gst/id3demux/: Port ID3 tag demuxer over to the new GstTagDemux in -base (now would be a good time to test re-importi...

Original commit message from CVS:
* gst/id3demux/gstid3demux.c:
* gst/id3demux/gstid3demux.h:
* gst/id3demux/id3tags.c:
* gst/id3demux/id3tags.h:
* gst/id3demux/id3v2frames.c:
Port ID3 tag demuxer over to the new GstTagDemux in -base
(now would be a good time to test re-importing your music
collection).

5 files changed, 123 insertions, 1171 deletions

diff --git a/gst/id3demux/gstid3demux.c b/gst/id3demux/gstid3demux.c
index 2fb2c47e..14713756 100644
--- a/gst/id3demux/gstid3demux.c
+++ b/gst/id3demux/gstid3demux.c
@@ -1,5 +1,6 @@
 /* -*- Mode: C; tab-width: 2; indent-tabs-mode: t; c-basic-offset: 2 -*- */
-/* Copyright 2005 Jan Schmidt <thaytan@mad.scientist.com>
+/* GStreamer ID3 tag demuxer
+ * Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
  * Copyright (C) 2003-2004 Benjamin Otte <otte@gnome.org>
  *
  * This library is free software; you can redistribute it and/or
@@ -43,7 +44,6 @@
 #include "config.h"
 #endif
 #include <gst/gst.h>
-#include <gst/base/gsttypefindhelper.h>
 #include <gst/gst-i18n-plugin.h>
 #include <gst/tag/tag.h>
 #include <string.h>
@@ -63,12 +63,7 @@ enum
   ARG_PREFER_V1
 };
 
-/* Require at least 4kB 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 */
-#define ID3_TYPE_FIND_MIN_SIZE 4096
-#define ID3_TYPE_FIND_MAX_SIZE 40960
+#define DEFAULT_PREFER_V1  FALSE
 
 GST_DEBUG_CATEGORY (id3demux_debug);
 #define GST_CAT_DEFAULT (id3demux_debug)
@@ -79,645 +74,157 @@ static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
     GST_STATIC_CAPS ("application/x-id3")
     );
 
-static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
-    GST_PAD_SRC,
-    GST_PAD_SOMETIMES,
-    GST_STATIC_CAPS ("ANY")
-    );
-
-static void gst_id3demux_class_init (GstID3DemuxClass * klass);
-static void gst_id3demux_base_init (GstID3DemuxClass * klass);
-static void gst_id3demux_init (GstID3Demux * id3demux);
-static void gst_id3demux_dispose (GObject * object);
+static gboolean gst_id3demux_identify_tag (GstTagDemux * demux,
+    GstBuffer * buffer, gboolean start_tag, guint * tag_size);
+static GstTagDemuxResult gst_id3demux_parse_tag (GstTagDemux * demux,
+    GstBuffer * buffer, gboolean start_tag, guint * tag_size,
+    GstTagList ** tags);
+static GstTagList *gst_id3demux_merge_tags (GstTagDemux * tagdemux,
+    const GstTagList * start_tags, const GstTagList * end_tags);
 
 static void gst_id3demux_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec);
 static void gst_id3demux_get_property (GObject * object, guint prop_id,
     GValue * value, GParamSpec * pspec);
 
-static GstFlowReturn gst_id3demux_chain (GstPad * pad, GstBuffer * buf);
-static gboolean gst_id3demux_sink_event (GstPad * pad, GstEvent * event);
-static gboolean gst_id3demux_src_activate_pull (GstPad * pad, gboolean active);
-static GstFlowReturn gst_id3demux_read_range (GstID3Demux * id3demux,
-    guint64 offset, guint length, GstBuffer ** buffer);
-
-static gboolean gst_id3demux_src_checkgetrange (GstPad * srcpad);
-static GstFlowReturn gst_id3demux_src_getrange (GstPad * srcpad,
-    guint64 offset, guint length, GstBuffer ** buffer);
-
-static gboolean gst_id3demux_add_srcpad (GstID3Demux * id3demux,
-    const GstCaps * new_caps);
-static gboolean gst_id3demux_remove_srcpad (GstID3Demux * id3demux);
-
-static gboolean gst_id3demux_srcpad_event (GstPad * pad, GstEvent * event);
-static gboolean gst_id3demux_sink_activate (GstPad * sinkpad);
-static GstStateChangeReturn gst_id3demux_change_state (GstElement * element,
-    GstStateChange transition);
-static gboolean gst_id3demux_pad_query (GstPad * pad, GstQuery * query);
-static const GstQueryType *gst_id3demux_get_query_types (GstPad * pad);
-static gboolean id3demux_get_upstream_size (GstID3Demux * id3demux);
-static void gst_id3demux_send_tag_event (GstID3Demux * id3demux);
-static gboolean gst_id3demux_send_new_segment (GstID3Demux * id3demux);
-
-static GstElementClass *parent_class = NULL;
-
-GType
-gst_id3demux_get_type (void)
-{
-  static GType plugin_type = 0;
-
-  if (!plugin_type) {
-    static const GTypeInfo plugin_info = {
-      sizeof (GstID3DemuxClass),
-      (GBaseInitFunc) gst_id3demux_base_init,
-      NULL,
-      (GClassInitFunc) gst_id3demux_class_init,
-      NULL,
-      NULL,
-      sizeof (GstID3Demux),
-      0,
-      (GInstanceInitFunc) gst_id3demux_init,
-    };
-    plugin_type = g_type_register_static (GST_TYPE_ELEMENT,
-        "GstID3Demux", &plugin_info, 0);
-  }
-  return plugin_type;
-}
+GST_BOILERPLATE (GstID3Demux, gst_id3demux, GstTagDemux, GST_TYPE_TAG_DEMUX);
 
 static void
-gst_id3demux_base_init (GstID3DemuxClass * klass)
+gst_id3demux_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_element_class_add_pad_template (element_class,
       gst_static_pad_template_get (&sink_factory));
+
   gst_element_class_set_details (element_class, &gst_id3demux_details);
 }
 
 static void
 gst_id3demux_class_init (GstID3DemuxClass * klass)
 {
-  GObjectClass *gobject_class;
-  GstElementClass *gstelement_class;
-
-  gobject_class = (GObjectClass *) klass;
-  gstelement_class = (GstElementClass *) klass;
-
-  parent_class = g_type_class_peek_parent (klass);
-
-  gobject_class->dispose = gst_id3demux_dispose;
+  GstTagDemuxClass *tagdemux_class = (GstTagDemuxClass *) klass;
+  GObjectClass *gobject_class = (GObjectClass *) klass;
 
   gobject_class->set_property = gst_id3demux_set_property;
   gobject_class->get_property = gst_id3demux_get_property;
 
-  gstelement_class->change_state = gst_id3demux_change_state;
-
   g_object_class_install_property (gobject_class, ARG_PREFER_V1,
       g_param_spec_boolean ("prefer-v1", "Prefer version 1 tag",
           "Prefer tags from ID3v1 tag at end of file when both ID3v1 "
-          "and ID3v2 tags are present", FALSE,
+          "and ID3v2 tags are present", DEFAULT_PREFER_V1,
           G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
-}
-
-static void
-gst_id3demux_reset (GstID3Demux * id3demux)
-{
-  GstBuffer **buffer_p = &id3demux->collect;
-  GstCaps **caps_p = &id3demux->src_caps;
-
-  id3demux->strip_start = 0;
-  id3demux->strip_end = 0;
-  id3demux->upstream_size = -1;
-  id3demux->state = GST_ID3DEMUX_READID3V2;
-  id3demux->send_tag_event = FALSE;
-
-  gst_buffer_replace (buffer_p, NULL);
-  gst_caps_replace (caps_p, NULL);
-
-  gst_id3demux_remove_srcpad (id3demux);
 
-  if (id3demux->event_tags) {
-    gst_tag_list_free (id3demux->event_tags);
-    id3demux->event_tags = NULL;
-  }
-  if (id3demux->parsed_tags) {
-    gst_tag_list_free (id3demux->parsed_tags);
-    id3demux->parsed_tags = NULL;
-  }
+  tagdemux_class->identify_tag = GST_DEBUG_FUNCPTR (gst_id3demux_identify_tag);
+  tagdemux_class->parse_tag = GST_DEBUG_FUNCPTR (gst_id3demux_parse_tag);
+  tagdemux_class->merge_tags = GST_DEBUG_FUNCPTR (gst_id3demux_merge_tags);
 
-  gst_segment_init (&id3demux->segment, GST_FORMAT_UNDEFINED);
-  id3demux->need_newseg = TRUE;
-  id3demux->newseg_update = FALSE;
-}
-
-static gboolean
-gst_id3demux_send_new_segment (GstID3Demux * id3demux)
-{
-  GstEvent *event;
-  gint64 start, stop, position;
-  GstSegment *seg = &id3demux->segment;
-
-  if (seg->format == GST_FORMAT_UNDEFINED) {
-    GST_LOG_OBJECT (id3demux,
-        "No new segment received before first buffer. Using default");
-    gst_segment_set_newsegment (seg, FALSE, 1.0,
-        GST_FORMAT_BYTES, id3demux->strip_start, -1, id3demux->strip_start);
-  }
-
-  /* Can't adjust segments in non-BYTES formats */
-  if (id3demux->segment.format != GST_FORMAT_BYTES) {
-    event = gst_event_new_new_segment_full (id3demux->newseg_update,
-        seg->rate, seg->applied_rate, seg->format, seg->start,
-        seg->stop, seg->time);
-    return gst_pad_push_event (id3demux->srcpad, event);
-  }
-
-  start = seg->start;
-  stop = seg->stop;
-  position = seg->time;
-
-  g_return_val_if_fail (start != -1, FALSE);
-  g_return_val_if_fail (position != -1, FALSE);
-
-  if (id3demux->strip_end > 0) {
-    if (id3demux_get_upstream_size (id3demux)) {
-      guint64 v1tag_offset = id3demux->upstream_size - id3demux->strip_end;
-
-      if (start >= v1tag_offset) {
-        /* Segment is completely within the ID3v1 tag, output an open-ended
-         * segment, even though all the buffers will get trimmed away */
-        start = v1tag_offset;
-        stop = -1;
-      }
-
-      if (stop != -1 && stop >= v1tag_offset) {
-        GST_DEBUG_OBJECT (id3demux,
-            "Segment crosses the ID3v1 tag. Trimming end");
-        stop = v1tag_offset;
-      }
-    }
-  }
-
-  if (id3demux->strip_start > 0) {
-    if (start > id3demux->strip_start)
-      start -= id3demux->strip_start;
-    else
-      start = 0;
-
-    if (position > id3demux->strip_start)
-      position -= id3demux->strip_start;
-    else
-      position = 0;
-
-    if (stop != -1) {
-      if (stop > id3demux->strip_start)
-        stop -= id3demux->strip_start;
-      else
-        stop = 0;
-    }
-  }
-
-  GST_DEBUG_OBJECT (id3demux,
-      "Sending new segment update %d, rate %g, format %d, "
-      "start %" G_GINT64_FORMAT ", stop %" G_GINT64_FORMAT ", position %"
-      G_GINT64_FORMAT, id3demux->newseg_update, seg->rate, seg->format,
-      start, stop, position);
-
-  event = gst_event_new_new_segment_full (id3demux->newseg_update,
-      seg->rate, seg->applied_rate, seg->format, start, stop, position);
-
-  return gst_pad_push_event (id3demux->srcpad, event);
+  tagdemux_class->min_start_size = ID3V2_HDR_SIZE;
+  tagdemux_class->min_end_size = ID3V1_TAG_SIZE;
 }
 
 static void
-gst_id3demux_init (GstID3Demux * id3demux)
+gst_id3demux_init (GstID3Demux * id3demux, GstID3DemuxClass * klass)
 {
-  GstElementClass *klass = GST_ELEMENT_GET_CLASS (id3demux);
-
-  id3demux->sinkpad =
-      gst_pad_new_from_template (gst_element_class_get_pad_template (klass,
-          "sink"), "sink");
-  gst_pad_set_activate_function (id3demux->sinkpad,
-      GST_DEBUG_FUNCPTR (gst_id3demux_sink_activate));
-  gst_pad_set_event_function (id3demux->sinkpad,
-      GST_DEBUG_FUNCPTR (gst_id3demux_sink_event));
-  gst_pad_set_chain_function (id3demux->sinkpad,
-      GST_DEBUG_FUNCPTR (gst_id3demux_chain));
-  gst_element_add_pad (GST_ELEMENT (id3demux), id3demux->sinkpad);
-
-  id3demux->prefer_v1 = FALSE;
-  gst_id3demux_reset (id3demux);
-}
-
-static void
-gst_id3demux_dispose (GObject * object)
-{
-  GstID3Demux *id3demux = GST_ID3DEMUX (object);
-
-  gst_id3demux_reset (id3demux);
-
-  G_OBJECT_CLASS (parent_class)->dispose (object);
+  id3demux->prefer_v1 = DEFAULT_PREFER_V1;
 }
 
 static gboolean
-gst_id3demux_add_srcpad (GstID3Demux * id3demux, const GstCaps * new_caps)
+gst_id3demux_identify_tag (GstTagDemux * demux, GstBuffer * buf,
+    gboolean start_tag, guint * tag_size)
 {
-  if (id3demux->src_caps == NULL ||
-      !gst_caps_is_equal (new_caps, id3demux->src_caps)) {
+  const guint8 *data = GST_BUFFER_DATA (buf);
 
-    gst_caps_replace (&(id3demux->src_caps), (GstCaps *) new_caps);
-    if (id3demux->srcpad != NULL) {
-      GST_DEBUG_OBJECT (id3demux, "Changing src pad caps to %" GST_PTR_FORMAT,
-          id3demux->src_caps);
+  if (start_tag) {
+    if (data[0] != 'I' || data[1] != 'D' || data[2] != '3')
+      goto no_marker;
 
-      gst_pad_set_caps (id3demux->srcpad, id3demux->src_caps);
-    }
+    *tag_size = id3demux_calc_id3v2_tag_size (buf);
   } else {
-    /* caps didn't change */
-  }
-
-  if (id3demux->srcpad == NULL) {
-    id3demux->srcpad = gst_pad_new_from_static_template (&src_factory, "src");
-    g_return_val_if_fail (id3demux->srcpad != NULL, FALSE);
-
-    gst_pad_set_query_type_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_get_query_types));
-    gst_pad_set_query_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_pad_query));
-    gst_pad_set_event_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_srcpad_event));
-    gst_pad_set_activatepull_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_src_activate_pull));
-    gst_pad_set_checkgetrange_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_src_checkgetrange));
-    gst_pad_set_getrange_function (id3demux->srcpad,
-        GST_DEBUG_FUNCPTR (gst_id3demux_src_getrange));
-
-    gst_pad_use_fixed_caps (id3demux->srcpad);
-
-    if (id3demux->src_caps)
-      gst_pad_set_caps (id3demux->srcpad, id3demux->src_caps);
-
-    GST_DEBUG_OBJECT (id3demux, "Adding src pad with caps %" GST_PTR_FORMAT,
-        id3demux->src_caps);
+    if (data[0] != 'T' || data[1] != 'A' || data[2] != 'G')
+      goto no_marker;
 
-    gst_object_ref (id3demux->srcpad);
-    gst_pad_set_active (id3demux->srcpad, TRUE);
-    if (!(gst_element_add_pad (GST_ELEMENT (id3demux), id3demux->srcpad)))
-      return FALSE;
-    gst_element_no_more_pads (GST_ELEMENT (id3demux));
+    *tag_size = ID3V1_TAG_SIZE;
   }
 
-  return TRUE;
-}
-
-static gboolean
-gst_id3demux_remove_srcpad (GstID3Demux * id3demux)
-{
-  gboolean res = TRUE;
-
-  if (id3demux->srcpad != NULL) {
-    GST_DEBUG_OBJECT (id3demux, "Removing src pad");
-    res = gst_element_remove_pad (GST_ELEMENT (id3demux), id3demux->srcpad);
-    g_return_val_if_fail (res != FALSE, FALSE);
-    gst_object_unref (id3demux->srcpad);
-    id3demux->srcpad = NULL;
-  }
-
-  return res;
-};
-
-/* will return FALSE if buffer is beyond end of data; will return TRUE
- * if buffer was trimmed successfully or didn't need trimming, but may
- * also return TRUE and set *buf_ref to NULL if the buffer was before
- * the start of the data */
-static gboolean
-gst_id3demux_trim_buffer (GstID3Demux * id3demux, 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 ID3v1 tag at the end of file, trim it */
-  if (id3demux->strip_end > 0) {
-    if (id3demux_get_upstream_size (id3demux)) {
-      guint64 v1tag_offset = id3demux->upstream_size - id3demux->strip_end;
-
-      if (out_offset >= v1tag_offset) {
-        GST_DEBUG_OBJECT (id3demux, "Buffer is past the end of the data");
-        goto no_out_buffer_end;
-      }
-
-      if (out_offset + out_size > v1tag_offset) {
-        out_size = v1tag_offset - out_offset;
-        need_sub = TRUE;
-      }
-    }
-  }
-
-  if (id3demux->strip_start > 0) {
-    /* If the buffer crosses the ID3v2 tag at the start of file, trim it */
-    if (out_offset <= id3demux->strip_start) {
-      if (out_offset + out_size <= id3demux->strip_start) {
-        GST_DEBUG_OBJECT (id3demux, "Buffer is before the start of the data");
-        goto no_out_buffer_start;
-      }
-
-      trim_start = id3demux->strip_start - out_offset;
-      out_size -= trim_start;
-      out_offset = 0;
-    } else {
-      out_offset -= id3demux->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 (id3demux, "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 (id3demux, "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, id3demux->src_caps);
-  }
+  GST_INFO_OBJECT (demux, "Found ID3v%u marker, tag_size = %u",
+      (start_tag) ? 2 : 1, *tag_size);
 
   return TRUE;
 
-no_out_buffer_end:
+no_marker:
   {
-    gst_buffer_unref (buf);
-    *buf_ref = NULL;
+    GST_DEBUG_OBJECT (demux, "No ID3v%u marker found", (start_tag) ? 2 : 1);
     return FALSE;
   }
-no_out_buffer_start:
-  {
-    gst_buffer_unref (buf);
-    *buf_ref = NULL;
-    return TRUE;
-  }
 }
 
-static GstFlowReturn
-gst_id3demux_chain (GstPad * pad, GstBuffer * buf)
+static GstTagDemuxResult
+gst_id3demux_parse_tag (GstTagDemux * demux, GstBuffer * buffer,
+    gboolean start_tag, guint * tag_size, GstTagList ** tags)
 {
-  GstID3Demux *id3demux;
-
-  id3demux = GST_ID3DEMUX (GST_PAD_PARENT (pad));
-  g_return_val_if_fail (GST_IS_ID3DEMUX (id3demux), GST_FLOW_ERROR);
+  if (start_tag) {
+    ID3TagsResult res;          /* FIXME: make id3tags.c return tagmuxresult values */
 
-  /* Update our segment last_stop info */
-  if (id3demux->segment.format == GST_FORMAT_BYTES) {
-    if (GST_BUFFER_OFFSET_IS_VALID (buf))
-      id3demux->segment.last_stop = GST_BUFFER_OFFSET (buf);
-    id3demux->segment.last_stop += GST_BUFFER_SIZE (buf);
-  } else if (id3demux->segment.format == GST_FORMAT_TIME) {
-    if (GST_BUFFER_TIMESTAMP_IS_VALID (buf))
-      id3demux->segment.last_stop = GST_BUFFER_TIMESTAMP (buf);
-    if (GST_BUFFER_DURATION_IS_VALID (buf))
-      id3demux->segment.last_stop += GST_BUFFER_DURATION (buf);
-  }
+    res = id3demux_read_id3v2_tag (buffer, tag_size, tags);
 
-  if (id3demux->collect == NULL) {
-    id3demux->collect = buf;
+    if (G_LIKELY (res == ID3TAGS_READ_TAG))
+      return GST_TAG_DEMUX_RESULT_OK;
+    else
+      return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
   } else {
-    id3demux->collect = gst_buffer_join (id3demux->collect, buf);
-  }
-  buf = NULL;
-
-  switch (id3demux->state) {
-    case GST_ID3DEMUX_READID3V2:
-      if (GST_BUFFER_SIZE (id3demux->collect) < 3)
-        break;                  /* Go get more data first */
-
-      /* need to set offset of first buffer to 0 or trimming won't work */
-      if (!GST_BUFFER_OFFSET_IS_VALID (id3demux->collect) &&
-          memcmp (GST_BUFFER_DATA (id3demux->collect), "ID3", 3) == 0) {
-        GST_WARNING_OBJECT (id3demux, "Fixing up first buffer without offset");
-        id3demux->collect =
-            gst_buffer_make_metadata_writable (id3demux->collect);
-        GST_BUFFER_OFFSET (id3demux->collect) = 0;
-      }
-
-      /* 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_IS_VALID (id3demux->collect) ||
-          GST_BUFFER_OFFSET (id3demux->collect) != 0) {
-        GST_DEBUG_OBJECT (id3demux,
-            "Received buffer with non-zero offset %" G_GINT64_FORMAT
-            ". Can't read tags", GST_BUFFER_OFFSET (id3demux->collect));
-      } else {
-        ID3TagsResult tag_result;
-
-        tag_result = id3demux_read_id3v2_tag (id3demux->collect,
-            &id3demux->strip_start, &id3demux->parsed_tags);
-        if (tag_result == ID3TAGS_MORE_DATA)
-          break;                /* Go get more data and try again */
-        else if (tag_result == ID3TAGS_BROKEN_TAG)
-          GST_WARNING_OBJECT (id3demux,
-              "Ignoring broken ID3v2 tag of size %d", id3demux->strip_start);
-        else
-          GST_DEBUG_OBJECT (id3demux, "Found an ID3v2 tag of size %d\n",
-              id3demux->strip_start);
-
-        id3demux->send_tag_event = TRUE;
-      }
-      id3demux->state = GST_ID3DEMUX_TYPEFINDING;
-
-      /* Fall-through */
-    case GST_ID3DEMUX_TYPEFINDING:{
-      GstTypeFindProbability probability = 0;
-      GstBuffer *typefind_buf = NULL;
-      GstCaps *caps;
-
-      if (GST_BUFFER_SIZE (id3demux->collect) <
-          ID3_TYPE_FIND_MIN_SIZE + id3demux->strip_start)
-        break;                  /* Go get more data first */
-
-      GST_DEBUG_OBJECT (id3demux, "Typefinding with size %d",
-          GST_BUFFER_SIZE (id3demux->collect));
+    *tags = gst_tag_list_new_from_id3v1 (GST_BUFFER_DATA (buffer));
 
-      /* Trim the buffer and adjust offset for typefinding */
-      typefind_buf = id3demux->collect;
-      gst_buffer_ref (typefind_buf);
-      if (!gst_id3demux_trim_buffer (id3demux, &typefind_buf))
-        return GST_FLOW_UNEXPECTED;
+    if (G_UNLIKELY (*tags == NULL))
+      return GST_TAG_DEMUX_RESULT_BROKEN_TAG;
 
-      if (typefind_buf == NULL)
-        break;                  /* Still need more data */
-
-      caps = gst_type_find_helper_for_buffer (GST_OBJECT (id3demux),
-          typefind_buf, &probability);
-
-      if (caps == NULL) {
-        if (GST_BUFFER_SIZE (typefind_buf) < ID3_TYPE_FIND_MAX_SIZE) {
-          /* Just break for more data */
-          gst_buffer_unref (typefind_buf);
-          return GST_FLOW_OK;
-        }
-
-        /* We failed typefind */
-        GST_ELEMENT_ERROR (id3demux, STREAM, TYPE_NOT_FOUND, (NULL),
-            ("Could not detect type for contents within an ID3 tag"));
-        gst_buffer_unref (typefind_buf);
-        gst_buffer_unref (id3demux->collect);
-        id3demux->collect = NULL;
-        return GST_FLOW_ERROR;
-      }
-
-      GST_DEBUG_OBJECT (id3demux, "Found type %" GST_PTR_FORMAT " with a "
-          "probability of %u, buf size was %u", caps, probability,
-          GST_BUFFER_SIZE (typefind_buf));
-
-      gst_buffer_unref (typefind_buf);
-
-      if (!gst_id3demux_add_srcpad (id3demux, caps)) {
-        GST_DEBUG_OBJECT (id3demux, "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 */
-      id3demux->state = GST_ID3DEMUX_STREAMING;
-
-      /* Now that typefinding is complete, post the
-       * tags message */
-      if (id3demux->parsed_tags != NULL) {
-        gst_element_post_message (GST_ELEMENT (id3demux),
-            gst_message_new_tag (GST_OBJECT (id3demux),
-                gst_tag_list_copy (id3demux->parsed_tags)));
-      }
-      /* fall-through */
-    }
-    case GST_ID3DEMUX_STREAMING:{
-      GstBuffer *outbuf = NULL;
-
-      if (id3demux->send_tag_event) {
-        gst_id3demux_send_tag_event (id3demux);
-        id3demux->send_tag_event = FALSE;
-      }
-
-      /* Trim the buffer and adjust offset */
-      if (id3demux->collect) {
-        outbuf = id3demux->collect;
-        id3demux->collect = NULL;
-        if (!gst_id3demux_trim_buffer (id3demux, &outbuf))
-          return GST_FLOW_UNEXPECTED;
-      }
-      if (outbuf) {
-        if (G_UNLIKELY (id3demux->srcpad == NULL)) {
-          gst_buffer_unref (outbuf);
-          return GST_FLOW_ERROR;
-        }
-
-        GST_DEBUG_OBJECT (id3demux, "Pushing buffer %p", outbuf);
-
-        /* Ensure the caps are set correctly */
-        outbuf = gst_buffer_make_metadata_writable (outbuf);
-        gst_buffer_set_caps (outbuf, GST_PAD_CAPS (id3demux->srcpad));
-
-        /* Might need a new segment before the buffer */
-        if (id3demux->need_newseg) {
-          gst_id3demux_send_new_segment (id3demux);
-          id3demux->need_newseg = FALSE;
-        }
-
-        return gst_pad_push (id3demux->srcpad, outbuf);
-      }
-    }
+    *tag_size = ID3V1_TAG_SIZE;
+    return GST_TAG_DEMUX_RESULT_OK;
   }
-  return GST_FLOW_OK;
-
-error:
-  GST_DEBUG_OBJECT (id3demux, "error in chain function");
-
-  return GST_FLOW_ERROR;
 }
 
-static gboolean
-gst_id3demux_sink_event (GstPad * pad, GstEvent * event)
+static GstTagList *
+gst_id3demux_merge_tags (GstTagDemux * tagdemux, const GstTagList * start_tags,
+    const GstTagList * end_tags)
 {
-  GstID3Demux *demux;
-  gboolean ret;
+  GstID3Demux *id3demux;
+  GstTagList *merged;
+  gboolean prefer_v1;
 
-  demux = GST_ID3DEMUX (gst_pad_get_parent (pad));
+  id3demux = GST_ID3DEMUX (tagdemux);
 
-  switch (GST_EVENT_TYPE (event)) {
-    case GST_EVENT_EOS:
-      if (demux->srcpad == NULL) {
-        GST_WARNING_OBJECT (demux, "EOS before we found a type");
-        GST_ELEMENT_ERROR (demux, STREAM, TYPE_NOT_FOUND, (NULL), (NULL));
-      }
-      ret = gst_pad_event_default (pad, event);
-      break;
-    case GST_EVENT_NEWSEGMENT:{
-      gboolean update;
-      gdouble rate, arate;
-      GstFormat format;
-      gint64 start, stop, position;
+  GST_OBJECT_LOCK (id3demux);
+  prefer_v1 = id3demux->prefer_v1;
+  GST_OBJECT_UNLOCK (id3demux);
 
-      gst_event_parse_new_segment_full (event, &update, &rate, &arate,
-          &format, &start, &stop, &position);
+  /* we merge in REPLACE mode, so put the less important tags first */
+  if (prefer_v1)
+    merged = gst_tag_list_merge (start_tags, end_tags, GST_TAG_MERGE_REPLACE);
+  else
+    merged = gst_tag_list_merge (end_tags, start_tags, GST_TAG_MERGE_REPLACE);
 
-      gst_segment_set_newsegment_full (&demux->segment, update, rate,
-          arate, format, start, stop, position);
-      demux->newseg_update = update;
-      demux->need_newseg = TRUE;
-      gst_event_unref (event);
-      ret = TRUE;
-      break;
-    }
-    default:
-      ret = gst_pad_event_default (pad, event);
-      break;
-  }
+  GST_LOG_OBJECT (id3demux, "start  tags: %" GST_PTR_FORMAT, start_tags);
+  GST_LOG_OBJECT (id3demux, "end    tags: %" GST_PTR_FORMAT, end_tags);
+  GST_LOG_OBJECT (id3demux, "merged tags: %" GST_PTR_FORMAT, merged);
 
-  gst_object_unref (demux);
-  return ret;
+  return merged;
 }
 
-
 static void
 gst_id3demux_set_property (GObject * object, guint prop_id,
     const GValue * value, GParamSpec * pspec)
 {
   GstID3Demux *id3demux;
 
-  g_return_if_fail (GST_IS_ID3DEMUX (object));
   id3demux = GST_ID3DEMUX (object);
 
   switch (prop_id) {
-    case ARG_PREFER_V1:
+    case ARG_PREFER_V1:{
+      GST_OBJECT_LOCK (id3demux);
       id3demux->prefer_v1 = g_value_get_boolean (value);
+      GST_OBJECT_UNLOCK (id3demux);
       break;
+    }
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -730,12 +237,13 @@ gst_id3demux_get_property (GObject * object, guint prop_id,
 {
   GstID3Demux *id3demux;
 
-  g_return_if_fail (GST_IS_ID3DEMUX (object));
   id3demux = GST_ID3DEMUX (object);
 
   switch (prop_id) {
     case ARG_PREFER_V1:
+      GST_OBJECT_LOCK (id3demux);
       g_value_set_boolean (value, id3demux->prefer_v1);
+      GST_OBJECT_UNLOCK (id3demux);
       break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
@@ -744,493 +252,6 @@ gst_id3demux_get_property (GObject * object, guint prop_id,
 }
 
 static gboolean
-id3demux_get_upstream_size (GstID3Demux * id3demux)
-{
-  GstFormat format;
-  gint64 result;
-
-  /* Short-cut if we already queried upstream */
-  if (id3demux->upstream_size > 0)
-    return TRUE;
-
-  format = GST_FORMAT_BYTES;
-  if (!gst_pad_query_peer_duration (id3demux->sinkpad, &format, &result) ||
-      result < 0) {
-    return FALSE;
-  }
-
-  id3demux->upstream_size = result;
-  return TRUE;
-}
-
-static gboolean
-gst_id3demux_srcpad_event (GstPad * pad, GstEvent * event)
-{
-  gboolean res = FALSE;
-  GstID3Demux *id3demux = GST_ID3DEMUX (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 &&
-          id3demux->state == GST_ID3DEMUX_STREAMING &&
-          gst_pad_is_linked (id3demux->sinkpad)) {
-        GstEvent *upstream;
-
-        switch (cur_type) {
-          case GST_SEEK_TYPE_SET:
-            if (cur == -1)
-              cur = 0;
-            cur += id3demux->strip_start;
-            break;
-          case GST_SEEK_TYPE_CUR:
-            break;
-          case GST_SEEK_TYPE_END:
-            /* Adjust the seek to be relative to the start of any ID3v1 tag */
-            if (cur > 0)
-              cur = 0;
-            cur -= id3demux->strip_end;
-            break;
-          default:
-            g_assert_not_reached ();
-            break;
-        }
-        switch (stop_type) {
-          case GST_SEEK_TYPE_SET:
-            if (stop != -1) {
-              /* -1 means the end of the file, pass it upstream intact */
-              stop += id3demux->strip_start;
-            }
-            break;
-          case GST_SEEK_TYPE_CUR:
-            break;
-          case GST_SEEK_TYPE_END:
-            /* Adjust the seek to be relative to the start of any ID3v1 tag */
-            if (stop > 0)
-              stop = 0;
-            stop -= id3demux->strip_end;
-            break;
-          default:
-            break;
-        }
-        upstream = gst_event_new_seek (rate, format, flags,
-            cur_type, cur, stop_type, stop);
-        res = gst_pad_push_event (id3demux->sinkpad, upstream);
-      }
-      break;
-    }
-    default:
-      break;
-  }
-
-  gst_event_unref (event);
-  return res;
-}
-
-/* Read and interpret any ID3v1 tag when activating in pull_range */
-static gboolean
-gst_id3demux_read_id3v1 (GstID3Demux * id3demux, GstTagList ** tags)
-{
-  GstBuffer *buffer = NULL;
-  gboolean res = FALSE;
-  ID3TagsResult tag_res;
-  GstFlowReturn flow_ret;
-  guint64 id3v1_offset;
-
-  if (id3demux->upstream_size < ID3V1_TAG_SIZE)
-    return TRUE;
-  id3v1_offset = id3demux->upstream_size - ID3V1_TAG_SIZE;
-
-  flow_ret = gst_pad_pull_range (id3demux->sinkpad, id3v1_offset,
-      ID3V1_TAG_SIZE, &buffer);
-  if (flow_ret != GST_FLOW_OK) {
-    GST_DEBUG_OBJECT (id3demux,
-        "Could not read data from start of file ret=%d", flow_ret);
-    goto beach;
-  }
-
-  if (GST_BUFFER_SIZE (buffer) != ID3V1_TAG_SIZE) {
-    GST_DEBUG_OBJECT (id3demux,
-        "Only managed to read %u bytes from file - not an ID3 file",
-        GST_BUFFER_SIZE (buffer));
-    goto beach;
-  }
-
-  tag_res = id3demux_read_id3v1_tag (buffer, &id3demux->strip_end, tags);
-  if (tag_res == ID3TAGS_READ_TAG) {
-    GST_DEBUG_OBJECT (id3demux,
-        "Read ID3v1 tag - trimming %d bytes from end of file",
-        id3demux->strip_end);
-    res = TRUE;
-  } else if (tag_res == ID3TAGS_BROKEN_TAG) {
-    GST_WARNING_OBJECT (id3demux, "Ignoring broken ID3v1 tag");
-    res = TRUE;
-  }
-beach:
-  if (buffer)
-    gst_buffer_unref (buffer);
-  return res;
-}
-
-/* Read and interpret any ID3v2 tag when activating in pull_range */
-static gboolean
-gst_id3demux_read_id3v2 (GstID3Demux * id3demux, GstTagList ** tags)
-{
-  GstBuffer *buffer = NULL;
-  gboolean res = FALSE;
-  ID3TagsResult tag_res;
-  GstFlowReturn flow_ret;
-
-  /* Handle ID3V2 tag. Try with 4kB to start with */
-  flow_ret = gst_pad_pull_range (id3demux->sinkpad, 0, 4096, &buffer);
-  if (flow_ret != GST_FLOW_OK) {
-    GST_DEBUG_OBJECT (id3demux,
-        "Could not read data from start of file ret=%d", flow_ret);
-    goto beach;
-  }
-
-  if (GST_BUFFER_SIZE (buffer) < ID3V2_HDR_SIZE) {
-    GST_DEBUG_OBJECT (id3demux,
-        "Only managed to read %u bytes from file - not an ID3 file",
-        GST_BUFFER_SIZE (buffer));
-    goto beach;
-  }
-
-  tag_res = id3demux_read_id3v2_tag (buffer, &id3demux->strip_start, tags);
-  if (tag_res == ID3TAGS_MORE_DATA) {
-    /* Need more data to interpret the tag */
-    if (buffer) {
-      gst_buffer_unref (buffer);
-      buffer = NULL;
-    }
-    g_assert (id3demux->strip_start > ID3V2_HDR_SIZE);
-
-    GST_DEBUG_OBJECT (id3demux, "Reading %u bytes to decode ID3v2",
-        id3demux->strip_start);
-    flow_ret = gst_pad_pull_range (id3demux->sinkpad, 0, id3demux->strip_start,
-        &buffer);
-    if (flow_ret != GST_FLOW_OK) {
-      GST_DEBUG_OBJECT (id3demux,
-          "Could not read data from start of file ret=%d", flow_ret);
-      goto beach;
-    }
-    tag_res = id3demux_read_id3v2_tag (buffer, &id3demux->strip_start, tags);
-  }
-
-  if (tag_res == ID3TAGS_READ_TAG) {
-    res = TRUE;
-    GST_DEBUG_OBJECT (id3demux, "Read ID3v2 tag of size %d",
-        id3demux->strip_start);
-  } else if (tag_res == ID3TAGS_BROKEN_TAG) {
-    res = TRUE;
-    GST_WARNING_OBJECT (id3demux, "Ignoring broken ID3v2 tag of size %d",
-        id3demux->strip_start);
-  }
-beach:
-  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_id3demux_sink_activate (GstPad * sinkpad)
-{
-  GstTypeFindProbability probability = 0;
-  GstID3Demux *id3demux = GST_ID3DEMUX (GST_PAD_PARENT (sinkpad));
-  gboolean ret = FALSE;
-  GstCaps *caps = NULL;
-
-  /* 1: */
-  /* If we can activate pull_range upstream, then read any ID3v1 and ID3v2
-   * tags, otherwise activate in push mode and the chain function will 
-   * collect buffers, read the ID3v2 tag and output a buffer to end
-   * preroll.
-   */
-  if (!gst_pad_check_pull_range (sinkpad) ||
-      !gst_pad_activate_pull (sinkpad, TRUE)) {
-    GST_DEBUG_OBJECT (id3demux,
-        "No pull mode. Changing to push, but won't be able to read ID3v1 tags");
-    id3demux->state = GST_ID3DEMUX_READID3V2;
-    return gst_pad_activate_push (sinkpad, TRUE);
-  }
-
-  /* Look for tags at start and end of file */
-  GST_DEBUG_OBJECT (id3demux, "Activated pull mode. Looking for tags");
-  if (!id3demux_get_upstream_size (id3demux))
-    return FALSE;
-
-  id3demux->strip_start = 0;
-  id3demux->strip_end = 0;
-
-
-  if (id3demux->prefer_v1) {
-    if (!gst_id3demux_read_id3v2 (id3demux, &(id3demux->parsed_tags)))
-      return FALSE;
-    if (!gst_id3demux_read_id3v1 (id3demux, &(id3demux->parsed_tags)))
-      return FALSE;
-  } else {
-    if (!gst_id3demux_read_id3v1 (id3demux, &(id3demux->parsed_tags)))
-      return FALSE;
-    if (!gst_id3demux_read_id3v2 (id3demux, &(id3demux->parsed_tags)))
-      return FALSE;
-  }
-  if (id3demux->parsed_tags != NULL) {
-    id3demux->send_tag_event = TRUE;
-  }
-
-  /* 3 - Do typefinding on data */
-  caps = gst_type_find_helper_get_range (GST_OBJECT (id3demux),
-      (GstTypeFindHelperGetRangeFunction) gst_id3demux_read_range,
-      id3demux->upstream_size - id3demux->strip_start - id3demux->strip_end,
-      &probability);
-
-  GST_DEBUG_OBJECT (id3demux, "Found type %" GST_PTR_FORMAT " with a "
-      "probability of %u", caps, probability);
-
-  /* 4 - Deactivate pull mode */
-  if (!gst_pad_activate_pull (sinkpad, FALSE)) {
-    if (caps)
-      gst_caps_unref (caps);
-    GST_DEBUG_OBJECT (id3demux,
-        "Could not deactivate sinkpad after reading tags");
-    return FALSE;
-  }
-
-  /* 5 - If we didn't find the caps, fail */
-  if (caps == NULL) {
-    GST_ELEMENT_ERROR (id3demux, STREAM, TYPE_NOT_FOUND, (NULL),
-        ("Could not detect type for contents within an ID3 tag"));
-    goto done_activate;
-  }
-
-  /* Now that we've finished typefinding, post tag message on bus */
-  if (id3demux->parsed_tags != NULL) {
-    gst_element_post_message (GST_ELEMENT (id3demux),
-        gst_message_new_tag (GST_OBJECT (id3demux),
-            gst_tag_list_copy (id3demux->parsed_tags)));
-  }
-
-  /* tag reading and typefinding were already done, don't do them again in
-     the chain function if we end up in push mode */
-  id3demux->state = GST_ID3DEMUX_STREAMING;
-
-  /* 6 Add the srcpad for output now we know caps. */
-  if (!gst_id3demux_add_srcpad (id3demux, caps)) {
-    GST_DEBUG_OBJECT (id3demux, "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 (id3demux->srcpad, TRUE);
-    ret &= gst_pad_activate_push (sinkpad, TRUE);
-  }
-
-done_activate:
-
-  if (caps)
-    gst_caps_unref (caps);
-
-  return ret;
-}
-
-static gboolean
-gst_id3demux_src_activate_pull (GstPad * pad, gboolean active)
-{
-  GstID3Demux *id3demux = GST_ID3DEMUX (GST_PAD_PARENT (pad));
-
-  return gst_pad_activate_pull (id3demux->sinkpad, active);
-}
-
-static gboolean
-gst_id3demux_src_checkgetrange (GstPad * srcpad)
-{
-  GstID3Demux *id3demux = GST_ID3DEMUX (GST_PAD_PARENT (srcpad));
-
-  return gst_pad_check_pull_range (id3demux->sinkpad);
-}
-
-static GstFlowReturn
-gst_id3demux_read_range (GstID3Demux * id3demux,
-    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 ID3 information. 
-   * For the returned buffer, adjust the output offset to match what downstream
-   * should see */
-  in_offset = offset + id3demux->strip_start;
-
-  if (!id3demux_get_upstream_size (id3demux))
-    return GST_FLOW_ERROR;
-
-  if (in_offset + length >= id3demux->upstream_size - id3demux->strip_end) {
-    if (in_offset + id3demux->strip_end >= id3demux->upstream_size)
-      return GST_FLOW_UNEXPECTED;
-    in_length = id3demux->upstream_size - id3demux->strip_end - in_offset;
-  } else {
-    in_length = length;
-  }
-
-  ret = gst_pad_pull_range (id3demux->sinkpad, in_offset, in_length, buffer);
-  if (ret == GST_FLOW_OK && *buffer) {
-    if (!gst_id3demux_trim_buffer (id3demux, buffer))
-      goto read_beyond_end;
-
-    /* this should only happen in streaming mode */
-    g_assert (*buffer != NULL);
-
-    gst_buffer_set_caps (*buffer, id3demux->src_caps);
-  }
-
-  return ret;
-
-read_beyond_end:
-  {
-    GST_DEBUG_OBJECT (id3demux, "attempted read beyond end of file");
-    if (*buffer != NULL) {
-      gst_buffer_unref (buffer);
-      *buffer = NULL;
-    }
-    return GST_FLOW_UNEXPECTED;
-  }
-}
-
-static GstFlowReturn
-gst_id3demux_src_getrange (GstPad * srcpad,
-    guint64 offset, guint length, GstBuffer ** buffer)
-{
-  GstID3Demux *id3demux = GST_ID3DEMUX (GST_PAD_PARENT (srcpad));
-
-  if (id3demux->send_tag_event) {
-    gst_id3demux_send_tag_event (id3demux);
-    id3demux->send_tag_event = FALSE;
-  }
-  return gst_id3demux_read_range (id3demux, offset, length, buffer);
-}
-
-static GstStateChangeReturn
-gst_id3demux_change_state (GstElement * element, GstStateChange transition)
-{
-  GstStateChangeReturn ret;
-  GstID3Demux *id3demux = GST_ID3DEMUX (element);
-
-  ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
-
-  switch (transition) {
-    case GST_STATE_CHANGE_PAUSED_TO_READY:
-      gst_id3demux_reset (id3demux);
-      break;
-    default:
-      break;
-  }
-  return ret;
-}
-
-static gboolean
-gst_id3demux_pad_query (GstPad * pad, GstQuery * query)
-{
-  /* For a position or duration query, adjust the returned
-   * bytes to strip off the id3v1 and id3v2 areas */
-
-  GstID3Demux *id3demux = GST_ID3DEMUX (GST_PAD_PARENT (pad));
-  GstPad *peer = NULL;
-  GstFormat format;
-  gint64 result;
-
-  if ((peer = gst_pad_get_peer (id3demux->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 -= id3demux->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 -= id3demux->strip_start + id3demux->strip_end;
-        gst_query_set_duration (query, format, result);
-      }
-      break;
-    }
-    default:
-      break;
-  }
-
-  return TRUE;
-}
-
-static const GstQueryType *
-gst_id3demux_get_query_types (GstPad * pad)
-{
-  static const GstQueryType types[] = {
-    GST_QUERY_POSITION,
-    GST_QUERY_DURATION,
-    0
-  };
-
-  return types;
-}
-
-static void
-gst_id3demux_send_tag_event (GstID3Demux * id3demux)
-{
-  /* FIXME: what's the correct merge mode? Docs need to tell... */
-  GstTagList *merged = gst_tag_list_merge (id3demux->event_tags,
-      id3demux->parsed_tags, GST_TAG_MERGE_KEEP);
-
-  if (merged) {
-    GstEvent *event = gst_event_new_tag (merged);
-
-    GST_EVENT_TIMESTAMP (event) = 0;
-    GST_DEBUG_OBJECT (id3demux, "Sending tag event on src pad");
-    gst_pad_push_event (id3demux->srcpad, event);
-  }
-}
-
-static gboolean
 plugin_init (GstPlugin * plugin)
 {
   GST_DEBUG_CATEGORY_INIT (id3demux_debug, "id3demux", 0,
diff --git a/gst/id3demux/gstid3demux.h b/gst/id3demux/gstid3demux.h
index 7f9e18fd..a875502b 100644
--- a/gst/id3demux/gstid3demux.h
+++ b/gst/id3demux/gstid3demux.h
@@ -1,4 +1,5 @@
-/* Copyright 2005 Jan Schmidt <thaytan@mad.scientist.com>
+/* GStreamer ID3 tag demuxer
+ * Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
  * Copyright (C) 2003-2004 Benjamin Otte <otte@gnome.org>
  *
  * This library is free software; you can redistribute it and/or
@@ -20,7 +21,7 @@
 #ifndef __GST_ID3DEMUX_H__
 #define __GST_ID3DEMUX_H__
 
-#include <gst/gst.h>
+#include <gst/tag/gsttagdemux.h>
 
 G_BEGIN_DECLS
 
@@ -38,42 +39,16 @@ G_BEGIN_DECLS
 typedef struct _GstID3Demux      GstID3Demux;
 typedef struct _GstID3DemuxClass GstID3DemuxClass;
 
-typedef enum {
-  GST_ID3DEMUX_READID3V2,
-  GST_ID3DEMUX_TYPEFINDING,
-  GST_ID3DEMUX_STREAMING
-} GstID3DemuxState;
-
 struct _GstID3Demux
 {
-  GstElement element;
-
-  GstPad *sinkpad, *srcpad;
-
-  /* Number of bytes to remove from the start of file (ID3v2) */
-  guint strip_start;
-  /* Number of bytes to remove from the end of file (ID3v1) */
-  guint strip_end;
-  
-  gint64 upstream_size;
+  GstTagDemux tagdemux;
 
-  GstID3DemuxState state;
-  GstBuffer *collect;
-  GstCaps *src_caps;
-  
-  gboolean prefer_v1;
-  GstTagList *event_tags;
-  GstTagList *parsed_tags;
-  gboolean send_tag_event;
-
-  GstSegment segment;
-  gboolean need_newseg;
-  gboolean newseg_update;
+  gboolean prefer_v1;     /* prefer ID3v1 tags over ID3v2 tags? */
 };
 
 struct _GstID3DemuxClass 
 {
-  GstElementClass parent_class;
+  GstTagDemuxClass parent_class;
 };
 
 GType gst_id3demux_get_type (void);
@@ -81,3 +56,4 @@ GType gst_id3demux_get_type (void);
 G_END_DECLS
 
 #endif /* __GST_ID3DEMUX_H__ */
+
diff --git a/gst/id3demux/id3tags.c b/gst/id3demux/id3tags.c
index 249acd0a..b017f2a6 100644
--- a/gst/id3demux/id3tags.c
+++ b/gst/id3demux/id3tags.c
@@ -35,7 +35,7 @@ static ID3TagsResult
 id3demux_id3v2_frames_to_tag_list (ID3TagsWorking * work, guint size);
 
 guint
-read_synch_uint (guint8 * data, guint size)
+read_synch_uint (const guint8 * data, guint size)
 {
   gint i;
   guint result = 0;
@@ -62,50 +62,42 @@ read_synch_uint (guint8 * data, guint size)
   return result;
 }
 
-ID3TagsResult
-id3demux_read_id3v1_tag (GstBuffer * buffer, guint * id3v1_size,
-    GstTagList ** tags)
+guint
+id3demux_calc_id3v2_tag_size (GstBuffer * buf)
 {
-  GstTagList *new_tags;
-
-  guint8 *data;
+  guint8 *data, flags;
+  guint size;
 
-  g_return_val_if_fail (buffer != NULL, ID3TAGS_V1_BAD_SIZE);
+  g_assert (buf != NULL);
+  g_assert (GST_BUFFER_SIZE (buf) >= ID3V2_HDR_SIZE);
 
-  data = GST_BUFFER_DATA (buffer);
-
-  if (GST_BUFFER_SIZE (buffer) != ID3V1_TAG_SIZE)
-    return ID3TAGS_V1_BAD_SIZE;
+  data = GST_BUFFER_DATA (buf);
 
-  /* Check that buffer starts with 'TAG' */
-  if (data[0] != 'T' || data[1] != 'A' || data[2] != 'G') {
-    if (id3v1_size)
-      *id3v1_size = 0;
-    GST_DEBUG ("No ID3v1 tag in data");
-    return ID3TAGS_READ_TAG;
+  /* Check for 'ID3' string at start of buffer */
+  if (data[0] != 'I' || data[1] != 'D' || data[2] != '3') {
+    GST_DEBUG ("No ID3v2 tag in data");
+    return 0;
   }
 
-  g_return_val_if_fail (tags != NULL, ID3TAGS_READ_TAG);
+  /* Read the flags */
+  flags = data[5];
 
-  new_tags = gst_tag_list_new_from_id3v1 (GST_BUFFER_DATA (buffer));
-  if (new_tags == NULL)
-    return ID3TAGS_BROKEN_TAG;
+  /* Read the size from the header */
+  size = read_synch_uint (data + 6, 4);
+  if (size == 0)
+    return ID3V2_HDR_SIZE;
 
-  if (*tags) {
-    GstTagList *merged;
+  size += ID3V2_HDR_SIZE;
 
-    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;
+  /* Expand the read size to include a footer if there is one */
+  if ((flags & ID3V2_HDR_FLAG_FOOTER))
+    size += 10;
 
-  if (id3v1_size)
-    *id3v1_size = ID3V1_TAG_SIZE;
-  return ID3TAGS_READ_TAG;
+  GST_DEBUG ("ID3v2 tag, size: %u bytes", size);
+  return size;
 }
 
+/* caller must pass buffer with full ID3 tag */
 ID3TagsResult
 id3demux_read_id3v2_tag (GstBuffer * buffer, guint * id3v2_size,
     GstTagList ** tags)
@@ -117,24 +109,16 @@ id3demux_read_id3v2_tag (GstBuffer * buffer, guint * id3v2_size,
   ID3TagsResult result;
   guint16 version;
 
-  g_return_val_if_fail (buffer != NULL, ID3TAGS_MORE_DATA);
+  read_size = id3demux_calc_id3v2_tag_size (buffer);
 
-  if (GST_BUFFER_SIZE (buffer) < ID3V2_MARK_SIZE)
-    return ID3TAGS_MORE_DATA;   /* Need more data to decide with */
-
-  data = GST_BUFFER_DATA (buffer);
+  if (id3v2_size)
+    *id3v2_size = read_size;
 
-  /* Check for 'ID3' string at start of buffer */
-  if (data[0] != 'I' || data[1] != 'D' || data[2] != '3') {
-    if (id3v2_size)
-      *id3v2_size = 0;
-    GST_DEBUG ("No ID3v2 tag in data");
-    return ID3TAGS_READ_TAG;
-  }
+  /* Ignore tag if it has no frames attached, but skip the header then */
+  if (read_size <= ID3V2_HDR_SIZE)
+    return ID3TAGS_BROKEN_TAG;
 
-  /* OK, get enough data to read the entire header */
-  if (GST_BUFFER_SIZE (buffer) < ID3V2_HDR_SIZE)
-    return ID3TAGS_MORE_DATA;   /* Need more data to decide with */
+  data = GST_BUFFER_DATA (buffer);
 
   /* Read the version */
   version = GST_READ_UINT16_BE (data + 3);
@@ -142,24 +126,6 @@ id3demux_read_id3v2_tag (GstBuffer * buffer, guint * id3v2_size,
   /* Read the flags */
   flags = data[5];
 
-  /* Read the size from the header */
-  read_size = read_synch_uint (data + 6, 4);
-  if (read_size == 0) {
-    /* Tag has no frames attached. Ignore it, but skip the header */
-    if (id3v2_size)
-      *id3v2_size = ID3V2_HDR_SIZE;
-    return ID3TAGS_BROKEN_TAG;
-  }
-  read_size += ID3V2_HDR_SIZE;
-
-  /* Expand the read size to include a footer if there is one */
-  if (flags & ID3V2_HDR_FLAG_FOOTER) {
-    read_size += 10;
-  }
-
-  if (id3v2_size)
-    *id3v2_size = read_size;
-
   /* Validate the version. At the moment, we only support up to 2.4.0 */
   if (ID3V2_VER_MAJOR (version) > 4 || ID3V2_VER_MINOR (version) > 0) {
     GST_WARNING ("ID3v2 tag is from revision 2.%d.%d, "
@@ -168,6 +134,7 @@ id3demux_read_id3v2_tag (GstBuffer * buffer, guint * id3v2_size,
     return ID3TAGS_READ_TAG;
   }
 
+  /* This shouldn't really happen! Caller should have checked first */
   if (GST_BUFFER_SIZE (buffer) < read_size) {
     GST_DEBUG
         ("Found ID3v2 tag with revision 2.%d.%d - need %u more bytes to read",
@@ -194,18 +161,7 @@ id3demux_read_id3v2_tag (GstBuffer * buffer, guint * id3v2_size,
 
   result = id3demux_id3v2_frames_to_tag_list (&work, read_size);
 
-  /* Actually read the tags */
-  if (work.tags != NULL) {
-    if (*tags) {
-      GstTagList *merged;
-
-      merged = gst_tag_list_merge (*tags, work.tags, GST_TAG_MERGE_REPLACE);
-      gst_tag_list_free (*tags);
-      gst_tag_list_free (work.tags);
-      *tags = merged;
-    } else
-      *tags = work.tags;
-  }
+  *tags = work.tags;
 
   if (work.prev_genre)
     g_free (work.prev_genre);
diff --git a/gst/id3demux/id3tags.h b/gst/id3demux/id3tags.h
index 85a17cd4..705a6a0d 100644
--- a/gst/id3demux/id3tags.h
+++ b/gst/id3demux/id3tags.h
@@ -31,18 +31,17 @@ G_BEGIN_DECLS
 #define ID3V2_HDR_SIZE 10
 
 typedef enum {
-  ID3TAGS_V1_BAD_SIZE,
   ID3TAGS_MORE_DATA,
   ID3TAGS_READ_TAG,
   ID3TAGS_BROKEN_TAG
 } ID3TagsResult;
 
 /* From id3tags.c */
-ID3TagsResult id3demux_read_id3v1_tag (GstBuffer *buffer, guint *id3v1_size,
-  GstTagList **tags);
+guint id3demux_calc_id3v2_tag_size (GstBuffer * buf);
 ID3TagsResult id3demux_read_id3v2_tag (GstBuffer *buffer, guint *id3v2_size,
   GstTagList **tags);
-G_END_DECLS
+
+guint read_synch_uint (const guint8 * data, guint size);
 
 /* Things shared by id3tags.c and id3v2frames.c */
 #define ID3V2_VERSION 0x0400
@@ -119,4 +118,6 @@ enum {
 /* From id3v2frames.c */
 gboolean id3demux_id3v2_parse_frame (ID3TagsWorking *work);
 
+G_END_DECLS
+
 #endif
diff --git a/gst/id3demux/id3v2frames.c b/gst/id3demux/id3v2frames.c
index 153d4943..76d4cbc3 100644
--- a/gst/id3demux/id3v2frames.c
+++ b/gst/id3demux/id3v2frames.c
@@ -61,8 +61,6 @@ static gboolean parse_picture_frame (ID3TagsWorking * work);
 #define ID3V2_ENCODING_UTF16BE 0x02
 #define ID3V2_ENCODING_UTF8    0x03
 
-extern guint read_synch_uint (guint8 * data, guint size);
-
 gboolean
 id3demux_id3v2_parse_frame (ID3TagsWorking * work)
 {