gstreamer/gst/mpegstream/gstmpegdemux.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 <gstmpegdemux.h>

GST_DEBUG_CATEGORY_EXTERN (GST_CAT_SEEK);

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

/* MPEG2Demux signals and args */
enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  ARG_BIT_RATE,
  ARG_MPEG2,
  /* 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 audio_factory =
GST_STATIC_PAD_TEMPLATE ("audio_%02d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS ("audio/mpeg, "
	"mpegversion = (int) 1, " "layer = (int) { 1, 2 }")
    );

static GstStaticPadTemplate video_src_factory =
GST_STATIC_PAD_TEMPLATE ("video_%02d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS ("video/mpeg, "
	"mpegversion = (int) { 1, 2 }, " "systemstream = (boolean) FALSE")
    );

static GstStaticPadTemplate private1_factory =
GST_STATIC_PAD_TEMPLATE ("private_stream_1_%02d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS ("audio/x-ac3")
    );

static GstStaticPadTemplate private2_factory =
GST_STATIC_PAD_TEMPLATE ("private_stream_2",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS_ANY);

static GstStaticPadTemplate pcm_factory =
GST_STATIC_PAD_TEMPLATE ("pcm_stream_%02d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS ("audio/x-raw-int, "
	"endianness = (int) BIG_ENDIAN, "
	"signed = (boolean) TRUE, "
	"width = (int) { 16, 20, 24 }, "
	"depth = (int) { 16, 20, 24 }, "
	"rate = (int) { 48000, 96000 }, " "channels = (int) [ 1, 8 ]")
    );

static GstStaticPadTemplate subtitle_factory =
GST_STATIC_PAD_TEMPLATE ("subtitle_stream_%d",
    GST_PAD_SRC,
    GST_PAD_SOMETIMES,
    GST_STATIC_CAPS_ANY);

static void gst_mpeg_demux_class_init (GstMPEGDemuxClass * klass);
static void gst_mpeg_demux_base_init (GstMPEGDemuxClass * klass);
static void gst_mpeg_demux_init (GstMPEGDemux * mpeg_demux);

static gboolean gst_mpeg_demux_parse_packhead (GstMPEGParse * mpeg_parse,
    GstBuffer * buffer);
static gboolean gst_mpeg_demux_parse_syshead (GstMPEGParse * mpeg_parse,
    GstBuffer * buffer);
static gboolean gst_mpeg_demux_parse_packet (GstMPEGParse * mpeg_parse,
    GstBuffer * buffer);
static gboolean gst_mpeg_demux_parse_pes (GstMPEGParse * mpeg_parse,
    GstBuffer * buffer);
static void gst_mpeg_demux_send_data (GstMPEGParse * mpeg_parse, GstData * data,
    GstClockTime time);

static void gst_mpeg_demux_lpcm_set_caps (GstPad * pad, guint8 sample_info);
static void gst_mpeg_demux_dvd_audio_clear (GstMPEGDemux * mpeg_demux,
    int channel);

static void gst_mpeg_demux_handle_discont (GstMPEGParse * mpeg_parse);
static gboolean gst_mpeg_demux_handle_src_event (GstPad * pad,
    GstEvent * event);

const GstFormat *gst_mpeg_demux_get_src_formats (GstPad * pad);
static void gst_mpeg_demux_set_index (GstElement * element, GstIndex * index);
static GstIndex *gst_mpeg_demux_get_index (GstElement * element);

static GstElementStateReturn gst_mpeg_demux_change_state (GstElement * element);

static GstMPEGParseClass *parent_class = NULL;

/*static guint gst_mpeg_demux_signals[LAST_SIGNAL] = { 0 };*/

GType
mpeg_demux_get_type (void)
{
  static GType mpeg_demux_type = 0;

  if (!mpeg_demux_type) {
    static const GTypeInfo mpeg_demux_info = {
      sizeof (GstMPEGDemuxClass),
      (GBaseInitFunc) gst_mpeg_demux_base_init,
      NULL,
      (GClassInitFunc) gst_mpeg_demux_class_init,
      NULL,
      NULL,
      sizeof (GstMPEGDemux),
      0,
      (GInstanceInitFunc) gst_mpeg_demux_init,
    };
    mpeg_demux_type =
	g_type_register_static (GST_TYPE_MPEG_PARSE, "GstMPEGDemux",
	&mpeg_demux_info, 0);
  }
  return mpeg_demux_type;
}

static void
gst_mpeg_demux_base_init (GstMPEGDemuxClass * 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_add_pad_template (element_class,
      gst_static_pad_template_get (&video_src_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&private1_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&private2_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&pcm_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&subtitle_factory));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&audio_factory));
  gst_element_class_set_details (element_class, &mpeg_demux_details);

}

static void
gst_mpeg_demux_class_init (GstMPEGDemuxClass * klass)
{
  GstMPEGParseClass *mpeg_parse_class;
  GstElementClass *gstelement_class;

  parent_class = g_type_class_ref (GST_TYPE_MPEG_PARSE);

  mpeg_parse_class = (GstMPEGParseClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  gstelement_class->change_state = gst_mpeg_demux_change_state;
  gstelement_class->set_index = gst_mpeg_demux_set_index;
  gstelement_class->get_index = gst_mpeg_demux_get_index;

  mpeg_parse_class->parse_packhead = gst_mpeg_demux_parse_packhead;
  mpeg_parse_class->parse_syshead = gst_mpeg_demux_parse_syshead;
  mpeg_parse_class->parse_packet = gst_mpeg_demux_parse_packet;
  mpeg_parse_class->parse_pes = gst_mpeg_demux_parse_pes;
  mpeg_parse_class->send_data = gst_mpeg_demux_send_data;
  mpeg_parse_class->handle_discont = gst_mpeg_demux_handle_discont;

}

static void
gst_mpeg_demux_init (GstMPEGDemux * mpeg_demux)
{
  gint i;
  GstMPEGParse *mpeg_parse = GST_MPEG_PARSE (mpeg_demux);

  gst_element_remove_pad (GST_ELEMENT (mpeg_parse), mpeg_parse->sinkpad);
  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_element_remove_pad (GST_ELEMENT (mpeg_parse), mpeg_parse->srcpad);

  /* i think everything is already zero'd, but oh well */
  for (i = 0; i < NUM_PRIVATE_1_STREAMS; i++) {
    mpeg_demux->private_1_stream[i] = NULL;
  }
  for (i = 0; i < NUM_PCM_STREAMS; i++) {
    mpeg_demux->pcm_stream[i] = NULL;
  }
  for (i = 0; i < NUM_SUBTITLE_STREAMS; i++) {
    mpeg_demux->subtitle_stream[i] = NULL;
  }
  mpeg_demux->private_2_stream = NULL;
  for (i = 0; i < NUM_VIDEO_STREAMS; i++) {
    mpeg_demux->video_stream[i] = NULL;
  }
  for (i = 0; i < NUM_AUDIO_STREAMS; i++) {
    mpeg_demux->audio_stream[i] = NULL;
  }

  GST_FLAG_SET (mpeg_demux, GST_ELEMENT_EVENT_AWARE);
}

static GstMPEGStream *
gst_mpeg_demux_new_stream (void)
{
  GstMPEGStream *stream;

  stream = g_new0 (GstMPEGStream, 1);

  return stream;
}

static void
gst_mpeg_demux_send_data (GstMPEGParse * mpeg_parse, GstData * data,
    GstClockTime time)
{
  /* GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (mpeg_parse); */

  if (GST_IS_BUFFER (data)) {
    gst_buffer_unref (GST_BUFFER (data));
  } else {
    GstEvent *event = GST_EVENT (data);

    switch (GST_EVENT_TYPE (event)) {
      default:
	gst_pad_event_default (mpeg_parse->sinkpad, event);
	break;
    }
  }
}
static void
gst_mpeg_demux_handle_discont (GstMPEGParse * mpeg_parse)
{
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (mpeg_parse);
  gint64 current_time = MPEGTIME_TO_GSTTIME (mpeg_parse->current_scr);
  gint i;

  GST_DEBUG ("discont %" G_GUINT64_FORMAT "\n", current_time);

  for (i = 0; i < NUM_VIDEO_STREAMS; i++) {
    if (mpeg_demux->video_stream[i] &&
	GST_PAD_IS_USABLE (mpeg_demux->video_stream[i]->pad)) {
      GstEvent *discont;

      discont = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME,
	  current_time, NULL);

      gst_pad_push (mpeg_demux->video_stream[i]->pad, GST_DATA (discont));
    }
    if (mpeg_demux->audio_stream[i] &&
	GST_PAD_IS_USABLE (mpeg_demux->audio_stream[i]->pad)) {
      GstEvent *discont;

      discont = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME,
	  current_time, NULL);

      gst_pad_push (mpeg_demux->audio_stream[i]->pad, GST_DATA (discont));
    }
  }
}

static gboolean
gst_mpeg_demux_parse_packhead (GstMPEGParse * mpeg_parse, GstBuffer * buffer)
{
  guint8 *buf;

  parent_class->parse_packhead (mpeg_parse, buffer);

  GST_DEBUG ("in parse_packhead");

  buf = GST_BUFFER_DATA (buffer);
  /* do something usefull here */

  return TRUE;
}

static gint
_demux_get_writer_id (GstIndex * index, GstPad * pad)
{
  gint id;

  if (!gst_index_get_writer_id (index, GST_OBJECT (pad), &id)) {
    GST_CAT_WARNING_OBJECT (GST_CAT_SEEK, index,
	"can't get index id for %s:%s", GST_DEBUG_PAD_NAME (pad));
    return -1;
  } else {
    GST_CAT_LOG_OBJECT (GST_CAT_SEEK, index,
	"got index id %d for %s:%s", id, GST_DEBUG_PAD_NAME (pad));
    return id;
  }
}

static gboolean
gst_mpeg_demux_parse_syshead (GstMPEGParse * mpeg_parse, GstBuffer * buffer)
{
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (mpeg_parse);
  guint16 header_length;
  guchar *buf;

  GST_DEBUG ("in parse_syshead");

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

  header_length = GUINT16_FROM_BE (*(guint16 *) buf);
  GST_DEBUG ("header_length %d", header_length);
  buf += 2;

  /* marker:1==1 ! rate_bound:22 | marker:1==1 */
  buf += 3;

  /* audio_bound:6==1 ! fixed:1 | constrained:1 */
  buf += 1;

  /* audio_lock:1 | video_lock:1 | marker:1==1 | video_bound:5 */
  buf += 1;

  /* apacket_rate_restriction:1 | reserved:7==0x7F */
  buf += 1;

  if (!GST_MPEG_PARSE_IS_MPEG2 (mpeg_demux)) {
    gint stream_count = (header_length - 6) / 3;
    gint i, j = 0;

    GST_DEBUG ("number of streams=%d ", stream_count);

    for (i = 0; i < stream_count; i++) {
      guint8 stream_id;
      gboolean STD_buffer_bound_scale;
      guint16 STD_buffer_size_bound;
      guint32 buf_byte_size_bound;
      gchar *name = NULL;
      GstMPEGStream **outstream = NULL;
      GstPadTemplate *newtemp = NULL;
      GstCaps *caps = NULL;

      stream_id = *buf++;
      if (!(stream_id & 0x80)) {
	GST_DEBUG ("error in system header length");
	return FALSE;
      }

      /* check marker bits */
      if ((*buf & 0xC0) != 0xC0) {
	GST_DEBUG ("expecting placeholder bit values '11' after stream id\n");
	return FALSE;
      }

      STD_buffer_bound_scale = *buf & 0x20;
      STD_buffer_size_bound = ((guint16) (*buf++ & 0x1F)) << 8;
      STD_buffer_size_bound |= *buf++;

      if (STD_buffer_bound_scale == 0) {
	buf_byte_size_bound = STD_buffer_size_bound * 128;
      } else {
	buf_byte_size_bound = STD_buffer_size_bound * 1024;
      }

      if (stream_id == 0xBD) {
	/* private_stream_1 */
	name = NULL;
	outstream = NULL;
      } else if (stream_id == 0xBF) {
	/* private_stream_2 */
	name = g_strdup_printf ("private_stream_2");
	outstream = &mpeg_demux->private_2_stream;
	newtemp = gst_static_pad_template_get (&private2_factory);
      } else if (stream_id >= 0xC0 && stream_id < 0xE0) {
	/* Audio */
	name = g_strdup_printf ("audio_%02d", stream_id & 0x1F);
	outstream = &mpeg_demux->audio_stream[stream_id & 0x1F];
	newtemp = gst_static_pad_template_get (&audio_factory);
      } else if (stream_id >= 0xE0 && stream_id < 0xF0) {
	/* Video */
	name = g_strdup_printf ("video_%02d", stream_id & 0x0F);
	outstream = &mpeg_demux->video_stream[stream_id & 0x0F];
	newtemp = gst_static_pad_template_get (&video_src_factory);
	if (!GST_MPEG_PARSE_IS_MPEG2 (mpeg_demux)) {
	  caps = gst_caps_new_simple ("video/mpeg",
	      "mpegversion", G_TYPE_INT, 1,
	      "systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
	} else {
	  caps = gst_caps_new_simple ("video/mpeg",
	      "mpegversion", G_TYPE_INT, 2,
	      "systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
	}
      } else {
	GST_DEBUG ("unknown stream id %d", stream_id);
      }

      GST_DEBUG ("stream ID 0x%02X (%s)", stream_id, name);
      GST_DEBUG ("STD_buffer_bound_scale %d", STD_buffer_bound_scale);
      GST_DEBUG ("STD_buffer_size_bound %d or %d bytes",
	  STD_buffer_size_bound, buf_byte_size_bound);

      /* create the pad and add it to self if it does not yet exist
       * this should trigger the NEW_PAD signal, which should be caught by
       * the app and used to attach to desired streams.
       */
      if (outstream && *outstream == NULL) {
	GstPad **outpad;

	*outstream = gst_mpeg_demux_new_stream ();
	outpad = &((*outstream)->pad);

	*outpad = gst_pad_new_from_template (newtemp, name);

	gst_pad_set_formats_function (*outpad, gst_mpeg_demux_get_src_formats);
	gst_pad_set_convert_function (*outpad, gst_mpeg_parse_convert_src);
	gst_pad_set_event_mask_function (*outpad,
	    gst_mpeg_parse_get_src_event_masks);
	gst_pad_set_event_function (*outpad, gst_mpeg_demux_handle_src_event);
	gst_pad_set_query_type_function (*outpad,
	    gst_mpeg_parse_get_src_query_types);
	gst_pad_set_query_function (*outpad, gst_mpeg_parse_handle_src_query);
	if (caps && gst_caps_is_fixed (caps))
	  gst_pad_use_explicit_caps (*outpad);

	if (caps && gst_caps_is_fixed (caps))
	  gst_pad_set_explicit_caps (*outpad, caps);
	else if (caps)
	  gst_caps_free (caps);

	gst_element_add_pad (GST_ELEMENT (mpeg_demux), (*outpad));

	gst_pad_set_element_private (*outpad, *outstream);

	(*outstream)->size_bound = buf_byte_size_bound;
	mpeg_demux->total_size_bound += buf_byte_size_bound;

	if (mpeg_demux->index)
	  (*outstream)->index_id =
	      _demux_get_writer_id (mpeg_demux->index, *outpad);

	if (GST_PAD_IS_USABLE (*outpad)) {
	  GstEvent *event;
	  gint64 time;

	  time = mpeg_parse->current_scr;

	  event = gst_event_new_discontinuous (FALSE, GST_FORMAT_TIME,
	      MPEGTIME_TO_GSTTIME (time), NULL);

	  gst_pad_push (*outpad, GST_DATA (event));
	}
      } else {
	/* we won't be needing this. */
	if (name)
	  g_free (name);
      }

      j++;
    }
  }

  return TRUE;
}

static gboolean
gst_mpeg_demux_parse_packet (GstMPEGParse * mpeg_parse, GstBuffer * buffer)
{
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (mpeg_parse);
  guint8 id;
  guint16 headerlen;

  guint16 packet_length;
  gboolean STD_buffer_bound_scale;
  guint16 STD_buffer_size_bound;
  guint64 dts;
  guint8 ps_id_code;
  gint64 pts = -1;

  guint16 datalen;

  GstMPEGStream **outstream = NULL;
  GstPad *outpad = NULL;
  GstBuffer *outbuf;
  guint8 *buf, *basebuf;
  gint64 timestamp;

  GST_DEBUG ("in parse_packet");

  basebuf = buf = GST_BUFFER_DATA (buffer);
  id = *(buf + 3);
  buf += 4;

  /* start parsing */
  packet_length = GUINT16_FROM_BE (*((guint16 *) buf));

  GST_DEBUG ("got packet_length %d", packet_length);
  headerlen = 2;
  buf += 2;

  /* loop through looping for stuffing bits, STD, PTS, DTS, etc */
  do {
    guint8 bits = *buf++;

    /* stuffing bytes */
    switch (bits & 0xC0) {
      case 0xC0:
	if (bits == 0xff) {
	  GST_DEBUG ("have stuffing byte");
	} else {
	  GST_DEBUG ("expected stuffing byte");
	}
	headerlen++;
	break;
      case 0x40:
	GST_DEBUG ("have STD");

	STD_buffer_bound_scale = bits & 0x20;
	STD_buffer_size_bound = ((guint16) (bits & 0x1F)) << 8;
	STD_buffer_size_bound |= *buf++;

	headerlen += 2;
	break;
      case 0x00:
	switch (bits & 0x30) {
	  case 0x20:
	    /* pts:3 ! 1 ! pts:15 ! 1 | pts:15 ! 1 */
	    pts = ((guint64) (bits & 0x0E)) << 29;
	    pts |= ((guint64) * buf++) << 22;
	    pts |= ((guint64) (*buf++ & 0xFE)) << 14;
	    pts |= ((guint64) * buf++) << 7;
	    pts |= ((guint64) (*buf++ & 0xFE)) >> 1;

	    GST_DEBUG ("PTS = %" G_GUINT64_FORMAT, pts);
	    headerlen += 5;
	    goto done;
	  case 0x30:
	    /* pts:3 ! 1 ! pts:15 ! 1 | pts:15 ! 1 */
	    pts = ((guint64) (bits & 0x0E)) << 29;
	    pts |= ((guint64) * buf++) << 22;
	    pts |= ((guint64) (*buf++ & 0xFE)) << 14;
	    pts |= ((guint64) * buf++) << 7;
	    pts |= ((guint64) (*buf++ & 0xFE)) >> 1;

	    /* sync:4 ! pts:3 ! 1 ! pts:15 ! 1 | pts:15 ! 1 */
	    dts = ((guint64) (*buf++ & 0x0E)) << 29;
	    dts |= ((guint64) * buf++) << 22;
	    dts |= ((guint64) (*buf++ & 0xFE)) << 14;
	    dts |= ((guint64) * buf++) << 7;
	    dts |= ((guint64) (*buf++ & 0xFE)) >> 1;

	    GST_DEBUG ("PTS = %" G_GUINT64_FORMAT ", DTS = %" G_GUINT64_FORMAT,
		pts, dts);
	    headerlen += 10;
	    goto done;
	  case 0x00:
	    GST_DEBUG ("have no pts/dts");
	    GST_DEBUG ("got trailer bits %x", (bits & 0x0f));
	    if ((bits & 0x0f) != 0xf) {
	      GST_DEBUG ("not a valid packet time sequence");
	      return FALSE;
	    }
	    headerlen++;
	  default:
	    goto done;
	}
      default:
	goto done;
    }
  } while (1);
  GST_DEBUG ("done with header loop");

done:

  /* calculate the amount of real data in this packet */
  datalen = packet_length - headerlen + 2;
  GST_DEBUG ("headerlen is %d, datalen is %d", headerlen, datalen);

  if (id == 0xBD) {
    /* private_stream_1 */
    /* first find the track code */
    ps_id_code = *(basebuf + headerlen);

    if (ps_id_code >= 0x80 && ps_id_code <= 0x87) {
      /* make sure it's valid */
      GST_DEBUG ("0x%02X: we have a private_stream_1 (AC3) packet, track %d",
	  id, ps_id_code - 0x80);
      outstream = &mpeg_demux->private_1_stream[ps_id_code - 0x80];
      /* scrap first 4 bytes (so-called "mystery AC3 tag") */
      headerlen += 4;
      datalen -= 4;
    }
  } else if (id == 0xBF) {
    /* private_stream_2 */
    GST_DEBUG ("0x%02X: we have a private_stream_2 packet", id);
    outstream = &mpeg_demux->private_2_stream;
  } else if (id >= 0xC0 && id <= 0xDF) {
    /* audio */
    GST_DEBUG ("0x%02X: we have an audio packet", id);
    outstream = &mpeg_demux->audio_stream[id & 0x1F];
  } else if (id >= 0xE0 && id <= 0xEF) {
    /* video */
    GST_DEBUG ("0x%02X: we have a video packet", id);
    outstream = &mpeg_demux->video_stream[id & 0x0F];
  }

  /* if we don't know what it is, bail */
  if (outstream == NULL) {
    GST_DEBUG ("unknown packet id 0x%02X !!", id);
    return FALSE;
  }

  outpad = (*outstream)->pad;

  /* the pad should have been created in parse_syshead */
  if (outpad == NULL) {
    GST_DEBUG ("unexpected packet id 0x%02X!!", id);
    return FALSE;
  }

  /* attach pts, if any */
  if (pts != -1) {
    pts += mpeg_parse->adjust;
    timestamp = MPEGTIME_TO_GSTTIME (pts);

    if (mpeg_demux->index) {
      gst_index_add_association (mpeg_demux->index,
	  (*outstream)->index_id, 0,
	  GST_FORMAT_BYTES, GST_BUFFER_OFFSET (buffer),
	  GST_FORMAT_TIME, timestamp, 0);
    }
  } else {
    timestamp = GST_CLOCK_TIME_NONE;
  }

  /* create the buffer and send it off to the Other Side */
  if (GST_PAD_IS_LINKED (outpad) && datalen > 0) {
    GST_DEBUG ("creating subbuffer len %d", datalen);

    /* if this is part of the buffer, create a subbuffer */
    outbuf = gst_buffer_create_sub (buffer, headerlen + 4, datalen);

    GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
    GST_BUFFER_OFFSET (outbuf) = GST_BUFFER_OFFSET (buffer) + headerlen + 4;

    GST_DEBUG ("pushing buffer of len %d id %d, ts %" G_GINT64_FORMAT,
	datalen, id, GST_BUFFER_TIMESTAMP (outbuf));

    gst_pad_push (outpad, GST_DATA (outbuf));
  }

  return TRUE;
}

static gboolean
gst_mpeg_demux_parse_pes (GstMPEGParse * mpeg_parse, GstBuffer * buffer)
{
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (mpeg_parse);
  guint8 id;
  gint64 pts = -1;

  guint16 packet_length;
  guint8 header_data_length = 0;

  guint16 datalen;
  guint16 headerlen;
  guint8 ps_id_code = 0x80;

  GstMPEGStream **outstream = NULL;
  GstPad **outpad = NULL;
  GstBuffer *outbuf;
  GstPadTemplate *newtemp = NULL;
  guint8 *buf, *basebuf;

  GST_DEBUG ("in parse_pes");

  basebuf = buf = GST_BUFFER_DATA (buffer);
  id = *(buf + 3);
  buf += 4;

  /* start parsing */
  packet_length = GUINT16_FROM_BE (*((guint16 *) buf));

  GST_DEBUG ("got packet_length %d", packet_length);
  buf += 2;

  /* we don't operate on: program_stream_map, padding_stream, */
  /* private_stream_2, ECM, EMM, or program_stream_directory  */
  if ((id != 0xBC) && (id != 0xBE) && (id != 0xBF) && (id != 0xF0) &&
      (id != 0xF1) && (id != 0xFF)) {
    guchar flags1 = *buf++;
    guchar flags2 = *buf++;

    if ((flags1 & 0xC0) != 0x80) {
      return FALSE;
    }

    header_data_length = *buf++;

    GST_DEBUG ("header_data_length is %d", header_data_length);

    /* check for PTS */
    if ((flags2 & 0x80)) {
      /*if ((flags2 & 0x80) && id == 0xe0) { */
      pts = ((guint64) (*buf++ & 0x0E)) << 29;
      pts |= ((guint64) * buf++) << 22;
      pts |= ((guint64) (*buf++ & 0xFE)) << 14;
      pts |= ((guint64) * buf++) << 7;
      pts |= ((guint64) (*buf++ & 0xFE)) >> 1;

      GST_DEBUG ("%x PTS = %" G_GUINT64_FORMAT, id, MPEGTIME_TO_GSTTIME (pts));

    }
    if ((flags2 & 0x40)) {
      GST_DEBUG ("%x DTS found", id);
      buf += 5;
    }
    if ((flags2 & 0x20)) {
      GST_DEBUG ("%x ESCR found", id);
      buf += 6;
    }
    if ((flags2 & 0x10)) {
      guint32 es_rate;

      es_rate = ((guint32) (*buf++ & 0x07)) << 14;
      es_rate |= ((guint32) (*buf++)) << 7;
      es_rate |= ((guint32) (*buf++ & 0xFE)) >> 1;
      GST_DEBUG ("%x ES Rate found", id);
    }
    /* FIXME: lots of PES parsing missing here... */

  }

  /* calculate the amount of real data in this PES packet */
  /* constant is 2 bytes packet_length, 2 bytes of bits, 1 byte header len */
  headerlen = 5 + header_data_length;
  /* constant is 2 bytes of bits, 1 byte header len */
  datalen = packet_length - (3 + header_data_length);
  GST_DEBUG ("headerlen is %d, datalen is %d", headerlen, datalen);

  if (id == 0xBD) {
    /* private_stream_1 */
    /* first find the track code */
    ps_id_code = *(basebuf + headerlen + 4);

    if (ps_id_code >= 0x80 && ps_id_code <= 0x87) {
      GST_DEBUG ("we have a private_stream_1 (AC3) packet, track %d",
	  ps_id_code - 0x80);
      outstream = &mpeg_demux->private_1_stream[ps_id_code - 0x80];
      /* scrap first 4 bytes (so-called "mystery AC3 tag") */
      headerlen += 4;
      datalen -= 4;
    } else if (ps_id_code >= 0xA0 && ps_id_code <= 0xA7) {
      GST_DEBUG ("we have a pcm_stream packet, track %d", ps_id_code - 0xA0);
      outstream = &mpeg_demux->pcm_stream[ps_id_code - 0xA0];

      /* Check for changes in the sample format. */
      if (*outstream != NULL &&
	  basebuf[headerlen + 9] !=
	  mpeg_demux->lpcm_sample_info[ps_id_code - 0xA0]) {
	/* Change the pad caps. */
	gst_mpeg_demux_lpcm_set_caps ((*outstream)->pad,
	    basebuf[headerlen + 9]);
      }

      /* Store the sample info. */
      mpeg_demux->lpcm_sample_info[ps_id_code - 0xA0] = basebuf[headerlen + 9];

      /* Get rid of the LPCM header. */
      headerlen += 7;
      datalen -= 7;
    } else if (ps_id_code >= 0x20 && ps_id_code <= 0x2F) {
      GST_DEBUG ("we have a subtitle_stream packet, track %d",
	  ps_id_code - 0x20);
      outstream = &mpeg_demux->subtitle_stream[ps_id_code - 0x20];
      headerlen += 1;
      datalen -= 1;
    } else {
      GST_DEBUG ("0x%02X: unknown id %x", id, ps_id_code);
    }
  } else if (id == 0xBF) {
    /* private_stream_2 */
    GST_DEBUG ("we have a private_stream_2 packet");
    outstream = &mpeg_demux->private_2_stream;
  } else if (id >= 0xC0 && id <= 0xDF) {
    /* audio */
    GST_DEBUG ("we have an audio packet");
    outstream = &mpeg_demux->audio_stream[id - 0xC0];
  } else if (id >= 0xE0 && id <= 0xEF) {
    /* video */
    GST_DEBUG ("we have a video packet");
    outstream = &mpeg_demux->video_stream[id - 0xE0];
  } else {
    GST_DEBUG ("we have a unknown packet");
  }

  /* if we don't know what it is, bail */
  if (outstream == NULL)
    return TRUE;

  /* create the pad and add it if we don't already have one.            */
  /* this should trigger the NEW_PAD signal, which should be caught by  */
  /* the app and used to attach to desired streams.                     */
  if ((*outstream) == NULL) {
    gchar *name = NULL;
    GstCaps *caps = NULL;

    /* we have to name the stream approriately */
    if (id == 0xBD) {
      /* private_stream_1 */
      if (ps_id_code >= 0x80 && ps_id_code <= 0x87) {
	/* Erase any DVD audio pads. */
	gst_mpeg_demux_dvd_audio_clear (mpeg_demux, ps_id_code - 0x80);

	name = g_strdup_printf ("private_stream_1_%d", ps_id_code - 0x80);
	newtemp = gst_static_pad_template_get (&private1_factory);
      } else if (ps_id_code >= 0xA0 && ps_id_code <= 0xA7) {
	/* Erase any DVD audio pads. */
	gst_mpeg_demux_dvd_audio_clear (mpeg_demux, ps_id_code - 0xA0);

	name = g_strdup_printf ("pcm_stream_%d", ps_id_code - 0xA0);
	newtemp = gst_static_pad_template_get (&pcm_factory);
      } else if (ps_id_code >= 0x20 && ps_id_code <= 0x2F) {
	name = g_strdup_printf ("subtitle_stream_%d", ps_id_code - 0x20);
	newtemp = gst_static_pad_template_get (&subtitle_factory);
      } else {
	name = g_strdup_printf ("unknown_stream_%d", ps_id_code);
      }
    } else if (id == 0xBF) {
      /* private_stream_2 */
      name = g_strdup ("private_stream_2");
      newtemp = gst_static_pad_template_get (&private2_factory);
    } else if (id >= 0xC0 && id <= 0xDF) {
      /* audio */
      name = g_strdup_printf ("audio_%02d", id - 0xC0);
      newtemp = gst_static_pad_template_get (&audio_factory);
    } else if (id >= 0xE0 && id <= 0xEF) {
      /* video */
      name = g_strdup_printf ("video_%02d", id - 0xE0);
      newtemp = gst_static_pad_template_get (&video_src_factory);
      if (!GST_MPEG_PARSE_IS_MPEG2 (mpeg_demux)) {
	caps = gst_caps_new_simple ("video/mpeg",
	    "mpegversion", G_TYPE_INT, 1,
	    "systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
      } else {
	caps = gst_caps_new_simple ("video/mpeg",
	    "mpegversion", G_TYPE_INT, 2,
	    "systemstream", G_TYPE_BOOLEAN, FALSE, NULL);
      }
    } else {
      /* unknown */
      name = g_strdup_printf ("unknown");
    }

    if (newtemp) {

      *outstream = gst_mpeg_demux_new_stream ();
      outpad = &((*outstream)->pad);

      /* create the pad and add it to self */
      *outpad = gst_pad_new_from_template (newtemp, name);
      gst_element_add_pad (GST_ELEMENT (mpeg_demux), *outpad);

      gst_pad_set_formats_function (*outpad, gst_mpeg_demux_get_src_formats);
      gst_pad_set_convert_function (*outpad, gst_mpeg_parse_convert_src);
      gst_pad_set_event_mask_function (*outpad,
	  gst_mpeg_parse_get_src_event_masks);
      gst_pad_set_event_function (*outpad, gst_mpeg_demux_handle_src_event);
      gst_pad_set_query_type_function (*outpad,
	  gst_mpeg_parse_get_src_query_types);
      gst_pad_set_query_function (*outpad, gst_mpeg_parse_handle_src_query);
      gst_pad_use_explicit_caps (*outpad);

      if (ps_id_code < 0xA0 || ps_id_code > 0xA7) {
	gst_pad_set_explicit_caps (*outpad, caps);
      } else {
	gst_mpeg_demux_lpcm_set_caps (*outpad,
	    mpeg_demux->lpcm_sample_info[ps_id_code - 0xA0]);
      }

      gst_pad_set_element_private (*outpad, *outstream);

      if (mpeg_demux->index)
	(*outstream)->index_id =
	    _demux_get_writer_id (mpeg_demux->index, *outpad);
    } else {
      g_warning ("cannot create pad %s, no template for %02x", name, id);
    }
    if (name)
      g_free (name);
  }

  if (*outstream) {
    gint64 timestamp;

    outpad = &((*outstream)->pad);

    /* attach pts, if any */
    if (pts != -1) {
      pts += mpeg_parse->adjust;
      timestamp = MPEGTIME_TO_GSTTIME (pts);

      if (mpeg_demux->index) {
	gst_index_add_association (mpeg_demux->index,
	    (*outstream)->index_id, 0,
	    GST_FORMAT_BYTES, GST_BUFFER_OFFSET (buffer),
	    GST_FORMAT_TIME, timestamp, 0);
      }
    } else {
      timestamp = GST_CLOCK_TIME_NONE;
    }

    /* create the buffer and send it off to the Other Side */
    if (*outpad && GST_PAD_IS_USABLE (*outpad)) {
      /* if this is part of the buffer, create a subbuffer */
      GST_DEBUG ("creating subbuffer len %d", datalen);

      outbuf = gst_buffer_create_sub (buffer, headerlen + 4, datalen);

      GST_BUFFER_TIMESTAMP (outbuf) = timestamp;
      GST_BUFFER_OFFSET (outbuf) = GST_BUFFER_OFFSET (buffer) + headerlen + 4;

      gst_pad_push (*outpad, GST_DATA (outbuf));
    }
  }

  return TRUE;
}

/**
 * Set the capabilities of the given pad based on the provided LPCM
 * sample information.
 */
static void
gst_mpeg_demux_lpcm_set_caps (GstPad * pad, guint8 sample_info)
{
  gint width, rate, channels;
  GstCaps *caps;

  /* Determine the sample width. */
  switch (sample_info & 0xC0) {
    case 0x80:
      width = 24;
      break;
    case 0x40:
      width = 20;
      break;
    default:
      width = 16;
      break;
  }

  /* Determine the rate. */
  if (sample_info & 0x10) {
    rate = 96000;
  } else {
    rate = 48000;
  }

  /* Determine the number of channels. */
  channels = (sample_info & 0x7) + 1;

  caps = gst_caps_new_simple ("audio/x-raw-int",
      "endianness", G_TYPE_INT, G_BIG_ENDIAN,
      "signed", G_TYPE_BOOLEAN, TRUE,
      "width", G_TYPE_INT, width,
      "depth", G_TYPE_INT, width,
      "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels, NULL);
  gst_pad_set_explicit_caps (pad, caps);
}

/**
 * Erase the DVD audio pad (if any) associated to the given channel.
 */
static void
gst_mpeg_demux_dvd_audio_clear (GstMPEGDemux * mpeg_demux, int channel)
{
  GstMPEGStream **stream = NULL;

  if (mpeg_demux->private_1_stream[channel] != NULL) {
    stream = &mpeg_demux->private_1_stream[channel];
  } else if (mpeg_demux->pcm_stream[channel] != NULL) {
    stream = &mpeg_demux->pcm_stream[channel];
  }

  if (stream == NULL) {
    return;
  }

  gst_pad_unlink ((*stream)->pad, gst_pad_get_peer ((*stream)->pad));
  gst_element_remove_pad (GST_ELEMENT (mpeg_demux), (*stream)->pad);

  g_free (*stream);
  *stream = NULL;
}


const GstFormat *
gst_mpeg_demux_get_src_formats (GstPad * pad)
{
  static const GstFormat formats[] = {
    GST_FORMAT_TIME,		/* we prefer seeking on time */
    GST_FORMAT_BYTES,
    0
  };
  return formats;
}

static gboolean
index_seek (GstPad * pad, GstEvent * event, gint64 * offset)
{
  GstIndexEntry *entry;
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (gst_pad_get_parent (pad));
  GstMPEGStream *stream = gst_pad_get_element_private (pad);

  entry = gst_index_get_assoc_entry (mpeg_demux->index, stream->index_id,
      GST_INDEX_LOOKUP_BEFORE, 0,
      GST_EVENT_SEEK_FORMAT (event), GST_EVENT_SEEK_OFFSET (event));
  if (!entry) {
    GST_CAT_WARNING (GST_CAT_SEEK, "%s:%s index %s %" G_GINT64_FORMAT
	" -> failed",
	GST_DEBUG_PAD_NAME (pad),
	gst_format_get_details (GST_EVENT_SEEK_FORMAT (event))->nick,
	GST_EVENT_SEEK_OFFSET (event));
    return FALSE;
  }

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

static gboolean
normal_seek (GstPad * pad, GstEvent * event, gint64 * offset)
{
  gboolean res = FALSE;
  gint64 adjust;
  GstFormat format;
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (gst_pad_get_parent (pad));

  format = GST_EVENT_SEEK_FORMAT (event);

  res = gst_pad_convert (pad, GST_FORMAT_BYTES, mpeg_demux->total_size_bound,
      &format, &adjust);

  if (res) {
    *offset = MAX (GST_EVENT_SEEK_OFFSET (event) - adjust, 0);

    GST_CAT_DEBUG (GST_CAT_SEEK, "%s:%s guestimate %" G_GINT64_FORMAT
	" %s -> %" G_GINT64_FORMAT
	" (total_size_bound = %" G_GINT64_FORMAT ")",
	GST_DEBUG_PAD_NAME (pad),
	GST_EVENT_SEEK_OFFSET (event),
	gst_format_get_details (GST_EVENT_SEEK_FORMAT (event))->nick,
	*offset, mpeg_demux->total_size_bound);
  }

  return res;
}

static gboolean
gst_mpeg_demux_handle_src_event (GstPad * pad, GstEvent * event)
{
  gboolean res = FALSE;
  GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (gst_pad_get_parent (pad));

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

      if (mpeg_demux->index)
	res = index_seek (pad, event, &desired_offset);
      if (!res)
	res = normal_seek (pad, event, &desired_offset);

      if (res) {
	GstEvent *new_event;

	new_event =
	    gst_event_new_seek (GST_EVENT_SEEK_TYPE (event), desired_offset);
	res = gst_mpeg_parse_handle_src_event (pad, new_event);
      }
      gst_event_unref (event);
      break;
    }
    case GST_EVENT_NAVIGATION:
      return gst_pad_send_event (GST_PAD_PEER (GST_MPEG_PARSE (mpeg_demux)->
	      sinkpad), event);
      break;
    default:
      gst_event_unref (event);
      break;
  }
  return res;
}

static GstElementStateReturn
gst_mpeg_demux_change_state (GstElement * element)
{
  /* GstMPEGDemux *mpeg_demux = GST_MPEG_DEMUX (element); */

  switch (GST_STATE_TRANSITION (element)) {
    case GST_STATE_READY_TO_PAUSED:
      break;
    case GST_STATE_PAUSED_TO_READY:
      break;
    case GST_STATE_READY_TO_NULL:
      break;
    default:
      break;
  }

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

static void
gst_mpeg_demux_set_index (GstElement * element, GstIndex * index)
{
  GstMPEGDemux *mpeg_demux;

  GST_ELEMENT_CLASS (parent_class)->set_index (element, index);

  mpeg_demux = GST_MPEG_DEMUX (element);

  mpeg_demux->index = index;
}

static GstIndex *
gst_mpeg_demux_get_index (GstElement * element)
{
  GstMPEGDemux *mpeg_demux;

  mpeg_demux = GST_MPEG_DEMUX (element);

  return mpeg_demux->index;
}


gboolean
gst_mpeg_demux_plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "mpegdemux",
      GST_RANK_PRIMARY, GST_TYPE_MPEG_DEMUX);
}