gstreamer/gst/mpegstream/gstmpegparse.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */


/*#define GST_DEBUG_ENABLED*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gstmpegparse.h"
#include "gstmpegclock.h"

static GstFormat scr_format;

GST_DEBUG_CATEGORY_EXTERN (GST_CAT_SEEK);

/* elementfactory information */
static GstElementDetails mpeg_parse_details = {
  "MPEG System Parser",
  "Codec/Parser",
  "Parses MPEG1 and MPEG2 System Streams",
  "Erik Walthinsen <omega@cse.ogi.edu>\n"
  "Wim Taymans <wim.taymans@chello.be>"
};

#define CLASS(o)	GST_MPEG_PARSE_CLASS (G_OBJECT_GET_CLASS (o))

#define DEFAULT_MAX_DISCONT	10000

/* GstMPEGParse signals and args */
enum {
  /* FILL ME */
  LAST_SIGNAL
};

enum {
  ARG_0,
  ARG_SYNC,
  ARG_MAX_DISCONT,
  ARG_STREAMINFO,
  /* FILL ME */
};

static GstStaticPadTemplate sink_factory =
GST_STATIC_PAD_TEMPLATE (
  "sink",
  GST_PAD_SINK,
  GST_PAD_ALWAYS,
  GST_STATIC_CAPS ("video/mpeg, "
      "mpegversion = (int) [ 1, 2 ], "
      "systemstream = (boolean) TRUE"
  )
);

static GstStaticPadTemplate src_factory =
GST_STATIC_PAD_TEMPLATE (
  "src",
  GST_PAD_SRC,
  GST_PAD_ALWAYS,
  GST_STATIC_CAPS ("video/mpeg, "
      "mpegversion = (int) [ 1, 2 ], "
      "systemstream = (boolean) TRUE"
  )
);

static void 		gst_mpeg_parse_class_init	(GstMPEGParseClass *klass);
static void 		gst_mpeg_parse_base_init	(GstMPEGParseClass *klass);
static void 		gst_mpeg_parse_init		(GstMPEGParse *mpeg_parse);
static GstElementStateReturn
			gst_mpeg_parse_change_state	(GstElement *element);

static void 		gst_mpeg_parse_set_clock 	(GstElement *element, GstClock *clock);

static gboolean		gst_mpeg_parse_parse_packhead 	(GstMPEGParse *mpeg_parse, GstBuffer *buffer);
static void 		gst_mpeg_parse_send_data	(GstMPEGParse *mpeg_parse, GstData *data, GstClockTime time);
static void 		gst_mpeg_parse_handle_discont 	(GstMPEGParse *mpeg_parse);

static void 		gst_mpeg_parse_loop 		(GstElement *element);

static void 		gst_mpeg_parse_get_property	(GObject *object, guint prop_id, 
							 GValue *value, GParamSpec *pspec);
static void 		gst_mpeg_parse_set_property	(GObject *object, guint prop_id, 
							 const GValue *value, GParamSpec *pspec);
static void 		gst_mpeg_parse_set_index 	(GstElement *element, GstIndex *index);
static GstIndex*	gst_mpeg_parse_get_index 	(GstElement *element);

static gboolean 	gst_mpeg_parse_release_locks 	(GstElement *element);

static GstElementClass *parent_class = NULL;
/*static guint gst_mpeg_parse_signals[LAST_SIGNAL] = { 0 };*/

GType
gst_mpeg_parse_get_type (void)
{
  static GType mpeg_parse_type = 0;

  if (!mpeg_parse_type) {
    static const GTypeInfo mpeg_parse_info = {
      sizeof(GstMPEGParseClass),
      (GBaseInitFunc)gst_mpeg_parse_base_init,
      NULL,
      (GClassInitFunc)gst_mpeg_parse_class_init,
      NULL,
      NULL,
      sizeof(GstMPEGParse),
      0,
      (GInstanceInitFunc)gst_mpeg_parse_init,
    };
    mpeg_parse_type = g_type_register_static(GST_TYPE_ELEMENT, "GstMPEGParse", &mpeg_parse_info, 0);
  }
  return mpeg_parse_type;
}

static void
gst_mpeg_parse_base_init (GstMPEGParseClass *klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_set_details (element_class, &mpeg_parse_details);
}

static void
gst_mpeg_parse_class_init (GstMPEGParseClass *klass) 
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass*)klass;
  gstelement_class = (GstElementClass*)klass;

  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);

  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_SYNC,
    g_param_spec_boolean ("sync", "Sync", "Synchronize on the stream SCR",
                          FALSE, G_PARAM_READWRITE));
  g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_MAX_DISCONT,
    g_param_spec_int ("max_discont", "Max Discont", "The maximun allowed SCR discontinuity",
                      0, G_MAXINT, DEFAULT_MAX_DISCONT, G_PARAM_READWRITE));

  gobject_class->get_property = gst_mpeg_parse_get_property;
  gobject_class->set_property = gst_mpeg_parse_set_property;

  gstelement_class->change_state  = gst_mpeg_parse_change_state;
  gstelement_class->set_clock     = gst_mpeg_parse_set_clock;
  gstelement_class->get_index     = gst_mpeg_parse_get_index;
  gstelement_class->set_index     = gst_mpeg_parse_set_index;
  gstelement_class->release_locks = gst_mpeg_parse_release_locks;

  klass->parse_packhead = gst_mpeg_parse_parse_packhead;
  klass->parse_syshead 	= NULL;
  klass->parse_packet 	= NULL;
  klass->parse_pes 	= NULL;
  klass->send_data 	= gst_mpeg_parse_send_data;
  klass->handle_discont	= gst_mpeg_parse_handle_discont;

  /* FIXME: this is a hack.  We add the pad templates here instead
   * in the base_init function, since the derived class (mpegdemux)
   * uses different pads.  IMO, this is wrong. */
  gst_element_class_add_pad_template (gstelement_class,
		gst_static_pad_template_get (&src_factory));
  gst_element_class_add_pad_template (gstelement_class,
		gst_static_pad_template_get (&sink_factory));
}

static void
gst_mpeg_parse_init (GstMPEGParse *mpeg_parse)
{
  mpeg_parse->sinkpad = gst_pad_new_from_template(
		  gst_static_pad_template_get (&sink_factory), "sink");
  gst_element_add_pad(GST_ELEMENT(mpeg_parse),mpeg_parse->sinkpad);
  gst_pad_set_formats_function (mpeg_parse->sinkpad, gst_mpeg_parse_get_src_formats);
  gst_pad_set_convert_function (mpeg_parse->sinkpad, gst_mpeg_parse_convert_src);

  mpeg_parse->srcpad = gst_pad_new_from_template(
		  gst_static_pad_template_get (&src_factory), "src");
  gst_element_add_pad(GST_ELEMENT(mpeg_parse),mpeg_parse->srcpad);
  gst_pad_set_formats_function (mpeg_parse->srcpad, gst_mpeg_parse_get_src_formats);
  gst_pad_set_convert_function (mpeg_parse->srcpad, gst_mpeg_parse_convert_src);
  gst_pad_set_event_mask_function (mpeg_parse->srcpad, gst_mpeg_parse_get_src_event_masks);
  gst_pad_set_event_function (mpeg_parse->srcpad, gst_mpeg_parse_handle_src_event);
  gst_pad_set_query_type_function (mpeg_parse->srcpad, gst_mpeg_parse_get_src_query_types);
  gst_pad_set_query_function (mpeg_parse->srcpad, gst_mpeg_parse_handle_src_query);
  gst_pad_use_explicit_caps (mpeg_parse->srcpad);

  gst_element_set_loop_function (GST_ELEMENT (mpeg_parse), gst_mpeg_parse_loop);

  mpeg_parse->packetize = NULL;
  mpeg_parse->sync = FALSE;
  mpeg_parse->id = NULL;
  mpeg_parse->max_discont = DEFAULT_MAX_DISCONT;

  GST_FLAG_SET (mpeg_parse, GST_ELEMENT_EVENT_AWARE);
}

static void
gst_mpeg_parse_set_clock (GstElement *element, GstClock *clock)
{   
  GstMPEGParse *parse = GST_MPEG_PARSE (element);

  parse->clock = clock;
} 

#if 0
static void
gst_mpeg_parse_update_streaminfo (GstMPEGParse *mpeg_parse)
{
  GstProps *props;
  GstPropsEntry *entry;
  gboolean mpeg2 = GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize);
  GstCaps *caps;

  props = gst_props_empty_new ();

  entry = gst_props_entry_new ("mpegversion", G_TYPE_INT (mpeg2 ? 2 : 1));
  gst_props_add_entry (props, (GstPropsEntry *) entry);

  entry = gst_props_entry_new ("bitrate", G_TYPE_INT (mpeg_parse->mux_rate * 400)); 
  gst_props_add_entry (props, (GstPropsEntry *) entry);

  caps = gst_caps_new ("mpeg_streaminfo",
	               "application/x-gst-streaminfo",
	  	       props);

  gst_caps_replace_sink (&mpeg_parse->streaminfo, caps);
  g_object_notify (G_OBJECT (mpeg_parse), "streaminfo");
}
#endif

static void
gst_mpeg_parse_send_data (GstMPEGParse *mpeg_parse, GstData *data, GstClockTime time)
{
  if (GST_IS_EVENT (data)) {
    GstEvent *event = GST_EVENT (data);

    switch (GST_EVENT_TYPE (event)) {
      default:
	gst_pad_event_default (mpeg_parse->sinkpad, event);
	break;
    }
  }
  else {
    if (!GST_PAD_CAPS (mpeg_parse->srcpad)) {
      gboolean mpeg2 = GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize);

      gst_pad_set_explicit_caps (mpeg_parse->srcpad,
	  gst_caps_new_simple ("video/mpeg",
	    "mpegversion",  G_TYPE_INT,  (mpeg2 ? 2 : 1),
	    "systemstream", G_TYPE_BOOLEAN, TRUE,
	    "parsed",       G_TYPE_BOOLEAN, TRUE, NULL));
    }

    GST_BUFFER_TIMESTAMP (data) = time;
    GST_DEBUG ("current_scr %" G_GINT64_FORMAT, time);

    if (GST_PAD_IS_USABLE (mpeg_parse->srcpad))
      gst_pad_push (mpeg_parse->srcpad, GST_DATA (data));
    else
      gst_data_unref (data);
  }
}

static void
gst_mpeg_parse_handle_discont (GstMPEGParse *mpeg_parse)
{
  GstEvent *event;

  event = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME, 
		  MPEGTIME_TO_GSTTIME (mpeg_parse->current_scr), NULL);

  if (GST_PAD_IS_USABLE (mpeg_parse->srcpad))
    gst_pad_push (mpeg_parse->srcpad, GST_DATA (event));
  else
    gst_event_unref (event);
}

static gboolean
gst_mpeg_parse_parse_packhead (GstMPEGParse *mpeg_parse, GstBuffer *buffer)
{
  guint8 *buf;
  guint64 scr, scr_adj, scr_orig;
  guint32 scr1, scr2;
  guint32 new_rate;

  GST_DEBUG ("in parse_packhead");

  buf = GST_BUFFER_DATA (buffer);
  buf += 4;

  scr1 = GUINT32_FROM_BE (*(guint32*) buf);
  scr2 = GUINT32_FROM_BE (*(guint32*) (buf+4));

  if (GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize)) {
    guint32 scr_ext;

    /* :2=01 ! scr:3 ! marker:1==1 ! scr:15 ! marker:1==1 ! scr:15 */
    scr  = (scr1 & 0x38000000) << 3;
    scr |= (scr1 & 0x03fff800) << 4;
    scr |= (scr1 & 0x000003ff) << 5;
    scr |= (scr2 & 0xf8000000) >> 27;

    scr_ext = (scr2 & 0x03fe0000) >> 17;

    scr = (scr * 300 + scr_ext % 300) / 300;

    GST_DEBUG ("%" G_GINT64_FORMAT " %d, %08x %08x %" G_GINT64_FORMAT " diff: %" G_GINT64_FORMAT, 
		    scr, scr_ext, scr1, scr2, mpeg_parse->bytes_since_scr, 
		    scr - mpeg_parse->current_scr);

    buf += 6;
    new_rate = (GUINT32_FROM_BE ((*(guint32 *) buf)) & 0xfffffc00) >> 10;
  }
  else {
    scr  = (scr1 & 0x0e000000) << 5;
    scr |= (scr1 & 0x00fffe00) << 6;
    scr |= (scr1 & 0x000000ff) << 7;
    scr |= (scr2 & 0xfe000000) >> 25;

    buf += 5;
    /* we do this byte by byte because buf[3] might be outside of buf's
     * memory space */
    new_rate = (buf[0] & 0x7f) << 15;
    new_rate |= buf[1] << 7;
    new_rate |= buf[2] >> 1;
  }

  scr_orig = scr;
  mpeg_parse->bytes_since_scr = 0;
  scr_adj = scr + mpeg_parse->adjust;

  if (mpeg_parse->next_scr == -1) {
    mpeg_parse->next_scr = scr;
  }

  GST_DEBUG ("SCR is %" G_GUINT64_FORMAT " (%" G_GUINT64_FORMAT ") next: %" 
	     G_GINT64_FORMAT " (%" G_GINT64_FORMAT ") diff: %" G_GINT64_FORMAT " (%" 
	     G_GINT64_FORMAT ")", 
		  scr, 
		  MPEGTIME_TO_GSTTIME (scr),
		  mpeg_parse->next_scr,
		  MPEGTIME_TO_GSTTIME (mpeg_parse->next_scr),
		  scr - mpeg_parse->next_scr,
		  MPEGTIME_TO_GSTTIME (scr) -
		  MPEGTIME_TO_GSTTIME (mpeg_parse->next_scr));

  if (ABS ((gint64)mpeg_parse->next_scr - (gint64)(scr_adj)) > mpeg_parse->max_discont) {
    GST_DEBUG ("discontinuity detected; expected: %" 
	       G_GUINT64_FORMAT " got: %" G_GUINT64_FORMAT " real:%" 
	       G_GINT64_FORMAT " adjust:%" G_GINT64_FORMAT, 
           mpeg_parse->next_scr, scr_adj, scr, mpeg_parse->adjust);

    mpeg_parse->adjust = mpeg_parse->next_scr - scr;
    scr = mpeg_parse->next_scr;

    GST_DEBUG ("new adjust: %" G_GINT64_FORMAT, mpeg_parse->adjust);
  }
  else {
    scr = scr_adj;
  }

  if (mpeg_parse->index && GST_INDEX_IS_WRITABLE (mpeg_parse->index)) {
    /* update index if any */
    gst_index_add_association (mpeg_parse->index, mpeg_parse->index_id, 
		    	       GST_ASSOCIATION_FLAG_KEY_UNIT,
		               GST_FORMAT_BYTES, GST_BUFFER_OFFSET (buffer), 
			       GST_FORMAT_TIME, MPEGTIME_TO_GSTTIME (scr), 0);
  }

  mpeg_parse->current_scr = scr;
  mpeg_parse->scr_pending = FALSE;

  if (mpeg_parse->mux_rate != new_rate) {
    mpeg_parse->mux_rate = new_rate;

    //gst_mpeg_parse_update_streaminfo (mpeg_parse);
    GST_DEBUG ("stream is %1.3fMbs", (mpeg_parse->mux_rate * 400) / 1000000.0);
  }

  return TRUE;
}

static void
gst_mpeg_parse_loop (GstElement *element)
{
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (element);
  GstData *data;
  guint id;
  gboolean mpeg2;
  GstClockTime time;

  data = gst_mpeg_packetize_read (mpeg_parse->packetize);
  if (!data)
    return;

  id = GST_MPEG_PACKETIZE_ID (mpeg_parse->packetize);
  mpeg2 = GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize);
    
  if (GST_IS_BUFFER (data)) {
    GstBuffer *buffer = GST_BUFFER (data);

    GST_DEBUG ("have chunk 0x%02X", id);

    switch (id) {
      case 0xb9:
	break;
      case 0xba:
        if (CLASS (mpeg_parse)->parse_packhead) {
	  CLASS (mpeg_parse)->parse_packhead (mpeg_parse, buffer);
	}
	break;
      case 0xbb:
	if (CLASS (mpeg_parse)->parse_syshead) {
	  CLASS (mpeg_parse)->parse_syshead (mpeg_parse, buffer);
	}
	break;
      default:
        if (mpeg2 && ((id < 0xBD) || (id > 0xFE))) {
          g_warning ("******** unknown id 0x%02X", id); 
        }
	else {
	  if (mpeg2) {
	    if (CLASS (mpeg_parse)->parse_pes) {
	      CLASS (mpeg_parse)->parse_pes (mpeg_parse, buffer);
	    }
	  }
	  else {
	    if (CLASS (mpeg_parse)->parse_packet) {
	      CLASS (mpeg_parse)->parse_packet (mpeg_parse, buffer);
	    }
	  }
        }
    }
  }

  time = MPEGTIME_TO_GSTTIME (mpeg_parse->current_scr);

  if (GST_IS_EVENT (data)) {
    GstEvent *event = GST_EVENT (data);

    switch (GST_EVENT_TYPE (event)) {
      case GST_EVENT_DISCONTINUOUS:
        GST_DEBUG ("event: %d\n", GST_EVENT_TYPE (data));

        mpeg_parse->discont_pending = TRUE;
        mpeg_parse->packetize->resync = TRUE;
	gst_event_unref (event);
	return;
      default:
	break;
    }
    if (CLASS (mpeg_parse)->send_data)
      CLASS (mpeg_parse)->send_data (mpeg_parse, data, time);
    else
      gst_event_unref (event);
  }
  else {
    guint64 size;
	    
    /* we're not sending data as long as no new SCR was found */
    if (mpeg_parse->discont_pending) {
      if (!mpeg_parse->scr_pending) {
        if (mpeg_parse->clock && mpeg_parse->sync) {
          gst_clock_handle_discont (mpeg_parse->clock, MPEGTIME_TO_GSTTIME (mpeg_parse->current_scr));
        }
	if (CLASS (mpeg_parse)->handle_discont) {
	  CLASS (mpeg_parse)->handle_discont (mpeg_parse);
	}
        mpeg_parse->discont_pending = FALSE;
      }
      else {
	GST_DEBUG ("waiting for SCR\n");
      }
      gst_buffer_unref (GST_BUFFER (data));
      return;

    }

    size = GST_BUFFER_SIZE (data);
    mpeg_parse->bytes_since_scr += size;

    if (!GST_PAD_CAPS (mpeg_parse->sinkpad)) {
      gboolean mpeg2 = GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize);

      if (gst_pad_try_set_caps (mpeg_parse->sinkpad,
	    gst_caps_new_simple ("video/mpeg",
	      "mpegversion",  G_TYPE_INT,  (mpeg2 ? 2 : 1),
	      "systemstream", G_TYPE_BOOLEAN, TRUE,
	      "parsed",       G_TYPE_BOOLEAN, TRUE, NULL)) < 0)
      {
	gst_element_error (GST_ELEMENT (mpeg_parse), "could no set sink caps");
	return;
      }
    }

    if (CLASS (mpeg_parse)->send_data)
      CLASS (mpeg_parse)->send_data (mpeg_parse, data, time);

    if (mpeg_parse->clock && mpeg_parse->sync && !mpeg_parse->discont_pending) {
      mpeg_parse->id = gst_clock_new_single_shot_id (mpeg_parse->clock, time);

      GST_DEBUG ("syncing mpegparse");
      gst_element_clock_wait (GST_ELEMENT (mpeg_parse), mpeg_parse->id, NULL);
      gst_clock_id_free (mpeg_parse->id);
      mpeg_parse->id = NULL;
    }

    if (mpeg_parse->current_scr != -1)
    {
      guint64 scr, bss, br;

      scr = mpeg_parse->current_scr;
      bss = mpeg_parse->bytes_since_scr;
      br = mpeg_parse->mux_rate * 50;
      
      if (br) {
        if (GST_MPEG_PACKETIZE_IS_MPEG2 (mpeg_parse->packetize)) {
          /* 
	   * The mpeg spec says something like this, but that doesn't really work:
	   *
	   * mpeg_parse->next_scr = (scr * br + bss * CLOCK_FREQ) / (CLOCK_FREQ + br);
	   */
          mpeg_parse->next_scr = scr + (bss * CLOCK_FREQ) / br;
        }
        else {
          /* we are interpolating the scr here */
          mpeg_parse->next_scr = scr + (bss * CLOCK_FREQ) / br;
        }
      }
      else {
	/* no bitrate known */
        mpeg_parse->next_scr = scr;
      }

      GST_DEBUG ("size: %" G_GINT64_FORMAT ", total since SCR: %" G_GINT64_FORMAT ", next SCR: %" G_GINT64_FORMAT, 
		       size, bss, mpeg_parse->next_scr);
    }
  }
}

const GstFormat*
gst_mpeg_parse_get_src_formats (GstPad *pad)
{
  static const GstFormat formats[] = {
    GST_FORMAT_BYTES,
    GST_FORMAT_TIME,		
    0 
  };
  return formats;
}

gboolean
gst_mpeg_parse_convert_src (GstPad *pad, GstFormat src_format, gint64 src_value,
		            GstFormat *dest_format, gint64 *dest_value)
{
  gboolean res = TRUE;
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (gst_pad_get_parent (pad));

  switch (src_format) {
    case GST_FORMAT_BYTES:
      switch (*dest_format) {
        case GST_FORMAT_DEFAULT:
          *dest_format = GST_FORMAT_TIME;
        case GST_FORMAT_TIME:
	  if (mpeg_parse->mux_rate == 0)
	    res = FALSE;
	  else
            *dest_value = src_value * GST_SECOND / (mpeg_parse->mux_rate * 50);
          break;
        default:
          res = FALSE;
      }
      break;
    case GST_FORMAT_TIME:
      switch (*dest_format) {
        case GST_FORMAT_DEFAULT:
          *dest_format = GST_FORMAT_BYTES;
        case GST_FORMAT_BYTES:
          *dest_value = mpeg_parse->mux_rate * 50 * src_value / GST_SECOND;
          break;
        default:
          res = FALSE;
      }
      break;
    default:
      res = FALSE;
      break;
  }
  return res;
}

const GstQueryType*
gst_mpeg_parse_get_src_query_types (GstPad *pad)
{
  static const GstQueryType types[] = {
    GST_QUERY_TOTAL,
    GST_QUERY_POSITION,
    0 
  };
  return types;
}

gboolean
gst_mpeg_parse_handle_src_query (GstPad *pad, GstQueryType type, 
			         GstFormat *format, gint64 *value)
{
  gboolean res = TRUE;
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (gst_pad_get_parent (pad));
  GstFormat src_format;
  gint64 src_value;

  switch (type) {
    case GST_QUERY_TOTAL:
    {
      switch (*format) {
        case GST_FORMAT_DEFAULT:
          *format = GST_FORMAT_TIME;
          /* fallthrough */
	default:
	  src_format = GST_FORMAT_BYTES;
	  if (!gst_pad_query (GST_PAD_PEER (mpeg_parse->sinkpad),
			      GST_QUERY_TOTAL, &src_format, &src_value)) 
	  {
	    res = FALSE;
	  }
	  break;
      }
      break;
    }
    case GST_QUERY_POSITION:
    {
      switch (*format) {
        case GST_FORMAT_DEFAULT:
          *format = GST_FORMAT_TIME;
          /* fallthrough */
	default:
	  src_format = GST_FORMAT_TIME;
          src_value = MPEGTIME_TO_GSTTIME (mpeg_parse->current_scr);
	  break;
      }
      break;
    }
    default:
      res = FALSE;
      break;
  }

  /* bring to requested format */
  if (res)
    res = gst_pad_convert (pad, src_format, src_value, format, value);

  return res;
}

const GstEventMask*
gst_mpeg_parse_get_src_event_masks (GstPad *pad)
{
  static const GstEventMask masks[] = {
    { GST_EVENT_SEEK, GST_SEEK_METHOD_SET | GST_SEEK_FLAG_FLUSH },
    { 0, }
  };
  return masks;
}

static gboolean
index_seek (GstPad *pad, GstEvent *event, guint64 *offset, gint64 *scr)
{
  GstIndexEntry *entry;
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (gst_pad_get_parent (pad));

  entry = gst_index_get_assoc_entry (mpeg_parse->index, mpeg_parse->index_id,
                                     GST_INDEX_LOOKUP_BEFORE, 0,
                                     GST_EVENT_SEEK_FORMAT (event),
	                             GST_EVENT_SEEK_OFFSET (event));
  if (!entry)
    return FALSE;

  if (gst_index_entry_assoc_map (entry, GST_FORMAT_BYTES, offset)) {
    gint64 time;

    if (gst_index_entry_assoc_map (entry, GST_FORMAT_TIME, &time)) {
      *scr = GSTTIME_TO_MPEGTIME (time);
    }
    GST_CAT_DEBUG (GST_CAT_SEEK, "%s:%s index %s %" G_GINT64_FORMAT
		   " -> %" G_GINT64_FORMAT " bytes, scr=%" G_GINT64_FORMAT,
		   GST_DEBUG_PAD_NAME (pad),
		   gst_format_get_details (GST_EVENT_SEEK_FORMAT (event))->nick,
		   GST_EVENT_SEEK_OFFSET (event),
		   *offset, *scr);
    return TRUE;
  }
  return FALSE;
}

static gboolean
normal_seek (GstPad *pad, GstEvent *event, guint64 *offset, gint64 *scr)
{
  gboolean res;
  GstFormat format;
  gint64 time;

  /* bring offset to bytes */
  format = GST_FORMAT_BYTES;
  res  = gst_pad_convert (pad, 
		          GST_EVENT_SEEK_FORMAT (event),
		          GST_EVENT_SEEK_OFFSET (event),
		          &format,
		          offset);
  /* bring offset to time */
  format = GST_FORMAT_TIME;
  res &= gst_pad_convert (pad, 
		          GST_EVENT_SEEK_FORMAT (event),
		          GST_EVENT_SEEK_OFFSET (event),
			  &format,
			  &time);

  /* convert to scr */
  *scr = GSTTIME_TO_MPEGTIME (time);

  return res;
}

gboolean
gst_mpeg_parse_handle_src_event (GstPad *pad, GstEvent *event)
{
  gboolean res = FALSE;
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (gst_pad_get_parent (pad));

  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_SEEK:
    {
      guint64 desired_offset;
      guint64 expected_scr;

      /* first to to use the index if we have one */
      if (mpeg_parse->index) 
        res = index_seek (pad, event, &desired_offset, &expected_scr);
      /* nothing found, try fuzzy seek */
      if (!res) 
        res = normal_seek (pad, event, &desired_offset, &expected_scr);

      if (!res)
	break;
	      
      GST_DEBUG ("sending seek to %" G_GINT64_FORMAT, desired_offset);
      if (gst_bytestream_seek (mpeg_parse->packetize->bs, desired_offset, GST_SEEK_METHOD_SET)) {
        mpeg_parse->discont_pending = TRUE;
        mpeg_parse->scr_pending = TRUE;
        mpeg_parse->next_scr = expected_scr;
        mpeg_parse->current_scr = -1;
        mpeg_parse->adjust = 0;
        res = TRUE;
      }
      break;
    }
    default:
      break;
  }
  gst_event_unref (event);
  return res;
}

static GstElementStateReturn
gst_mpeg_parse_change_state (GstElement *element) 
{
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (element);

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_READY_TO_PAUSED:
      if (!mpeg_parse->packetize) {
        mpeg_parse->packetize = gst_mpeg_packetize_new (mpeg_parse->sinkpad, GST_MPEG_PACKETIZE_SYSTEM);
      }
      /* initialize parser state */
      mpeg_parse->current_scr = 0;
      mpeg_parse->bytes_since_scr = 0;
      mpeg_parse->adjust = 0;
      mpeg_parse->next_scr = 0;

      /* zero counters (should be done at RUNNING?) */
      mpeg_parse->mux_rate = 0;
      mpeg_parse->discont_pending = FALSE;
      mpeg_parse->scr_pending = FALSE;
      break;
    case GST_STATE_PAUSED_TO_READY:
      if (mpeg_parse->packetize) {
        gst_mpeg_packetize_destroy (mpeg_parse->packetize);
        mpeg_parse->packetize = NULL;
      }
      //gst_caps_replace (&mpeg_parse->streaminfo, NULL);
      break;
    default:
      break;
  }

  return GST_ELEMENT_CLASS (parent_class)->change_state (element);
}

static void
gst_mpeg_parse_get_property (GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
  GstMPEGParse *mpeg_parse;

  mpeg_parse = GST_MPEG_PARSE(object);

  switch (prop_id) {
    case ARG_SYNC: 
      g_value_set_boolean (value, mpeg_parse->sync);
      break;
    case ARG_MAX_DISCONT: 
      g_value_set_int (value, mpeg_parse->max_discont);
      break;
    default: 
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_mpeg_parse_set_property (GObject *object, guint prop_id, 
			     const GValue *value, GParamSpec *pspec)
{
  GstMPEGParse *mpeg_parse;

  mpeg_parse = GST_MPEG_PARSE (object);

  switch (prop_id) {
    case ARG_SYNC: 
      mpeg_parse->sync = g_value_get_boolean (value); 
      break;
    case ARG_MAX_DISCONT: 
      mpeg_parse->max_discont = g_value_get_int (value); 
      break;
    default: 
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_mpeg_parse_set_index (GstElement *element, GstIndex *index)
{
  GstMPEGParse *mpeg_parse;

  mpeg_parse = GST_MPEG_PARSE (element);
  
  mpeg_parse->index = index;

  gst_index_get_writer_id (index, GST_OBJECT (mpeg_parse->sinkpad),
		           &mpeg_parse->index_id);
  gst_index_add_format (index, mpeg_parse->index_id, scr_format);
}

static GstIndex*
gst_mpeg_parse_get_index (GstElement *element)
{
  GstMPEGParse *mpeg_parse;

  mpeg_parse = GST_MPEG_PARSE (element);
  
  return mpeg_parse->index;
}

static gboolean
gst_mpeg_parse_release_locks (GstElement *element)
{
  GstMPEGParse *mpeg_parse;

  mpeg_parse = GST_MPEG_PARSE (element);

  if (mpeg_parse->id) {
    gst_clock_id_unlock (mpeg_parse->id);
  }

  return TRUE;
}

gboolean
gst_mpeg_parse_plugin_init (GstPlugin *plugin)
{
  scr_format = gst_format_register ("scr", "The MPEG system clock reference time");

  return gst_element_register (plugin, "mpegparse",
			       GST_RANK_NONE, GST_TYPE_MPEG_PARSE);
}