gstreamer/gst/mpegtsparse/mpegtspacketizer.c

/*
 * mpegtspacketizer.c - 
 * Copyright (C) 2007 Alessandro Decina
 * 
 * Authors:
 *   Alessandro Decina <alessandro@nnva.org>
 *
 * 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.
 */

#include "mpegtspacketizer.h"

GST_DEBUG_CATEGORY_STATIC (mpegts_packetizer_debug);
#define GST_CAT_DEFAULT mpegts_packetizer_debug

G_DEFINE_TYPE (MpegTSPacketizer, mpegts_packetizer, G_TYPE_OBJECT);

static void mpegts_packetizer_dispose (GObject * object);
static void mpegts_packetizer_finalize (GObject * object);

#define CONTINUITY_UNSET 255
#define MAX_CONTINUITY 15
#define SECTION_VERSION_NUMBER_NOTSET 255

typedef struct
{
  guint8 table_id;
  /* the spec says sub_table_extension is the fourth and fifth byte of a 
   * section when the section_syntax_indicator is set to a value of "1". If 
   * section_syntax_indicator is 0, sub_table_extension will be set to 0 */
  guint16 sub_table_extension;
  guint continuity_counter;
  GstAdapter *section_adapter;
  guint section_length;
  guint8 section_version_number;
} MpegTSPacketizerStream;

static MpegTSPacketizerStream *
mpegts_packetizer_stream_new (guint8 table_id, guint16 sub_table_extension)
{
  MpegTSPacketizerStream *stream;

  stream = (MpegTSPacketizerStream *) g_new0 (MpegTSPacketizerStream, 1);
  stream->section_adapter = gst_adapter_new ();
  stream->table_id = table_id;
  stream->sub_table_extension = sub_table_extension;
  stream->continuity_counter = CONTINUITY_UNSET;
  stream->section_version_number = SECTION_VERSION_NUMBER_NOTSET;
  return stream;
}

static void
mpegts_packetizer_stream_free (MpegTSPacketizerStream * stream)
{
  gst_adapter_clear (stream->section_adapter);
  g_object_unref (stream->section_adapter);
  g_free (stream);
}

static void
mpegts_packetizer_clear_section (MpegTSPacketizer * packetizer,
    MpegTSPacketizerStream * stream)
{
  gst_adapter_clear (stream->section_adapter);
  stream->continuity_counter = CONTINUITY_UNSET;
  stream->section_length = 0;
}

static void
mpegts_packetizer_class_init (MpegTSPacketizerClass * klass)
{
  GObjectClass *gobject_class;

  gobject_class = G_OBJECT_CLASS (klass);

  gobject_class->dispose = mpegts_packetizer_dispose;
  gobject_class->finalize = mpegts_packetizer_finalize;
}

static void
mpegts_packetizer_init (MpegTSPacketizer * packetizer)
{
  packetizer->adapter = gst_adapter_new ();
  packetizer->streams = g_hash_table_new (g_str_hash, g_str_equal);
}

static void
mpegts_packetizer_dispose (GObject * object)
{
  MpegTSPacketizer *packetizer = GST_MPEGTS_PACKETIZER (object);

  if (!packetizer->disposed) {
    gst_adapter_clear (packetizer->adapter);
    g_object_unref (packetizer->adapter);
    packetizer->disposed = TRUE;
  }

  if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose)
    G_OBJECT_CLASS (mpegts_packetizer_parent_class)->dispose (object);
}

static gboolean
stream_foreach_remove (gpointer key, gpointer value, gpointer data)
{
  MpegTSPacketizerStream *stream;

  stream = (MpegTSPacketizerStream *) value;
  mpegts_packetizer_stream_free (stream);

  return TRUE;
}

static void
mpegts_packetizer_finalize (GObject * object)
{
  MpegTSPacketizer *packetizer = GST_MPEGTS_PACKETIZER (object);

  g_hash_table_foreach_remove (packetizer->streams,
      stream_foreach_remove, packetizer);
  g_hash_table_destroy (packetizer->streams);

  if (G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize)
    G_OBJECT_CLASS (mpegts_packetizer_parent_class)->finalize (object);
}

static gboolean
mpegts_packetizer_parse_adaptation_field_control (MpegTSPacketizer * packetizer,
    MpegTSPacketizerPacket * packet)
{
  guint8 length;

  length = *packet->data;
  packet->data += 1;

  if (packet->adaptation_field_control == 0x02) {
    /* no payload, adaptation field of 183 bytes */
    if (length != 183) {
      GST_DEBUG ("PID %d afc == 0x%x and length %d != 183",
          packet->pid, packet->adaptation_field_control, length);
    }
  } else if (length > 182) {
    GST_DEBUG ("PID %d afc == 0x%01x and length %d > 182",
        packet->pid, packet->adaptation_field_control, length);
  }

  /* skip the adaptation field body for now */
  if (packet->data + length > packet->data_end) {
    GST_DEBUG ("PID %d afc length %d overflows the buffer current %d max %d",
        packet->pid, length, packet->data - packet->data_start,
        packet->data_end - packet->data_start);
    return FALSE;
  }

  packet->data += length;

  return TRUE;
}

static gboolean
mpegts_packetizer_parse_packet (MpegTSPacketizer * packetizer,
    MpegTSPacketizerPacket * packet)
{
  guint8 *data;

  data = GST_BUFFER_DATA (packet->buffer);
  /* skip sync_byte */
  data++;

  packet->payload_unit_start_indicator = (*data >> 6) & 0x01;
  packet->pid = GST_READ_UINT16_BE (data) & 0x1FFF;
  data += 2;

  packet->adaptation_field_control = (*data >> 4) & 0x03;
  packet->continuity_counter = *data & 0x0F;
  data += 1;

  packet->data = data;

  if (packet->adaptation_field_control & 0x02)
    if (!mpegts_packetizer_parse_adaptation_field_control (packetizer, packet))
      return FALSE;

  if (packet->adaptation_field_control & 0x01)
    packet->payload = packet->data;
  else
    packet->payload = NULL;

  return TRUE;
}

static gboolean
mpegts_packetizer_parse_section_header (MpegTSPacketizer * packetizer,
    MpegTSPacketizerStream * stream, MpegTSPacketizerSection * section)
{
  guint8 tmp;
  guint8 *data;

  section->complete = TRUE;
  /* get the section buffer, pass the ownership to the caller */
  section->buffer = gst_adapter_take_buffer (stream->section_adapter,
      3 + stream->section_length);
  data = GST_BUFFER_DATA (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  /* skip to the version byte */
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  if (!section->current_next_indicator)
    goto not_applicable;

  if (section->version_number == stream->section_version_number)
    goto not_applicable;

  stream->section_version_number = section->version_number;

  return TRUE;

not_applicable:
  section->complete = FALSE;
  gst_buffer_unref (section->buffer);
  return TRUE;
}

static gboolean
mpegts_packetizer_parse_descriptors (MpegTSPacketizer * packetizer,
    guint8 ** buffer, guint8 * buffer_end, GValueArray * descriptors)
{
  guint8 tag, length;
  guint8 *data;
  GValue value = { 0 };
  GString *desc;

  data = *buffer;

  while (data < buffer_end) {
    tag = *data++;
    length = *data++;

    if (data + length > buffer_end) {
      GST_WARNING ("invalid descriptor length %d now at %d max %d",
          length, data - *buffer, buffer_end - *buffer);
      goto error;
    }

    /* include tag and length */
    desc = g_string_new_len ((gchar *) data - 2, length + 2);
    data += length;

    g_value_init (&value, G_TYPE_GSTRING);
    g_value_take_boxed (&value, desc);
    g_value_array_append (descriptors, &value);
    g_value_unset (&value);
  }

  if (data != buffer_end) {
    GST_WARNING ("descriptors size %d expected %d",
        data - *buffer, buffer_end - *buffer);
    goto error;
  }

  *buffer = data;

  return TRUE;
error:
  return FALSE;
}

GstStructure *
mpegts_packetizer_parse_pat (MpegTSPacketizer * packetizer,
    MpegTSPacketizerSection * section)
{
  GstStructure *pat_info = NULL;
  guint8 *data, *end;
  guint transport_stream_id;
  guint8 tmp;
  guint program_number;
  guint pmt_pid;
  GValue entries = { 0 };
  GValue value = { 0 };
  GstStructure *entry = NULL;
  gchar *struct_name;

  data = GST_BUFFER_DATA (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  transport_stream_id = GST_READ_UINT16_BE (data);
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  /* skip section_number and last_section_number */
  data += 2;

  pat_info = gst_structure_new ("pat",
      "transport-stream-id", G_TYPE_UINT, transport_stream_id, NULL);
  g_value_init (&entries, GST_TYPE_LIST);
  /* stop at the CRC */
  end = GST_BUFFER_DATA (section->buffer) + GST_BUFFER_SIZE (section->buffer);
  while (data < end - 4) {
    program_number = GST_READ_UINT16_BE (data);
    data += 2;

    pmt_pid = GST_READ_UINT16_BE (data) & 0x1FFF;
    data += 2;

    struct_name = g_strdup_printf ("program-%d", program_number);
    entry = gst_structure_new (struct_name,
        "program-number", G_TYPE_UINT, program_number,
        "pid", G_TYPE_UINT, pmt_pid, NULL);
    g_free (struct_name);

    g_value_init (&value, GST_TYPE_STRUCTURE);
    g_value_take_boxed (&value, entry);
    gst_value_list_append_value (&entries, &value);
    g_value_unset (&value);
  }

  gst_structure_set_value (pat_info, "programs", &entries);
  g_value_unset (&entries);

  if (data != end - 4) {
    /* FIXME: check the CRC before parsing the packet */
    GST_ERROR ("at the end of PAT data != end - 4");
    gst_structure_free (pat_info);

    return NULL;
  }

  return pat_info;
}

GstStructure *
mpegts_packetizer_parse_pmt (MpegTSPacketizer * packetizer,
    MpegTSPacketizerSection * section)
{
  GstStructure *pmt = NULL;
  guint8 *data, *end;
  guint16 program_number;
  guint8 tmp;
  guint pcr_pid;
  guint program_info_length;
  guint8 stream_type;
  guint16 pid;
  guint stream_info_length;
  GValueArray *descriptors;
  GValue stream_value = { 0 };
  GValue programs = { 0 };
  GstStructure *stream_info = NULL;
  gchar *struct_name;

  /* fixed header + CRC == 16 */
  if (GST_BUFFER_SIZE (section->buffer) < 16) {
    GST_WARNING ("PID %d invalid PMT size %d",
        section->pid, section->section_length);
    goto error;
  }

  data = GST_BUFFER_DATA (section->buffer);
  end = data + GST_BUFFER_SIZE (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  program_number = GST_READ_UINT16_BE (data);
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  /* skip section_number and last_section_number */
  data += 2;

  pcr_pid = GST_READ_UINT16_BE (data) & 0x1FFF;
  data += 2;

  program_info_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  struct_name = g_strdup ("pmt");
  pmt = gst_structure_new (struct_name,
      "program-number", G_TYPE_UINT, program_number,
      "pcr-pid", G_TYPE_UINT, pcr_pid,
      "version-number", G_TYPE_UINT, section->version_number, NULL);
  g_free (struct_name);

  if (program_info_length) {
    /* check that the buffer is large enough to contain at least
     * program_info_length bytes + CRC */
    if (data + program_info_length + 4 > end) {
      GST_WARNING ("PID %d invalid program info length %d "
          "left %d", section->pid, program_info_length, end - data);
      goto error;
    }

    descriptors = g_value_array_new (0);
    if (!mpegts_packetizer_parse_descriptors (packetizer,
            &data, data + program_info_length, descriptors)) {
      g_value_array_free (descriptors);
      goto error;
    }

    gst_structure_set (pmt, "descriptors", G_TYPE_VALUE_ARRAY, descriptors,
        NULL);
    g_value_array_free (descriptors);
  }

  g_value_init (&programs, GST_TYPE_LIST);
  /* parse entries, cycle until there's space for another entry (at least 5
   * bytes) plus the CRC */
  while (data <= end - 4 - 5) {
    stream_type = *data++;

    pid = GST_READ_UINT16_BE (data) & 0x1FFF;
    data += 2;

    stream_info_length = GST_READ_UINT16_BE (data) & 0x0FFF;
    data += 2;

    if (data + stream_info_length + 4 > end) {
      GST_WARNING ("PID %d invalid stream info length %d "
          "left %d", section->pid, stream_info_length, end - data);
      g_value_unset (&programs);
      goto error;
    }

    struct_name = g_strdup_printf ("pid-%d", pid);
    stream_info = gst_structure_new (struct_name,
        "pid", G_TYPE_UINT, pid, "stream-type", G_TYPE_UINT, stream_type, NULL);
    g_free (struct_name);

    if (stream_info_length) {
      descriptors = g_value_array_new (0);
      if (!mpegts_packetizer_parse_descriptors (packetizer,
              &data, data + stream_info_length, descriptors)) {
        g_value_unset (&programs);
        gst_structure_free (stream_info);
        g_value_array_free (descriptors);
        goto error;
      }

      gst_structure_set (stream_info,
          "descriptors", G_TYPE_VALUE_ARRAY, descriptors, NULL);
      g_value_array_free (descriptors);
    }

    g_value_init (&stream_value, GST_TYPE_STRUCTURE);
    g_value_take_boxed (&stream_value, stream_info);
    gst_value_list_append_value (&programs, &stream_value);
    g_value_unset (&stream_value);
  }

  gst_structure_set_value (pmt, "streams", &programs);
  g_value_unset (&programs);

  g_assert (data == end - 4);

  return pmt;

error:
  if (pmt)
    gst_structure_free (pmt);

  return NULL;
}

GstStructure *
mpegts_packetizer_parse_nit (MpegTSPacketizer * packetizer,
    MpegTSPacketizerSection * section)
{
  GstStructure *nit = NULL, *transport = NULL;
  guint8 *data, *end, *entry_begin;
  guint16 network_id, transport_stream_id, original_network_id;
  guint tmp;
  guint16 descriptors_loop_length, transport_stream_loop_length;
  GValue transports = { 0 };
  GValue transport_value = { 0 };
  GValueArray *descriptors = NULL;
  gchar *dbg_str;

  /* fixed header + CRC == 16 */
  if (GST_BUFFER_SIZE (section->buffer) < 23) {
    GST_WARNING ("PID %d invalid NIT size %d",
        section->pid, section->section_length);
    goto error;
  }

  data = GST_BUFFER_DATA (section->buffer);
  end = data + GST_BUFFER_SIZE (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  if (data + section->section_length != end) {
    GST_WARNING ("PID %d invalid NIT section length %d expected %d",
        section->pid, section->section_length, end - data);
    goto error;
  }

  network_id = GST_READ_UINT16_BE (data);
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  /* skip section_number and last_section_number */
  data += 2;

  descriptors_loop_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  nit = gst_structure_new ("nit",
      "network-id", G_TYPE_UINT, network_id,
      "version-number", G_TYPE_UINT, section->version_number,
      "current-next-indicator", G_TYPE_UINT, section->current_next_indicator,
      NULL);

  /* see if the buffer is large enough */
  if (descriptors_loop_length) {
    if (data + descriptors_loop_length > end - 4) {
      GST_WARNING ("PID %d invalid NIT descriptors loop length %d",
          section->pid, descriptors_loop_length);
      gst_structure_free (nit);
      goto error;
    }

    descriptors = g_value_array_new (0);
    if (!mpegts_packetizer_parse_descriptors (packetizer,
            &data, data + descriptors_loop_length, descriptors)) {
      gst_structure_free (nit);
      g_value_array_free (descriptors);
      goto error;
    }

    gst_structure_set (nit, "descriptors", G_TYPE_VALUE_ARRAY, descriptors,
        NULL);
    g_value_array_free (descriptors);
  }

  transport_stream_loop_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  g_value_init (&transports, GST_TYPE_LIST);
  /* read up to the CRC */
  while (transport_stream_loop_length - 4 > 0) {
    gchar *transport_name;

    entry_begin = data;

    if (transport_stream_loop_length < 10) {
      /* each entry must be at least 6 bytes (+ 4bytes CRC) */
      GST_WARNING ("PID %d invalid NIT entry size %d",
          section->pid, transport_stream_loop_length);
      goto error;
    }

    transport_stream_id = GST_READ_UINT16_BE (data);
    data += 2;

    original_network_id = GST_READ_UINT16_BE (data);
    data += 2;

    descriptors_loop_length = GST_READ_UINT16_BE (data) & 0x0FFF;
    data += 2;

    transport_name = g_strdup_printf ("transport-%d", transport_stream_id);
    transport = gst_structure_new (transport_name,
        "transport-stream-id", G_TYPE_UINT, transport_stream_id,
        "original-network-id", G_TYPE_UINT, original_network_id, NULL);
    g_free (transport_name);

    if (descriptors_loop_length) {
      if (data + descriptors_loop_length > end - 4) {
        GST_WARNING ("PID %d invalid NIT entry %d descriptors loop length %d",
            section->pid, transport_stream_id, descriptors_loop_length);
        gst_structure_free (transport);
        goto error;
      }

      descriptors = g_value_array_new (0);
      if (!mpegts_packetizer_parse_descriptors (packetizer,
              &data, data + descriptors_loop_length, descriptors)) {
        gst_structure_free (transport);
        g_value_array_free (descriptors);
        goto error;
      }

      gst_structure_set (transport, "descriptors", G_TYPE_VALUE_ARRAY,
          descriptors, NULL);
      g_value_array_free (descriptors);
    }

    g_value_init (&transport_value, GST_TYPE_STRUCTURE);
    g_value_take_boxed (&transport_value, transport);
    gst_value_list_append_value (&transports, &transport_value);
    g_value_unset (&transport_value);

    transport_stream_loop_length -= data - entry_begin;
  }

  if (data != end - 4) {
    GST_WARNING ("PID %d invalid NIT parsed %d length %d",
        section->pid, data - GST_BUFFER_DATA (section->buffer),
        GST_BUFFER_SIZE (section->buffer));
    goto error;
  }

  gst_structure_set_value (nit, "transports", &transports);
  g_value_unset (&transports);

  dbg_str = gst_structure_to_string (nit);
  GST_DEBUG ("NIT %s", dbg_str);
  g_free (dbg_str);

  return nit;

error:
  if (nit)
    gst_structure_free (nit);

  if (GST_VALUE_HOLDS_LIST (&transports))
    g_value_unset (&transports);

  return NULL;
}

GstStructure *
mpegts_packetizer_parse_sdt (MpegTSPacketizer * packetizer,
    MpegTSPacketizerSection * section)
{
  GstStructure *sdt = NULL, *service = NULL;
  guint8 *data, *end, *entry_begin;
  guint16 transport_stream_id, original_network_id, service_id;
  guint tmp;
  guint sdt_info_length;
  gboolean EIT_schedule, EIT_present_following;
  guint8 running_status;
  gboolean scrambled;
  guint descriptors_loop_length;
  GValue services = { 0 };
  GValueArray *descriptors = NULL;
  GValue service_value = { 0 };
  gchar *dbg_str;

  /* fixed header + CRC == 16 */
  if (GST_BUFFER_SIZE (section->buffer) < 14) {
    GST_WARNING ("PID %d invalid SDT size %d",
        section->pid, section->section_length);
    goto error;
  }

  data = GST_BUFFER_DATA (section->buffer);
  end = data + GST_BUFFER_SIZE (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  if (data + section->section_length != end) {
    GST_WARNING ("PID %d invalid SDT section length %d expected %d",
        section->pid, section->section_length, end - data);
    goto error;
  }

  transport_stream_id = GST_READ_UINT16_BE (data);
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  /* skip section_number and last_section_number */
  data += 2;

  original_network_id = GST_READ_UINT16_BE (data);
  data += 2;

  /* skip reserved byte */
  data += 1;

  sdt = gst_structure_new ("sdt",
      "transport-stream-id", G_TYPE_UINT, transport_stream_id,
      "version-number", G_TYPE_UINT, section->version_number,
      "current-next-indicator", G_TYPE_UINT, section->current_next_indicator,
      "original-network-id", G_TYPE_UINT, original_network_id, NULL);

  sdt_info_length = section->section_length - 8;
  g_value_init (&services, GST_TYPE_LIST);
  /* read up to the CRC */
  while (sdt_info_length - 4 > 0) {
    gchar *service_name;

    entry_begin = data;

    if (sdt_info_length < 9) {
      /* each entry must be at least 5 bytes (+4 bytes for the CRC) */
      GST_WARNING ("PID %d invalid SDT entry size %d",
          section->pid, sdt_info_length);
      goto error;
    }

    service_id = GST_READ_UINT16_BE (data);
    data += 2;

    /* reserved */
    data += 1;

    tmp = GST_READ_UINT16_BE (data);
    data += 2;

    EIT_schedule = (tmp >> 15);
    EIT_present_following = (tmp >> 14) & 0x01;
    running_status = (tmp >> 5) & 0x03;
    scrambled = (tmp >> 4) & 0x01;
    descriptors_loop_length = tmp & 0x0FFF;

    service_name = g_strdup_printf ("service-%d", service_id);
    service = gst_structure_new (service_name, NULL);
    g_free (service_name);

    if (descriptors_loop_length) {
      if (data + descriptors_loop_length > end - 4) {
        GST_WARNING ("PID %d invalid SDT entry %d descriptors loop length %d",
            section->pid, service_id, descriptors_loop_length);
        gst_structure_free (service);
        goto error;
      }

      descriptors = g_value_array_new (0);
      if (!mpegts_packetizer_parse_descriptors (packetizer,
              &data, data + descriptors_loop_length, descriptors)) {
        gst_structure_free (service);
        g_value_array_free (descriptors);
        goto error;
      }

      gst_structure_set (service, "descriptors", G_TYPE_VALUE_ARRAY,
          descriptors, NULL);
      g_value_array_free (descriptors);
    }

    g_value_init (&service_value, GST_TYPE_STRUCTURE);
    g_value_take_boxed (&service_value, service);
    gst_value_list_append_value (&services, &service_value);
    g_value_unset (&service_value);

    sdt_info_length -= data - entry_begin;
  }

  if (data != end - 4) {
    GST_WARNING ("PID %d invalid SDT parsed %d length %d",
        section->pid, data - GST_BUFFER_DATA (section->buffer),
        GST_BUFFER_SIZE (section->buffer));
    goto error;
  }

  gst_structure_set_value (sdt, "services", &services);
  g_value_unset (&services);

  dbg_str = gst_structure_to_string (sdt);
  g_free (dbg_str);

  return sdt;

error:
  if (sdt)
    gst_structure_free (sdt);

  if (GST_VALUE_HOLDS_LIST (&services))
    g_value_unset (&services);

  return NULL;
}

GstStructure *
mpegts_packetizer_parse_eit (MpegTSPacketizer * packetizer,
    MpegTSPacketizerSection * section)
{
  GstStructure *eit = NULL, *event = NULL;
  guint service_id, last_table_id, segment_last_section_number;
  guint transport_stream_id, original_network_id;
  gboolean free_ca_mode;
  guint event_id, running_status;
  guint64 start_and_duration;
  GstClockTime start_time, duration;
  guint8 *data, *end;
  guint16 descriptors_loop_length;
  GValue events = { 0 };
  GValue event_value = { 0 };
  GValueArray *descriptors = NULL;
  gchar *dbg_str, *event_name;
  guint tmp;

  /* fixed header + CRC == 16 */
  if (GST_BUFFER_SIZE (section->buffer) < 18) {
    GST_WARNING ("PID %d invalid EIT size %d",
        section->pid, section->section_length);
    goto error;
  }

  data = GST_BUFFER_DATA (section->buffer);
  end = data + GST_BUFFER_SIZE (section->buffer);

  section->table_id = *data++;
  section->section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  if (data + section->section_length != end) {
    GST_WARNING ("PID %d invalid EIT section length %d expected %d",
        section->pid, section->section_length, end - data);
    goto error;
  }

  service_id = GST_READ_UINT16_BE (data);
  data += 2;

  tmp = *data++;
  section->version_number = (tmp >> 1) & 0x1F;
  section->current_next_indicator = tmp & 0x01;

  /* skip section_number and last_section_number */
  data += 2;

  transport_stream_id = GST_READ_UINT16_BE (data);
  data += 2;
  original_network_id = GST_READ_UINT16_BE (data);
  data += 2;
  segment_last_section_number = *data;
  data += 1;
  last_table_id = *data;
  data += 1;

  eit = gst_structure_new ("eit",
      "version-number", G_TYPE_UINT, section->version_number,
      "current-next-indicator", G_TYPE_UINT, section->current_next_indicator,
      "service-id", G_TYPE_UINT, service_id,
      "transport-stream-id", G_TYPE_UINT, transport_stream_id,
      "original-network-id", G_TYPE_UINT, original_network_id,
      "segment-last-section-number", G_TYPE_UINT, segment_last_section_number,
      "last-table-id", G_TYPE_UINT, last_table_id, NULL);

  g_value_init (&events, GST_TYPE_LIST);
  while (data < end - 4) {
    /* 12 is the minimum entry size + CRC */
    if (end - data < 12 + 4) {
      GST_WARNING ("PID %d invalid EIT entry length %d",
          section->pid, end - 4 - data);
      gst_structure_free (eit);
      goto error;
    }

    event_id = GST_READ_UINT16_BE (data);
    data += 2;
    start_and_duration = GST_READ_UINT64_BE (data);
    start_time = start_and_duration >> 24;
    duration = start_and_duration & 0xFFFFFF;
    data += 8;
    running_status = *data >> 5;
    free_ca_mode = (*data >> 4) & 0x01;
    descriptors_loop_length = GST_READ_UINT16_BE (data) & 0x0FFF;
    data += 2;

    event_name = g_strdup_printf ("event-%d", event_id);
    /* FIXME: parse the date */
    event = gst_structure_new (event_name,
        "event-id", G_TYPE_UINT, event_id,
        "start-time", G_TYPE_UINT, 0,
        "duration", G_TYPE_UINT, 0,
        "running-status", G_TYPE_UINT, running_status,
        "free-ca-mode", G_TYPE_BOOLEAN, free_ca_mode, NULL);
    g_free (event_name);

    if (descriptors_loop_length) {
      if (data + descriptors_loop_length > end - 4) {
        GST_WARNING ("PID %d invalid EIT descriptors loop length %d",
            section->pid, descriptors_loop_length);
        gst_structure_free (event);
        goto error;
      }

      descriptors = g_value_array_new (0);
      if (!mpegts_packetizer_parse_descriptors (packetizer,
              &data, data + descriptors_loop_length, descriptors)) {
        gst_structure_free (event);
        g_value_array_free (descriptors);
        goto error;
      }
      gst_structure_set (event, "descriptors", G_TYPE_VALUE_ARRAY, descriptors,
          NULL);
      g_value_array_free (descriptors);
    }

    g_value_init (&event_value, GST_TYPE_STRUCTURE);
    g_value_take_boxed (&event_value, event);
    gst_value_list_append_value (&events, &event_value);
    g_value_unset (&event_value);
  }

  if (data != end - 4) {
    GST_WARNING ("PID %d invalid EIT parsed %d length %d",
        section->pid, data - GST_BUFFER_DATA (section->buffer),
        GST_BUFFER_SIZE (section->buffer));
    goto error;
  }

  gst_structure_set_value (eit, "events", &events);
  g_value_unset (&events);

  dbg_str = gst_structure_to_string (eit);
  GST_DEBUG ("EIT %s", dbg_str);
  g_free (dbg_str);

  return eit;

error:
  if (eit)
    gst_structure_free (eit);

  if (GST_VALUE_HOLDS_LIST (&events))
    g_value_unset (&events);

  return NULL;
}

static void
foreach_stream_clear (gpointer key, gpointer value, gpointer data)
{
  MpegTSPacketizerStream *stream = (MpegTSPacketizerStream *) value;

  /* remove the stream */
  g_object_unref (stream->section_adapter);
  g_free (stream);
}

static gboolean
remove_all (gpointer key, gpointer value, gpointer user_data)
{
  return TRUE;
}

void
mpegts_packetizer_clear (MpegTSPacketizer * packetizer)
{
  g_hash_table_foreach (packetizer->streams, foreach_stream_clear, packetizer);

  /* FIXME can't use remove_all because we don't depend on 2.12 yet */
  g_hash_table_foreach_remove (packetizer->streams, remove_all, NULL);
  gst_adapter_clear (packetizer->adapter);
}

MpegTSPacketizer *
mpegts_packetizer_new ()
{
  MpegTSPacketizer *packetizer;

  packetizer =
      GST_MPEGTS_PACKETIZER (g_object_new (GST_TYPE_MPEGTS_PACKETIZER, NULL));

  return packetizer;
}

void
mpegts_packetizer_push (MpegTSPacketizer * packetizer, GstBuffer * buffer)
{
  g_return_if_fail (GST_IS_MPEGTS_PACKETIZER (packetizer));
  g_return_if_fail (GST_IS_BUFFER (buffer));

  gst_adapter_push (packetizer->adapter, buffer);
}

gboolean
mpegts_packetizer_has_packets (MpegTSPacketizer * packetizer)
{
  g_return_val_if_fail (GST_IS_MPEGTS_PACKETIZER (packetizer), FALSE);

  return gst_adapter_available (packetizer->adapter) >= 188;
}

gboolean
mpegts_packetizer_next_packet (MpegTSPacketizer * packetizer,
    MpegTSPacketizerPacket * packet)
{
  guint8 sync_byte;
  gboolean ret = FALSE;

  g_return_val_if_fail (GST_IS_MPEGTS_PACKETIZER (packetizer), FALSE);
  g_return_val_if_fail (packet != NULL, FALSE);

  packet->buffer = NULL;
  while (gst_adapter_available (packetizer->adapter) >= 188) {
    sync_byte = *gst_adapter_peek (packetizer->adapter, 1);
    if (sync_byte != 0x47) {
      GST_DEBUG ("lost sync %02x", sync_byte);
      gst_adapter_flush (packetizer->adapter, 1);
      continue;
    }

    packet->buffer = gst_adapter_take_buffer (packetizer->adapter, 188);
    packet->data_start = GST_BUFFER_DATA (packet->buffer);
    packet->data_end =
        GST_BUFFER_DATA (packet->buffer) + GST_BUFFER_SIZE (packet->buffer);
    ret = mpegts_packetizer_parse_packet (packetizer, packet);
    break;
  }

  return ret;
}

void
mpegts_packetizer_clear_packet (MpegTSPacketizer * packetizer,
    MpegTSPacketizerPacket * packet)
{
  g_return_if_fail (GST_IS_MPEGTS_PACKETIZER (packetizer));
  g_return_if_fail (packet != NULL);

  if (packet->buffer)
    gst_buffer_unref (packet->buffer);
  packet->buffer = NULL;
  packet->continuity_counter = 0;
  packet->payload_unit_start_indicator = 0;
  packet->payload = NULL;
  packet->data_start = NULL;
  packet->data_end = NULL;
}

gboolean
mpegts_packetizer_push_section (MpegTSPacketizer * packetizer,
    MpegTSPacketizerPacket * packet, MpegTSPacketizerSection * section)
{
  gboolean res = FALSE;
  MpegTSPacketizerStream *stream;
  guint8 pointer, table_id;
  guint16 sub_table_extension;
  guint section_length;
  GstBuffer *sub_buf;
  guint8 *data;
  gchar *sub_table_identifier;

  g_return_val_if_fail (GST_IS_MPEGTS_PACKETIZER (packetizer), FALSE);
  g_return_val_if_fail (packet != NULL, FALSE);
  g_return_val_if_fail (section != NULL, FALSE);

  data = packet->data;
  section->pid = packet->pid;

  if (packet->payload_unit_start_indicator == 1) {
    pointer = *data++;
    if (data + pointer > packet->data_end) {
      GST_WARNING ("PID %d PSI section pointer points past the end "
          "of the buffer", packet->pid);
      goto out;
    }

    data += pointer;
  }
  table_id = *data++;
  /* sub_table_extension should be read from 4th and 5th bytes only if 
   * section_syntax_indicator is 1 */
  if ((data[0] & 0x80) == 0)
    sub_table_extension = 0;
  else
    sub_table_extension = GST_READ_UINT16_BE (data + 2);
  sub_table_identifier =
      g_strdup_printf ("%d,%d", table_id, sub_table_extension);
  GST_DEBUG ("sub table identifier is: %s", sub_table_identifier);
  stream = (MpegTSPacketizerStream *) g_hash_table_lookup (packetizer->streams,
      sub_table_identifier);
  if (stream == NULL) {
    stream = mpegts_packetizer_stream_new (table_id, sub_table_extension);
    g_hash_table_insert (packetizer->streams, sub_table_identifier, stream);
  } else {
    g_free (sub_table_identifier);
  }

  section_length = GST_READ_UINT16_BE (data) & 0x0FFF;
  data += 2;

  /* create a sub buffer from the start of the section (table_id and
   * section_length included) to the end */
  sub_buf = gst_buffer_create_sub (packet->buffer,
      data - 3 - GST_BUFFER_DATA (packet->buffer), packet->data_end - data + 3);

  if (packet->payload_unit_start_indicator) {
    if (stream->continuity_counter != CONTINUITY_UNSET) {
      GST_WARNING ("PID %d payload_unit_start_indicator set but section "
          "not complete (last_continuity: %d continuity: %d sec len %d buffer %d avail %d",
          packet->pid, stream->continuity_counter, packet->continuity_counter,
          section_length, GST_BUFFER_SIZE (sub_buf),
          gst_adapter_available (stream->section_adapter));
      mpegts_packetizer_clear_section (packetizer, stream);
    }

    stream->continuity_counter = packet->continuity_counter;
    stream->section_length = section_length;
    gst_adapter_push (stream->section_adapter, sub_buf);

    res = TRUE;
  } else if (packet->continuity_counter == stream->continuity_counter + 1 ||
      (stream->continuity_counter == MAX_CONTINUITY &&
          packet->continuity_counter == 0)) {
    stream->continuity_counter = packet->continuity_counter;
    gst_adapter_push (stream->section_adapter, sub_buf);

    res = TRUE;
  } else {
    GST_WARNING ("PID %d section discontinuity "
        "(last_continuity: %d continuity: %d", packet->pid,
        stream->continuity_counter, packet->continuity_counter);
    mpegts_packetizer_clear_section (packetizer, stream);
    gst_buffer_unref (sub_buf);
  }

  if (res) {
    /* we pushed some data in the section adapter, see if the section is
     * complete now */

    /* >= as sections can be padded and padding is not included in
     * section_length */
    if (gst_adapter_available (stream->section_adapter) >=
        stream->section_length + 3) {

      res = mpegts_packetizer_parse_section_header (packetizer,
          stream, section);

      /* flush stuffing bytes */
      mpegts_packetizer_clear_section (packetizer, stream);
    } else {
      /* section not complete yet */
      section->complete = FALSE;
    }
  } else {
    section->complete = FALSE;
  }

out:
  packet->data = data;
  return res;
}

void
mpegts_packetizer_init_debug ()
{
  GST_DEBUG_CATEGORY_INIT (mpegts_packetizer_debug, "mpegtspacketizer", 0,
      "MPEG transport stream parser");
}