identify function to decide whether the stream has a supported tag or
+ *  not. A class parsing ID3v1 tags, for example, would set min_end_size to
+ *  128 bytes.
+ *  </para></listitem>
+ * </itemizedlist>
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gsttagdemux.h"
+
+#include <gst/gst-i18n-plugin.h>
+#include <string.h>
+
+typedef enum
+{
+  GST_TAG_DEMUX_READ_START_TAG,
+  GST_TAG_DEMUX_TYPEFINDING,
+  GST_TAG_DEMUX_STREAMING
+} GstTagDemuxState;
+
+struct _GstTagDemuxPrivate
+{
+  GstPad *srcpad;
+  GstPad *sinkpad;
+
+  /* Number of bytes to remove from the
+   * start of file (tag at beginning) */
+  guint strip_start;
+
+  /* Number of bytes to remove from the
+   * end of file (tag at end) */
+  guint strip_end;
+
+  gint64 upstream_size;
+
+  GstTagDemuxState state;
+  GstBuffer *collect;
+  GstCaps *src_caps;
+
+  GstTagList *event_tags;
+  GstTagList *parsed_tags;
+  gboolean send_tag_event;
+};
+
+/* Require at least 8kB of data before we attempt typefind. 
+ * Seems a decent value based on test files
+ * 40kB is massive overkill for the maximum, I think, but it 
+ * doesn't do any harm (tpm: increased to 64kB after watching
+ * typefinding fail on a wavpack file that needed 42kB to succeed) */
+#define TYPE_FIND_MIN_SIZE 8192
+#define TYPE_FIND_MAX_SIZE 65536
+
+GST_DEBUG_CATEGORY_STATIC (tagdemux_debug);
+#define GST_CAT_DEFAULT (tagdemux_debug)
+
+static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_SOMETIMES,
+    GST_STATIC_CAPS ("ANY")
+    );
+
+static void gst_tag_demux_dispose (GObject * object);
+
+static GstFlowReturn gst_tag_demux_chain (GstPad * pad, GstBuffer * buf);
+
+static gboolean gst_tag_demux_src_activate_pull (GstPad * pad, gboolean active);
+static GstFlowReturn gst_tag_demux_read_range (GstTagDemux * tagdemux,
+    guint64 offset, guint length, GstBuffer ** buffer);
+
+static gboolean gst_tag_demux_src_checkgetrange (GstPad * srcpad);
+static GstFlowReturn gst_tag_demux_src_getrange (GstPad * srcpad,
+    guint64 offset, guint length, GstBuffer ** buffer);
+
+static gboolean gst_tag_demux_add_srcpad (GstTagDemux * tagdemux,
+    GstCaps * new_caps);
+static gboolean gst_tag_demux_remove_srcpad (GstTagDemux * tagdemux);
+
+static gboolean gst_tag_demux_srcpad_event (GstPad * pad, GstEvent * event);
+static gboolean gst_tag_demux_sink_activate (GstPad * sinkpad);
+static GstStateChangeReturn gst_tag_demux_change_state (GstElement * element,
+    GstStateChange transition);
+static gboolean gst_tag_demux_pad_query (GstPad * pad, GstQuery * query);
+static const GstQueryType *gst_tag_demux_get_query_types (GstPad * pad);
+static gboolean gst_tag_demux_get_upstream_size (GstTagDemux * tagdemux);
+static GstCaps *gst_tag_demux_do_typefind (GstTagDemux * tagdemux,
+    GstBuffer * buffer);
+static void gst_tag_demux_send_tag_event (GstTagDemux * tagdemux);
+
+static void gst_tag_demux_base_init (gpointer g_class);
+static void gst_tag_demux_class_init (gpointer g_class, gpointer d);
+static void gst_tag_demux_init (GstTagDemux * obj, GstTagDemuxClass * klass);
+
+static gpointer parent_class;   /* NULL */
+
+/* Cannot use boilerplate macros here because we want the abstract flag */
+GType
+gst_tag_demux_get_type (void)
+{
+  static GType object_type;     /* 0 */
+
+  if (object_type == 0) {
+    static const GTypeInfo object_info = {
+      sizeof (GstTagDemuxClass),
+      gst_tag_demux_base_init,
+      NULL,                     /* base_finalize */
+      gst_tag_demux_class_init,
+      NULL,                     /* class_finalize */
+      NULL,                     /* class_data */
+      sizeof (GstTagDemux),
+      0,                        /* n_preallocs */
+      (GInstanceInitFunc) gst_tag_demux_init
+    };
+
+    /* FIXME: register as 'GstApeDemuxBase' for now */
+    object_type = g_type_register_static (GST_TYPE_ELEMENT,
+        "GstTagDemux", &object_info, G_TYPE_FLAG_ABSTRACT);
+  }
+
+  return object_type;
+}
+
+static void
+gst_tag_demux_base_init (gpointer klass)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_factory));
+
+  GST_DEBUG_CATEGORY_INIT (tagdemux_debug, "tagdemux", 0,
+      "GStreamer tag demux base class");
+}
+
+static void
+gst_tag_demux_class_init (gpointer klass, gpointer d)
+{
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  parent_class = g_type_class_peek_parent (klass);
+
+  gobject_class->dispose = gst_tag_demux_dispose;
+
+  element_class->change_state = GST_DEBUG_FUNCPTR (gst_tag_demux_change_state);
+
+  g_type_class_add_private (klass, sizeof (GstTagDemuxPrivate));
+}
+
+static void
+gst_tag_demux_reset (GstTagDemux * tagdemux)
+{
+  tagdemux->priv->strip_start = 0;
+  tagdemux->priv->strip_end = 0;
+  tagdemux->priv->upstream_size = -1;
+  tagdemux->priv->state = GST_TAG_DEMUX_READ_START_TAG;
+  tagdemux->priv->send_tag_event = FALSE;
+
+  gst_buffer_replace (&(tagdemux->priv->collect), NULL);
+  gst_caps_replace (&(tagdemux->priv->src_caps), NULL);
+
+  gst_tag_demux_remove_srcpad (tagdemux);
+
+  if (tagdemux->priv->event_tags) {
+    gst_tag_list_free (tagdemux->priv->event_tags);
+    tagdemux->priv->event_tags = NULL;
+  }
+  if (tagdemux->priv->parsed_tags) {
+    gst_tag_list_free (tagdemux->priv->parsed_tags);
+    tagdemux->priv->parsed_tags = NULL;
+  }
+}
+
+static void
+gst_tag_demux_init (GstTagDemux * demux, GstTagDemuxClass * gclass)
+{
+  GstElementClass *element_klass = GST_ELEMENT_CLASS (gclass);
+  GstPadTemplate *tmpl;
+
+  demux->priv = g_type_instance_get_private ((GTypeInstance *) demux,
+      GST_TYPE_TAG_DEMUX);
+
+  /* subclasses must set these to sane values */
+  demux->min_start_size = 0;
+  demux->min_end_size = 0;
+
+  /* subclasses may set these, we just set defaults */
+  demux->prefer_start_tag = TRUE;
+
+  tmpl = gst_element_class_get_pad_template (element_klass, "sink");
+  if (tmpl) {
+    demux->priv->sinkpad = gst_pad_new_from_template (tmpl, "sink");
+
+    gst_pad_set_activate_function (demux->priv->sinkpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_sink_activate));
+    gst_pad_set_chain_function (demux->priv->sinkpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_chain));
+    gst_element_add_pad (GST_ELEMENT (demux), demux->priv->sinkpad);
+  }
+
+  gst_tag_demux_reset (demux);
+}
+
+static void
+gst_tag_demux_dispose (GObject * object)
+{
+  GstTagDemux *tagdemux = GST_TAG_DEMUX (object);
+
+  gst_tag_demux_reset (tagdemux);
+
+  G_OBJECT_CLASS (parent_class)->dispose (object);
+}
+
+static gboolean
+gst_tag_demux_add_srcpad (GstTagDemux * tagdemux, GstCaps * new_caps)
+{
+  GstPad *srcpad = NULL;
+
+  if (tagdemux->priv->src_caps == NULL ||
+      !gst_caps_is_equal (new_caps, tagdemux->priv->src_caps)) {
+
+    gst_caps_replace (&(tagdemux->priv->src_caps), new_caps);
+    if (tagdemux->priv->srcpad != NULL) {
+      GST_DEBUG_OBJECT (tagdemux, "Changing src pad caps to %" GST_PTR_FORMAT,
+          tagdemux->priv->src_caps);
+
+      gst_pad_set_caps (tagdemux->priv->srcpad, tagdemux->priv->src_caps);
+    }
+  } else {
+    /* Caps never changed */
+    gst_caps_unref (new_caps);
+  }
+
+  if (tagdemux->priv->srcpad == NULL) {
+    srcpad = tagdemux->priv->srcpad =
+        gst_pad_new_from_template (gst_element_class_get_pad_template
+        (GST_ELEMENT_GET_CLASS (tagdemux), "src"), "src");
+    g_return_val_if_fail (tagdemux->priv->srcpad != NULL, FALSE);
+
+    gst_pad_set_query_type_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_get_query_types));
+    gst_pad_set_query_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_pad_query));
+    gst_pad_set_event_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_srcpad_event));
+    gst_pad_set_activatepull_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_src_activate_pull));
+    gst_pad_set_checkgetrange_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_src_checkgetrange));
+    gst_pad_set_getrange_function (tagdemux->priv->srcpad,
+        GST_DEBUG_FUNCPTR (gst_tag_demux_src_getrange));
+
+    gst_pad_use_fixed_caps (tagdemux->priv->srcpad);
+
+    if (tagdemux->priv->src_caps)
+      gst_pad_set_caps (tagdemux->priv->srcpad, tagdemux->priv->src_caps);
+
+    GST_DEBUG_OBJECT (tagdemux, "Adding src pad with caps %" GST_PTR_FORMAT,
+        tagdemux->priv->src_caps);
+
+    gst_object_ref (tagdemux->priv->srcpad);
+    if (!(gst_element_add_pad (GST_ELEMENT (tagdemux), tagdemux->priv->srcpad)))
+      return FALSE;
+    gst_element_no_more_pads (GST_ELEMENT (tagdemux));
+  }
+
+  return TRUE;
+}
+
+static gboolean
+gst_tag_demux_remove_srcpad (GstTagDemux * demux)
+{
+  gboolean res = TRUE;
+
+  if (demux->priv->srcpad != NULL) {
+    GST_DEBUG_OBJECT (demux, "Removing src pad");
+    res = gst_element_remove_pad (GST_ELEMENT (demux), demux->priv->srcpad);
+    g_return_val_if_fail (res != FALSE, FALSE);
+    gst_object_unref (demux->priv->srcpad);
+    demux->priv->srcpad = NULL;
+  }
+
+  return res;
+};
+
+static gboolean
+gst_tag_demux_trim_buffer (GstTagDemux * tagdemux, GstBuffer ** buf_ref)
+{
+  GstBuffer *buf = *buf_ref;
+
+  guint trim_start = 0;
+  guint out_size = GST_BUFFER_SIZE (buf);
+  guint64 out_offset = GST_BUFFER_OFFSET (buf);
+  gboolean need_sub = FALSE;
+
+  /* Adjust offset and length */
+  if (!GST_BUFFER_OFFSET_IS_VALID (buf)) {
+    /* Can't change anything without an offset */
+    return TRUE;
+  }
+
+  /* If the buffer crosses the tag at the end of file, trim it */
+  if (tagdemux->priv->strip_end > 0) {
+    if (gst_tag_demux_get_upstream_size (tagdemux)) {
+      guint64 v1tag_offset =
+          tagdemux->priv->upstream_size - tagdemux->priv->strip_end;
+
+      if (out_offset >= v1tag_offset) {
+        GST_DEBUG_OBJECT (tagdemux, "Buffer is past the end of the data");
+        goto no_out_buffer;
+      }
+
+      if (out_offset + out_size > v1tag_offset) {
+        out_size = v1tag_offset - out_offset;
+        need_sub = TRUE;
+      }
+    }
+  }
+
+  if (tagdemux->priv->strip_start > 0) {
+    /* If the buffer crosses the tag at the start of file, trim it */
+    if (out_offset <= tagdemux->priv->strip_start) {
+      if (out_offset + out_size <= tagdemux->priv->strip_start) {
+        GST_DEBUG_OBJECT (tagdemux, "Buffer is before the start of the data");
+        goto no_out_buffer;
+      }
+
+      trim_start = tagdemux->priv->strip_start - out_offset;
+      out_size -= trim_start;
+      out_offset = 0;
+    } else {
+      out_offset -= tagdemux->priv->strip_start;
+    }
+    need_sub = TRUE;
+  }
+
+  g_assert (out_size > 0);
+
+  if (need_sub == TRUE) {
+    if (out_size != GST_BUFFER_SIZE (buf) || !gst_buffer_is_writable (buf)) {
+      GstBuffer *sub;
+
+      GST_DEBUG_OBJECT (tagdemux, "Sub-buffering to trim size %d offset %"
+          G_GINT64_FORMAT " to %d offset %" G_GINT64_FORMAT,
+          GST_BUFFER_SIZE (buf), GST_BUFFER_OFFSET (buf), out_size, out_offset);
+
+      sub = gst_buffer_create_sub (buf, trim_start, out_size);
+      g_return_val_if_fail (sub != NULL, FALSE);
+      gst_buffer_unref (buf);
+      *buf_ref = buf = sub;
+    } else {
+      GST_DEBUG_OBJECT (tagdemux, "Adjusting buffer from size %d offset %"
+          G_GINT64_FORMAT " to %d offset %" G_GINT64_FORMAT,
+          GST_BUFFER_SIZE (buf), GST_BUFFER_OFFSET (buf), out_size, out_offset);
+    }
+
+    GST_BUFFER_OFFSET (buf) = out_offset;
+    GST_BUFFER_OFFSET_END (buf) = out_offset + out_size;
+    gst_buffer_set_caps (buf, tagdemux->priv->src_caps);
+  }
+
+  return TRUE;
+
+no_out_buffer:
+  gst_buffer_unref (buf);
+  *buf_ref = NULL;
+  return TRUE;
+}
+
+static void
+gst_tag_demux_chain_parse_tag (GstTagDemux * demux, GstBuffer * collect)
+{
+  GstTagDemuxResult parse_ret;
+  GstTagDemuxClass *klass;
+  guint tagsize = 0;
+  guint available;
+
+  klass = GST_TAG_DEMUX_CLASS (G_OBJECT_GET_CLASS (demux));
+
+  /* If we receive a buffer that's from the middle of the file, 
+   * we can't read tags so move to typefinding */
+  if (GST_BUFFER_OFFSET (collect) != 0) {
+    GST_DEBUG_OBJECT (demux, "Received buffer from non-zero offset %"
+        G_GINT64_FORMAT ". Can't read tags", GST_BUFFER_OFFSET (collect));
+    demux->priv->state = GST_TAG_DEMUX_TYPEFINDING;
+    return;
+  }
+
+  g_assert (klass->identify_tag != NULL);
+  g_assert (klass->parse_tag != NULL);
+
+  available = GST_BUFFER_SIZE (collect);
+
+  if (available < demux->min_start_size) {
+    GST_DEBUG_OBJECT (demux, "Only %u bytes available, but %u needed "
+        "to identify tag", available, demux->min_start_size);
+    return;                     /* wait for more data */
+  }
+
+  if (!klass->identify_tag (demux, collect, TRUE, &tagsize)) {
+    GST_DEBUG_OBJECT (demux, "Could not identify start tag");
+    demux->priv->state = GST_TAG_DEMUX_TYPEFINDING;
+    return;
+  }
+
+  GST_DEBUG_OBJECT (demux, "Identified tag, size = %u bytes", tagsize);
+
+  do {
+    GstTagList *tags = NULL;
+    guint newsize, saved_size;
+
+    demux->priv->strip_start = tagsize;
+
+    if (available < tagsize) {
+      GST_DEBUG_OBJECT (demux, "Only %u bytes available, but %u needed "
+          "to parse tag", available, tagsize);
+      return;                   /* wait for more data */
+    }
+
+    saved_size = GST_BUFFER_SIZE (collect);
+    GST_BUFFER_SIZE (collect) = tagsize;
+    newsize = tagsize;
+
+    parse_ret = klass->parse_tag (demux, collect, TRUE, &newsize, &tags);
+
+    GST_BUFFER_SIZE (collect) = saved_size;
+
+    switch (parse_ret) {
+      case GST_TAG_DEMUX_RESULT_OK:
+        demux->priv->strip_start = newsize;
+        demux->priv->parsed_tags = tags;
+        GST_DEBUG_OBJECT (demux, "Read start tag of size %u", newsize);
+        break;
+      case GST_TAG_DEMUX_RESULT_BROKEN_TAG:
+        demux->priv->strip_start = newsize;
+        demux->priv->parsed_tags = tags;
+        GST_WARNING_OBJECT (demux, "Ignoring broken start tag of size %d",
+            demux->priv->strip_start);
+        break;
+      case GST_TAG_DEMUX_RESULT_AGAIN:
+        GST_DEBUG_OBJECT (demux, "Re-parse, this time with %u bytes", newsize);
+        g_assert (newsize != tagsize);
+        tagsize = newsize;
+        break;
+    }
+  } while (parse_ret == GST_TAG_DEMUX_RESULT_AGAIN);
+
+  GST_LOG_OBJECT (demux, "Parsed tag. Proceeding to typefinding");
+  demux->priv->state = GST_TAG_DEMUX_TYPEFINDING;
+  demux->priv->send_tag_event = TRUE;
+}
+
+static GstFlowReturn
+gst_tag_demux_chain (GstPad * pad, GstBuffer * buf)
+{
+  GstTagDemux *demux;
+
+  demux = GST_TAG_DEMUX (GST_PAD_PARENT (pad));
+  g_return_val_if_fail (GST_IS_TAG_DEMUX (demux), GST_FLOW_ERROR);
+
+  if (demux->priv->collect == NULL) {
+    demux->priv->collect = buf;
+  } else {
+    demux->priv->collect = gst_buffer_join (demux->priv->collect, buf);
+  }
+  buf = NULL;
+
+  switch (demux->priv->state) {
+    case GST_TAG_DEMUX_READ_START_TAG:
+      gst_tag_demux_chain_parse_tag (demux, demux->priv->collect);
+      if (demux->priv->state != GST_TAG_DEMUX_TYPEFINDING)
+        break;
+      /* Fall-through */
+    case GST_TAG_DEMUX_TYPEFINDING:{
+      GstCaps *caps;
+      GstBuffer *typefind_buf = NULL;
+
+      if (GST_BUFFER_SIZE (demux->priv->collect) < TYPE_FIND_MIN_SIZE)
+        break;                  /* Go get more data first */
+
+      GST_DEBUG_OBJECT (demux, "Typefinding with size %d",
+          GST_BUFFER_SIZE (demux->priv->collect));
+
+      /* Trim the buffer and adjust offset for typefinding */
+      typefind_buf = demux->priv->collect;
+      gst_buffer_ref (typefind_buf);
+      if (!gst_tag_demux_trim_buffer (demux, &typefind_buf))
+        return GST_FLOW_ERROR;
+
+      caps = gst_tag_demux_do_typefind (demux, typefind_buf);
+
+      if (caps == NULL) {
+        if (GST_BUFFER_SIZE (typefind_buf) < TYPE_FIND_MAX_SIZE) {
+          /* Just break for more data */
+          gst_buffer_unref (typefind_buf);
+          return GST_FLOW_OK;
+        }
+
+        /* We failed typefind */
+        GST_ELEMENT_ERROR (demux, STREAM, TYPE_NOT_FOUND, (NULL), (NULL));
+        gst_buffer_unref (typefind_buf);
+        gst_buffer_unref (demux->priv->collect);
+        demux->priv->collect = NULL;
+        return GST_FLOW_ERROR;
+      }
+      gst_buffer_unref (typefind_buf);
+
+      if (!gst_tag_demux_add_srcpad (demux, caps)) {
+        GST_DEBUG_OBJECT (demux, "Failed to add srcpad");
+        gst_caps_unref (caps);
+        goto error;
+      }
+      gst_caps_unref (caps);
+
+      /* Move onto streaming and fall-through to push out existing
+       * data */
+      demux->priv->state = GST_TAG_DEMUX_STREAMING;
+      /* fall-through */
+    }
+    case GST_TAG_DEMUX_STREAMING:{
+      GstBuffer *outbuf = NULL;
+
+      if (demux->priv->send_tag_event) {
+        gst_tag_demux_send_tag_event (demux);
+        demux->priv->send_tag_event = FALSE;
+      }
+
+      /* Trim the buffer and adjust offset */
+      if (demux->priv->collect) {
+        outbuf = demux->priv->collect;
+        demux->priv->collect = NULL;
+        if (!gst_tag_demux_trim_buffer (demux, &outbuf))
+          return GST_FLOW_ERROR;
+      }
+      if (outbuf) {
+        if (G_UNLIKELY (demux->priv->srcpad == NULL)) {
+          gst_buffer_unref (outbuf);
+          return GST_FLOW_ERROR;
+        }
+
+        GST_DEBUG_OBJECT (demux, "Pushing buffer %p", outbuf);
+        /* gst_util_dump_mem (GST_BUFFER_DATA (outbuf),
+           GST_BUFFER_SIZE (outbuf)); */
+        return gst_pad_push (demux->priv->srcpad, outbuf);
+      }
+    }
+  }
+  return GST_FLOW_OK;
+
+error:
+  GST_DEBUG_OBJECT (demux, "error in chain function");
+
+  return GST_FLOW_ERROR;
+}
+
+static gboolean
+gst_tag_demux_get_upstream_size (GstTagDemux * tagdemux)
+{
+  GstQuery *query;
+  GstPad *peer = NULL;
+  GstFormat format;
+  gint64 result;
+  gboolean res = FALSE;
+
+  /* Short-cut if we already queried upstream */
+  if (tagdemux->priv->upstream_size > 0)
+    return TRUE;
+
+  if ((peer = gst_pad_get_peer (tagdemux->priv->sinkpad)) == NULL)
+    return FALSE;
+
+  query = gst_query_new_duration (GST_FORMAT_BYTES);
+  gst_query_set_duration (query, GST_FORMAT_BYTES, -1);
+
+  if (!gst_pad_query (peer, query))
+    goto out;
+
+  gst_query_parse_duration (query, &format, &result);
+
+  if (format != GST_FORMAT_BYTES || result == -1)
+    goto out;
+
+  tagdemux->priv->upstream_size = result;
+  res = TRUE;
+
+out:
+  gst_object_unref (peer);
+  return res;
+}
+
+static gboolean
+gst_tag_demux_srcpad_event (GstPad * pad, GstEvent * event)
+{
+  gboolean res = FALSE;
+  GstTagDemux *tagdemux = GST_TAG_DEMUX (GST_PAD_PARENT (pad));
+
+  /* Handle SEEK events, with adjusted byte offsets and sizes. */
+
+  switch (GST_EVENT_TYPE (event)) {
+    case GST_EVENT_SEEK:
+    {
+      gdouble rate;
+      GstFormat format;
+      GstSeekType cur_type, stop_type;
+      GstSeekFlags flags;
+      gint64 cur, stop;
+
+      gst_event_parse_seek (event, &rate, &format, &flags,
+          &cur_type, &cur, &stop_type, &stop);
+
+      if (format == GST_FORMAT_BYTES &&
+          tagdemux->priv->state == GST_TAG_DEMUX_STREAMING &&
+          gst_pad_is_linked (tagdemux->priv->sinkpad)) {
+        GstEvent *upstream;
+
+        switch (cur_type) {
+          case GST_SEEK_TYPE_SET:
+            cur += tagdemux->priv->strip_start;
+            break;
+          case GST_SEEK_TYPE_CUR:
+            break;
+          case GST_SEEK_TYPE_END:
+            cur += tagdemux->priv->strip_end;
+            break;
+          default:
+            g_assert_not_reached ();
+            break;
+        }
+        switch (stop_type) {
+          case GST_SEEK_TYPE_SET:
+            stop += tagdemux->priv->strip_start;
+            break;
+          case GST_SEEK_TYPE_CUR:
+            break;
+          case GST_SEEK_TYPE_END:
+            stop += tagdemux->priv->strip_end;
+            break;
+          default:
+            break;
+        }
+        upstream = gst_event_new_seek (rate, format, flags,
+            cur_type, cur, stop_type, stop);
+        res = gst_pad_push_event (tagdemux->priv->sinkpad, upstream);
+      }
+      break;
+    }
+    default:
+      break;
+  }
+
+  gst_event_unref (event);
+  return res;
+}
+
+/* takes ownership of new_tags */
+
+static void
+gst_tag_demux_merge_tags (GstTagList ** tags, GstTagList * new_tags)
+{
+  g_return_if_fail (tags != NULL);
+
+  if (new_tags == NULL)
+    return;
+
+  GST_LOG ("New tags: %" GST_PTR_FORMAT, new_tags);
+
+  if (*tags != NULL) {
+    GstTagList *merged;
+
+    merged = gst_tag_list_merge (*tags, new_tags, GST_TAG_MERGE_REPLACE);
+    gst_tag_list_free (*tags);
+    gst_tag_list_free (new_tags);
+    *tags = merged;
+  } else {
+    *tags = new_tags;
+  }
+
+  GST_LOG ("Tags now: %" GST_PTR_FORMAT, *tags);
+}
+
+/* Read and interpret any end tag when activating in pull_range.
+ * Returns FALSE if pad activation should fail. */
+static gboolean
+gst_tag_demux_pull_end_tag (GstTagDemux * demux, GstTagList ** tags)
+{
+  GstTagDemuxResult parse_ret;
+  GstTagDemuxClass *klass;
+  GstFlowReturn flow_ret;
+  GstTagList *new_tags = NULL;
+  GstBuffer *buffer = NULL;
+  gboolean have_tag;
+  gboolean res = FALSE;
+  guint64 offset;
+  guint tagsize;
+
+  klass = GST_TAG_DEMUX_CLASS (G_OBJECT_GET_CLASS (demux));
+
+  g_assert (klass->identify_tag != NULL);
+  g_assert (klass->parse_tag != NULL);
+
+  if (demux->min_end_size == 0) {
+    GST_DEBUG_OBJECT (demux, "Not looking for tag at the end");
+    return TRUE;
+  }
+
+  if (demux->priv->upstream_size < demux->min_end_size) {
+    GST_DEBUG_OBJECT (demux, "File too small");
+    return TRUE;
+  }
+
+  /* Pull enough to identify the tag and retrieve its total size */
+  offset = demux->priv->upstream_size - demux->min_end_size;
+
+  flow_ret = gst_pad_pull_range (demux->priv->sinkpad, offset,
+      demux->min_end_size, &buffer);
+
+  if (flow_ret != GST_FLOW_OK) {
+    GST_DEBUG_OBJECT (demux, "Could not read tag header from end of file, "
+        "ret = %s", gst_flow_get_name (flow_ret));
+    goto done;
+  }
+
+  if (GST_BUFFER_SIZE (buffer) < demux->min_end_size) {
+    GST_DEBUG_OBJECT (demux, "Only managed to read %u bytes from file "
+        "(required: %u bytes)", GST_BUFFER_SIZE (buffer), demux->min_end_size);
+    goto done;
+  }
+
+  have_tag = klass->identify_tag (demux, buffer, FALSE, &tagsize);
+
+  if (!have_tag) {
+    GST_DEBUG_OBJECT (demux, "Could not find tag at end");
+    goto done;
+  }
+
+  /* Now pull the entire tag */
+  do {
+    guint newsize, saved_size;
+
+    GST_DEBUG_OBJECT (demux, "Identified tag at end, size=%u bytes", tagsize);
+
+    demux->priv->strip_end = tagsize;
+
+    g_assert (tagsize >= demux->min_end_size);
+
+    /* Get buffer that's exactly the requested size */
+    if (GST_BUFFER_SIZE (buffer) != tagsize) {
+      gst_buffer_unref (buffer);
+      buffer = NULL;
+
+      offset = demux->priv->upstream_size - tagsize;
+
+      flow_ret = gst_pad_pull_range (demux->priv->sinkpad, offset,
+          tagsize, &buffer);
+
+      if (flow_ret != GST_FLOW_OK) {
+        GST_DEBUG_OBJECT (demux, "Could not read data from end of file at "
+            "offset %" G_GUINT64_FORMAT ". ret = %s", offset,
+            gst_flow_get_name (flow_ret));
+        goto done;
+      }
+
+      if (GST_BUFFER_SIZE (buffer) < tagsize) {
+        GST_DEBUG_OBJECT (demux, "Only managed to read %u bytes from file",
+            GST_BUFFER_SIZE (buffer));
+        goto done;
+      }
+    }
+
+    GST_BUFFER_OFFSET (buffer) = offset;
+
+    saved_size = GST_BUFFER_SIZE (buffer);
+    GST_BUFFER_SIZE (buffer) = tagsize;
+    newsize = tagsize;
+
+    parse_ret = klass->parse_tag (demux, buffer, FALSE, &newsize, &new_tags);
+
+    GST_BUFFER_SIZE (buffer) = saved_size;
+
+    switch (parse_ret) {
+      case GST_TAG_DEMUX_RESULT_OK:
+        res = TRUE;
+        demux->priv->strip_end = newsize;
+        GST_DEBUG_OBJECT (demux, "Read tag at end, size %d",
+            demux->priv->strip_end);
+        break;
+      case GST_TAG_DEMUX_RESULT_BROKEN_TAG:
+        res = TRUE;
+        demux->priv->strip_end = newsize;
+        GST_WARNING_OBJECT (demux, "Ignoring broken tag at end, size %d",
+            demux->priv->strip_end);
+        break;
+      case GST_TAG_DEMUX_RESULT_AGAIN:
+        GST_DEBUG_OBJECT (demux, "Re-parse, this time with %d bytes", newsize);
+        g_assert (newsize != tagsize);
+        tagsize = newsize;
+        break;
+    }
+  } while (parse_ret == GST_TAG_DEMUX_RESULT_AGAIN);
+
+  gst_tag_demux_merge_tags (tags, new_tags);
+  new_tags = NULL;
+
+done:
+  if (new_tags)
+    gst_tag_list_free (new_tags);
+  if (buffer)
+    gst_buffer_unref (buffer);
+  return res;
+}
+
+/* Read and interpret any tag at the start when activating in
+ * pull_range. Returns FALSE if pad activation should fail. */
+static gboolean
+gst_tag_demux_pull_start_tag (GstTagDemux * demux, GstTagList ** tags)
+{
+  GstTagDemuxResult parse_ret;
+  GstTagDemuxClass *klass;
+  GstFlowReturn flow_ret;
+  GstTagList *new_tags = NULL;
+  GstBuffer *buffer = NULL;
+  gboolean have_tag;
+  gboolean res = FALSE;
+  guint req, tagsize;
+
+  klass = GST_TAG_DEMUX_CLASS (G_OBJECT_GET_CLASS (demux));
+
+  g_assert (klass->identify_tag != NULL);
+  g_assert (klass->parse_tag != NULL);
+
+  if (demux->min_start_size == 0) {
+    GST_DEBUG_OBJECT (demux, "Not looking for tag at the beginning");
+    return TRUE;
+  }
+
+  /* Handle tag at start. Try with 4kB to start with */
+  req = MAX (demux->min_start_size, 4096);
+
+  /* Pull enough to identify the tag and retrieve its total size */
+  flow_ret = gst_pad_pull_range (demux->priv->sinkpad, 0, req, &buffer);
+  if (flow_ret != GST_FLOW_OK) {
+    GST_DEBUG_OBJECT (demux, "Could not read data from start of file ret=%s",
+        gst_flow_get_name (flow_ret));
+    goto done;
+  }
+
+  if (GST_BUFFER_SIZE (buffer) < demux->min_start_size) {
+    GST_DEBUG_OBJECT (demux, "Only managed to read %u bytes from file - "
+        "no tag in this file", GST_BUFFER_SIZE (buffer));
+    goto done;
+  }
+
+  have_tag = klass->identify_tag (demux, buffer, TRUE, &tagsize);
+
+  if (!have_tag) {
+    GST_DEBUG_OBJECT (demux, "Could not find start tag");
+    res = TRUE;
+    goto done;
+  }
+
+  GST_DEBUG_OBJECT (demux, "Identified start tag, size = %u bytes", tagsize);
+
+  do {
+    guint newsize, saved_size;
+
+    demux->priv->strip_start = tagsize;
+
+    /* Now pull the entire tag */
+    g_assert (tagsize >= demux->min_start_size);
+
+    if (GST_BUFFER_SIZE (buffer) < tagsize) {
+      gst_buffer_unref (buffer);
+      buffer = NULL;
+
+      flow_ret = gst_pad_pull_range (demux->priv->sinkpad, 0, tagsize, &buffer);
+      if (flow_ret != GST_FLOW_OK) {
+        GST_DEBUG_OBJECT (demux, "Could not read data from start of file, "
+            "ret = %s", gst_flow_get_name (flow_ret));
+        goto done;
+      }
+
+      if (GST_BUFFER_SIZE (buffer) < tagsize) {
+        GST_DEBUG_OBJECT (demux, "Only managed to read %u bytes from file",
+            GST_BUFFER_SIZE (buffer));
+        goto done;
+      }
+    }
+
+    saved_size = GST_BUFFER_SIZE (buffer);
+    GST_BUFFER_SIZE (buffer) = tagsize;
+    newsize = tagsize;
+    parse_ret = klass->parse_tag (demux, buffer, TRUE, &newsize, &new_tags);
+
+    GST_BUFFER_SIZE (buffer) = saved_size;
+
+    switch (parse_ret) {
+      case GST_TAG_DEMUX_RESULT_OK:
+        res = TRUE;
+        demux->priv->strip_start = newsize;
+        GST_DEBUG_OBJECT (demux, "Read start tag of size %d", newsize);
+        break;
+      case GST_TAG_DEMUX_RESULT_BROKEN_TAG:
+        res = TRUE;
+        demux->priv->strip_start = newsize;
+        GST_WARNING_OBJECT (demux, "Ignoring broken start tag of size %d",
+            demux->priv->strip_start);
+        break;
+      case GST_TAG_DEMUX_RESULT_AGAIN:
+        GST_DEBUG_OBJECT (demux, "Re-parse, this time with %d bytes", newsize);
+        g_assert (newsize != tagsize);
+        tagsize = newsize;
+        break;
+    }
+  } while (parse_ret == GST_TAG_DEMUX_RESULT_AGAIN);
+
+  gst_tag_demux_merge_tags (tags, new_tags);
+  new_tags = NULL;
+
+done:
+  if (new_tags)
+    gst_tag_list_free (new_tags);
+  if (buffer)
+    gst_buffer_unref (buffer);
+  return res;
+}
+
+/* This function operates similarly to gst_type_find_element_activate
+ * in the typefind element
+ * 1. try to activate in pull mode. if not, switch to push and succeed.
+ * 2. try to read tags in pull mode
+ * 3. typefind the contents
+ * 4. deactivate pull mode.
+ * 5. if we didn't find any caps, fail.
+ * 6. Add the srcpad
+ * 7. if the sink pad is activated, we are in pull mode. succeed.
+ *    otherwise activate both pads in push mode and succeed.
+ */
+static gboolean
+gst_tag_demux_sink_activate (GstPad * sinkpad)
+{
+  GstTagDemux *demux = GST_TAG_DEMUX (GST_PAD_PARENT (sinkpad));
+  gboolean ret = FALSE;
+  GstBuffer *buf = NULL;
+  GstCaps *caps = NULL;
+  GstFlowReturn flow_ret;
+
+  /* 1: */
+  /* If we can activate pull_range upstream, then read any end and start
+   * tags, otherwise activate in push mode and the chain function will 
+   * collect buffers, read the start tag and output a buffer to end
+   * preroll.
+   */
+  if (!gst_pad_check_pull_range (sinkpad) ||
+      !gst_pad_activate_pull (sinkpad, TRUE)) {
+    GST_DEBUG_OBJECT (demux, "No pull mode. Changing to push, but won't be "
+        "able to read end tags");
+    demux->priv->state = GST_TAG_DEMUX_READ_START_TAG;
+    return gst_pad_activate_push (sinkpad, TRUE);
+  }
+
+  /* Look for tags at start and end of file */
+  GST_DEBUG_OBJECT (demux, "Activated pull mode. Looking for tags");
+  if (!gst_tag_demux_get_upstream_size (demux))
+    return FALSE;
+
+  demux->priv->strip_start = 0;
+  demux->priv->strip_end = 0;
+
+  /* we merge in REPLACE mode, so read the less important tag first */
+  if (demux->prefer_start_tag) {
+    if (!gst_tag_demux_pull_end_tag (demux, &demux->priv->parsed_tags) &&
+        !gst_tag_demux_pull_start_tag (demux, &demux->priv->parsed_tags)) {
+      return FALSE;
+    }
+  } else {
+    if (!gst_tag_demux_pull_start_tag (demux, &demux->priv->parsed_tags) &&
+        !gst_tag_demux_pull_end_tag (demux, &demux->priv->parsed_tags)) {
+      return FALSE;
+    }
+  }
+
+  if (demux->priv->parsed_tags != NULL) {
+    demux->priv->send_tag_event = TRUE;
+  }
+
+  flow_ret = gst_tag_demux_read_range (demux, 0, TYPE_FIND_MAX_SIZE, &buf);
+  if (flow_ret != GST_FLOW_OK) {
+    GST_DEBUG_OBJECT (demux, "Could not read data from start of file ret=%s",
+        gst_flow_get_name (flow_ret));
+    goto done_activate;
+  }
+
+  /* gst_util_dump_mem (GST_BUFFER_DATA (buf), GST_BUFFER_SIZE (buf)); */
+  caps = gst_tag_demux_do_typefind (demux, buf);
+  gst_buffer_unref (buf);
+  buf = NULL;
+
+  /* 4 - Deactivate pull mode */
+  if (!gst_pad_activate_pull (sinkpad, FALSE)) {
+    if (caps)
+      gst_caps_unref (caps);
+    GST_DEBUG_OBJECT (demux, "Could not deactivate sinkpad after reading tags");
+    return FALSE;
+  }
+
+  /* 5 - If we didn't find the caps, fail */
+  if (caps == NULL) {
+    GST_DEBUG_OBJECT (demux, "Could not detect type of contents");
+    GST_ELEMENT_ERROR (demux, STREAM, TYPE_NOT_FOUND, (NULL), (NULL));
+    goto done_activate;
+  }
+
+  /* tag reading and typefinding were already done, don't do them again in
+   * the chain function if we end up in push mode */
+  demux->priv->state = GST_TAG_DEMUX_STREAMING;
+
+  /* 6 Add the srcpad for output now we know caps. */
+  /* add_srcpad takes ownership of the caps */
+  if (!gst_tag_demux_add_srcpad (demux, caps)) {
+    GST_DEBUG_OBJECT (demux, "Could not add source pad");
+    goto done_activate;
+  }
+
+  /* 7 - if the sinkpad is active, it was done by downstream so we're 
+   * done, otherwise switch to push */
+  ret = TRUE;
+  if (!gst_pad_is_active (sinkpad)) {
+    ret = gst_pad_activate_push (demux->priv->srcpad, TRUE);
+    ret &= gst_pad_activate_push (sinkpad, TRUE);
+  }
+
+done_activate:
+  if (buf)
+    gst_buffer_unref (buf);
+
+  return ret;
+}
+
+static gboolean
+gst_tag_demux_src_activate_pull (GstPad * pad, gboolean active)
+{
+  GstTagDemux *demux = GST_TAG_DEMUX (GST_PAD_PARENT (pad));
+
+  return gst_pad_activate_pull (demux->priv->sinkpad, active);
+}
+
+static gboolean
+gst_tag_demux_src_checkgetrange (GstPad * srcpad)
+{
+  GstTagDemux *demux = GST_TAG_DEMUX (GST_PAD_PARENT (srcpad));
+
+  return gst_pad_check_pull_range (demux->priv->sinkpad);
+}
+
+static GstFlowReturn
+gst_tag_demux_read_range (GstTagDemux * demux,
+    guint64 offset, guint length, GstBuffer ** buffer)
+{
+  GstFlowReturn ret;
+  guint64 in_offset;
+  guint in_length;
+
+  g_return_val_if_fail (buffer != NULL, GST_FLOW_ERROR);
+
+  /* Adjust offset and length of the request to trim off tag information. 
+   * For the returned buffer, adjust the output offset to match what downstream
+   * should see */
+  in_offset = offset + demux->priv->strip_start;
+
+  if (!gst_tag_demux_get_upstream_size (demux))
+    return GST_FLOW_ERROR;
+
+  if (in_offset + length >= demux->priv->upstream_size - demux->priv->strip_end)
+    in_length = demux->priv->upstream_size - demux->priv->strip_end - in_offset;
+  else
+    in_length = length;
+
+  ret = gst_pad_pull_range (demux->priv->sinkpad, in_offset, in_length, buffer);
+
+  if (ret == GST_FLOW_OK && *buffer) {
+    if (!gst_tag_demux_trim_buffer (demux, buffer))
+      goto error;
+  }
+
+  return ret;
+
+error:
+  if (*buffer != NULL) {
+    gst_buffer_unref (buffer);
+    *buffer = NULL;
+  }
+  return GST_FLOW_ERROR;
+}
+
+static GstFlowReturn
+gst_tag_demux_src_getrange (GstPad * srcpad,
+    guint64 offset, guint length, GstBuffer ** buffer)
+{
+  GstTagDemux *demux = GST_TAG_DEMUX (GST_PAD_PARENT (srcpad));
+  GstFlowReturn flow_ret;
+
+  if (demux->priv->send_tag_event) {
+    gst_tag_demux_send_tag_event (demux);
+    demux->priv->send_tag_event = FALSE;
+  }
+  flow_ret = gst_tag_demux_read_range (demux, offset, length, buffer);
+/*
+  if (flow_ret == GST_FLOW_OK) {
+    gst_util_dump_mem (GST_BUFFER_DATA (*buffer), GST_BUFFER_SIZE (*buffer));
+  }
+*/
+  return flow_ret;
+}
+
+static GstStateChangeReturn
+gst_tag_demux_change_state (GstElement * element, GstStateChange transition)
+{
+  GstStateChangeReturn ret;
+  GstTagDemux *demux = GST_TAG_DEMUX (element);
+
+  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+  switch (transition) {
+    case GST_STATE_CHANGE_PAUSED_TO_READY:
+      gst_tag_demux_reset (demux);
+      break;
+    default:
+      break;
+  }
+  return ret;
+}
+
+static gboolean
+gst_tag_demux_pad_query (GstPad * pad, GstQuery * query)
+{
+  /* For a position or duration query, adjust the returned
+   * bytes to strip off the end and start areas */
+
+  GstTagDemux *demux = GST_TAG_DEMUX (GST_PAD_PARENT (pad));
+  GstPad *peer = NULL;
+  GstFormat format;
+  gint64 result;
+
+  if ((peer = gst_pad_get_peer (demux->priv->sinkpad)) == NULL)
+    return FALSE;
+
+  if (!gst_pad_query (peer, query)) {
+    gst_object_unref (peer);
+    return FALSE;
+  }
+
+  gst_object_unref (peer);
+
+  switch (GST_QUERY_TYPE (query)) {
+    case GST_QUERY_POSITION:
+    {
+      gst_query_parse_position (query, &format, &result);
+      if (format == GST_FORMAT_BYTES) {
+        result -= demux->priv->strip_start;
+        gst_query_set_position (query, format, result);
+      }
+      break;
+    }
+    case GST_QUERY_DURATION:
+    {
+      gst_query_parse_duration (query, &format, &result);
+      if (format == GST_FORMAT_BYTES) {
+        result -= demux->priv->strip_start + demux->priv->strip_end;
+        gst_query_set_duration (query, format, result);
+      }
+      break;
+    }
+    default:
+      break;
+  }
+
+  return TRUE;
+}
+
+static const GstQueryType *
+gst_tag_demux_get_query_types (GstPad * pad)
+{
+  static const GstQueryType types[] = {
+    GST_QUERY_POSITION,
+    GST_QUERY_DURATION,
+    0
+  };
+
+  return types;
+}
+
+typedef struct
+{
+  guint best_probability;
+  GstCaps *caps;
+  GstBuffer *buffer;
+} SimpleTypeFind;
+
+static guint8 *
+simple_find_peek (gpointer data, gint64 offset, guint size)
+{
+  SimpleTypeFind *find = (SimpleTypeFind *) data;
+
+  if (offset < 0)
+    return NULL;
+
+  if (GST_BUFFER_SIZE (find->buffer) >= offset + size) {
+    return GST_BUFFER_DATA (find->buffer) + offset;
+  }
+  return NULL;
+}
+static void
+simple_find_suggest (gpointer data, guint probability, const GstCaps * caps)
+{
+  SimpleTypeFind *find = (SimpleTypeFind *) data;
+
+  if (probability > find->best_probability) {
+    GstCaps *copy = gst_caps_copy (caps);
+
+    gst_caps_replace (&find->caps, copy);
+    gst_caps_unref (copy);
+    find->best_probability = probability;
+  }
+}
+
+static GstCaps *
+gst_tag_demux_do_typefind (GstTagDemux * tagdemux, GstBuffer * buffer)
+{
+  GList *walk, *type_list;
+  SimpleTypeFind find;
+  GstTypeFind gst_find;
+
+  walk = type_list = gst_type_find_factory_get_list ();
+
+  find.buffer = buffer;
+  find.best_probability = 0;
+  find.caps = NULL;
+  gst_find.data = &find;
+  gst_find.peek = simple_find_peek;
+  gst_find.get_length = NULL;
+  gst_find.suggest = simple_find_suggest;
+  while (walk) {
+    GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (walk->data);
+
+    gst_type_find_factory_call_function (factory, &gst_find);
+    if (find.best_probability >= GST_TYPE_FIND_MAXIMUM)
+      break;
+    walk = g_list_next (walk);
+  }
+  gst_plugin_feature_list_free (type_list);
+  if (find.best_probability > 0) {
+    GST_DEBUG ("Found caps %" GST_PTR_FORMAT " with buf size %u", find.caps,
+        GST_BUFFER_SIZE (buffer));
+    return find.caps;
+  }
+
+  return NULL;
+}
+
+static void
+gst_tag_demux_send_tag_event (GstTagDemux * demux)
+{
+  /* FIXME: what's the correct merge mode? Docs need to tell... */
+  GstTagList *merged = gst_tag_list_merge (demux->priv->event_tags,
+      demux->priv->parsed_tags, GST_TAG_MERGE_KEEP);
+
+  if (demux->priv->parsed_tags)
+    gst_element_post_message (GST_ELEMENT (demux),
+        gst_message_new_tag (GST_OBJECT (demux),
+            gst_tag_list_copy (demux->priv->parsed_tags)));
+
+  if (merged) {
+    GstEvent *event = gst_event_new_tag (merged);
+
+    GST_EVENT_TIMESTAMP (event) = 0;
+    GST_DEBUG_OBJECT (demux, "Sending tag event on src pad");
+    gst_pad_push_event (demux->priv->srcpad, event);
+  }
+}
diff --git a/gst/apetag/gsttagdemux.h b/gst/apetag/gsttagdemux.h
new file mode 100644
index 00000000..631bafe8
--- /dev/null
+++ b/gst/apetag/gsttagdemux.h
@@ -0,0 +1,105 @@
+/* GStreamer Base Class for Tag Demuxing
+ * Copyright (C) 2005  Jan Schmidt <thaytan@mad.scientist.com>
+ * Copyright (C) 2006  Tim-Philipp Müller <tim centricular net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GST_TAG_DEMUX_H__
+#define __GST_TAG_DEMUX_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_TAG_DEMUX            (gst_tag_demux_get_type())
+#define GST_TAG_DEMUX(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_TAG_DEMUX,GstTagDemux))
+#define GST_TAG_DEMUX_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_TAG_DEMUX,GstTagDemuxClass))
+#define GST_IS_TAG_DEMUX(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_TAG_DEMUX))
+#define GST_IS_TAG_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_TAG_DEMUX))
+
+typedef struct _GstTagDemux        GstTagDemux;
+typedef struct _GstTagDemuxClass   GstTagDemuxClass;
+typedef struct _GstTagDemuxPrivate GstTagDemuxPrivate;
+
+/**
+ * GstTagDemuxResult:
+ * @GST_TAG_DEMUX_RESULT_BROKEN_TAG: cannot parse tag, just skip it
+ * @GST_TAG_DEMUX_RESULT_AGAIN     : call again with less or more data
+ * @GST_TAG_DEMUX_RESULT_OK	   : parsed tag successfully
+ *
+ * Result values from the parse_tag virtual function.
+ */
+typedef enum {
+  GST_TAG_DEMUX_RESULT_BROKEN_TAG,
+  GST_TAG_DEMUX_RESULT_AGAIN,
+  GST_TAG_DEMUX_RESULT_OK
+} GstTagDemuxResult;
+
+struct _GstTagDemux
+{
+  GstElement element;
+
+  /* Minimum size required to identify a tag at the start and
+   * determine its total size (0 = not interested in start) */
+  guint         min_start_size;
+
+  /* Minimum size required to identify a tag at the end and
+   * determine its total size (0 = not interested in end) */
+  guint         min_end_size;
+
+  /* Prefer start tags over end tags (default: yes) */
+  gboolean      prefer_start_tag;
+
+  /*< private >*/
+  gpointer      reserved[GST_PADDING];
+  GstTagDemuxPrivate *priv;
+};
+
+/* Note: subclass must also add a sink pad template in its base_init */
+struct _GstTagDemuxClass 
+{
+  GstElementClass parent_class;
+
+  /* vtable */
+
+  /* Identify tag and determine the size required to parse the tag. Buffer
+   * may be larger than the specified minimum size. */
+  gboolean               (*identify_tag)  (GstTagDemux * demux,
+                                           GstBuffer   * buffer,
+                                           gboolean      start_tag,
+                                           guint       * tag_size);
+
+  /* Parse the tag. Buffer should be exactly the size determined by
+   * identify_tag() before. parse_tag() may change tag_size and return
+   * GST_TAG_DEMUX_RESULT_AGAIN to request a larger or smaller buffer.
+   * parse_tag() is also permitted to adjust tag_size to a smaller value
+   * and return GST_TAG_DEMUX_RESULT_OK. */
+  GstTagDemuxResult      (*parse_tag)     (GstTagDemux * demux,
+                                           GstBuffer   * buffer,
+                                           gboolean      start_tag,
+                                           guint       * tag_size,
+                                           GstTagList ** tags);
+
+  /*< private >*/
+  gpointer   reserved[GST_PADDING];
+};
+
+GType gst_tag_demux_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_TAG_DEMUX_H__ */