gst/typefind/gsttypefindfunctions.c

/* GStreamer
 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
 * Copyright (C) 2005-2009 Tim-Philipp Müller <tim centricular net>
 * Copyright (C) 2009 Sebastian Dröge <sebastian.droege@collabora.co.uk>
 *
 * gsttypefindfunctions.c: collection of various typefind functions
 *
 * 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., 51 Franklin St, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <glib.h>
#include <glib/gprintf.h>

/* don't want to add gio xdgmime typefinder if gio was disabled via configure */
#ifdef HAVE_GIO
#include <gio/gio.h>
#define USE_GIO
#endif

#include <gst/gst.h>

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#include <gst/pbutils/pbutils.h>
#include <gst/base/gstbytereader.h>

GST_DEBUG_CATEGORY_STATIC (type_find_debug);
#define GST_CAT_DEFAULT type_find_debug

/* DataScanCtx: helper for typefind functions that scan through data
 * step-by-step, to avoid doing a peek at each and every offset */

#define DATA_SCAN_CTX_CHUNK_SIZE 4096

typedef struct
{
  guint64 offset;
  const guint8 *data;
  guint size;
} DataScanCtx;

static inline void
data_scan_ctx_advance (GstTypeFind * tf, DataScanCtx * c, guint bytes_to_skip)
{
  c->offset += bytes_to_skip;
  if (G_LIKELY (c->size > bytes_to_skip)) {
    c->size -= bytes_to_skip;
    c->data += bytes_to_skip;
  } else {
    c->data += c->size;
    c->size = 0;
  }
}

static inline gboolean
data_scan_ctx_ensure_data (GstTypeFind * tf, DataScanCtx * c, guint min_len)
{
  const guint8 *data;
  guint64 len;
  guint chunk_len = MAX (DATA_SCAN_CTX_CHUNK_SIZE, min_len);

  if (G_LIKELY (c->size >= min_len))
    return TRUE;

  data = gst_type_find_peek (tf, c->offset, chunk_len);
  if (G_LIKELY (data != NULL)) {
    c->data = data;
    c->size = chunk_len;
    return TRUE;
  }

  /* if there's less than our chunk size, try to get as much as we can, but
   * always at least min_len bytes (we might be typefinding the first buffer
   * of the stream and not have as much data available as we'd like) */
  len = gst_type_find_get_length (tf);
  if (len > 0) {
    len = CLAMP (len - c->offset, min_len, chunk_len);
  } else {
    len = min_len;
  }

  data = gst_type_find_peek (tf, c->offset, len);
  if (data != NULL) {
    c->data = data;
    c->size = len;
    return TRUE;
  }

  return FALSE;
}

static inline gboolean
data_scan_ctx_memcmp (GstTypeFind * tf, DataScanCtx * c, guint offset,
    const gchar * data, guint len)
{
  if (G_UNLIKELY (offset + len >= G_MAXUINT32))
    return FALSE;

  if (!data_scan_ctx_ensure_data (tf, c, offset + len))
    return FALSE;

  return (memcmp (c->data + offset, data, len) == 0);
}

/*** text/plain ***/
static gboolean xml_check_first_element (GstTypeFind * tf,
    const gchar * element, guint elen, gboolean strict);
static gboolean sdp_check_header (GstTypeFind * tf);

static GstStaticCaps utf8_caps = GST_STATIC_CAPS ("text/plain");

#define UTF8_CAPS gst_static_caps_get(&utf8_caps)

static gboolean
utf8_type_find_have_valid_utf8_at_offset (GstTypeFind * tf, guint64 offset,
    GstTypeFindProbability * prob)
{
  const guint8 *data;

  /* randomly decided values */
  guint min_size = 16;          /* minimum size  */
  guint size = 32 * 1024;       /* starting size */
  guint probability = 95;       /* starting probability */
  guint step = 10;              /* how much we reduce probability in each
                                 * iteration */

  while (probability > step && size > min_size) {
    data = gst_type_find_peek (tf, offset, size);
    if (data) {
      gchar *end;
      gchar *start = (gchar *) data;

      if (g_utf8_validate (start, size, (const gchar **) &end) || (end - start + 4 > size)) {   /* allow last char to be cut off */
        *prob = probability;
        return TRUE;
      }
      *prob = 0;
      return FALSE;
    }
    size /= 2;
    probability -= step;
  }
  *prob = 0;
  return FALSE;
}

static void
utf8_type_find (GstTypeFind * tf, gpointer unused)
{
  GstTypeFindProbability start_prob, mid_prob;
  guint64 length;

  /* leave xml to the xml typefinders */
  if (xml_check_first_element (tf, "", 0, TRUE))
    return;

  /* leave sdp to the sdp typefinders */
  if (sdp_check_header (tf))
    return;

  /* check beginning of stream */
  if (!utf8_type_find_have_valid_utf8_at_offset (tf, 0, &start_prob))
    return;

  GST_LOG ("start is plain text with probability of %u", start_prob);

  /* POSSIBLE is the highest probability we ever return if we can't
   * probe into the middle of the file and don't know its length */

  length = gst_type_find_get_length (tf);
  if (length == 0 || length == (guint64) - 1) {
    gst_type_find_suggest (tf, MIN (start_prob, GST_TYPE_FIND_POSSIBLE),
        UTF8_CAPS);
    return;
  }

  if (length < 64 * 1024) {
    gst_type_find_suggest (tf, start_prob, UTF8_CAPS);
    return;
  }

  /* check middle of stream */
  if (!utf8_type_find_have_valid_utf8_at_offset (tf, length / 2, &mid_prob))
    return;

  GST_LOG ("middle is plain text with probability of %u", mid_prob);
  gst_type_find_suggest (tf, (start_prob + mid_prob) / 2, UTF8_CAPS);
}

/*** text/utf-16 and text/utf-32} ***/
/* While UTF-8 is unicode too, using text/plain for UTF-16 and UTF-32
   is going to break stuff. */

typedef struct
{
  size_t bomlen;
  const char *const bom;
    gboolean (*checker) (const guint8 *, gint, gint);
  int boost;
  int endianness;
} GstUnicodeTester;

static gboolean
check_utf16 (const guint8 * data, gint len, gint endianness)
{
  GstByteReader br;
  guint16 high, low;

  low = high = 0;

  if (len & 1)
    return FALSE;

  gst_byte_reader_init (&br, data, len);
  while (len >= 2) {
    /* test first for a single 16 bit value in the BMP */
    if (endianness == G_BIG_ENDIAN)
      high = gst_byte_reader_get_uint16_be_unchecked (&br);
    else
      high = gst_byte_reader_get_uint16_le_unchecked (&br);
    if (high >= 0xD800 && high <= 0xDBFF) {
      /* start of a surrogate pair */
      if (len < 4)
        return FALSE;
      len -= 2;
      if (endianness == G_BIG_ENDIAN)
        low = gst_byte_reader_get_uint16_be_unchecked (&br);
      else
        low = gst_byte_reader_get_uint16_le_unchecked (&br);
      if (low >= 0xDC00 && low <= 0xDFFF) {
        /* second half of the surrogate pair */
      } else
        return FALSE;
    } else {
      if (high >= 0xDC00 && high <= 0xDFFF)
        return FALSE;
    }
    len -= 2;
  }
  return TRUE;
}

static gboolean
check_utf32 (const guint8 * data, gint len, gint endianness)
{
  if (len & 3)
    return FALSE;
  while (len > 3) {
    guint32 v;
    if (endianness == G_BIG_ENDIAN)
      v = GST_READ_UINT32_BE (data);
    else
      v = GST_READ_UINT32_LE (data);
    if (v >= 0x10FFFF)
      return FALSE;
    data += 4;
    len -= 4;
  }
  return TRUE;
}

static void
unicode_type_find (GstTypeFind * tf, const GstUnicodeTester * tester,
    guint n_tester, const char *media_type, gboolean require_bom)
{
  gsize n;
  gsize len = 4;
  const guint8 *data = gst_type_find_peek (tf, 0, len);
  int prob = -1;
  const gint max_scan_size = 256 * 1024;
  int endianness = 0;

  if (!data) {
    len = 2;
    data = gst_type_find_peek (tf, 0, len);
    if (!data)
      return;
  }

  /* find a large enough size that works */
  while (len < max_scan_size) {
    size_t newlen = len << 1;
    const guint8 *newdata = gst_type_find_peek (tf, 0, newlen);
    if (!newdata)
      break;
    len = newlen;
    data = newdata;
  }

  for (n = 0; n < n_tester; ++n) {
    int bom_boost = 0, tmpprob;
    if (len >= tester[n].bomlen) {
      if (!memcmp (data, tester[n].bom, tester[n].bomlen))
        bom_boost = tester[n].boost;
    }
    if (require_bom && bom_boost == 0)
      continue;
    if (!(*tester[n].checker) (data, len, tester[n].endianness))
      continue;
    tmpprob = GST_TYPE_FIND_POSSIBLE - 20 + bom_boost;
    if (tmpprob > prob) {
      prob = tmpprob;
      endianness = tester[n].endianness;
    }
  }

  if (prob > 0) {
    GST_DEBUG ("This is valid %s %s", media_type,
        endianness == G_BIG_ENDIAN ? "be" : "le");
    gst_type_find_suggest_simple (tf, prob, media_type,
        "endianness", G_TYPE_INT, endianness, NULL);
  }
}

static GstStaticCaps utf16_caps = GST_STATIC_CAPS ("text/utf-16");

#define UTF16_CAPS gst_static_caps_get(&utf16_caps)

static void
utf16_type_find (GstTypeFind * tf, gpointer unused)
{
  static const GstUnicodeTester utf16tester[2] = {
    {2, "\xff\xfe", check_utf16, 10, G_LITTLE_ENDIAN},
    {2, "\xfe\xff", check_utf16, 20, G_BIG_ENDIAN},
  };
  unicode_type_find (tf, utf16tester, G_N_ELEMENTS (utf16tester),
      "text/utf-16", TRUE);
}

static GstStaticCaps utf32_caps = GST_STATIC_CAPS ("text/utf-32");

#define UTF32_CAPS gst_static_caps_get(&utf32_caps)

static void
utf32_type_find (GstTypeFind * tf, gpointer unused)
{
  static const GstUnicodeTester utf32tester[2] = {
    {4, "\xff\xfe\x00\x00", check_utf32, 10, G_LITTLE_ENDIAN},
    {4, "\x00\x00\xfe\xff", check_utf32, 20, G_BIG_ENDIAN}
  };
  unicode_type_find (tf, utf32tester, G_N_ELEMENTS (utf32tester),
      "text/utf-32", TRUE);
}

/*** text/uri-list ***/

static GstStaticCaps uri_caps = GST_STATIC_CAPS ("text/uri-list");

#define URI_CAPS (gst_static_caps_get(&uri_caps))
#define BUFFER_SIZE 16          /* If the string is < 16 bytes we're screwed */
#define INC_BUFFER {                                                    \
  pos++;                                                                \
  if (pos == BUFFER_SIZE) {                                             \
    pos = 0;                                                            \
    offset += BUFFER_SIZE;                                              \
    data = gst_type_find_peek (tf, offset, BUFFER_SIZE);                \
    if (data == NULL) return;                                           \
  } else {                                                              \
    data++;                                                             \
  }                                                                     \
}
static void
uri_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, BUFFER_SIZE);
  guint pos = 0;
  guint offset = 0;

  if (data) {
    /* Search for # comment lines */
    while (*data == '#') {
      /* Goto end of line */
      while (*data != '\n') {
        INC_BUFFER;
      }

      INC_BUFFER;
    }

    if (!g_ascii_isalpha (*data)) {
      /* Had a non alpha char - can't be uri-list */
      return;
    }

    INC_BUFFER;

    while (g_ascii_isalnum (*data)) {
      INC_BUFFER;
    }

    if (*data != ':') {
      /* First non alpha char is not a : */
      return;
    }

    /* Get the next 2 bytes as well */
    data = gst_type_find_peek (tf, offset + pos, 3);
    if (data == NULL)
      return;

    if (data[1] != '/' && data[2] != '/') {
      return;
    }

    gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, URI_CAPS);
  }
}

/*** application/itc ***/
static GstStaticCaps itc_caps = GST_STATIC_CAPS ("application/itc");
#define ITC_CAPS (gst_static_caps_get(&itc_caps))

static void
itc_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  guint8 magic[8] = { 0x00, 0x00, 0x01, 0x1C, 0x69, 0x74, 0x63, 0x68 };
  guint8 preamble[4] = { 0x00, 0x00, 0x00, 0x02 };
  guint8 artwork_marker[8] = { 0x00, 0x00, 0x00, 0x00, 0x61, 0x72, 0x74, 0x77 };
  guint8 item_marker[4] = { 0x69, 0x74, 0x65, 0x6D };
  GstTypeFindProbability itc_prob = GST_TYPE_FIND_NONE;
  int i;

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 8)))
    return;

  if (memcmp (c.data, magic, 8))
    return;

  /* At least we found the right magic */
  itc_prob = GST_TYPE_FIND_MINIMUM;
  data_scan_ctx_advance (tf, &c, 8);

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 12)))
    goto done;

  /* Check preamble 3 consecutive times */
  for (i = 0; i < 3; i++) {
    if (memcmp (c.data, preamble, 4))
      goto done;
    data_scan_ctx_advance (tf, &c, 4);
  }

  itc_prob = GST_TYPE_FIND_POSSIBLE;

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 8)))
    goto done;

  if (memcmp (c.data, artwork_marker, 8))
    goto done;

  itc_prob = GST_TYPE_FIND_LIKELY;
  data_scan_ctx_advance (tf, &c, 8);

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 256)))
    goto done;

  /* ...and 256 0x00 padding bytes on what looks like the header's end */
  for (i = 0; i < 256; i++) {
    if (c.data[i])
      goto done;
  }

  itc_prob = GST_TYPE_FIND_NEARLY_CERTAIN;
  data_scan_ctx_advance (tf, &c, 256);

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 8)))
    goto done;

  if (memcmp (c.data + 4, item_marker, 4))
    goto done;

  itc_prob = GST_TYPE_FIND_MAXIMUM;

done:
  gst_type_find_suggest (tf, itc_prob, ITC_CAPS);
}

/*** application/x-hls ***/

static GstStaticCaps hls_caps = GST_STATIC_CAPS ("application/x-hls");
#define HLS_CAPS (gst_static_caps_get(&hls_caps))

/* See http://tools.ietf.org/html/draft-pantos-http-live-streaming-05 */
static void
hls_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  /* Minimum useful size is #EXTM3U\n + 1 tag + ':' = 30 bytes */
  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 30)))
    return;

  if (memcmp (c.data, "#EXTM3U", 7))
    return;

  data_scan_ctx_advance (tf, &c, 7);

  /* Check only the first 4KB */
  while (c.offset < 4096) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 21)))
      return;

    /* Search for # comment lines */
    if (c.data[0] == '#' && (memcmp (c.data, "#EXT-X-TARGETDURATION", 21) == 0
            || memcmp (c.data, "#EXT-X-STREAM-INF", 17) == 0
            || memcmp (c.data, "#EXT-X-MEDIA", 12) == 0)) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, HLS_CAPS);
      return;
    }

    data_scan_ctx_advance (tf, &c, 1);
  }
}


/*** application/xml **********************************************************/

#define XML_BUFFER_SIZE 16
#define XML_INC_BUFFER {                                                \
  pos++;                                                                \
  if (pos == XML_BUFFER_SIZE) {                                         \
    pos = 0;                                                            \
    offset += XML_BUFFER_SIZE;                                          \
    data = gst_type_find_peek (tf, offset, XML_BUFFER_SIZE);            \
    if (data == NULL) return FALSE;                                     \
  } else {                                                              \
    data++;                                                             \
  }                                                                     \
}

#define XML_INC_BUFFER_DATA {                                           \
  pos++;                                                                \
  if (pos >= length) {                                                  \
    return FALSE;                                                       \
  } else {                                                              \
    data++;                                                             \
  }                                                                     \
}

static gboolean
xml_check_first_element_from_data (const guint8 * data, guint length,
    const gchar * element, guint elen, gboolean strict)
{
  gboolean got_xmldec;
  guint pos = 0;

  g_return_val_if_fail (data != NULL, FALSE);

  if (length <= 5)
    return FALSE;

  /* look for the XMLDec
   * see XML spec 2.8, Prolog and Document Type Declaration
   * http://www.w3.org/TR/2004/REC-xml-20040204/#sec-prolog-dtd */
  got_xmldec = (memcmp (data, "<?xml", 5) == 0);

  if (strict && !got_xmldec)
    return FALSE;

  /* skip XMLDec in any case if we've got one */
  if (got_xmldec) {
    pos += 5;
    data += 5;
  }

  /* look for the first element, it has to be the requested element. Bail
   * out if it is not within the first 4kB. */
  while (pos < MIN (4096, length)) {
    while (*data != '<' && pos < MIN (4096, length)) {
      XML_INC_BUFFER_DATA;
    }

    XML_INC_BUFFER_DATA;
    if (!g_ascii_isalpha (*data)) {
      /* if not alphabetic, it's a PI or an element / attribute declaration
       * like <?xxx or <!xxx */
      XML_INC_BUFFER_DATA;
      continue;
    }

    /* the first normal element, check if it's the one asked for */
    if (pos + elen + 1 >= length)
      return FALSE;
    return (element && strncmp ((const char *) data, element, elen) == 0);
  }

  return FALSE;
}

static gboolean
xml_check_first_element (GstTypeFind * tf, const gchar * element, guint elen,
    gboolean strict)
{
  gboolean got_xmldec;
  const guint8 *data;
  guint offset = 0;
  guint pos = 0;

  data = gst_type_find_peek (tf, 0, XML_BUFFER_SIZE);
  if (!data)
    return FALSE;

  /* look for the XMLDec
   * see XML spec 2.8, Prolog and Document Type Declaration
   * http://www.w3.org/TR/2004/REC-xml-20040204/#sec-prolog-dtd */
  got_xmldec = (memcmp (data, "<?xml", 5) == 0);

  if (strict && !got_xmldec)
    return FALSE;

  /* skip XMLDec in any case if we've got one */
  if (got_xmldec) {
    pos += 5;
    data += 5;
  }

  /* look for the first element, it has to be the requested element. Bail
   * out if it is not within the first 4kB. */
  while (data && (offset + pos) < 4096) {
    while (*data != '<' && (offset + pos) < 4096) {
      XML_INC_BUFFER;
    }

    XML_INC_BUFFER;
    if (!g_ascii_isalpha (*data)) {
      /* if not alphabetic, it's a PI or an element / attribute declaration
       * like <?xxx or <!xxx */
      XML_INC_BUFFER;
      continue;
    }

    /* the first normal element, check if it's the one asked for */
    data = gst_type_find_peek (tf, offset + pos, elen + 1);
    return (data && element && strncmp ((char *) data, element, elen) == 0);
  }

  return FALSE;
}

static GstStaticCaps generic_xml_caps = GST_STATIC_CAPS ("application/xml");

#define GENERIC_XML_CAPS (gst_static_caps_get(&generic_xml_caps))
static void
xml_type_find (GstTypeFind * tf, gpointer unused)
{
  if (xml_check_first_element (tf, "", 0, TRUE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MINIMUM, GENERIC_XML_CAPS);
  }
}

/*** application/dash+xml ****************************************************/

static GstStaticCaps dash_caps = GST_STATIC_CAPS ("application/dash+xml");

#define DASH_CAPS gst_static_caps_get (&dash_caps)

static void
dash_mpd_type_find (GstTypeFind * tf, gpointer unused)
{
  if (xml_check_first_element (tf, "MPD", 3, FALSE) ||
      xml_check_first_element (tf, "mpd", 3, FALSE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, DASH_CAPS);
  }
}

/*** application/xges ****************************************************/

static GstStaticCaps xges_caps = GST_STATIC_CAPS ("application/xges");

#define XGES_CAPS gst_static_caps_get (&xges_caps)

static void
xges_type_find (GstTypeFind * tf, gpointer unused)
{
  if (xml_check_first_element (tf, "ges", 3, FALSE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, XGES_CAPS);
  }
}


/*** application/sdp *********************************************************/

static GstStaticCaps sdp_caps = GST_STATIC_CAPS ("application/sdp");

#define SDP_CAPS (gst_static_caps_get(&sdp_caps))
static gboolean
sdp_check_header (GstTypeFind * tf)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 5);
  if (!data)
    return FALSE;

  /* sdp must start with v=0[\r]\n */
  if (memcmp (data, "v=0", 3))
    return FALSE;

  if (data[3] == '\r' && data[4] == '\n')
    return TRUE;
  if (data[3] == '\n')
    return TRUE;

  return FALSE;
}

static void
sdp_type_find (GstTypeFind * tf, gpointer unused)
{
  if (sdp_check_header (tf))
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SDP_CAPS);
}

/*** application/smil *********************************************************/

static GstStaticCaps smil_caps = GST_STATIC_CAPS ("application/smil");

#define SMIL_CAPS (gst_static_caps_get(&smil_caps))
static void
smil_type_find (GstTypeFind * tf, gpointer unused)
{
  if (xml_check_first_element (tf, "smil", 4, FALSE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SMIL_CAPS);
  }
}

/*** application/ttml+xml *****************************************************/

static GstStaticCaps ttml_xml_caps = GST_STATIC_CAPS ("application/ttml+xml");

#define TTML_XML_CAPS (gst_static_caps_get(&ttml_xml_caps))
static void
ttml_xml_type_find (GstTypeFind * tf, gpointer unused)
{
  if (xml_check_first_element (tf, "tt", 2, FALSE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, TTML_XML_CAPS);
  }
}

/*** text/html ***/

static GstStaticCaps html_caps = GST_STATIC_CAPS ("text/html");

#define HTML_CAPS gst_static_caps_get (&html_caps)

static void
html_type_find (GstTypeFind * tf, gpointer unused)
{
  const gchar *d, *data;

  data = (const gchar *) gst_type_find_peek (tf, 0, 16);
  if (!data)
    return;

  if (!g_ascii_strncasecmp (data, "<!DOCTYPE HTML", 14)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, HTML_CAPS);
  } else if (xml_check_first_element (tf, "html", 4, FALSE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, HTML_CAPS);
  } else if ((d = memchr (data, '<', 16))) {
    data = (const gchar *) gst_type_find_peek (tf, d - data, 6);
    if (data && g_ascii_strncasecmp (data, "<html>", 6) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, HTML_CAPS);
    }
  }
}

/*** audio/midi ***/

static GstStaticCaps mid_caps = GST_STATIC_CAPS ("audio/midi");

#define MID_CAPS gst_static_caps_get(&mid_caps)
static void
mid_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  /* http://jedi.ks.uiuc.edu/~johns/links/music/midifile.html */
  if (data && data[0] == 'M' && data[1] == 'T' && data[2] == 'h'
      && data[3] == 'd')
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MID_CAPS);
}

/*** audio/mobile-xmf ***/

static GstStaticCaps mxmf_caps = GST_STATIC_CAPS ("audio/mobile-xmf");

#define MXMF_CAPS gst_static_caps_get(&mxmf_caps)
static void
mxmf_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = NULL;

  /* Search FileId "XMF_" 4 bytes */
  data = gst_type_find_peek (tf, 0, 4);
  if (data && data[0] == 'X' && data[1] == 'M' && data[2] == 'F'
      && data[3] == '_') {
    /* Search Format version "2.00" 4 bytes */
    data = gst_type_find_peek (tf, 4, 4);
    if (data && data[0] == '2' && data[1] == '.' && data[2] == '0'
        && data[3] == '0') {
      /* Search TypeId 2     1 byte */
      data = gst_type_find_peek (tf, 11, 1);
      if (data && data[0] == 2) {
        gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MXMF_CAPS);
      }
    }
  }
}


/*** video/x-fli ***/

static GstStaticCaps flx_caps = GST_STATIC_CAPS ("video/x-fli");

#define FLX_CAPS gst_static_caps_get(&flx_caps)
static void
flx_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 134);

  if (data) {
    /* check magic and the frame type of the first frame */
    if ((data[4] == 0x11 || data[4] == 0x12 ||
            data[4] == 0x30 || data[4] == 0x44) &&
        data[5] == 0xaf &&
        ((data[132] == 0x00 || data[132] == 0xfa) && data[133] == 0xf1)) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, FLX_CAPS);
    }
    return;
  }
  data = gst_type_find_peek (tf, 0, 6);
  if (data) {
    /* check magic only */
    if ((data[4] == 0x11 || data[4] == 0x12 ||
            data[4] == 0x30 || data[4] == 0x44) && data[5] == 0xaf) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, FLX_CAPS);
    }
    return;
  }
}

/*** application/x-id3 ***/

static GstStaticCaps id3_caps = GST_STATIC_CAPS ("application/x-id3");

#define ID3_CAPS gst_static_caps_get(&id3_caps)
static void
id3v2_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 10);

  if (data && memcmp (data, "ID3", 3) == 0 &&
      data[3] != 0xFF && data[4] != 0xFF &&
      (data[6] & 0x80) == 0 && (data[7] & 0x80) == 0 &&
      (data[8] & 0x80) == 0 && (data[9] & 0x80) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, ID3_CAPS);
  }
}

static void
id3v1_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, -128, 3);

  if (data && memcmp (data, "TAG", 3) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, ID3_CAPS);
  }
}

/*** application/x-ape ***/

static GstStaticCaps apetag_caps = GST_STATIC_CAPS ("application/x-apetag");

#define APETAG_CAPS gst_static_caps_get(&apetag_caps)
static void
apetag_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;

  /* APEv1/2 at start of file */
  data = gst_type_find_peek (tf, 0, 8);
  if (data && !memcmp (data, "APETAGEX", 8)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, APETAG_CAPS);
    return;
  }

  /* APEv1/2 at end of file */
  data = gst_type_find_peek (tf, -32, 8);
  if (data && !memcmp (data, "APETAGEX", 8)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, APETAG_CAPS);
    return;
  }
}

/*** audio/x-ttafile ***/

static GstStaticCaps tta_caps = GST_STATIC_CAPS ("audio/x-ttafile");

#define TTA_CAPS gst_static_caps_get(&tta_caps)
static void
tta_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 3);

  if (data) {
    if (memcmp (data, "TTA", 3) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, TTA_CAPS);
      return;
    }
  }
}

/*** audio/x-flac ***/
static GstStaticCaps flac_caps = GST_STATIC_CAPS ("audio/x-flac");

#define FLAC_CAPS (gst_static_caps_get(&flac_caps))

static void
flac_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 4)))
    return;

  /* standard flac (also old/broken flac-in-ogg with an initial 4-byte marker
   * packet and without the usual packet framing) */
  if (memcmp (c.data, "fLaC", 4) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, FLAC_CAPS);
    return;
  }

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 6)))
    return;

  /* flac-in-ogg, see http://flac.sourceforge.net/ogg_mapping.html */
  if (memcmp (c.data, "\177FLAC\001", 6) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, FLAC_CAPS);
    return;
  }

/* disabled because it happily typefinds /dev/urandom as audio/x-flac, and
 * because I yet have to see header-less flac in the wild */
#if 0
  /* flac without headers (subset format) */
  /* 64K should be enough */
  while (c.offset < (64 * 1024)) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 4)))
      break;

    /* look for frame header,
     * http://flac.sourceforge.net/format.html#frame_header
     */
    if (c.data[0] == 0xff && (c.data[1] >> 2) == 0x3e) {
      /* bit 15 in the header must be 0 */
      if (((c.data[1] >> 1) & 0x01) == 0x01)
        goto advance;

      /* blocksize must be != 0x00 */
      if ((c.data[2] >> 4) == 0x00)
        goto advance;

      /* samplerate must be != 0x0f */
      if ((c.data[2] & 0x0f) == 0x0f)
        goto advance;
      /* also 0 is invalid, as it means get the info from the header and we
       * don't have headers if we are here */
      if ((c.data[2] & 0x0f) == 0x00)
        goto advance;

      /* channel assignment must be < 11 */
      if ((c.data[3] >> 4) >= 11)
        goto advance;

      /* sample size must be != 0x07 and != 0x05 */
      if (((c.data[3] >> 1) & 0x07) == 0x07)
        goto advance;
      if (((c.data[3] >> 1) & 0x07) == 0x05)
        goto advance;
      /* also 0 is invalid, as it means get the info from the header and we
       * don't have headers if we are here */
      if (((c.data[3] >> 1) & 0x07) == 0x00)
        goto advance;

      /* next bit must be 0 */
      if ((c.data[3] & 0x01) == 0x01)
        goto advance;

      /* FIXME: shouldn't we include the crc check ? */

      GST_DEBUG ("Found flac without headers at %d", (gint) c.offset);
      gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, FLAC_CAPS);
      return;
    }
  advance:
    data_scan_ctx_advance (tf, &c, 1);
  }
#endif
}

/* TODO: we could probably make a generic function for this.. */
static gint
aac_type_find_scan_loas_frames_ep (GstTypeFind * tf, DataScanCtx * scan_ctx,
    gint max_frames)
{
  DataScanCtx c = *scan_ctx;
  guint16 snc;
  guint len;
  gint count = 0;

  do {
    if (!data_scan_ctx_ensure_data (tf, &c, 5))
      break;

    /* EPAudioSyncStream */
    len = ((c.data[2] & 0x0f) << 9) | (c.data[3] << 1) |
        ((c.data[4] & 0x80) >> 7);

    if (len == 0 || !data_scan_ctx_ensure_data (tf, &c, len + 2)) {
      GST_DEBUG ("Wrong sync or next frame not within reach, len=%u", len);
      break;
    }

    /* check length of frame  */
    snc = GST_READ_UINT16_BE (c.data + len);
    if (snc != 0x4de1) {
      GST_DEBUG ("No sync found at 0x%" G_GINT64_MODIFIER "x", c.offset + len);
      break;
    }

    ++count;

    GST_DEBUG ("Found LOAS syncword #%d at offset 0x%" G_GINT64_MODIFIER "x, "
        "framelen %u", count, c.offset, len);

    data_scan_ctx_advance (tf, &c, len);
  } while (count < max_frames && (c.offset - scan_ctx->offset) < 64 * 1024);

  GST_DEBUG ("found %d consecutive frames", count);
  return count;
}

static gint
aac_type_find_scan_loas_frames (GstTypeFind * tf, DataScanCtx * scan_ctx,
    gint max_frames)
{
  DataScanCtx c = *scan_ctx;
  guint16 snc;
  guint len;
  gint count = 0;

  do {
    if (!data_scan_ctx_ensure_data (tf, &c, 3))
      break;

    /* AudioSyncStream */
    len = ((c.data[1] & 0x1f) << 8) | c.data[2];
    /* add size of sync stream header */
    len += 3;

    if (len == 0 || !data_scan_ctx_ensure_data (tf, &c, len + 2)) {
      GST_DEBUG ("Wrong sync or next frame not within reach, len=%u", len);
      break;
    }

    /* check length of frame  */
    snc = GST_READ_UINT16_BE (c.data + len);
    if ((snc & 0xffe0) != 0x56e0) {
      GST_DEBUG ("No sync found at 0x%" G_GINT64_MODIFIER "x", c.offset + len);
      break;
    }

    ++count;

    GST_DEBUG ("Found LOAS syncword #%d at offset 0x%" G_GINT64_MODIFIER "x, "
        "framelen %u", count, c.offset, len);

    data_scan_ctx_advance (tf, &c, len);
  } while (count < max_frames && (c.offset - scan_ctx->offset) < 64 * 1024);

  GST_DEBUG ("found %d consecutive frames", count);
  return count;
}

/*** audio/mpeg version 2, 4 ***/

static GstStaticCaps aac_caps = GST_STATIC_CAPS ("audio/mpeg, "
    "mpegversion = (int) { 2, 4 }, framed = (bool) false");
#define AAC_CAPS (gst_static_caps_get(&aac_caps))
#define AAC_AMOUNT (4096)
static void
aac_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  GstTypeFindProbability best_probability = GST_TYPE_FIND_NONE;
  GstCaps *best_caps = NULL;
  gint best_count = 0;

  while (c.offset < AAC_AMOUNT) {
    guint snc, len, offset, i;

    /* detect adts header or adif header.
     * The ADIF header is 4 bytes, that should be OK. The ADTS header, on
     * the other hand, is 14 bits only, so we require one valid frame with
     * again a valid syncpoint on the next one (28 bits) for certainty. We
     * require 4 kB, which is quite a lot, since frames are generally 200-400
     * bytes.
     * LOAS has 2 possible syncwords, which are 11 bits and 16 bits long.
     * The following stream syntax depends on which one is found.
     */
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 6)))
      break;

    snc = GST_READ_UINT16_BE (c.data);
    if (G_UNLIKELY ((snc & 0xfff6) == 0xfff0)) {
      /* ADTS header - find frame length */
      GST_DEBUG ("Found one ADTS syncpoint at offset 0x%" G_GINT64_MODIFIER
          "x, tracing next...", c.offset);
      len = ((c.data[3] & 0x03) << 11) |
          (c.data[4] << 3) | ((c.data[5] & 0xe0) >> 5);

      if (len == 0 || !data_scan_ctx_ensure_data (tf, &c, len + 6)) {
        GST_DEBUG ("Wrong sync or next frame not within reach, len=%u", len);
        goto next;
      }

      offset = len;
      /* check if there's a second ADTS frame */
      snc = GST_READ_UINT16_BE (c.data + offset);
      if ((snc & 0xfff6) == 0xfff0) {
        GstCaps *caps;
        guint mpegversion, sample_freq_idx, channel_config, profile_idx, rate;
        guint8 audio_config[2];

        mpegversion = (c.data[1] & 0x08) ? 2 : 4;
        profile_idx = c.data[2] >> 6;
        sample_freq_idx = ((c.data[2] & 0x3c) >> 2);
        channel_config = ((c.data[2] & 0x01) << 2) + (c.data[3] >> 6);

        GST_DEBUG ("Found second ADTS-%d syncpoint at offset 0x%"
            G_GINT64_MODIFIER "x, framelen %u", mpegversion, c.offset, len);

        /* 0xd and 0xe are reserved. 0xf means the sample frequency is directly
         * specified in the header, but that's not allowed for ADTS */
        if (sample_freq_idx > 0xc) {
          GST_DEBUG ("Unexpected sample frequency index %d or wrong sync",
              sample_freq_idx);
          goto next;
        }

        rate = gst_codec_utils_aac_get_sample_rate_from_index (sample_freq_idx);
        GST_LOG ("ADTS: profile=%u, rate=%u", profile_idx, rate);

        /* The ADTS frame header is slightly different from the
         * AudioSpecificConfig defined for the MPEG-4 container, so we just
         * construct enough of it for getting the level here. */
        /* ADTS counts profiles from 0 instead of 1 to save bits */
        audio_config[0] = (profile_idx + 1) << 3;
        audio_config[0] |= (sample_freq_idx >> 1) & 0x7;
        audio_config[1] = (sample_freq_idx & 0x1) << 7;
        audio_config[1] |= (channel_config & 0xf) << 3;

        caps = gst_caps_new_simple ("audio/mpeg",
            "framed", G_TYPE_BOOLEAN, FALSE,
            "mpegversion", G_TYPE_INT, mpegversion,
            "stream-format", G_TYPE_STRING, "adts", NULL);

        gst_codec_utils_aac_caps_set_level_and_profile (caps, audio_config, 2);

        /* add rate and number of channels if we can */
        if (channel_config != 0 && channel_config <= 7) {
          const guint channels_map[] = { 0, 1, 2, 3, 4, 5, 6, 8 };

          gst_caps_set_simple (caps, "channels", G_TYPE_INT,
              channels_map[channel_config], "rate", G_TYPE_INT, rate, NULL);
        }

        /* length of the second ADTS frame */
        len = ((c.data[offset + 3] & 0x03) << 11) |
            (c.data[offset + 4] << 3) | ((c.data[offset + 5] & 0xe0) >> 5);

        if (len == 0 || !data_scan_ctx_ensure_data (tf, &c, offset + len + 6)) {
          GST_DEBUG ("Wrong sync or next frame not within reach, len=%u", len);
          gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, caps);
        } else {
          offset += len;
          /* find more aac sync to select correctly */
          /* check if there's a third/fourth/fifth/sixth ADTS frame, if there is a sixth frame, set probability to maximum:100% */
          for (i = 3; i <= 6; i++) {
            len = ((c.data[offset + 3] & 0x03) << 11) |
                (c.data[offset + 4] << 3) | ((c.data[offset + 5] & 0xe0) >> 5);
            if (len == 0
                || !data_scan_ctx_ensure_data (tf, &c, offset + len + 6)) {
              GST_DEBUG ("Wrong sync or next frame not within reach, len=%u",
                  len);
              break;
            }
            snc = GST_READ_UINT16_BE (c.data + offset);
            if ((snc & 0xfff6) == 0xfff0) {
              GST_DEBUG ("Find %und Sync..probability is %u ", i,
                  GST_TYPE_FIND_LIKELY + 5 * (i - 2));
              offset += len;
            } else {
              break;
            }
          }
          gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY + 5 * (i - 3), caps);

        }
        gst_caps_unref (caps);
        break;
      }

      GST_DEBUG ("No next frame found... (should have been at 0x%x)", len);
    } else if (G_UNLIKELY ((snc & 0xffe0) == 0x56e0 || snc == 0x4de1)) {
      gint count;

      /* LOAS frame */
      GST_INFO ("Possible LOAS syncword at offset 0x%" G_GINT64_MODIFIER
          "x, scanning for more frames...", c.offset);

      if (snc == 0x4de1)
        count = aac_type_find_scan_loas_frames_ep (tf, &c, 20);
      else
        count = aac_type_find_scan_loas_frames (tf, &c, 20);

      if (count >= 3 && count > best_count) {
        gst_caps_replace (&best_caps, NULL);
        best_caps = gst_caps_new_simple ("audio/mpeg",
            "framed", G_TYPE_BOOLEAN, FALSE,
            "mpegversion", G_TYPE_INT, 4,
            "stream-format", G_TYPE_STRING, "loas", NULL);
        best_count = count;
        best_probability = GST_TYPE_FIND_POSSIBLE - 10 + count * 3;
        if (best_probability >= GST_TYPE_FIND_LIKELY)
          break;
      }
    } else if (!memcmp (c.data, "ADIF", 4)) {
      /* ADIF header */
      gst_type_find_suggest_simple (tf, GST_TYPE_FIND_LIKELY, "audio/mpeg",
          "framed", G_TYPE_BOOLEAN, FALSE, "mpegversion", G_TYPE_INT, 4,
          "stream-format", G_TYPE_STRING, "adif", NULL);
      break;
    }

  next:

    data_scan_ctx_advance (tf, &c, 1);
  }

  if (best_probability > GST_TYPE_FIND_NONE) {
    gst_type_find_suggest (tf, best_probability, best_caps);
    gst_caps_unref (best_caps);
  }
}

/*** audio/mpeg version 1 ***/

/*
 * The chance that random data is identified as a valid mp3 header is 63 / 2^18
 * (0.024%) per try. This makes the function for calculating false positives
 *   1 - (1 - ((63 / 2 ^18) ^ GST_MP3_TYPEFIND_MIN_HEADERS)) ^ buffersize)
 * This has the following probabilities of false positives:
 * datasize               MIN_HEADERS
 * (bytes)      1       2       3       4
 * 4096         62.6%    0.02%   0%      0%
 * 16384        98%      0.09%   0%      0%
 * 1 MiB       100%      5.88%   0%      0%
 * 1 GiB       100%    100%      1.44%   0%
 * 1 TiB       100%    100%    100%      0.35%
 * This means that the current choice (3 headers by most of the time 4096 byte
 * buffers is pretty safe for now.
 *
 * The max. size of each frame is 1440 bytes, which means that for N frames to
 * be detected, we need 1440 * GST_MP3_TYPEFIND_MIN_HEADERS + 3 bytes of data.
 * Assuming we step into the stream right after the frame header, this
 * means we need 1440 * (GST_MP3_TYPEFIND_MIN_HEADERS + 1) - 1 + 3 bytes
 * of data (5762) to always detect any mp3.
 */

static const guint mp3types_bitrates[2][3][16] =
    { {{0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448,},
    {0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384,},
    {0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320,}},
{{0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256,},
    {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160,},
    {0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160,}},
};

static const guint mp3types_freqs[3][3] = { {11025, 12000, 8000},
{22050, 24000, 16000},
{44100, 48000, 32000}
};

static inline guint
mp3_type_frame_length_from_header (guint32 header, guint * put_layer,
    guint * put_channels, guint * put_bitrate, guint * put_samplerate,
    gboolean * may_be_free_format, gint possible_free_framelen)
{
  guint bitrate, layer, length, mode, samplerate, version, channels;

  if ((header & 0xffe00000) != 0xffe00000)
    return 0;

  /* we don't need extension, copyright, original or
   * emphasis for the frame length */
  header >>= 6;

  /* mode */
  mode = header & 0x3;
  header >>= 3;

  /* padding */
  length = header & 0x1;
  header >>= 1;

  /* sampling frequency */
  samplerate = header & 0x3;
  if (samplerate == 3)
    return 0;
  header >>= 2;

  /* bitrate index */
  bitrate = header & 0xF;
  if (bitrate == 0 && possible_free_framelen == -1) {
    GST_LOG ("Possibly a free format mp3 - signaling");
    *may_be_free_format = TRUE;
  }
  if (bitrate == 15 || (bitrate == 0 && possible_free_framelen == -1))
    return 0;

  /* ignore error correction, too */
  header >>= 5;

  /* layer */
  layer = 4 - (header & 0x3);
  if (layer == 4)
    return 0;
  header >>= 2;

  /* version 0=MPEG2.5; 2=MPEG2; 3=MPEG1 */
  version = header & 0x3;
  if (version == 1)
    return 0;

  /* lookup */
  channels = (mode == 3) ? 1 : 2;
  samplerate = mp3types_freqs[version > 0 ? version - 1 : 0][samplerate];
  if (bitrate == 0) {
    /* possible freeform mp3 */
    if (layer == 1) {
      length *= 4;
      length += possible_free_framelen;
      bitrate = length * samplerate / 48000;
    } else {
      length += possible_free_framelen;
      bitrate = length * samplerate /
          ((layer == 3 && version != 3) ? 72000 : 144000);
    }
    /* freeform mp3 should have a higher-than-usually-allowed bitrate */
    GST_LOG ("calculated bitrate: %u, max usually: %u", bitrate,
        mp3types_bitrates[version == 3 ? 0 : 1][layer - 1][14]);
    if (bitrate < mp3types_bitrates[version == 3 ? 0 : 1][layer - 1][14])
      return 0;
  } else {
    /* calculating */
    bitrate = mp3types_bitrates[version == 3 ? 0 : 1][layer - 1][bitrate];
    if (layer == 1) {
      length = ((12000 * bitrate / samplerate) + length) * 4;
    } else {
      length += ((layer == 3
              && version != 3) ? 72000 : 144000) * bitrate / samplerate;
    }
  }

  GST_LOG ("mp3typefind: calculated mp3 frame length of %u bytes", length);
  GST_LOG
      ("mp3typefind: samplerate = %u - bitrate = %u - layer = %u - version = %u"
      " - channels = %u", samplerate, bitrate, layer, version, channels);

  if (put_layer)
    *put_layer = layer;
  if (put_channels)
    *put_channels = channels;
  if (put_bitrate)
    *put_bitrate = bitrate;
  if (put_samplerate)
    *put_samplerate = samplerate;

  return length;
}


static GstStaticCaps mp3_caps = GST_STATIC_CAPS ("audio/mpeg, "
    "mpegversion = (int) 1, layer = (int) [ 1, 3 ]");
#define MP3_CAPS (gst_static_caps_get(&mp3_caps))
/*
 * random values for typefinding
 * if no more data is available, we will return a probability of
 * (found_headers/TRY_HEADERS) * (MAXIMUM * (TRY_SYNC - bytes_skipped)
 *        / TRY_SYNC)
 * if found_headers >= MIN_HEADERS
 */
#define GST_MP3_TYPEFIND_MIN_HEADERS (2)
#define GST_MP3_TYPEFIND_TRY_HEADERS (5)
#define GST_MP3_TYPEFIND_TRY_SYNC (GST_TYPE_FIND_MAXIMUM * 100) /* 10kB */
#define GST_MP3_TYPEFIND_SYNC_SIZE (2048)
#define GST_MP3_WRONG_HEADER (10)

static void
mp3_type_find_at_offset (GstTypeFind * tf, guint64 start_off,
    guint * found_layer, GstTypeFindProbability * found_prob)
{
  const guint8 *data = NULL;
  const guint8 *data_end = NULL;
  guint size;
  guint64 skipped;
  gint last_free_offset = -1;
  gint last_free_framelen = -1;
  gboolean headerstart = TRUE;

  *found_layer = 0;
  *found_prob = 0;

  size = 0;
  skipped = 0;
  while (skipped < GST_MP3_TYPEFIND_TRY_SYNC) {
    if (size <= 0) {
      size = GST_MP3_TYPEFIND_SYNC_SIZE * 2;
      do {
        size /= 2;
        data = gst_type_find_peek (tf, skipped + start_off, size);
      } while (size > 10 && !data);
      if (!data)
        break;
      data_end = data + size;
    }
    if (*data == 0xFF) {
      const guint8 *head_data = NULL;
      guint layer = 0, bitrate, samplerate, channels;
      guint found = 0;          /* number of valid headers found */
      guint64 offset = skipped;
      gboolean changed = FALSE;
      guint prev_layer = 0;
      guint prev_channels = 0, prev_samplerate = 0;

      while (found < GST_MP3_TYPEFIND_TRY_HEADERS) {
        guint32 head;
        guint length;
        gboolean free = FALSE;

        if ((gint64) (offset - skipped + 4) >= 0 &&
            data + offset - skipped + 4 < data_end) {
          head_data = data + offset - skipped;
        } else {
          head_data = gst_type_find_peek (tf, offset + start_off, 4);
        }
        if (!head_data)
          break;
        head = GST_READ_UINT32_BE (head_data);
        if (!(length = mp3_type_frame_length_from_header (head, &layer,
                    &channels, &bitrate, &samplerate, &free,
                    last_free_framelen))) {
          if (free) {
            if (last_free_offset == -1)
              last_free_offset = offset;
            else {
              last_free_framelen = offset - last_free_offset;
              offset = last_free_offset;
              continue;
            }
          } else {
            last_free_framelen = -1;
          }

          /* Mark the fact that we didn't find a valid header at the beginning */
          if (found == 0)
            headerstart = FALSE;

          GST_LOG ("%d. header at offset %" G_GUINT64_FORMAT
              " (0x%" G_GINT64_MODIFIER "x) was not an mp3 header "
              "(possibly-free: %s)", found + 1, start_off + offset,
              start_off + offset, free ? "yes" : "no");
          break;
        }
        if ((prev_layer && prev_layer != layer) ||
            /* (prev_bitrate && prev_bitrate != bitrate) || <-- VBR */
            (prev_samplerate && prev_samplerate != samplerate) ||
            (prev_channels && prev_channels != channels)) {
          /* this means an invalid property, or a change, which might mean
           * that this is not a mp3 but just a random bytestream. It could
           * be a freaking funky encoded mp3 though. We'll just not count
           * this header*/
          if (prev_layer)
            changed = TRUE;
        } else {
          found++;
          GST_LOG ("found %d. header at offset %" G_GUINT64_FORMAT " (0x%"
              G_GINT64_MODIFIER "X)", found, start_off + offset,
              start_off + offset);
        }
        prev_layer = layer;
        prev_channels = channels;
        prev_samplerate = samplerate;

        offset += length;
      }
      g_assert (found <= GST_MP3_TYPEFIND_TRY_HEADERS);
      if (found != 0 && head_data == NULL &&
          gst_type_find_peek (tf, offset + start_off - 1, 1) == NULL)
        /* Incomplete last frame - don't count it. */
        found--;
      if (found == GST_MP3_TYPEFIND_TRY_HEADERS ||
          (found >= GST_MP3_TYPEFIND_MIN_HEADERS && head_data == NULL)) {
        /* we can make a valid guess */
        guint probability = found * GST_TYPE_FIND_MAXIMUM *
            (GST_MP3_TYPEFIND_TRY_SYNC - skipped) /
            GST_MP3_TYPEFIND_TRY_HEADERS / GST_MP3_TYPEFIND_TRY_SYNC;

        if (!headerstart
            && probability > (GST_TYPE_FIND_MINIMUM + GST_MP3_WRONG_HEADER))
          probability -= GST_MP3_WRONG_HEADER;
        if (probability < GST_TYPE_FIND_MINIMUM)
          probability = GST_TYPE_FIND_MINIMUM;
        if (start_off > 0)
          probability /= 2;
        if (!changed)
          probability = (probability + GST_TYPE_FIND_MAXIMUM) / 2;

        GST_INFO
            ("audio/mpeg calculated %u  =  %u  *  %u / %u  *  (%u - %"
            G_GUINT64_FORMAT ") / %u", probability, GST_TYPE_FIND_MAXIMUM,
            found, GST_MP3_TYPEFIND_TRY_HEADERS, GST_MP3_TYPEFIND_TRY_SYNC,
            (guint64) skipped, GST_MP3_TYPEFIND_TRY_SYNC);
        /* make sure we're not id3 tagged */
        head_data = gst_type_find_peek (tf, -128, 3);
        if (head_data && (memcmp (head_data, "TAG", 3) == 0)) {
          probability = 0;
        }
        g_assert (probability <= GST_TYPE_FIND_MAXIMUM);

        *found_prob = probability;
        if (probability > 0)
          *found_layer = layer;
        return;
      }
    }
    data++;
    skipped++;
    size--;
  }
}

static void
mp3_type_find (GstTypeFind * tf, gpointer unused)
{
  GstTypeFindProbability prob, mid_prob;
  const guint8 *data;
  guint layer, mid_layer;
  guint64 length;

  mp3_type_find_at_offset (tf, 0, &layer, &prob);
  length = gst_type_find_get_length (tf);

  if (length == 0 || length == (guint64) - 1) {
    if (prob != 0)
      goto suggest;
    return;
  }

  /* if we're pretty certain already, skip the additional check */
  if (prob >= GST_TYPE_FIND_LIKELY)
    goto suggest;

  mp3_type_find_at_offset (tf, length / 2, &mid_layer, &mid_prob);

  if (mid_prob > 0) {
    if (prob == 0) {
      GST_LOG ("detected audio/mpeg only in the middle (p=%u)", mid_prob);
      layer = mid_layer;
      prob = mid_prob;
      goto suggest;
    }

    if (layer != mid_layer) {
      GST_WARNING ("audio/mpeg layer discrepancy: %u vs. %u", layer, mid_layer);
      return;                   /* FIXME: or should we just go with the one in the middle? */
    }

    /* detected mpeg audio both in middle of the file and at the start */
    prob = (prob + mid_prob) / 2;
    goto suggest;
  }

  /* a valid header right at the start makes it more likely
   * that this is actually plain mpeg-1 audio */
  if (prob > 0) {
    data = gst_type_find_peek (tf, 0, 4);       /* use min. frame size? */
    if (data && mp3_type_frame_length_from_header (GST_READ_UINT32_BE (data),
            &layer, NULL, NULL, NULL, NULL, 0) != 0) {
      prob = MIN (prob + 10, GST_TYPE_FIND_MAXIMUM);
    }
  }

  if (prob > 0)
    goto suggest;

  return;

suggest:
  {
    g_return_if_fail (layer >= 1 && layer <= 3);

    gst_type_find_suggest_simple (tf, prob, "audio/mpeg",
        "mpegversion", G_TYPE_INT, 1, "layer", G_TYPE_INT, layer,
        "parsed", G_TYPE_BOOLEAN, FALSE, NULL);
  }
}

/*** audio/x-musepack ***/

static GstStaticCaps musepack_caps =
GST_STATIC_CAPS ("audio/x-musepack, streamversion= (int) { 7, 8 }");

#define MUSEPACK_CAPS (gst_static_caps_get(&musepack_caps))
static void
musepack_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);
  GstTypeFindProbability prop = GST_TYPE_FIND_MINIMUM;
  gint streamversion = -1;

  if (data && memcmp (data, "MP+", 3) == 0) {
    streamversion = 7;
    if ((data[3] & 0x7f) == 7) {
      prop = GST_TYPE_FIND_MAXIMUM;
    } else {
      prop = GST_TYPE_FIND_LIKELY + 10;
    }
  } else if (data && memcmp (data, "MPCK", 4) == 0) {
    streamversion = 8;
    prop = GST_TYPE_FIND_MAXIMUM;
  }

  if (streamversion != -1) {
    gst_type_find_suggest_simple (tf, prop, "audio/x-musepack",
        "streamversion", G_TYPE_INT, streamversion, NULL);
  }
}

/*** audio/x-ac3 ***/
/* FIXME 0.11: should be audio/ac3, but isn't for backwards compatibility */
static GstStaticCaps ac3_caps = GST_STATIC_CAPS ("audio/x-ac3");

#define AC3_CAPS (gst_static_caps_get(&ac3_caps))

static GstStaticCaps eac3_caps = GST_STATIC_CAPS ("audio/x-eac3");

#define EAC3_CAPS (gst_static_caps_get(&eac3_caps))

struct ac3_frmsize
{
  unsigned short bit_rate;
  unsigned short frm_size[3];
};

static const struct ac3_frmsize ac3_frmsizecod_tbl[] = {
  {32, {64, 69, 96}},
  {32, {64, 70, 96}},
  {40, {80, 87, 120}},
  {40, {80, 88, 120}},
  {48, {96, 104, 144}},
  {48, {96, 105, 144}},
  {56, {112, 121, 168}},
  {56, {112, 122, 168}},
  {64, {128, 139, 192}},
  {64, {128, 140, 192}},
  {80, {160, 174, 240}},
  {80, {160, 175, 240}},
  {96, {192, 208, 288}},
  {96, {192, 209, 288}},
  {112, {224, 243, 336}},
  {112, {224, 244, 336}},
  {128, {256, 278, 384}},
  {128, {256, 279, 384}},
  {160, {320, 348, 480}},
  {160, {320, 349, 480}},
  {192, {384, 417, 576}},
  {192, {384, 418, 576}},
  {224, {448, 487, 672}},
  {224, {448, 488, 672}},
  {256, {512, 557, 768}},
  {256, {512, 558, 768}},
  {320, {640, 696, 960}},
  {320, {640, 697, 960}},
  {384, {768, 835, 1152}},
  {384, {768, 836, 1152}},
  {448, {896, 975, 1344}},
  {448, {896, 976, 1344}},
  {512, {1024, 1114, 1536}},
  {512, {1024, 1115, 1536}},
  {576, {1152, 1253, 1728}},
  {576, {1152, 1254, 1728}},
  {640, {1280, 1393, 1920}},
  {640, {1280, 1394, 1920}}
};

static void
ac3_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  /* Search for an ac3 frame; not necessarily right at the start, but give it
   * a lower probability if not found right at the start. Check that the
   * frame is followed by a second frame at the expected offset.
   * We could also check the two ac3 CRCs, but we don't do that right now */
  while (c.offset < 1024) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 6)))
      break;

    if (c.data[0] == 0x0b && c.data[1] == 0x77) {
      guint bsid = c.data[5] >> 3;

      if (bsid <= 8) {
        /* ac3 */
        guint fscod = c.data[4] >> 6;
        guint frmsizecod = c.data[4] & 0x3f;

        if (fscod < 3 && frmsizecod < 38) {
          DataScanCtx c_next = c;
          guint frame_size;

          frame_size = ac3_frmsizecod_tbl[frmsizecod].frm_size[fscod];
          GST_LOG ("possible AC3 frame sync at offset %"
              G_GUINT64_FORMAT ", size=%u", c.offset, frame_size);
          if (data_scan_ctx_ensure_data (tf, &c_next, (frame_size * 2) + 5)) {
            data_scan_ctx_advance (tf, &c_next, frame_size * 2);

            if (c_next.data[0] == 0x0b && c_next.data[1] == 0x77) {
              fscod = c_next.data[4] >> 6;
              frmsizecod = c_next.data[4] & 0x3f;

              if (fscod < 3 && frmsizecod < 38) {
                GstTypeFindProbability prob;

                GST_LOG ("found second AC3 frame (size=%u), looks good",
                    ac3_frmsizecod_tbl[frmsizecod].frm_size[fscod]);
                if (c.offset == 0)
                  prob = GST_TYPE_FIND_MAXIMUM;
                else
                  prob = GST_TYPE_FIND_NEARLY_CERTAIN;

                gst_type_find_suggest (tf, prob, AC3_CAPS);
                return;
              }
            } else {
              GST_LOG ("no second AC3 frame found, false sync");
            }
          }
        }
      } else if (bsid <= 16 && bsid > 10) {
        /* eac3 */
        DataScanCtx c_next = c;
        guint frame_size;

        frame_size = (((c.data[2] & 0x07) << 8) + c.data[3]) + 1;
        GST_LOG ("possible E-AC3 frame sync at offset %"
            G_GUINT64_FORMAT ", size=%u", c.offset, frame_size);
        if (data_scan_ctx_ensure_data (tf, &c_next, (frame_size * 2) + 5)) {
          data_scan_ctx_advance (tf, &c_next, frame_size * 2);

          if (c_next.data[0] == 0x0b && c_next.data[1] == 0x77) {
            GstTypeFindProbability prob;

            GST_LOG ("found second E-AC3 frame, looks good");
            if (c.offset == 0)
              prob = GST_TYPE_FIND_MAXIMUM;
            else
              prob = GST_TYPE_FIND_NEARLY_CERTAIN;

            gst_type_find_suggest (tf, prob, EAC3_CAPS);
            return;
          } else {
            GST_LOG ("no second E-AC3 frame found, false sync");
          }
        }
      } else {
        GST_LOG ("invalid AC3 BSID: %u", bsid);
      }
    }
    data_scan_ctx_advance (tf, &c, 1);
  }
}

/*** audio/x-dts ***/
static GstStaticCaps dts_caps = GST_STATIC_CAPS ("audio/x-dts");
#define DTS_CAPS (gst_static_caps_get (&dts_caps))
#define DTS_MIN_FRAMESIZE 96
#define DTS_MAX_FRAMESIZE 18725 /* 16384*16/14 */

static gboolean
dts_parse_frame_header (DataScanCtx * c, guint * frame_size,
    guint * sample_rate, guint * channels, guint * depth, guint * endianness)
{
  static const int sample_rates[16] = { 0, 8000, 16000, 32000, 0, 0, 11025,
    22050, 44100, 0, 0, 12000, 24000, 48000, 96000, 192000
  };
  static const guint8 channels_table[16] = { 1, 2, 2, 2, 2, 3, 3, 4, 4, 5,
    6, 6, 6, 7, 8, 8
  };
  guint16 hdr[8];
  guint32 marker;
  guint num_blocks, chans, lfe, i;

  marker = GST_READ_UINT32_BE (c->data);

  /* raw big endian or 14-bit big endian */
  if (marker == 0x7FFE8001 || marker == 0x1FFFE800) {
    *endianness = G_BIG_ENDIAN;
    for (i = 0; i < G_N_ELEMENTS (hdr); ++i)
      hdr[i] = GST_READ_UINT16_BE (c->data + (i * sizeof (guint16)));
  } else
    /* raw little endian or 14-bit little endian */
  if (marker == 0xFE7F0180 || marker == 0xFF1F00E8) {
    *endianness = G_LITTLE_ENDIAN;
    for (i = 0; i < G_N_ELEMENTS (hdr); ++i)
      hdr[i] = GST_READ_UINT16_LE (c->data + (i * sizeof (guint16)));
  } else {
    return FALSE;
  }

  GST_LOG ("dts sync marker 0x%08x at offset %u", marker, (guint) c->offset);

  /* 14-bit mode */
  if (marker == 0x1FFFE800 || marker == 0xFF1F00E8) {
    if ((hdr[2] & 0xFFF0) != 0x07F0)
      return FALSE;
    /* discard top 2 bits (2 void), shift in 2 */
    hdr[0] = (hdr[0] << 2) | ((hdr[1] >> 12) & 0x0003);
    /* discard top 4 bits (2 void, 2 shifted into hdr[0]), shift in 4 etc. */
    hdr[1] = (hdr[1] << 4) | ((hdr[2] >> 10) & 0x000F);
    hdr[2] = (hdr[2] << 6) | ((hdr[3] >> 8) & 0x003F);
    hdr[3] = (hdr[3] << 8) | ((hdr[4] >> 6) & 0x00FF);
    hdr[4] = (hdr[4] << 10) | ((hdr[5] >> 4) & 0x03FF);
    hdr[5] = (hdr[5] << 12) | ((hdr[6] >> 2) & 0x0FFF);
    hdr[6] = (hdr[6] << 14) | ((hdr[7] >> 0) & 0x3FFF);
    g_assert (hdr[0] == 0x7FFE && hdr[1] == 0x8001);
    *depth = 14;
  } else {
    *depth = 16;
  }

  GST_LOG ("frame header: %04x%04x%04x%04x", hdr[2], hdr[3], hdr[4], hdr[5]);

  num_blocks = (hdr[2] >> 2) & 0x7F;
  *frame_size = (((hdr[2] & 0x03) << 12) | (hdr[3] >> 4)) + 1;
  chans = ((hdr[3] & 0x0F) << 2) | (hdr[4] >> 14);
  *sample_rate = sample_rates[(hdr[4] >> 10) & 0x0F];
  lfe = (hdr[5] >> 9) & 0x03;

  if (num_blocks < 5 || *frame_size < 96 || *sample_rate == 0)
    return FALSE;

  if (marker == 0x1FFFE800 || marker == 0xFF1F00E8)
    *frame_size = (*frame_size * 16) / 14;      /* FIXME: round up? */

  if (chans < G_N_ELEMENTS (channels_table))
    *channels = channels_table[chans] + ((lfe) ? 1 : 0);
  else
    *channels = 0;

  return TRUE;
}

static void
dts_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  /* Search for an dts frame; not necessarily right at the start, but give it
   * a lower probability if not found right at the start. Check that the
   * frame is followed by a second frame at the expected offset. */
  while (c.offset <= DTS_MAX_FRAMESIZE) {
    guint frame_size = 0, rate = 0, chans = 0, depth = 0, endianness = 0;

    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, DTS_MIN_FRAMESIZE)))
      return;

    if (G_UNLIKELY (dts_parse_frame_header (&c, &frame_size, &rate, &chans,
                &depth, &endianness))) {
      GstTypeFindProbability prob;
      DataScanCtx next_c;

      prob = (c.offset == 0) ? GST_TYPE_FIND_LIKELY : GST_TYPE_FIND_POSSIBLE;

      /* check for second frame sync */
      next_c = c;
      data_scan_ctx_advance (tf, &next_c, frame_size);
      if (data_scan_ctx_ensure_data (tf, &next_c, 4)) {
        GST_LOG ("frame size: %u 0x%04x", frame_size, frame_size);
        GST_MEMDUMP ("second frame sync", next_c.data, 4);
        if (GST_READ_UINT32_BE (c.data) == GST_READ_UINT32_BE (next_c.data))
          prob = GST_TYPE_FIND_MAXIMUM;
      }

      if (chans > 0) {
        gst_type_find_suggest_simple (tf, prob, "audio/x-dts",
            "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, chans,
            "depth", G_TYPE_INT, depth, "endianness", G_TYPE_INT, endianness,
            "framed", G_TYPE_BOOLEAN, FALSE, NULL);
      } else {
        gst_type_find_suggest_simple (tf, prob, "audio/x-dts",
            "rate", G_TYPE_INT, rate, "depth", G_TYPE_INT, depth,
            "endianness", G_TYPE_INT, endianness,
            "framed", G_TYPE_BOOLEAN, FALSE, NULL);
      }

      return;
    }

    data_scan_ctx_advance (tf, &c, 1);
  }
}

/*** gsm ***/

/* can only be detected by using the extension, in which case we use the default
 * GSM properties */
static GstStaticCaps gsm_caps =
GST_STATIC_CAPS ("audio/x-gsm, rate=8000, channels=1");

#define GSM_CAPS (gst_static_caps_get(&gsm_caps))

/*** wavpack ***/

static GstStaticCaps wavpack_caps =
GST_STATIC_CAPS ("audio/x-wavpack, framed = (boolean) false");

#define WAVPACK_CAPS (gst_static_caps_get(&wavpack_caps))

static GstStaticCaps wavpack_correction_caps =
GST_STATIC_CAPS ("audio/x-wavpack-correction, framed = (boolean) false");

#define WAVPACK_CORRECTION_CAPS (gst_static_caps_get(&wavpack_correction_caps))

static void
wavpack_type_find (GstTypeFind * tf, gpointer unused)
{
  GstTypeFindProbability base_prob = GST_TYPE_FIND_POSSIBLE;
  guint64 offset;
  guint32 blocksize;
  const guint8 *data;
  guint count_wv, count_wvc;

  data = gst_type_find_peek (tf, 0, 32);
  if (!data)
    return;

  if (data[0] != 'w' || data[1] != 'v' || data[2] != 'p' || data[3] != 'k')
    return;

  /* Note: wavpack blocks can be fairly large (easily 60-110k), possibly
   * larger than the max. limits imposed by certain typefinding elements
   * like id3demux or apedemux, so typefinding is most likely only going to
   * work in pull-mode */
  blocksize = GST_READ_UINT32_LE (data + 4);
  GST_LOG ("wavpack header, blocksize=0x%04x", blocksize);
  /* If bigger than maximum allowed blocksize, refuse */
  if (blocksize > 131072)
    return;
  count_wv = 0;
  count_wvc = 0;
  offset = 32;
  while (offset < 8 + blocksize) {
    guint32 sublen;

    /* get chunk header */
    GST_LOG ("peeking at chunk at offset 0x%04x", (guint) offset);
    data = gst_type_find_peek (tf, offset, 4);
    if (data == NULL)
      break;
    sublen = ((guint32) data[1]) << 1;
    if (data[0] & 0x80) {
      sublen |= (((guint32) data[2]) << 9) | (((guint32) data[3]) << 17);
      sublen += 1 + 3;          /* id + length */
    } else {
      sublen += 1 + 1;          /* id + length */
    }
    if (offset + sublen > 8 + blocksize) {
      GST_LOG ("chunk length too big (%u > %" G_GUINT64_FORMAT ")", sublen,
          blocksize - offset);
      break;
    }
    if ((data[0] & 0x20) == 0) {
      switch (data[0] & 0x0f) {
        case 0xa:              /* ID_WV_BITSTREAM  */
        case 0xc:              /* ID_WVX_BITSTREAM */
          ++count_wv;
          break;
        case 0xb:              /* ID_WVC_BITSTREAM */
          ++count_wvc;
          break;
        default:
          break;
      }
      if (count_wv >= 5 || count_wvc >= 5)
        break;
    }
    offset += sublen;
  }

  /* check for second block header */
  data = gst_type_find_peek (tf, 8 + blocksize, 4);
  if (data != NULL && memcmp (data, "wvpk", 4) == 0) {
    GST_DEBUG ("found second block sync");
    base_prob = GST_TYPE_FIND_LIKELY;
  }

  GST_DEBUG ("wvc=%d, wv=%d", count_wvc, count_wv);

  if (count_wvc > 0 && count_wvc > count_wv) {
    gst_type_find_suggest (tf,
        MIN (base_prob + 5 * count_wvc, GST_TYPE_FIND_NEARLY_CERTAIN),
        WAVPACK_CORRECTION_CAPS);
  } else if (count_wv > 0) {
    gst_type_find_suggest (tf,
        MIN (base_prob + 5 * count_wv, GST_TYPE_FIND_NEARLY_CERTAIN),
        WAVPACK_CAPS);
  }
}

/*** application/postscrip ***/
static GstStaticCaps postscript_caps =
GST_STATIC_CAPS ("application/postscript");

#define POSTSCRIPT_CAPS (gst_static_caps_get(&postscript_caps))

static void
postscript_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 3);
  if (!data)
    return;

  if (data[0] == 0x04)
    data++;
  if (data[0] == '%' && data[1] == '!')
    gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, POSTSCRIPT_CAPS);

}

/*** image/svg+xml ***/
static GstStaticCaps svg_caps = GST_STATIC_CAPS ("image/svg+xml");

#define SVG_CAPS (gst_static_caps_get(&svg_caps))

static void
svg_type_find (GstTypeFind * tf, gpointer unused)
{
  static const gchar svg_doctype[] = "!DOCTYPE svg";
  static const gchar svg_tag[] = "<svg";
  DataScanCtx c = { 0, NULL, 0 };

  while (c.offset <= 1024) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 12)))
      break;

    if (memcmp (svg_doctype, c.data, 12) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SVG_CAPS);
      return;
    } else if (memcmp (svg_tag, c.data, 4) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, SVG_CAPS);
      return;
    }
    data_scan_ctx_advance (tf, &c, 1);
  }
}

/*** multipart/x-mixed-replace mimestream ***/

static GstStaticCaps multipart_caps =
GST_STATIC_CAPS ("multipart/x-mixed-replace");
#define MULTIPART_CAPS gst_static_caps_get(&multipart_caps)

/* multipart/x-mixed replace is:
 *   <maybe some whitespace>--<some ascii chars>[\r]\n
 *   <more ascii chars>[\r]\nContent-type:<more ascii>[\r]\n */
static void
multipart_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;
  const guint8 *x;

#define MULTIPART_MAX_BOUNDARY_OFFSET 16
  data = gst_type_find_peek (tf, 0, MULTIPART_MAX_BOUNDARY_OFFSET);
  if (!data)
    return;

  for (x = data;
      x - data < MULTIPART_MAX_BOUNDARY_OFFSET - 2 && g_ascii_isspace (*x);
      x++);
  if (x[0] != '-' || x[1] != '-')
    return;

  /* Could be okay, peek what should be enough for a complete header */
#define MULTIPART_MAX_HEADER_SIZE 256
  data = gst_type_find_peek (tf, 0, MULTIPART_MAX_HEADER_SIZE);
  if (!data)
    return;

  for (x = data; x - data < MULTIPART_MAX_HEADER_SIZE - 14; x++) {
    if (!isascii (*x)) {
      return;
    }
    if (*x == '\n' &&
        !g_ascii_strncasecmp ("content-type:", (gchar *) x + 1, 13)) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MULTIPART_CAPS);
      return;
    }
  }
}

/*** video/mpeg systemstream ***/
static GstStaticCaps mpeg_sys_caps = GST_STATIC_CAPS ("video/mpeg, "
    "systemstream = (boolean) true, mpegversion = (int) [ 1, 2 ]");

#define MPEG_SYS_CAPS gst_static_caps_get(&mpeg_sys_caps)
#define IS_MPEG_HEADER(data) (G_UNLIKELY((((guint8 *)(data))[0] == 0x00) &&  \
                                         (((guint8 *)(data))[1] == 0x00) &&  \
                                         (((guint8 *)(data))[2] == 0x01)))

#define IS_MPEG_PACK_CODE(b) ((b) == 0xBA)
#define IS_MPEG_SYS_CODE(b) ((b) == 0xBB)
#define IS_MPEG_PACK_HEADER(data)       (IS_MPEG_HEADER (data) &&            \
                                         IS_MPEG_PACK_CODE (((guint8 *)(data))[3]))

#define IS_MPEG_PES_CODE(b) (((b) & 0xF0) == 0xE0 || ((b) & 0xF0) == 0xC0 || \
                             (b) >= 0xBD)
#define IS_MPEG_PES_HEADER(data)        (IS_MPEG_HEADER (data) &&            \
                                         IS_MPEG_PES_CODE (((guint8 *)(data))[3]))

#define MPEG2_MAX_PROBE_LENGTH (128 * 1024)     /* 128kB should be 64 packs of the
                                                 * most common 2kB pack size. */

#define MPEG2_MIN_SYS_HEADERS 2
#define MPEG2_MAX_SYS_HEADERS 5

static gboolean
mpeg_sys_is_valid_pack (GstTypeFind * tf, const guint8 * data, guint len,
    guint * pack_size)
{
  /* Check the pack header @ offset for validity, assuming that the 4 byte header
   * itself has already been checked. */
  guint8 stuff_len;

  if (len < 12)
    return FALSE;

  /* Check marker bits */
  if ((data[4] & 0xC4) == 0x44) {
    /* MPEG-2 PACK */
    if (len < 14)
      return FALSE;

    if ((data[6] & 0x04) != 0x04 ||
        (data[8] & 0x04) != 0x04 ||
        (data[9] & 0x01) != 0x01 || (data[12] & 0x03) != 0x03)
      return FALSE;

    stuff_len = data[13] & 0x07;

    /* Check the following header bytes, if we can */
    if ((14 + stuff_len + 4) <= len) {
      if (!IS_MPEG_HEADER (data + 14 + stuff_len))
        return FALSE;
    }
    if (pack_size)
      *pack_size = 14 + stuff_len;
    return TRUE;
  } else if ((data[4] & 0xF1) == 0x21) {
    /* MPEG-1 PACK */
    if ((data[6] & 0x01) != 0x01 ||
        (data[8] & 0x01) != 0x01 ||
        (data[9] & 0x80) != 0x80 || (data[11] & 0x01) != 0x01)
      return FALSE;

    /* Check the following header bytes, if we can */
    if ((12 + 4) <= len) {
      if (!IS_MPEG_HEADER (data + 12))
        return FALSE;
    }
    if (pack_size)
      *pack_size = 12;
    return TRUE;
  }

  return FALSE;
}

static gboolean
mpeg_sys_is_valid_pes (GstTypeFind * tf, const guint8 * data, guint len,
    guint * pack_size)
{
  guint pes_packet_len;

  /* Check the PES header at the given position, assuming the header code itself
   * was already checked */
  if (len < 6)
    return FALSE;

  /* For MPEG Program streams, unbounded PES is not allowed, so we must have a
   * valid length present */
  pes_packet_len = GST_READ_UINT16_BE (data + 4);
  if (pes_packet_len == 0)
    return FALSE;

  /* Check the following header, if we can */
  if (6 + pes_packet_len + 4 <= len) {
    if (!IS_MPEG_HEADER (data + 6 + pes_packet_len))
      return FALSE;
  }

  if (pack_size)
    *pack_size = 6 + pes_packet_len;
  return TRUE;
}

static gboolean
mpeg_sys_is_valid_sys (GstTypeFind * tf, const guint8 * data, guint len,
    guint * pack_size)
{
  guint sys_hdr_len;

  /* Check the System header at the given position, assuming the header code itself
   * was already checked */
  if (len < 6)
    return FALSE;
  sys_hdr_len = GST_READ_UINT16_BE (data + 4);
  if (sys_hdr_len < 6)
    return FALSE;

  /* Check the following header, if we can */
  if (6 + sys_hdr_len + 4 <= len) {
    if (!IS_MPEG_HEADER (data + 6 + sys_hdr_len))
      return FALSE;
  }

  if (pack_size)
    *pack_size = 6 + sys_hdr_len;

  return TRUE;
}

/* calculation of possibility to identify random data as mpeg systemstream:
 * bits that must match in header detection:            32 (or more)
 * chance that random data is identifed:                1/2^32
 * chance that MPEG2_MIN_PACK_HEADERS headers are identified:
 *       1/2^(32*MPEG2_MIN_PACK_HEADERS)
 * chance that this happens in MPEG2_MAX_PROBE_LENGTH bytes:
 *       1-(1+1/2^(32*MPEG2_MIN_PACK_HEADERS)^MPEG2_MAX_PROBE_LENGTH)
 * for current values:
 *       1-(1+1/2^(32*4)^101024)
 *       = <some_number>
 * Since we also check marker bits and pes packet lengths, this probability is a
 * very coarse upper bound.
 */
static void
mpeg_sys_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data, *data0, *first_sync, *end;
  gint mpegversion = 0;
  guint pack_headers = 0;
  guint pes_headers = 0;
  guint pack_size;
  guint since_last_sync = 0;
  guint32 sync_word = 0xffffffff;
  guint potential_headers = 0;

  G_STMT_START {
    gint len;

    len = MPEG2_MAX_PROBE_LENGTH;

    while (len >= 16) {
      data = gst_type_find_peek (tf, 0, 5 + len);
      if (data != NULL)
        break;
      len = len / 2;
    }

    if (!data)
      return;

    end = data + len;
  }
  G_STMT_END;

  data0 = data;
  first_sync = NULL;

  while (data < end) {
    sync_word <<= 8;
    if (sync_word == 0x00000100) {
      /* Found potential sync word */
      if (first_sync == NULL)
        first_sync = data - 3;

      if (since_last_sync > 4) {
        /* If more than 4 bytes since the last sync word, reset our counters,
         * as we're only interested in counting contiguous packets */
        pes_headers = pack_headers = 0;
      }
      pack_size = 0;

      potential_headers++;
      if (IS_MPEG_PACK_CODE (data[0])) {
        if ((data[1] & 0xC0) == 0x40) {
          /* MPEG-2 */
          mpegversion = 2;
        } else if ((data[1] & 0xF0) == 0x20) {
          mpegversion = 1;
        }
        if (mpegversion != 0 &&
            mpeg_sys_is_valid_pack (tf, data - 3, end - data + 3, &pack_size)) {
          pack_headers++;
        }
      } else if (IS_MPEG_PES_CODE (data[0])) {
        /* PES stream */
        if (mpeg_sys_is_valid_pes (tf, data - 3, end - data + 3, &pack_size)) {
          pes_headers++;
          if (mpegversion == 0)
            mpegversion = 2;
        }
      } else if (IS_MPEG_SYS_CODE (data[0])) {
        if (mpeg_sys_is_valid_sys (tf, data - 3, end - data + 3, &pack_size)) {
          pack_headers++;
        }
      }

      /* If we found a packet with a known size, skip the bytes in it and loop
       * around to check the next packet. */
      if (pack_size != 0) {
        data += pack_size - 3;
        sync_word = 0xffffffff;
        since_last_sync = 0;
        continue;
      }
    }

    sync_word |= data[0];
    since_last_sync++;
    data++;

    /* If we have found MAX headers, and *some* were pes headers (pack headers
     * are optional in an mpeg system stream) then return our high-probability
     * result */
    if (pes_headers > 0 && (pack_headers + pes_headers) > MPEG2_MAX_SYS_HEADERS)
      goto suggest;
  }

  /* If we at least saw MIN headers, and *some* were pes headers (pack headers
   * are optional in an mpeg system stream) then return a lower-probability
   * result */
  if (pes_headers > 0 && (pack_headers + pes_headers) > MPEG2_MIN_SYS_HEADERS)
    goto suggest;

  return;
suggest:
  {
    guint prob;

    prob = GST_TYPE_FIND_POSSIBLE + (10 * (pack_headers + pes_headers));
    prob = MIN (prob, GST_TYPE_FIND_MAXIMUM);

    /* With the above test, we get into problems when we try to typefind
       a MPEG stream from a small amount of data, which can happen when
       we get data pushed from a HTTP source. We thus make a second test
       to give higher probability if all the potential headers were either
       pack or pes headers (ie, no potential header was unrecognized). */
    if (potential_headers == pack_headers + pes_headers) {
      GST_LOG ("Only %u headers, but all were recognized", potential_headers);
      prob += 10;
      prob = MIN (prob, GST_TYPE_FIND_MAXIMUM);
    }

    /* lower probability if the first packet wasn't right at the start */
    if (data0 != first_sync && prob >= 10)
      prob -= 10;

    GST_LOG ("Suggesting MPEG %d system stream, %d packs, %d pes, prob %u%%",
        mpegversion, pack_headers, pes_headers, prob);

    gst_type_find_suggest_simple (tf, prob, "video/mpeg",
        "systemstream", G_TYPE_BOOLEAN, TRUE,
        "mpegversion", G_TYPE_INT, mpegversion, NULL);
  }
};

/*** video/mpegts Transport Stream ***/
static GstStaticCaps mpegts_caps = GST_STATIC_CAPS ("video/mpegts, "
    "systemstream = (boolean) true, packetsize = (int) [ 188, 208 ]");
#define MPEGTS_CAPS gst_static_caps_get(&mpegts_caps)

#define GST_MPEGTS_TYPEFIND_MIN_HEADERS 4
#define GST_MPEGTS_TYPEFIND_MAX_HEADERS 10
#define GST_MPEGTS_MAX_PACKET_SIZE 208
#define GST_MPEGTS_TYPEFIND_SYNC_SIZE \
            (GST_MPEGTS_TYPEFIND_MIN_HEADERS * GST_MPEGTS_MAX_PACKET_SIZE)
#define GST_MPEGTS_TYPEFIND_MAX_SYNC \
            (GST_MPEGTS_TYPEFIND_MAX_HEADERS * GST_MPEGTS_MAX_PACKET_SIZE)
#define GST_MPEGTS_TYPEFIND_SCAN_LENGTH \
            (GST_MPEGTS_TYPEFIND_MAX_SYNC * 4)

#define MPEGTS_HDR_SIZE 4
/* Check for sync byte, error_indicator == 0 and packet has payload.
 * Adaptation control field (data[3] & 0x30) may be zero for TS packets with
 * null PIDs. Still, these streams are valid TS streams (for null packets,
 * AFC is supposed to be 0x1, but the spec also says decoders should just
 * discard any packets with AFC = 0x00) */
#define IS_MPEGTS_HEADER(data) (data[0] == 0x47 && \
                                (data[1] & 0x80) == 0x00 && \
                                ((data[3] & 0x30) != 0x00 || \
                                ((data[3] & 0x30) == 0x00 && (data[1] & 0x1f) == 0x1f && (data[2] & 0xff) == 0xff)))

/* Helper function to search ahead at intervals of packet_size for mpegts
 * headers */
static gint
mpeg_ts_probe_headers (GstTypeFind * tf, guint64 offset, gint packet_size)
{
  /* We always enter this function having found at least one header already */
  gint found = 1;
  const guint8 *data = NULL;

  GST_LOG ("looking for mpeg-ts packets of size %u", packet_size);
  while (found < GST_MPEGTS_TYPEFIND_MAX_HEADERS) {
    offset += packet_size;

    data = gst_type_find_peek (tf, offset, MPEGTS_HDR_SIZE);
    if (data == NULL || !IS_MPEGTS_HEADER (data))
      return found;

    found++;
    GST_LOG ("mpeg-ts sync #%2d at offset %" G_GUINT64_FORMAT, found, offset);
  }

  return found;
}

/* Try and detect at least 4 packets in at most 10 packets worth of
 * data. Need to try several possible packet sizes */
static void
mpeg_ts_type_find (GstTypeFind * tf, gpointer unused)
{
  /* TS packet sizes to test: normal, DVHS packet size and
   * FEC with 16 or 20 byte codes packet size. */
  const gint pack_sizes[] = { 188, 192, 204, 208 };
  const guint8 *data = NULL;
  guint size = 0;
  guint64 skipped = 0;

  while (skipped < GST_MPEGTS_TYPEFIND_SCAN_LENGTH) {
    if (size < MPEGTS_HDR_SIZE) {
      data = gst_type_find_peek (tf, skipped, GST_MPEGTS_TYPEFIND_SYNC_SIZE);
      if (!data)
        break;
      size = GST_MPEGTS_TYPEFIND_SYNC_SIZE;
    }

    /* Have at least MPEGTS_HDR_SIZE bytes at this point */
    if (IS_MPEGTS_HEADER (data)) {
      gsize p;

      GST_LOG ("possible mpeg-ts sync at offset %" G_GUINT64_FORMAT, skipped);

      for (p = 0; p < G_N_ELEMENTS (pack_sizes); p++) {
        gint found;

        /* Probe ahead at size pack_sizes[p] */
        found = mpeg_ts_probe_headers (tf, skipped, pack_sizes[p]);
        if (found >= GST_MPEGTS_TYPEFIND_MIN_HEADERS) {
          gint probability;

          /* found at least 4 headers. 10 headers = MAXIMUM probability.
           * Arbitrarily, I assigned 10% probability for each header we
           * found, 40% -> 100% */
          probability = MIN (10 * found, GST_TYPE_FIND_MAXIMUM);

          gst_type_find_suggest_simple (tf, probability, "video/mpegts",
              "systemstream", G_TYPE_BOOLEAN, TRUE,
              "packetsize", G_TYPE_INT, pack_sizes[p], NULL);
          return;
        }
      }
    }
    data++;
    skipped++;
    size--;
  }
}

#define GST_MPEGVID_TYPEFIND_TRY_PICTURES 6
#define GST_MPEGVID_TYPEFIND_TRY_SYNC (100 * 1024)      /* 100 kB */

/* Scan ahead a maximum of max_extra_offset bytes until the next IS_MPEG_HEADER
 * offset.  After the call, offset will be after the 0x000001, i.e. at the 4th
 * byte of the MPEG header.  Returns TRUE if a header was found, FALSE if not.
 */
static gboolean
mpeg_find_next_header (GstTypeFind * tf, DataScanCtx * c,
    guint64 max_extra_offset)
{
  guint64 extra_offset;

  for (extra_offset = 0; extra_offset <= max_extra_offset; ++extra_offset) {
    if (!data_scan_ctx_ensure_data (tf, c, 4))
      return FALSE;
    if (IS_MPEG_HEADER (c->data)) {
      data_scan_ctx_advance (tf, c, 3);
      return TRUE;
    }
    data_scan_ctx_advance (tf, c, 1);
  }
  return FALSE;
}

/*** video/mpeg MPEG-4 elementary video stream ***/

static GstStaticCaps mpeg4_video_caps = GST_STATIC_CAPS ("video/mpeg, "
    "systemstream=(boolean)false, mpegversion=4, parsed=(boolean)false");
#define MPEG4_VIDEO_CAPS gst_static_caps_get(&mpeg4_video_caps)

/*
 * This typefind is based on the elementary video header defined in
 * http://xhelmboyx.tripod.com/formats/mpeg-layout.txt
 * In addition, it allows the visual object sequence header to be
 * absent, and even the VOS header to be absent.  In the latter case,
 * a number of VOPs have to be present.
 */
static void
mpeg4_video_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  gboolean seen_vios_at_0 = FALSE;
  gboolean seen_vios = FALSE;
  gboolean seen_vos = FALSE;
  gboolean seen_vol = FALSE;
  guint num_vop_headers = 0;
  guint8 sc;

  while (c.offset < GST_MPEGVID_TYPEFIND_TRY_SYNC) {
    if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES)
      break;

    if (!mpeg_find_next_header (tf, &c,
            GST_MPEGVID_TYPEFIND_TRY_SYNC - c.offset))
      break;

    sc = c.data[0];

    /* visual_object_sequence_start_code */
    if (sc == 0xB0) {
      if (seen_vios)
        break;                  /* Terminate at second vios */
      if (c.offset == 0)
        seen_vios_at_0 = TRUE;
      seen_vios = TRUE;
      data_scan_ctx_advance (tf, &c, 2);
      if (!mpeg_find_next_header (tf, &c, 0))
        break;

      sc = c.data[0];

      /* Optional metadata */
      if (sc == 0xB2)
        if (!mpeg_find_next_header (tf, &c, 24))
          break;
    }

    /* visual_object_start_code (consider it optional) */
    if (sc == 0xB5) {
      data_scan_ctx_advance (tf, &c, 2);
      /* may contain ID marker and YUV clamping */
      if (!mpeg_find_next_header (tf, &c, 7))
        break;

      sc = c.data[0];
    }

    /* video_object_start_code */
    if (sc <= 0x1F) {
      if (seen_vos)
        break;                  /* Terminate at second vos */
      seen_vos = TRUE;
      data_scan_ctx_advance (tf, &c, 2);
      continue;
    }

    /* video_object_layer_start_code */
    if (sc >= 0x20 && sc <= 0x2F) {
      seen_vol = TRUE;
      data_scan_ctx_advance (tf, &c, 5);
      continue;
    }

    /* video_object_plane_start_code */
    if (sc == 0xB6) {
      num_vop_headers++;
      data_scan_ctx_advance (tf, &c, 2);
      continue;
    }

    /* Unknown start code. */
  }

  if (num_vop_headers > 0 || seen_vol) {
    GstTypeFindProbability probability = 0;

    GST_LOG ("Found %d pictures, vios: %d, vos:%d, vol:%d", num_vop_headers,
        seen_vios, seen_vos, seen_vol);

    if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_vios_at_0
        && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_MAXIMUM - 1;
    else if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_vios
        && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 1;
    else if (seen_vios_at_0 && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 6;
    else if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_vos
        && seen_vol)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 6;
    else if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_vol)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 9;
    else if (num_vop_headers >= GST_MPEGVID_TYPEFIND_TRY_PICTURES)
      probability = GST_TYPE_FIND_LIKELY - 1;
    else if (num_vop_headers > 2 && seen_vios && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_LIKELY - 9;
    else if (seen_vios && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_LIKELY - 20;
    else if (num_vop_headers > 0 && seen_vos && seen_vol)
      probability = GST_TYPE_FIND_POSSIBLE;
    else if (num_vop_headers > 0)
      probability = GST_TYPE_FIND_POSSIBLE - 10;
    else if (seen_vos && seen_vol)
      probability = GST_TYPE_FIND_POSSIBLE - 20;

    gst_type_find_suggest (tf, probability, MPEG4_VIDEO_CAPS);
  }
}

/*** video/x-h263 H263 video stream ***/
static GstStaticCaps h263_video_caps =
GST_STATIC_CAPS ("video/x-h263, variant=(string)itu");

#define H263_VIDEO_CAPS gst_static_caps_get(&h263_video_caps)

#define H263_MAX_PROBE_LENGTH (128 * 1024)

static void
h263_video_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  guint64 data = 0xffff;        /* prevents false positive for first 2 bytes */
  guint64 psc = 0;
  guint8 ptype = 0;
  guint format;
  guint good = 0;
  guint bad = 0;
  guint pc_type, pb_mode;

  while (c.offset < H263_MAX_PROBE_LENGTH) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 4)))
      break;

    /* Find the picture start code */
    data = (data << 8) + c.data[0];
    psc = data & G_GUINT64_CONSTANT (0xfffffc0000);
    if (psc == 0x800000) {
      /* Found PSC */
      /* PTYPE */
      ptype = (data & 0x3fc) >> 2;
      /* Source Format */
      format = ptype & 0x07;

      /* Now that we have a Valid PSC, check if we also have a valid PTYPE and
         the Source Format, which should range between 1 and 5 */
      if (((ptype >> 6) == 0x2) && (format > 0 && format < 6)) {
        pc_type = data & 0x02;
        pb_mode = c.data[1] & 0x20 >> 4;
        if (!pc_type && pb_mode)
          bad++;
        else
          good++;
      } else
        bad++;

      /* FIXME: maybe bail out early if we get mostly bad syncs ? */
    }

    data_scan_ctx_advance (tf, &c, 1);
  }

  GST_LOG ("good: %d, bad: %d", good, bad);

  if (good > 2 * bad)
    gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, H263_VIDEO_CAPS);

  return;
}

/*** video/x-h264 H264 elementary video stream ***/

static GstStaticCaps h264_video_caps =
GST_STATIC_CAPS ("video/x-h264,stream-format=byte-stream");

#define H264_VIDEO_CAPS gst_static_caps_get(&h264_video_caps)

#define H264_MAX_PROBE_LENGTH (128 * 1024)      /* 128kB for HD should be enough. */

static void
h264_video_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  /* Stream consists of: a series of sync codes (00 00 00 01) followed
   * by NALs
   */
  gboolean seen_idr = FALSE;
  gboolean seen_sps = FALSE;
  gboolean seen_pps = FALSE;
  gboolean seen_ssps = FALSE;
  int nut, ref;
  int good = 0;
  int bad = 0;

  while (c.offset < H264_MAX_PROBE_LENGTH) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 4)))
      break;

    if (IS_MPEG_HEADER (c.data)) {
      nut = c.data[3] & 0x9f;   /* forbiden_zero_bit | nal_unit_type */
      ref = c.data[3] & 0x60;   /* nal_ref_idc */

      /* if forbidden bit is different to 0 won't be h264 */
      if (nut > 0x1f) {
        bad++;
        break;
      }

      /* collect statistics about the NAL types */
      if ((nut >= 1 && nut <= 13) || nut == 19) {
        if ((nut == 5 && ref == 0) ||
            ((nut == 6 || (nut >= 9 && nut <= 12)) && ref != 0)) {
          bad++;
        } else {
          if (nut == 7)
            seen_sps = TRUE;
          else if (nut == 8)
            seen_pps = TRUE;
          else if (nut == 5)
            seen_idr = TRUE;

          good++;
        }
      } else if (nut >= 14 && nut <= 33) {
        if (nut == 15) {
          seen_ssps = TRUE;
          good++;
        } else if (nut == 14 || nut == 20) {
          /* Sometimes we see NAL 14 or 20 without SSPS
           * if dropped into the middle of a stream -
           * just ignore those (don't add to bad count) */
          if (seen_ssps)
            good++;
        } else {
          /* reserved */
          /* Theoretically these are good, since if they exist in the
             stream it merely means that a newer backwards-compatible
             h.264 stream.  But we should be identifying that separately. */
          bad++;
        }
      } else {
        /* unspecified, application specific */
        /* don't consider these bad */
      }

      GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, idr:%d ssps:%d", good, bad,
          seen_pps, seen_sps, seen_idr, seen_ssps);

      if (seen_sps && seen_pps && seen_idr && good >= 10 && bad < 4) {
        gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, H264_VIDEO_CAPS);
        return;
      }

      data_scan_ctx_advance (tf, &c, 4);
    }
    data_scan_ctx_advance (tf, &c, 1);
  }

  GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, idr:%d ssps=%d", good, bad,
      seen_pps, seen_sps, seen_idr, seen_ssps);

  if (good >= 2 && bad == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, H264_VIDEO_CAPS);
  }
}

/*** video/x-h265 H265 elementary video stream ***/

static GstStaticCaps h265_video_caps =
GST_STATIC_CAPS ("video/x-h265,stream-format=byte-stream");

#define H265_VIDEO_CAPS gst_static_caps_get(&h265_video_caps)

#define H265_MAX_PROBE_LENGTH (128 * 1024)      /* 128kB for HD should be enough. */

static void
h265_video_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };

  /* Stream consists of: a series of sync codes (00 00 00 01) followed
   * by NALs
   */
  gboolean seen_irap = FALSE;
  gboolean seen_vps = FALSE;
  gboolean seen_sps = FALSE;
  gboolean seen_pps = FALSE;
  int nut;
  int good = 0;
  int bad = 0;

  while (c.offset < H265_MAX_PROBE_LENGTH) {
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 5)))
      break;

    if (IS_MPEG_HEADER (c.data)) {
      /* forbiden_zero_bit | nal_unit_type */
      nut = c.data[3] & 0xfe;

      /* if forbidden bit is different to 0 won't be h265 */
      if (nut > 0x7e) {
        bad++;
        break;
      }
      nut = nut >> 1;

      /* if nuh_layer_id is not zero or nuh_temporal_id_plus1 is zero then
       * it won't be h265 */
      if ((c.data[3] & 0x01) || (c.data[4] & 0xf8) || !(c.data[4] & 0x07)) {
        bad++;
        break;
      }

      /* collect statistics about the NAL types */
      if ((nut >= 0 && nut <= 9) || (nut >= 16 && nut <= 21) || (nut >= 32
              && nut <= 40)) {
        if (nut == 32)
          seen_vps = TRUE;
        else if (nut == 33)
          seen_sps = TRUE;
        else if (nut == 34)
          seen_pps = TRUE;
        else if (nut >= 16 && nut <= 21) {
          /* BLA, IDR and CRA pictures are belongs to be IRAP picture */
          /* we are not counting the reserved IRAP pictures (22 and 23) to good */
          seen_irap = TRUE;
        }

        good++;
      } else if ((nut >= 10 && nut <= 15) || (nut >= 22 && nut <= 31)
          || (nut >= 41 && nut <= 47)) {
        /* reserved values are counting as bad */
        bad++;
      } else {
        /* unspecified (48..63), application specific */
        /* don't consider these as bad */
      }

      GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, vps:%d, irap:%d", good, bad,
          seen_pps, seen_sps, seen_vps, seen_irap);

      if (seen_sps && seen_pps && seen_irap && good >= 10 && bad < 4) {
        gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, H265_VIDEO_CAPS);
        return;
      }

      data_scan_ctx_advance (tf, &c, 5);
    }
    data_scan_ctx_advance (tf, &c, 1);
  }

  GST_LOG ("good:%d, bad:%d, pps:%d, sps:%d, vps:%d, irap:%d", good, bad,
      seen_pps, seen_sps, seen_vps, seen_irap);

  if (good >= 2 && bad == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, H265_VIDEO_CAPS);
  }
}

/*** video/mpeg video stream ***/

static GstStaticCaps mpeg_video_caps = GST_STATIC_CAPS ("video/mpeg, "
    "systemstream = (boolean) false");
#define MPEG_VIDEO_CAPS gst_static_caps_get(&mpeg_video_caps)

/*
 * Idea is the same as MPEG system stream typefinding: We check each
 * byte of the stream to see if - from that point on - the stream
 * matches a predefined set of marker bits as defined in the MPEG
 * video specs.
 *
 * I'm sure someone will do a chance calculation here too.
 */

static void
mpeg_video_stream_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  gboolean seen_seq_at_0 = FALSE;
  gboolean seen_seq = FALSE;
  gboolean seen_gop = FALSE;
  guint64 last_pic_offset = 0;
  gint num_pic_headers = 0;
  gint found = 0;

  while (c.offset < GST_MPEGVID_TYPEFIND_TRY_SYNC) {
    if (found >= GST_MPEGVID_TYPEFIND_TRY_PICTURES)
      break;

    if (!data_scan_ctx_ensure_data (tf, &c, 5))
      break;

    if (!IS_MPEG_HEADER (c.data))
      goto next;

    /* a pack header indicates that this isn't an elementary stream */
    if (c.data[3] == 0xBA && mpeg_sys_is_valid_pack (tf, c.data, c.size, NULL))
      return;

    /* do we have a sequence header? */
    if (c.data[3] == 0xB3) {
      seen_seq_at_0 = seen_seq_at_0 || (c.offset == 0);
      seen_seq = TRUE;
      data_scan_ctx_advance (tf, &c, 4 + 8);
      continue;
    }

    /* or a GOP header */
    if (c.data[3] == 0xB8) {
      seen_gop = TRUE;
      data_scan_ctx_advance (tf, &c, 8);
      continue;
    }

    /* but what we'd really like to see is a picture header */
    if (c.data[3] == 0x00) {
      ++num_pic_headers;
      last_pic_offset = c.offset;
      data_scan_ctx_advance (tf, &c, 8);
      continue;
    }

    /* ... each followed by a slice header with slice_vertical_pos=1 that's
     * not too far away from the previously seen picture header. */
    if (c.data[3] == 0x01 && num_pic_headers > found &&
        (c.offset - last_pic_offset) >= 4 &&
        (c.offset - last_pic_offset) <= 64) {
      data_scan_ctx_advance (tf, &c, 4);
      found += 1;
      continue;
    }

  next:

    data_scan_ctx_advance (tf, &c, 1);
  }

  if (found > 0 || seen_seq) {
    GstTypeFindProbability probability = 0;

    GST_LOG ("Found %d pictures, seq:%d, gop:%d", found, seen_seq, seen_gop);

    if (found >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_seq && seen_gop)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 1;
    else if (found >= GST_MPEGVID_TYPEFIND_TRY_PICTURES && seen_seq)
      probability = GST_TYPE_FIND_NEARLY_CERTAIN - 9;
    else if (found >= GST_MPEGVID_TYPEFIND_TRY_PICTURES)
      probability = GST_TYPE_FIND_LIKELY;
    else if (seen_seq_at_0 && seen_gop && found > 2)
      probability = GST_TYPE_FIND_LIKELY - 10;
    else if (seen_seq && seen_gop && found > 2)
      probability = GST_TYPE_FIND_LIKELY - 20;
    else if (seen_seq_at_0 && found > 0)
      probability = GST_TYPE_FIND_POSSIBLE;
    else if (seen_seq && found > 0)
      probability = GST_TYPE_FIND_POSSIBLE - 5;
    else if (found > 0)
      probability = GST_TYPE_FIND_POSSIBLE - 10;
    else if (seen_seq)
      probability = GST_TYPE_FIND_POSSIBLE - 20;

    gst_type_find_suggest_simple (tf, probability, "video/mpeg",
        "systemstream", G_TYPE_BOOLEAN, FALSE,
        "mpegversion", G_TYPE_INT, 1, "parsed", G_TYPE_BOOLEAN, FALSE, NULL);
  }
}

/*** audio/x-aiff ***/

static GstStaticCaps aiff_caps = GST_STATIC_CAPS ("audio/x-aiff");

#define AIFF_CAPS gst_static_caps_get(&aiff_caps)
static void
aiff_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 16);

  if (data && memcmp (data, "FORM", 4) == 0) {
    data += 8;
    if (memcmp (data, "AIFF", 4) == 0 || memcmp (data, "AIFC", 4) == 0)
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, AIFF_CAPS);
  }
}

/*** audio/x-svx ***/

static GstStaticCaps svx_caps = GST_STATIC_CAPS ("audio/x-svx");

#define SVX_CAPS gst_static_caps_get(&svx_caps)
static void
svx_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 16);

  if (data && memcmp (data, "FORM", 4) == 0) {
    data += 8;
    if (memcmp (data, "8SVX", 4) == 0 || memcmp (data, "16SV", 4) == 0)
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SVX_CAPS);
  }
}

/*** audio/x-shorten ***/

static GstStaticCaps shn_caps = GST_STATIC_CAPS ("audio/x-shorten");

#define SHN_CAPS gst_static_caps_get(&shn_caps)
static void
shn_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  if (data && memcmp (data, "ajkg", 4) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SHN_CAPS);
  }
  data = gst_type_find_peek (tf, -8, 8);
  if (data && memcmp (data, "SHNAMPSK", 8) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SHN_CAPS);
  }
}

/*** application/x-ape ***/

static GstStaticCaps ape_caps = GST_STATIC_CAPS ("application/x-ape");

#define APE_CAPS gst_static_caps_get(&ape_caps)
static void
ape_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  if (data && memcmp (data, "MAC ", 4) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY + 10, APE_CAPS);
  }
}

/*** ISO FORMATS ***/

/*** audio/x-m4a ***/

static GstStaticCaps m4a_caps = GST_STATIC_CAPS ("audio/x-m4a");

#define M4A_CAPS (gst_static_caps_get(&m4a_caps))
static void
m4a_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 4, 8);

  if (data && (memcmp (data, "ftypM4A ", 8) == 0)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, M4A_CAPS);
  }
}

/*** application/x-3gp ***/

/* The Q is there because variables can't start with a number. */
static GstStaticCaps q3gp_caps = GST_STATIC_CAPS ("application/x-3gp");
#define Q3GP_CAPS (gst_static_caps_get(&q3gp_caps))

static const gchar *
q3gp_type_find_get_profile (const guint8 * data)
{
  switch (GST_MAKE_FOURCC (data[0], data[1], data[2], 0)) {
    case GST_MAKE_FOURCC ('3', 'g', 'g', 0):
      return "general";
    case GST_MAKE_FOURCC ('3', 'g', 'p', 0):
      return "basic";
    case GST_MAKE_FOURCC ('3', 'g', 's', 0):
      return "streaming-server";
    case GST_MAKE_FOURCC ('3', 'g', 'r', 0):
      return "progressive-download";
    default:
      break;
  }
  return NULL;
}

static void
q3gp_type_find (GstTypeFind * tf, gpointer unused)
{
  const gchar *profile;
  guint32 ftyp_size = 0;
  guint32 offset = 0;
  const guint8 *data = NULL;

  if ((data = gst_type_find_peek (tf, 0, 12)) == NULL) {
    return;
  }

  data += 4;
  if (memcmp (data, "ftyp", 4) != 0) {
    return;
  }

  /* check major brand */
  data += 4;
  if ((profile = q3gp_type_find_get_profile (data))) {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
        "application/x-3gp", "profile", G_TYPE_STRING, profile, NULL);
    return;
  }

  /* check compatible brands */
  if ((data = gst_type_find_peek (tf, 0, 4)) != NULL) {
    ftyp_size = GST_READ_UINT32_BE (data);
  }
  if ((data = gst_type_find_peek (tf, 0, ftyp_size)) != NULL) {
    for (offset = 16; offset + 4 < ftyp_size; offset += 4) {
      if ((profile = q3gp_type_find_get_profile (data + offset))) {
        gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
            "application/x-3gp", "profile", G_TYPE_STRING, profile, NULL);
        return;
      }
    }
  }

  return;

}

/*** video/mj2 and image/jp2 ***/
static GstStaticCaps mj2_caps = GST_STATIC_CAPS ("video/mj2");

#define MJ2_CAPS gst_static_caps_get(&mj2_caps)

static GstStaticCaps jp2_caps = GST_STATIC_CAPS ("image/jp2");

#define JP2_CAPS gst_static_caps_get(&jp2_caps)

static void
jp2_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 24);
  if (!data)
    return;

  /* jp2 signature */
  if (memcmp (data, "\000\000\000\014jP  \015\012\207\012", 12) != 0)
    return;

  /* check ftyp box */
  data += 12;
  if (memcmp (data + 4, "ftyp", 4) == 0) {
    if (memcmp (data + 8, "jp2 ", 4) == 0)
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, JP2_CAPS);
    else if (memcmp (data + 8, "mjp2", 4) == 0)
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MJ2_CAPS);
  }
}


static GstStaticCaps jpc_caps = GST_STATIC_CAPS ("image/x-jpc");

#define JPC_CAPS gst_static_caps_get(&jpc_caps)

static void
jpc_type_find (GstTypeFind * tf, gpointer unused)
{
  gboolean found_cod = FALSE;
  gboolean found_qcd = FALSE;
  gboolean found_sot = FALSE;
  const guint8 *data;
  gint offset = 0;
  const guint8 soc_siz[] = { 0xff, 0x4f, 0xff, 0x51 };

#define GST_TYPE_FIND_JPC_MARKER_SOT  0xFF90
#define GST_TYPE_FIND_JPC_MARKER_COD  0xFF52
#define GST_TYPE_FIND_JPC_MARKER_QCD  0xFF5C
#define GST_TYPE_FIND_JPC_MARKER_COC  0xFF53
#define GST_TYPE_FIND_JPC_MARKER_RGN  0xFF5E
#define GST_TYPE_FIND_JPC_MARKER_QCC  0xFF5D
#define GST_TYPE_FIND_JPC_MARKER_POC  0xFF5F
#define GST_TYPE_FIND_JPC_MARKER_PLM  0xFF57
#define GST_TYPE_FIND_JPC_MARKER_PPM  0xFF60
#define GST_TYPE_FIND_JPC_MARKER_TLM  0xFF55
#define GST_TYPE_FIND_JPC_MARKER_CRG  0xFF63
#define GST_TYPE_FIND_JPC_MARKER_COM  0xFF64
#define GST_TYPE_FIND_JPC_MARKER_CBD  0xFF78
#define GST_TYPE_FIND_JPC_MARKER_MCC  0xFF75
#define GST_TYPE_FIND_JPC_MARKER_MCT  0xFF74
#define GST_TYPE_FIND_JPC_MARKER_MCO  0xFF77


  /* SOC marker + SIZ marker */
  if ((data = gst_type_find_peek (tf, 0, 4)) != NULL) {
    if (memcmp (data, soc_siz, 4) != 0)
      return;
    offset += 4;
  } else {
    return;
  }

  while (!found_sot) {

    /* skip actual marker data */
    if ((data = gst_type_find_peek (tf, offset, 2)) != NULL) {
      offset += GST_READ_UINT16_BE (data);
    } else {
      return;
    }

    /* read marker */
    if ((data = gst_type_find_peek (tf, offset, 2)) != NULL) {
      guint16 marker = GST_READ_UINT16_BE (data);
      switch (marker) {
        case GST_TYPE_FIND_JPC_MARKER_SOT:
          found_sot = TRUE;
          break;
        case GST_TYPE_FIND_JPC_MARKER_COD:
          found_cod = TRUE;
          break;
        case GST_TYPE_FIND_JPC_MARKER_QCD:
          found_qcd = TRUE;
          break;
          /* optional header markers */
        case GST_TYPE_FIND_JPC_MARKER_COC:
        case GST_TYPE_FIND_JPC_MARKER_RGN:
        case GST_TYPE_FIND_JPC_MARKER_QCC:
        case GST_TYPE_FIND_JPC_MARKER_POC:
        case GST_TYPE_FIND_JPC_MARKER_PLM:
        case GST_TYPE_FIND_JPC_MARKER_PPM:
        case GST_TYPE_FIND_JPC_MARKER_TLM:
        case GST_TYPE_FIND_JPC_MARKER_CRG:
        case GST_TYPE_FIND_JPC_MARKER_COM:
        case GST_TYPE_FIND_JPC_MARKER_CBD:
        case GST_TYPE_FIND_JPC_MARKER_MCC:
        case GST_TYPE_FIND_JPC_MARKER_MCT:
        case GST_TYPE_FIND_JPC_MARKER_MCO:
          break;
          /* unrecognized marker */
        default:
          return;
      }
      offset += 2;
    } else {
      return;
    }
  }

  if (found_cod && found_qcd && found_sot)
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, JPC_CAPS);
}


/*** video/quicktime ***/

static GstStaticCaps qt_caps = GST_STATIC_CAPS ("video/quicktime");

#define QT_CAPS gst_static_caps_get(&qt_caps)
#define STRNCMP(x,y,z) (strncmp ((char*)(x), (char*)(y), z))

/* FIXME 0.11: go through http://www.ftyps.com/ */
static void
qt_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;
  guint tip = 0;
  guint64 offset = 0;
  guint64 size;
  const gchar *variant = NULL;

  while ((data = gst_type_find_peek (tf, offset, 12)) != NULL) {
    guint64 new_offset;

    if (STRNCMP (&data[4], "ftypqt  ", 8) == 0) {
      tip = GST_TYPE_FIND_MAXIMUM;
      break;
    }

    if (STRNCMP (&data[4], "ftypisom", 8) == 0 ||
        STRNCMP (&data[4], "ftypavc1", 8) == 0 ||
        STRNCMP (&data[4], "ftypmp42", 8) == 0) {
      tip = GST_TYPE_FIND_MAXIMUM;
      variant = "iso";
      break;
    }

    if (STRNCMP (&data[4], "ftypisml", 8) == 0 ||
        STRNCMP (&data[4], "ftypavc3", 8) == 0) {
      tip = GST_TYPE_FIND_MAXIMUM;
      variant = "iso-fragmented";
      break;
    }

    if (STRNCMP (&data[4], "ftypccff", 8) == 0) {
      tip = GST_TYPE_FIND_MAXIMUM;
      variant = "ccff";
      break;
    }

    /* box/atom types that are in common with ISO base media file format */
    if (STRNCMP (&data[4], "moov", 4) == 0 ||
        STRNCMP (&data[4], "mdat", 4) == 0 ||
        STRNCMP (&data[4], "ftyp", 4) == 0 ||
        STRNCMP (&data[4], "free", 4) == 0 ||
        STRNCMP (&data[4], "uuid", 4) == 0 ||
        STRNCMP (&data[4], "moof", 4) == 0 ||
        STRNCMP (&data[4], "skip", 4) == 0) {
      if (tip == 0) {
        tip = GST_TYPE_FIND_LIKELY;
      } else {
        tip = GST_TYPE_FIND_NEARLY_CERTAIN;
      }
    }
    /* other box/atom types, apparently quicktime specific */
    else if (STRNCMP (&data[4], "pnot", 4) == 0 ||
        STRNCMP (&data[4], "PICT", 4) == 0 ||
        STRNCMP (&data[4], "wide", 4) == 0 ||
        STRNCMP (&data[4], "prfl", 4) == 0) {
      tip = GST_TYPE_FIND_MAXIMUM;
      break;
    } else {
      tip = 0;
      break;
    }

    size = GST_READ_UINT32_BE (data);
    if (size + offset >= G_MAXINT64)
      break;
    /* check compatible brands rather than ever expaning major brands above */
    if ((STRNCMP (&data[4], "ftyp", 4) == 0) && (size >= 16)) {
      data = gst_type_find_peek (tf, offset, size);
      if (data == NULL)
        goto done;
      new_offset = 12;
      while (new_offset + 4 <= size) {
        if (STRNCMP (&data[new_offset], "isom", 4) == 0 ||
            STRNCMP (&data[new_offset], "dash", 4) == 0 ||
            STRNCMP (&data[new_offset], "avc1", 4) == 0 ||
            STRNCMP (&data[new_offset], "avc3", 4) == 0 ||
            STRNCMP (&data[new_offset], "mp41", 4) == 0 ||
            STRNCMP (&data[new_offset], "mp42", 4) == 0) {
          tip = GST_TYPE_FIND_MAXIMUM;
          variant = "iso";
          goto done;
        }
        new_offset += 4;
      }
    }
    if (size == 1) {
      const guint8 *sizedata;

      sizedata = gst_type_find_peek (tf, offset + 8, 8);
      if (sizedata == NULL)
        break;

      size = GST_READ_UINT64_BE (sizedata);
    } else {
      if (size < 8)
        break;
    }
    new_offset = offset + size;
    if (new_offset <= offset)
      break;
    if (new_offset + 16 >= G_MAXINT64)
      break;
    offset = new_offset;
  }

done:
  if (tip > 0) {
    if (variant) {
      GstCaps *caps = gst_caps_copy (QT_CAPS);

      gst_caps_set_simple (caps, "variant", G_TYPE_STRING, variant, NULL);
      gst_type_find_suggest (tf, tip, caps);
      gst_caps_unref (caps);
    } else {
      gst_type_find_suggest (tf, tip, QT_CAPS);
    }
  }
};


/*** image/x-quicktime ***/

static GstStaticCaps qtif_caps = GST_STATIC_CAPS ("image/x-quicktime");

#define QTIF_CAPS gst_static_caps_get(&qtif_caps)

/* how many atoms we check before we give up */
#define QTIF_MAXROUNDS 25

static void
qtif_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;
  gboolean found_idsc = FALSE;
  gboolean found_idat = FALSE;
  guint64 offset = 0;
  guint rounds = 0;

  while ((data = gst_type_find_peek (tf, offset, 8)) != NULL) {
    guint64 size;

    size = GST_READ_UINT32_BE (data);
    if (size == 1) {
      const guint8 *sizedata;

      sizedata = gst_type_find_peek (tf, offset + 8, 8);
      if (sizedata == NULL)
        break;

      size = GST_READ_UINT64_BE (sizedata);
    }
    if (size < 8)
      break;

    if (STRNCMP (data + 4, "idsc", 4) == 0)
      found_idsc = TRUE;
    if (STRNCMP (data + 4, "idat", 4) == 0)
      found_idat = TRUE;

    if (found_idsc && found_idat) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, QTIF_CAPS);
      return;
    }

    offset += size;
    if (offset + 8 >= G_MAXINT64)
      break;
    if (++rounds > QTIF_MAXROUNDS)
      break;
  }

  if (found_idsc || found_idat) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, QTIF_CAPS);
    return;
  }
};

/*** audio/x-mod ***/

static GstStaticCaps mod_caps = GST_STATIC_CAPS ("audio/x-mod");

#define MOD_CAPS gst_static_caps_get(&mod_caps)
/* FIXME: M15 CheckType to do */
static void
mod_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;
  GstTypeFindProbability probability;
  const char *mod_type = NULL;

  /* MOD */
  if ((data = gst_type_find_peek (tf, 1080, 4)) != NULL) {
    /* Protracker and variants */
    if ((memcmp (data, "M.K.", 4) == 0) ||
        (memcmp (data, "M!K!", 4) == 0) ||
        (memcmp (data, "M&K!", 4) == 0) || (memcmp (data, "N.T.", 4) == 0) ||
        /* Star Tracker */
        (memcmp (data, "FLT", 3) == 0 && isdigit (data[3])) ||
        (memcmp (data, "EXO", 3) == 0 && isdigit (data[3])) ||
        /* Oktalyzer (Amiga) */
        (memcmp (data, "OKTA", 4) == 0) || (memcmp (data, "OCTA", 4) == 0) ||
        /* Oktalyser (Atari) */
        (memcmp (data, "CD81", 4) == 0) ||
        /* Taketracker */
        (memcmp (data, "TDZ", 3) == 0 && isdigit (data[3])) ||
        /* Fasttracker */
        (memcmp (data + 1, "CHN", 3) == 0 && isdigit (data[0])) ||
        /* Fasttracker or Taketracker */
        (memcmp (data + 2, "CH", 2) == 0 && isdigit (data[0])
            && isdigit (data[1])) || (memcmp (data + 2, "CN", 2) == 0
            && isdigit (data[0]) && isdigit (data[1]))) {
      mod_type = "mod";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* J2B (Jazz Jackrabbit 2) */
  if ((data = gst_type_find_peek (tf, 0, 8)) != NULL) {
    if ((memcmp (data, "MUSE\xDE\xAD", 4) == 0) &&
        ((memcmp (data + 6, "\xBE\xEF", 2) == 0) ||
            (memcmp (data + 6, "\xBA\xBE", 2) == 0))) {
      mod_type = "j2b";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* AMS (Velvet Studio) */
  if ((data = gst_type_find_peek (tf, 0, 7)) != NULL) {
    if (memcmp (data, "AMShdr\x1A", 7) == 0) {
      mod_type = "velvet-ams";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* AMS (Extreme Tracker) */
  if ((data = gst_type_find_peek (tf, 0, 9)) != NULL) {
    if ((memcmp (data, "Extreme", 7) == 0) && (data[8] == 1)) {
      mod_type = "extreme-ams";
      probability = GST_TYPE_FIND_LIKELY;
      goto suggest_audio_mod_caps;
    }
  }
  /* ULT (Ultratracker) */
  if ((data = gst_type_find_peek (tf, 0, 14)) != NULL) {
    if (memcmp (data, "MAS_UTrack_V00", 14) == 0) {
      mod_type = "ult";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* DIGI (DigiBooster) */
  if ((data = gst_type_find_peek (tf, 0, 20)) != NULL) {
    if (memcmp (data, "DIGI Booster module\0", 20) == 0) {
      mod_type = "digi";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* PTM (PolyTracker) */
  if ((data = gst_type_find_peek (tf, 0x2C, 4)) != NULL) {
    if (memcmp (data, "PTMF", 4) == 0) {
      mod_type = "ptm";
      probability = GST_TYPE_FIND_LIKELY;
      goto suggest_audio_mod_caps;
    }
  }
  /* XM */
  if ((data = gst_type_find_peek (tf, 0, 38)) != NULL) {
    if ((memcmp (data, "Extended Module: ", 17) == 0) && (data[37] == 0x1A)) {
      mod_type = "xm";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* OKT */
  if (data || (data = gst_type_find_peek (tf, 0, 8)) != NULL) {
    if (memcmp (data, "OKTASONG", 8) == 0) {
      mod_type = "okt";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* Various formats with a 4-byte magic ID at the beginning of the file */
  if (data || (data = gst_type_find_peek (tf, 0, 4)) != NULL) {
    /* PSM (Protracker Studio PSM) */
    if (memcmp (data, "PSM", 3) == 0) {
      unsigned char fbyte = data[3];
      if ((fbyte == ' ') || (fbyte == 254)) {
        mod_type = "psm";
        probability = GST_TYPE_FIND_MAXIMUM;
        goto suggest_audio_mod_caps;
      }
    }
    /* 669 */
    if ((memcmp (data, "if", 2) == 0) || (memcmp (data, "JN", 2) == 0)) {
      mod_type = "669";
      probability = GST_TYPE_FIND_LIKELY;
      goto suggest_audio_mod_caps;
    }
    /* AMF */
    if ((memcmp (data, "AMF", 3) == 0) && (data[3] > 10) && (data[3] < 14)) {
      mod_type = "dsmi-amf";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* IT */
    if (memcmp (data, "IMPM", 4) == 0) {
      mod_type = "it";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* DBM (DigiBooster Pro) */
    if (memcmp (data, "DBM0", 4) == 0) {
      mod_type = "dbm";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* MDL (DigiTrakker) */
    if (memcmp (data, "DMDL", 4) == 0) {
      mod_type = "mdl";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* MT2 (MadTracker 2.0) */
    if (memcmp (data, "MT20", 4) == 0) {
      mod_type = "mt2";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* DMF (X-Tracker) */
    if (memcmp (data, "DDMF", 4) == 0) {
      mod_type = "dmf";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* MED */
    if ((memcmp (data, "MMD0", 4) == 0) || (memcmp (data, "MMD1", 4) == 0)) {
      mod_type = "med";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* MTM */
    if (memcmp (data, "MTM", 3) == 0) {
      mod_type = "mtm";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* DSM */
    if (memcmp (data, "RIFF", 4) == 0) {
      const guint8 *data2 = gst_type_find_peek (tf, 8, 4);

      if (data2) {
        if (memcmp (data2, "DSMF", 4) == 0) {
          mod_type = "dsm";
          probability = GST_TYPE_FIND_MAXIMUM;
          goto suggest_audio_mod_caps;
        }
      }
    }
    /* FAR (Farandole) */
    if (memcmp (data, "FAR\xFE", 4) == 0) {
      mod_type = "far";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
    /* FAM */
    if (memcmp (data, "FAM\xFE", 4) == 0) {
      const guint8 *data2 = gst_type_find_peek (tf, 44, 3);

      if (data2) {
        if (memcmp (data2, "compare", 3) == 0) {
          mod_type = "fam";
          probability = GST_TYPE_FIND_MAXIMUM;
          goto suggest_audio_mod_caps;
        }
        /* otherwise do not suggest anything */
      } else {
        mod_type = "fam";
        probability = GST_TYPE_FIND_LIKELY;
        goto suggest_audio_mod_caps;
      }
    }
    /* GDM */
    if (memcmp (data, "GDM\xFE", 4) == 0) {
      const guint8 *data2 = gst_type_find_peek (tf, 71, 4);

      if (data2) {
        if (memcmp (data2, "GMFS", 4) == 0) {
          mod_type = "gdm";
          probability = GST_TYPE_FIND_MAXIMUM;
          goto suggest_audio_mod_caps;
        }
        /* otherwise do not suggest anything */
      } else {
        mod_type = "gdm";
        probability = GST_TYPE_FIND_LIKELY;
        goto suggest_audio_mod_caps;
      }
    }
    /* UMX */
    if (memcmp (data, "\xC1\x83\x2A\x9E", 4) == 0) {
      mod_type = "umx";
      probability = GST_TYPE_FIND_POSSIBLE;
      goto suggest_audio_mod_caps;
    }
  }
  /* FAR (Farandole) (secondary detection) */
  if ((data = gst_type_find_peek (tf, 44, 3)) != NULL) {
    if (memcmp (data, "\x0D\x0A\x1A", 3) == 0) {
      mod_type = "far";
      probability = GST_TYPE_FIND_POSSIBLE;
      goto suggest_audio_mod_caps;
    }
  }
  /* IMF */
  if ((data = gst_type_find_peek (tf, 60, 4)) != NULL) {
    if (memcmp (data, "IM10", 4) == 0) {
      mod_type = "imf";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* S3M */
  if ((data = gst_type_find_peek (tf, 44, 4)) != NULL) {
    if (memcmp (data, "SCRM", 4) == 0) {
      mod_type = "s3m";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }
  /* STM */
  if ((data = gst_type_find_peek (tf, 20, 8)) != NULL) {
    if (g_ascii_strncasecmp ((gchar *) data, "!Scream!", 8) == 0 ||
        g_ascii_strncasecmp ((gchar *) data, "BMOD2STM", 8) == 0) {
      const guint8 *id, *stmtype;

      if ((id = gst_type_find_peek (tf, 28, 1)) == NULL)
        return;
      if ((stmtype = gst_type_find_peek (tf, 29, 1)) == NULL)
        return;
      if (*id == 0x1A && *stmtype == 2) {
        mod_type = "stm";
        probability = GST_TYPE_FIND_MAXIMUM;
        goto suggest_audio_mod_caps;
      }
    }
  }
  /* AMF */
  if ((data = gst_type_find_peek (tf, 0, 19)) != NULL) {
    if (memcmp (data, "ASYLUM Music Format", 19) == 0) {
      mod_type = "asylum-amf";
      probability = GST_TYPE_FIND_MAXIMUM;
      goto suggest_audio_mod_caps;
    }
  }

suggest_audio_mod_caps:
  if (mod_type != NULL) {
    GstCaps *caps = gst_caps_new_simple ("audio/x-mod",
        "type", G_TYPE_STRING, mod_type, NULL);

    gst_type_find_suggest (tf, probability, caps);
    gst_caps_unref (caps);
  }
}

/*** application/x-shockwave-flash ***/

static GstStaticCaps swf_caps =
GST_STATIC_CAPS ("application/x-shockwave-flash");
#define SWF_CAPS (gst_static_caps_get(&swf_caps))
static void
swf_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  if (data && (data[0] == 'F' || data[0] == 'C') &&
      data[1] == 'W' && data[2] == 'S') {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SWF_CAPS);
  }
}

/*** application/vnd.ms-sstr+xml ***/

static void
mss_manifest_load_utf16 (gunichar2 * utf16_ne, const guint8 * utf16_data,
    gsize data_size, guint data_endianness)
{
  memcpy (utf16_ne, utf16_data, data_size);
  if (data_endianness != G_BYTE_ORDER) {
    guint i;

    for (i = 0; i < data_size / 2; ++i)
      utf16_ne[i] = GUINT16_SWAP_LE_BE (utf16_ne[i]);
  }
}

static GstStaticCaps mss_manifest_caps =
GST_STATIC_CAPS ("application/vnd.ms-sstr+xml");
#define MSS_MANIFEST_CAPS (gst_static_caps_get(&mss_manifest_caps))
static void
mss_manifest_type_find (GstTypeFind * tf, gpointer unused)
{
  gunichar2 utf16_ne[512];
  const guint8 *data;
  guint data_endianness = 0;
  glong n_read = 0, size = 0;
  guint length;
  gchar *utf8;
  gboolean utf8_bom_detected = FALSE;

  if (xml_check_first_element (tf, "SmoothStreamingMedia", 20, TRUE)) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MSS_MANIFEST_CAPS);
    return;
  }

  length = gst_type_find_get_length (tf);

  /* try detecting the charset */
  data = gst_type_find_peek (tf, 0, 3);

  if (data == NULL)
    return;

  /* look for a possible BOM */
  if (data[0] == 0xEF && data[1] == 0xBB && data[2] == 0xBF)
    utf8_bom_detected = TRUE;
  else if (data[0] == 0xFF && data[1] == 0xFE)
    data_endianness = G_LITTLE_ENDIAN;
  else if (data[0] == 0xFE && data[1] == 0xFF)
    data_endianness = G_BIG_ENDIAN;
  else
    return;

  /* try a default that should be enough */
  if (length == 0)
    length = 512;
  else if (length < 64)
    return;
  else                          /* the first few bytes should be enough */
    length = MIN (1024, length);

  data = gst_type_find_peek (tf, 0, length);

  if (data == NULL)
    return;

  /* skip the BOM */
  data += 2;
  length -= 2;

  if (utf8_bom_detected) {
    /* skip last byte of the BOM */
    data++;
    length--;

    if (xml_check_first_element_from_data (data, length,
            "SmoothStreamingMedia", 20, TRUE))
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MSS_MANIFEST_CAPS);
  } else {
    length = GST_ROUND_DOWN_2 (length);

    /* convert to native endian UTF-16 */
    mss_manifest_load_utf16 (utf16_ne, data, length, data_endianness);

    /* and now convert to UTF-8 */
    utf8 = g_utf16_to_utf8 (utf16_ne, length / 2, &n_read, &size, NULL);
    if (utf8 != NULL && n_read > 0) {
      if (xml_check_first_element_from_data ((const guint8 *) utf8, size,
              "SmoothStreamingMedia", 20, TRUE))
        gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MSS_MANIFEST_CAPS);
    }
    g_free (utf8);
  }
}

/*** image/jpeg ***/

#define JPEG_MARKER_IS_START_OF_FRAME(x) \
    ((x)>=0xc0 && (x) <= 0xcf && (x)!=0xc4 && (x)!=0xc8 && (x)!=0xcc)

static GstStaticCaps jpeg_caps = GST_STATIC_CAPS ("image/jpeg");

#define JPEG_CAPS (gst_static_caps_get(&jpeg_caps))
static void
jpeg_type_find (GstTypeFind * tf, gpointer unused)
{
  GstTypeFindProbability prob = GST_TYPE_FIND_POSSIBLE;
  DataScanCtx c = { 0, NULL, 0 };
  GstCaps *caps;
  guint num_markers;

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 2)))
    return;

  if (c.data[0] != 0xff || c.data[1] != 0xd8)
    return;

  num_markers = 1;
  data_scan_ctx_advance (tf, &c, 2);

  caps = gst_caps_copy (JPEG_CAPS);

  while (data_scan_ctx_ensure_data (tf, &c, 4) && c.offset < (200 * 1024)) {
    guint16 len;
    guint8 marker;

    if (c.data[0] != 0xff)
      break;

    marker = c.data[1];
    if (G_UNLIKELY (marker == 0xff)) {
      data_scan_ctx_advance (tf, &c, 1);
      continue;
    }

    data_scan_ctx_advance (tf, &c, 2);

    /* we assume all markers we'll see before SOF have a payload length; if
     * that's not the case we'll just detect a false sync and bail out, but
     * still report POSSIBLE probability */
    len = GST_READ_UINT16_BE (c.data);

    GST_LOG ("possible JPEG marker 0x%02x (@0x%04x), segment length %u",
        marker, (guint) c.offset, len);

    if (!data_scan_ctx_ensure_data (tf, &c, len))
      break;

    if (marker == 0xc4 ||       /* DEFINE_HUFFMAN_TABLES          */
        marker == 0xcc ||       /* DEFINE_ARITHMETIC_CONDITIONING */
        marker == 0xdb ||       /* DEFINE_QUANTIZATION_TABLES     */
        marker == 0xdd ||       /* DEFINE_RESTART_INTERVAL        */
        marker == 0xfe) {       /* COMMENT                        */
      data_scan_ctx_advance (tf, &c, len);
      ++num_markers;
    } else if (marker == 0xe0 && len >= (2 + 4) &&      /* APP0 */
        data_scan_ctx_memcmp (tf, &c, 2, "JFIF", 4)) {
      GST_LOG ("found JFIF tag");
      prob = GST_TYPE_FIND_MAXIMUM;
      data_scan_ctx_advance (tf, &c, len);
      ++num_markers;
      /* we continue until we find a start of frame marker */
    } else if (marker == 0xe1 && len >= (2 + 4) &&      /* APP1 */
        data_scan_ctx_memcmp (tf, &c, 2, "Exif", 4)) {
      GST_LOG ("found Exif tag");
      prob = GST_TYPE_FIND_MAXIMUM;
      data_scan_ctx_advance (tf, &c, len);
      ++num_markers;
      /* we continue until we find a start of frame marker */
    } else if (marker >= 0xe0 && marker <= 0xef) {      /* APPn */
      data_scan_ctx_advance (tf, &c, len);
      ++num_markers;
    } else if (JPEG_MARKER_IS_START_OF_FRAME (marker) && len >= (2 + 8)) {
      int h, w;

      h = GST_READ_UINT16_BE (c.data + 2 + 1);
      w = GST_READ_UINT16_BE (c.data + 2 + 1 + 2);
      if (h == 0 || w == 0) {
        GST_WARNING ("bad width %u and/or height %u in SOF header", w, h);
        break;
      }

      GST_LOG ("SOF at offset %" G_GUINT64_FORMAT ", num_markers=%d, "
          "WxH=%dx%d", c.offset - 2, num_markers, w, h);

      if (num_markers >= 5 || prob == GST_TYPE_FIND_MAXIMUM)
        prob = GST_TYPE_FIND_MAXIMUM;
      else
        prob = GST_TYPE_FIND_LIKELY;

      gst_caps_set_simple (caps, "width", G_TYPE_INT, w,
          "height", G_TYPE_INT, h, "sof-marker", G_TYPE_INT, marker & 0xf,
          NULL);

      break;
    } else {
      GST_WARNING ("bad length or unexpected JPEG marker 0xff 0x%02x", marker);
      break;
    }
  }

  gst_type_find_suggest (tf, prob, caps);
  gst_caps_unref (caps);
}

/*** image/bmp ***/

static GstStaticCaps bmp_caps = GST_STATIC_CAPS ("image/bmp");

#define BMP_CAPS (gst_static_caps_get(&bmp_caps))
static void
bmp_type_find (GstTypeFind * tf, gpointer unused)
{
  DataScanCtx c = { 0, NULL, 0 };
  guint32 struct_size, w, h, planes, bpp;

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 54)))
    return;

  if (c.data[0] != 'B' || c.data[1] != 'M')
    return;

  /* skip marker + size */
  data_scan_ctx_advance (tf, &c, 2 + 4);

  /* reserved, must be 0 */
  if (c.data[0] != 0 || c.data[1] != 0 || c.data[2] != 0 || c.data[3] != 0)
    return;

  data_scan_ctx_advance (tf, &c, 2 + 2);

  /* offset to start of image data in bytes (check for sanity) */
  GST_LOG ("offset=%u", GST_READ_UINT32_LE (c.data));
  if (GST_READ_UINT32_LE (c.data) > (10 * 1024 * 1024))
    return;

  struct_size = GST_READ_UINT32_LE (c.data + 4);
  GST_LOG ("struct_size=%u", struct_size);

  data_scan_ctx_advance (tf, &c, 4 + 4);

  if (struct_size == 0x0C) {
    w = GST_READ_UINT16_LE (c.data);
    h = GST_READ_UINT16_LE (c.data + 2);
    planes = GST_READ_UINT16_LE (c.data + 2 + 2);
    bpp = GST_READ_UINT16_LE (c.data + 2 + 2 + 2);
  } else if (struct_size == 40 || struct_size == 64 || struct_size == 108
      || struct_size == 124 || struct_size == 0xF0) {
    w = GST_READ_UINT32_LE (c.data);
    h = GST_READ_UINT32_LE (c.data + 4);
    planes = GST_READ_UINT16_LE (c.data + 4 + 4);
    bpp = GST_READ_UINT16_LE (c.data + 4 + 4 + 2);
  } else {
    return;
  }

  /* image sizes sanity check */
  GST_LOG ("w=%u, h=%u, planes=%u, bpp=%u", w, h, planes, bpp);
  if (w == 0 || w > 0xfffff || h == 0 || h > 0xfffff || planes != 1 ||
      (bpp != 1 && bpp != 4 && bpp != 8 && bpp != 16 && bpp != 24 && bpp != 32))
    return;

  gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM, "image/bmp",
      "width", G_TYPE_INT, w, "height", G_TYPE_INT, h, "bpp", G_TYPE_INT, bpp,
      NULL);
}

/*** image/tiff ***/
static GstStaticCaps tiff_caps = GST_STATIC_CAPS ("image/tiff, "
    "endianness = (int) { BIG_ENDIAN, LITTLE_ENDIAN }");
#define TIFF_CAPS (gst_static_caps_get(&tiff_caps))
static GstStaticCaps tiff_be_caps = GST_STATIC_CAPS ("image/tiff, "
    "endianness = (int) BIG_ENDIAN");
#define TIFF_BE_CAPS (gst_static_caps_get(&tiff_be_caps))
static GstStaticCaps tiff_le_caps = GST_STATIC_CAPS ("image/tiff, "
    "endianness = (int) LITTLE_ENDIAN");
#define TIFF_LE_CAPS (gst_static_caps_get(&tiff_le_caps))
static void
tiff_type_find (GstTypeFind * tf, gpointer ununsed)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 8);
  guint8 le_header[4] = { 0x49, 0x49, 0x2A, 0x00 };
  guint8 be_header[4] = { 0x4D, 0x4D, 0x00, 0x2A };

  if (data) {
    if (memcmp (data, le_header, 4) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, TIFF_LE_CAPS);
    } else if (memcmp (data, be_header, 4) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, TIFF_BE_CAPS);
    }
  }
}

/*** image/x-exr ***/
static GstStaticCaps exr_caps = GST_STATIC_CAPS ("image/x-exr");
#define EXR_CAPS (gst_static_caps_get(&exr_caps))
static void
exr_type_find (GstTypeFind * tf, gpointer ununsed)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 8);

  if (data) {
    guint32 flags;

    if (GST_READ_UINT32_LE (data) != 0x01312f76)
      return;

    flags = GST_READ_UINT32_LE (data + 4);
    if ((flags & 0xff) != 1 && (flags & 0xff) != 2)
      return;

    /* If bit 9 is set, bit 11 and 12 must be 0 */
    if ((flags & 0x200) && (flags & 0x1800))
      return;

    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, EXR_CAPS);
  }
}


/*** PNM ***/

static GstStaticCaps pnm_caps = GST_STATIC_CAPS ("image/x-portable-bitmap; "
    "image/x-portable-graymap; image/x-portable-pixmap; "
    "image/x-portable-anymap");

#define PNM_CAPS (gst_static_caps_get(&pnm_caps))

#define IS_PNM_WHITESPACE(c) \
    ((c) == ' ' || (c) == '\r' || (c) == '\n' || (c) == 't')

static void
pnm_type_find (GstTypeFind * tf, gpointer ununsed)
{
  const gchar *media_type = NULL;
  DataScanCtx c = { 0, NULL, 0 };
  guint h = 0, w = 0;

  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 16)))
    return;

  /* see http://en.wikipedia.org/wiki/Netpbm_format */
  if (c.data[0] != 'P' || c.data[1] < '1' || c.data[1] > '7' ||
      !IS_PNM_WHITESPACE (c.data[2]) ||
      (c.data[3] != '#' && c.data[3] < '0' && c.data[3] > '9'))
    return;

  switch (c.data[1]) {
    case '1':
      media_type = "image/x-portable-bitmap";   /* ASCII */
      break;
    case '2':
      media_type = "image/x-portable-graymap";  /* ASCII */
      break;
    case '3':
      media_type = "image/x-portable-pixmap";   /* ASCII */
      break;
    case '4':
      media_type = "image/x-portable-bitmap";   /* Raw */
      break;
    case '5':
      media_type = "image/x-portable-graymap";  /* Raw */
      break;
    case '6':
      media_type = "image/x-portable-pixmap";   /* Raw */
      break;
    case '7':
      media_type = "image/x-portable-anymap";
      break;
    default:
      g_return_if_reached ();
  }

  /* try to extract width and height as well */
  if (c.data[1] != '7') {
    gchar s[64] = { 0, }
    , sep1, sep2;

    /* need to skip any comment lines first */
    data_scan_ctx_advance (tf, &c, 3);

    if (!data_scan_ctx_ensure_data (tf, &c, 1))
      return;

    while (c.data[0] == '#') {  /* we know there's still data left */
      data_scan_ctx_advance (tf, &c, 1);
      if (!data_scan_ctx_ensure_data (tf, &c, 1))
        return;

      while (c.data[0] != '\n' && c.data[0] != '\r') {
        data_scan_ctx_advance (tf, &c, 1);
        if (!data_scan_ctx_ensure_data (tf, &c, 1))
          return;
      }
      data_scan_ctx_advance (tf, &c, 1);
      GST_LOG ("skipped comment line in PNM header");
      if (!data_scan_ctx_ensure_data (tf, &c, 1))
        return;
    }

    if (!data_scan_ctx_ensure_data (tf, &c, 32) &&
        !data_scan_ctx_ensure_data (tf, &c, 4)) {
      return;
    }

    /* need to NUL-terminate data for sscanf */
    memcpy (s, c.data, MIN (sizeof (s) - 1, c.size));
    if (sscanf (s, "%u%c%u%c", &w, &sep1, &h, &sep2) == 4 &&
        IS_PNM_WHITESPACE (sep1) && IS_PNM_WHITESPACE (sep2) &&
        w > 0 && w < G_MAXINT && h > 0 && h < G_MAXINT) {
      GST_LOG ("extracted PNM width and height: %dx%d", w, h);
    } else {
      w = 0;
      h = 0;
    }
  } else {
    /* FIXME: extract width + height for anymaps too */
  }

  if (w > 0 && h > 0) {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM, media_type,
        "width", G_TYPE_INT, w, "height", G_TYPE_INT, h, NULL);
  } else {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_LIKELY, media_type, NULL);
  }
}

static GstStaticCaps sds_caps = GST_STATIC_CAPS ("audio/x-sds");

#define SDS_CAPS (gst_static_caps_get(&sds_caps))
static void
sds_type_find (GstTypeFind * tf, gpointer ununsed)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);
  guint8 mask[4] = { 0xFF, 0xFF, 0x80, 0xFF };
  guint8 match[4] = { 0xF0, 0x7E, 0, 0x01 };
  gint x;

  if (data) {
    for (x = 0; x < 4; x++) {
      if ((data[x] & mask[x]) != match[x]) {
        return;
      }
    }
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SDS_CAPS);
  }
}

static GstStaticCaps ircam_caps = GST_STATIC_CAPS ("audio/x-ircam");

#define IRCAM_CAPS (gst_static_caps_get(&ircam_caps))
static void
ircam_type_find (GstTypeFind * tf, gpointer ununsed)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);
  guint8 mask[4] = { 0xFF, 0xFF, 0xF8, 0xFF };
  guint8 match[4] = { 0x64, 0xA3, 0x00, 0x00 };
  gint x;
  gboolean matched = TRUE;

  if (!data) {
    return;
  }
  for (x = 0; x < 4; x++) {
    if ((data[x] & mask[x]) != match[x]) {
      matched = FALSE;
    }
  }
  if (matched) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, IRCAM_CAPS);
    return;
  }
  /* now try the reverse version */
  matched = TRUE;
  for (x = 0; x < 4; x++) {
    if ((data[x] & mask[3 - x]) != match[3 - x]) {
      matched = FALSE;
    }
  }
}

/*** Matroska/WebM ***/

#define EBML_HEADER           0x1A45DFA3
#define EBML_VERSION          0x4286
#define EBML_DOCTYPE          0x4282
#define EBML_DOCTYPE_VERSION  0x4287
#define MATROSKA_SEGMENT      0x18538067
#define MATROSKA_CLUSTER      0x1F43B675
#define MATROSKA_TRACKS       0x1654AE6B
#define MATROSKA_TRACK_ENTRY  0xAE
#define MATROSKA_TRACK_TYPE   0x83
#define MATROSKA_STEREO_MODE  0x53B8

#define EBML_MAX_LEN (2 * 1024 * 1024)

typedef enum
{
  EBML_DOCTYPE_UNKNOWN = 0,
  EBML_DOCTYPE_MATROSKA,
  EBML_DOCTYPE_WEBM
} GstEbmlDocType;

typedef struct
{
  GstEbmlDocType doctype;
  guint audio;
  guint video;
  guint other;
  guint video_stereo;
  guint chunks;
  guint tracks_ok;              /* if we've seen and fully parsed the TRACKS element */
} GstMatroskaInfo;

static inline guint
ebml_read_chunk_header (GstTypeFind * tf, DataScanCtx * c, guint max_size,
    guint32 * id, guint64 * size)
{
  guint64 mask;
  guint msbit_set, i, len, id_len;

  if (c->size < 12 || max_size < 1)
    return 0;

  /* element ID */
  *id = c->data[0];
  if ((c->data[0] & 0x80) == 0x80) {
    id_len = 1;
  } else if ((c->data[0] & 0xC0) == 0x40) {
    id_len = 2;
  } else if ((c->data[0] & 0xE0) == 0x20) {
    id_len = 3;
  } else if ((c->data[0] & 0xF0) == 0x10) {
    id_len = 4;
  } else {
    return 0;
  }

  if (max_size < id_len)
    return 0;

  for (i = 1; i < id_len; ++i) {
    *id = (*id << 8) | c->data[i];
  }

  data_scan_ctx_advance (tf, c, id_len);
  max_size -= id_len;

  /* size */
  if (max_size < 1 || c->data[0] == 0)
    return 0;

  msbit_set = g_bit_nth_msf (c->data[0], 8);
  mask = ((1 << msbit_set) - 1);
  *size = c->data[0] & mask;
  len = 7 - msbit_set;

  if (max_size < 1 + len)
    return 0;
  for (i = 0; i < len; ++i) {
    mask = (mask << 8) | 0xff;
    *size = (*size << 8) | c->data[1 + i];
  }

  data_scan_ctx_advance (tf, c, 1 + len);

  /* undefined/unknown size? (all bits 1) */
  if (*size == mask) {
    /* allow unknown size for SEGMENT chunk, bail out otherwise */
    if (*id == MATROSKA_SEGMENT)
      *size = G_MAXUINT64;
    else
      return 0;
  }

  return id_len + (1 + len);
}

static gboolean
ebml_parse_chunk (GstTypeFind * tf, DataScanCtx * ctx, guint32 chunk_id,
    guint chunk_size, GstMatroskaInfo * info, guint depth)
{                               /* FIXME: make sure input size is clipped to 32 bit */
  static const gchar SPACES[] = "                ";
  DataScanCtx c = *ctx;
  guint64 element_size = 0;
  guint32 id, hdr_len;

  if (depth >= 8)               /* keep SPACES large enough for depth */
    return FALSE;

  while (chunk_size > 0) {
    if (c.offset > EBML_MAX_LEN || !data_scan_ctx_ensure_data (tf, &c, 64))
      return FALSE;

    hdr_len = ebml_read_chunk_header (tf, &c, chunk_size, &id, &element_size);
    if (hdr_len == 0)
      return FALSE;

    g_assert (hdr_len <= chunk_size);
    chunk_size -= hdr_len;

    if (element_size > chunk_size)
      return FALSE;

    GST_DEBUG ("%s %08x, size %" G_GUINT64_FORMAT " / %" G_GUINT64_FORMAT,
        SPACES + sizeof (SPACES) - 1 - (2 * depth), id, element_size,
        hdr_len + element_size);

    if (element_size >= G_MAXUINT32) {
      GST_DEBUG ("Chunk too big for typefinding");
      return FALSE;
    }

    if (!data_scan_ctx_ensure_data (tf, &c, element_size)) {
      GST_DEBUG ("not enough data");
      return FALSE;
    }

    switch (id) {
      case EBML_DOCTYPE:
        if (element_size >= 8 && memcmp (c.data, "matroska", 8) == 0)
          info->doctype = EBML_DOCTYPE_MATROSKA;
        else if (element_size >= 4 && memcmp (c.data, "webm", 4) == 0)
          info->doctype = EBML_DOCTYPE_WEBM;
        break;
      case MATROSKA_SEGMENT:
        GST_LOG ("parsing segment");
        ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1);
        GST_LOG ("parsed segment, done");
        return FALSE;
      case MATROSKA_TRACKS:
        GST_LOG ("parsing tracks");
        info->tracks_ok =
            ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1);
        GST_LOG ("parsed tracks: %s, done (after %" G_GUINT64_FORMAT " bytes)",
            info->tracks_ok ? "ok" : "FAIL", c.offset + element_size);
        return FALSE;
      case MATROSKA_TRACK_ENTRY:
        GST_LOG ("parsing track entry");
        if (!ebml_parse_chunk (tf, &c, id, element_size, info, depth + 1))
          return FALSE;
        break;
      case MATROSKA_TRACK_TYPE:{
        guint type = 0, i;

        /* is supposed to always be 1-byte, but not everyone's following that */
        for (i = 0; i < element_size; ++i)
          type = (type << 8) | c.data[i];

        GST_DEBUG ("%s   track type %u",
            SPACES + sizeof (SPACES) - 1 - (2 * depth), type);

        if (type == 1)
          ++info->video;
        else if (c.data[0] == 2)
          ++info->audio;
        else
          ++info->other;
        break;
      }
      case MATROSKA_STEREO_MODE:
        ++info->video_stereo;
        break;
      case MATROSKA_CLUSTER:
        GST_WARNING ("cluster, bailing out (should've found tracks by now)");
        return FALSE;
      default:
        break;
    }
    data_scan_ctx_advance (tf, &c, element_size);
    chunk_size -= element_size;
    ++info->chunks;
  }

  return TRUE;
}

static GstStaticCaps matroska_caps = GST_STATIC_CAPS ("video/x-matroska");

#define MATROSKA_CAPS (gst_static_caps_get(&matroska_caps))
static void
matroska_type_find (GstTypeFind * tf, gpointer ununsed)
{
  GstTypeFindProbability prob;
  GstMatroskaInfo info = { 0, };
  const gchar *type_name;
  DataScanCtx c = { 0, NULL, 0 };
  gboolean is_audio;
  guint64 size;
  guint32 id, hdr_len;

  if (!data_scan_ctx_ensure_data (tf, &c, 64))
    return;

  if (GST_READ_UINT32_BE (c.data) != EBML_HEADER)
    return;

  while (c.offset < EBML_MAX_LEN && data_scan_ctx_ensure_data (tf, &c, 64)) {
    hdr_len = ebml_read_chunk_header (tf, &c, c.size, &id, &size);
    if (hdr_len == 0)
      return;

    GST_INFO ("=== top-level chunk %08x, size %" G_GUINT64_FORMAT
        " / %" G_GUINT64_FORMAT, id, size, size + hdr_len);

    if (!ebml_parse_chunk (tf, &c, id, size, &info, 0))
      break;
    data_scan_ctx_advance (tf, &c, size);
    GST_INFO ("=== done with chunk %08x", id);
    if (id == MATROSKA_SEGMENT)
      break;
  }

  GST_INFO ("audio=%u video=%u other=%u chunks=%u doctype=%d all_tracks=%d",
      info.audio, info.video, info.other, info.chunks, info.doctype,
      info.tracks_ok);

  /* perhaps we should bail out if tracks_ok is FALSE and wait for more data?
   * (we would need new API to signal this properly and prevent other
   * typefinders from taking over the decision then) */
  is_audio = (info.audio > 0 && info.video == 0 && info.other == 0);

  if (info.doctype == EBML_DOCTYPE_WEBM) {
    type_name = (is_audio) ? "audio/webm" : "video/webm";
  } else if (info.video > 0 && info.video_stereo) {
    type_name = "video/x-matroska-3d";
  } else {
    type_name = (is_audio) ? "audio/x-matroska" : "video/x-matroska";
  }

  if (info.doctype == EBML_DOCTYPE_UNKNOWN)
    prob = GST_TYPE_FIND_LIKELY;
  else
    prob = GST_TYPE_FIND_MAXIMUM;

  gst_type_find_suggest_simple (tf, prob, type_name, NULL);
}

/*** application/mxf ***/
static GstStaticCaps mxf_caps = GST_STATIC_CAPS ("application/mxf");

#define MXF_MAX_PROBE_LENGTH (1024 * 64)
#define MXF_CAPS (gst_static_caps_get(&mxf_caps))

/*
 * MXF files start with a header partition pack key of 16 bytes which is defined
 * at SMPTE-377M 6.1. Before this there can be up to 64K of run-in which _must_
 * not contain the partition pack key.
 */
static void
mxf_type_find (GstTypeFind * tf, gpointer ununsed)
{
  static const guint8 partition_pack_key[] =
      { 0x06, 0x0e, 0x2b, 0x34, 0x02, 0x05, 0x01, 0x01, 0x0d, 0x01, 0x02, 0x01,
    0x01
  };
  DataScanCtx c = { 0, NULL, 0 };

  while (c.offset <= MXF_MAX_PROBE_LENGTH) {
    guint i;
    if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 1024)))
      break;

    /* look over in chunks of 1kbytes to avoid too much overhead */

    for (i = 0; i < 1024 - 16; i++) {
      /* Check first byte before calling more expensive memcmp function */
      if (G_UNLIKELY (c.data[i] == 0x06
              && memcmp (c.data + i, partition_pack_key, 13) == 0)) {
        /* Header partition pack? */
        if (c.data[i + 13] != 0x02)
          goto advance;

        /* Partition status */
        if (c.data[i + 14] >= 0x05)
          goto advance;

        /* Reserved, must be 0x00 */
        if (c.data[i + 15] != 0x00)
          goto advance;

        gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, MXF_CAPS);
        return;
      }
    }

  advance:
    data_scan_ctx_advance (tf, &c, 1024 - 16);
  }
}

/*** video/x-dv ***/

static GstStaticCaps dv_caps = GST_STATIC_CAPS ("video/x-dv, "
    "systemstream = (boolean) true");
#define DV_CAPS (gst_static_caps_get(&dv_caps))
static void
dv_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 5);

  /* check for DIF  and DV flag */
  if (data && (data[0] == 0x1f) && (data[1] == 0x07) && (data[2] == 0x00)) {
    const gchar *format;

    if (data[3] & 0x80) {
      format = "PAL";
    } else {
      format = "NTSC";
    }

    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM, "video/x-dv",
        "systemstream", G_TYPE_BOOLEAN, TRUE,
        "format", G_TYPE_STRING, format, NULL);
  }
}


/*** Ogg variants ***/
static GstStaticCaps ogg_caps =
    GST_STATIC_CAPS ("application/ogg;video/ogg;audio/ogg;application/kate");

#define OGG_CAPS (gst_static_caps_get(&ogg_caps))

typedef enum
{
  OGG_AUDIO = 0,
  OGG_VIDEO,
  OGG_KATE,
  OGG_OTHER,
  OGG_SKELETON,
  OGG_ANNODEX,
  OGG_NUM
} GstOggStreamType;

static void
ogganx_type_find (GstTypeFind * tf, gpointer private)
{
  const gchar *media_type;
  DataScanCtx c = { 0, NULL, 0 };
  guint ogg_syncs = 0;
  guint hdr_count[OGG_NUM] = { 0, };
  static const struct
  {
    const gchar marker[10];
    guint8 marker_size;
    GstOggStreamType stream_type;
  } markers[] = {
    {
    "\001vorbis", 7, OGG_AUDIO}, {
    "\200theora", 7, OGG_VIDEO}, {
    "fLaC", 4, OGG_AUDIO}, {
    "\177FLAC", 5, OGG_AUDIO}, {
    "Speex", 5, OGG_AUDIO}, {
    "CMML\0\0\0\0", 8, OGG_OTHER}, {
    "PCM     ", 8, OGG_AUDIO}, {
    "Annodex", 7, OGG_ANNODEX}, {
    "fishead", 7, OGG_SKELETON}, {
    "AnxData", 7, OGG_ANNODEX}, {
    "CELT    ", 8, OGG_AUDIO}, {
    "\200kate\0\0\0", 8, OGG_KATE}, {
    "BBCD\0", 5, OGG_VIDEO}, {
    "OVP80\1\1", 7, OGG_VIDEO}, {
    "OpusHead", 8, OGG_AUDIO}, {
    "\001audio\0\0\0", 9, OGG_AUDIO}, {
    "\001video\0\0\0", 9, OGG_VIDEO}, {
    "\001text\0\0\0", 9, OGG_OTHER}
  };

  while (c.offset < 4096 && data_scan_ctx_ensure_data (tf, &c, 64)) {
    guint size, i;

    if (memcmp (c.data, "OggS", 5) != 0)
      break;

    ++ogg_syncs;

    /* check if BOS */
    if (c.data[5] != 0x02)
      break;

    /* headers should only have one segment */
    if (c.data[26] != 1)
      break;

    size = c.data[27];
    if (size < 8)
      break;

    data_scan_ctx_advance (tf, &c, 28);

    if (!data_scan_ctx_ensure_data (tf, &c, MAX (size, 8)))
      break;

    for (i = 0; i < G_N_ELEMENTS (markers); ++i) {
      if (memcmp (c.data, markers[i].marker, markers[i].marker_size) == 0) {
        ++hdr_count[markers[i].stream_type];
        break;
      }
    }

    if (i == G_N_ELEMENTS (markers)) {
      GST_MEMDUMP ("unknown Ogg stream marker", c.data, size);
      ++hdr_count[OGG_OTHER];
    }

    data_scan_ctx_advance (tf, &c, size);
  }

  if (ogg_syncs == 0)
    return;

  /* We don't bother with annodex types. FIXME: what about XSPF? */
  if (hdr_count[OGG_VIDEO] > 0) {
    media_type = "video/ogg";
  } else if (hdr_count[OGG_AUDIO] > 0) {
    media_type = "audio/ogg";
  } else if (hdr_count[OGG_KATE] > 0 && hdr_count[OGG_OTHER] == 0) {
    media_type = "application/kate";
  } else {
    media_type = "application/ogg";
  }

  GST_INFO ("found %s (audio:%u, video:%u, annodex:%u, skeleton:%u, other:%u)",
      media_type, hdr_count[OGG_AUDIO], hdr_count[OGG_VIDEO],
      hdr_count[OGG_ANNODEX], hdr_count[OGG_SKELETON], hdr_count[OGG_OTHER]);

  gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM, media_type, NULL);
}

/*** audio/x-vorbis ***/
static GstStaticCaps vorbis_caps = GST_STATIC_CAPS ("audio/x-vorbis");

#define VORBIS_CAPS (gst_static_caps_get(&vorbis_caps))
static void
vorbis_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 30);

  if (data) {
    guint blocksize_0;
    guint blocksize_1;

    /* 1 byte packet type (identification=0x01)
       6 byte string "vorbis"
       4 byte vorbis version */
    if (memcmp (data, "\001vorbis\000\000\000\000", 11) != 0)
      return;
    data += 11;
    /* 1 byte channels must be != 0 */
    if (data[0] == 0)
      return;
    data++;
    /* 4 byte samplerate must be != 0 */
    if (GST_READ_UINT32_LE (data) == 0)
      return;
    data += 16;
    /* blocksize checks */
    blocksize_0 = data[0] & 0x0F;
    blocksize_1 = (data[0] & 0xF0) >> 4;
    if (blocksize_0 > blocksize_1)
      return;
    if (blocksize_0 < 6 || blocksize_0 > 13)
      return;
    if (blocksize_1 < 6 || blocksize_1 > 13)
      return;
    data++;
    /* framing bit */
    if ((data[0] & 0x01) != 1)
      return;
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, VORBIS_CAPS);
  }
}

/*** video/x-theora ***/

static GstStaticCaps theora_caps = GST_STATIC_CAPS ("video/x-theora");

#define THEORA_CAPS (gst_static_caps_get(&theora_caps))
static void
theora_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 7);   //42);

  if (data) {
    if (data[0] != 0x80)
      return;
    if (memcmp (&data[1], "theora", 6) != 0)
      return;
    /* FIXME: make this more reliable when specs are out */

    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, THEORA_CAPS);
  }
}

/*** kate ***/
static void
kate_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 64);
  gchar category[16] = { 0, };

  if (G_UNLIKELY (data == NULL))
    return;

  /* see: http://wiki.xiph.org/index.php/OggKate#Format_specification */
  if (G_LIKELY (memcmp (data, "\200kate\0\0\0", 8) != 0))
    return;

  /* make sure we always have a NUL-terminated string */
  memcpy (category, data + 48, 15);
  GST_LOG ("kate category: %s", category);
  /* canonical categories for subtitles: subtitles, spu-subtitles, SUB, K-SPU */
  if (strcmp (category, "subtitles") == 0 || strcmp (category, "SUB") == 0 ||
      strcmp (category, "spu-subtitles") == 0 ||
      strcmp (category, "K-SPU") == 0) {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
        "subtitle/x-kate", NULL);
  } else {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
        "application/x-kate", NULL);
  }
}

/*** WEBVTTT subtitles ***/
static GstStaticCaps webvtt_caps =
GST_STATIC_CAPS ("application/x-subtitle-vtt, parsed=(boolean)false");
#define WEBVTT_CAPS (gst_static_caps_get(&webvtt_caps))

static void
webvtt_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 10);

  if (data == NULL)
    return;

  /* there might be a UTF-8 BOM at the beginning */
  if (memcmp (data, "WEBVTT", 6) != 0 && memcmp (data + 3, "WEBVTT", 6) != 0) {
    return;
  }

  if (data[0] != 'W') {
    if (data[0] != 0xef || data[1] != 0xbb || data[2] != 0xbf)
      return;                   /* Not a UTF-8 BOM */
    data += 3;
  }

  /* After the WEBVTT magic must be one of these chars:
   *   0x20 (space), 0x9 (tab), 0xa (LF) or 0xd (CR) */
  if (data[6] != 0x20 && data[6] != 0x9 && data[6] != 0xa && data[6] != 0xd) {
    return;
  }

  gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, WEBVTT_CAPS);
}

/*** application/x-ogm-video or audio***/

static GstStaticCaps ogmvideo_caps =
GST_STATIC_CAPS ("application/x-ogm-video");
#define OGMVIDEO_CAPS (gst_static_caps_get(&ogmvideo_caps))
static void
ogmvideo_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 9);

  if (data) {
    if (memcmp (data, "\001video\000\000\000", 9) != 0)
      return;
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, OGMVIDEO_CAPS);
  }
}

static GstStaticCaps ogmaudio_caps =
GST_STATIC_CAPS ("application/x-ogm-audio");
#define OGMAUDIO_CAPS (gst_static_caps_get(&ogmaudio_caps))
static void
ogmaudio_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 9);

  if (data) {
    if (memcmp (data, "\001audio\000\000\000", 9) != 0)
      return;
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, OGMAUDIO_CAPS);
  }
}

static GstStaticCaps ogmtext_caps = GST_STATIC_CAPS ("application/x-ogm-text");

#define OGMTEXT_CAPS (gst_static_caps_get(&ogmtext_caps))
static void
ogmtext_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 9);

  if (data) {
    if (memcmp (data, "\001text\000\000\000\000", 9) != 0)
      return;
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, OGMTEXT_CAPS);
  }
}

/*** audio/x-speex ***/

static GstStaticCaps speex_caps = GST_STATIC_CAPS ("audio/x-speex");

#define SPEEX_CAPS (gst_static_caps_get(&speex_caps))
static void
speex_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 80);

  if (data) {
    /* 8 byte string "Speex   "
       24 byte speex version string + int */
    if (memcmp (data, "Speex   ", 8) != 0)
      return;
    data += 32;

    /* 4 byte header size >= 80 */
    if (GST_READ_UINT32_LE (data) < 80)
      return;
    data += 4;

    /* 4 byte sample rate <= 48000 */
    if (GST_READ_UINT32_LE (data) > 48000)
      return;
    data += 4;

    /* currently there are only 3 speex modes. */
    if (GST_READ_UINT32_LE (data) > 3)
      return;
    data += 12;

    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, SPEEX_CAPS);
  }
}

/*** audio/x-celt ***/

static GstStaticCaps celt_caps = GST_STATIC_CAPS ("audio/x-celt");

#define CELT_CAPS (gst_static_caps_get(&celt_caps))
static void
celt_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 8);

  if (data) {
    /* 8 byte string "CELT   " */
    if (memcmp (data, "CELT    ", 8) != 0)
      return;

    /* TODO: Check other values of the CELT header */
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, CELT_CAPS);
  }
}

/*** application/x-ogg-skeleton ***/
static GstStaticCaps ogg_skeleton_caps =
GST_STATIC_CAPS ("application/x-ogg-skeleton, parsed=(boolean)FALSE");
#define OGG_SKELETON_CAPS (gst_static_caps_get(&ogg_skeleton_caps))
static void
oggskel_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 12);

  if (data) {
    /* 8 byte string "fishead\0" for the ogg skeleton stream */
    if (memcmp (data, "fishead\0", 8) != 0)
      return;
    data += 8;

    /* Require that the header contains version 3.0 */
    if (GST_READ_UINT16_LE (data) != 3)
      return;
    data += 2;
    if (GST_READ_UINT16_LE (data) != 0)
      return;

    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, OGG_SKELETON_CAPS);
  }
}

static GstStaticCaps cmml_caps = GST_STATIC_CAPS ("text/x-cmml");

#define CMML_CAPS (gst_static_caps_get(&cmml_caps))
static void
cmml_type_find (GstTypeFind * tf, gpointer private)
{
  /* Header is 12 bytes minimum (though we don't check the minor version */
  const guint8 *data = gst_type_find_peek (tf, 0, 12);

  if (data) {

    /* 8 byte string "CMML\0\0\0\0" for the magic number */
    if (memcmp (data, "CMML\0\0\0\0", 8) != 0)
      return;
    data += 8;

    /* Require that the header contains at least version 2.0 */
    if (GST_READ_UINT16_LE (data) < 2)
      return;

    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, CMML_CAPS);
  }
}

/*** application/x-tar ***/

static GstStaticCaps tar_caps = GST_STATIC_CAPS ("application/x-tar");

#define TAR_CAPS (gst_static_caps_get(&tar_caps))
#define OLDGNU_MAGIC "ustar  "  /* 7 chars and a NUL */
#define NEWGNU_MAGIC "ustar"    /* 5 chars and a NUL */
static void
tar_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 257, 8);

  /* of course we are not certain, but we don't want other typefind funcs
   * to detect formats of files within the tar archive, e.g. mp3s */
  if (data) {
    if (memcmp (data, OLDGNU_MAGIC, 8) == 0) {  /* sic */
      gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, TAR_CAPS);
    } else if (memcmp (data, NEWGNU_MAGIC, 6) == 0 &&   /* sic */
        g_ascii_isdigit (data[6]) && g_ascii_isdigit (data[7])) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, TAR_CAPS);
    }
  }
}

/*** application/x-ar ***/

static GstStaticCaps ar_caps = GST_STATIC_CAPS ("application/x-ar");

#define AR_CAPS (gst_static_caps_get(&ar_caps))
static void
ar_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 24);

  if (data && memcmp (data, "!<arch>", 7) == 0) {
    gint i;

    for (i = 7; i < 24; ++i) {
      if (!g_ascii_isprint (data[i]) && data[i] != '\n') {
        gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, AR_CAPS);
      }
    }

    gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, AR_CAPS);
  }
}

/*** audio/x-au ***/

/* NOTE: we cannot replace this function with TYPE_FIND_REGISTER_START_WITH,
 * as it is only possible to register one typefind factory per 'name'
 * (which is in this case the caps), and the first one would be replaced by
 * the second one. */
static GstStaticCaps au_caps = GST_STATIC_CAPS ("audio/x-au");

#define AU_CAPS (gst_static_caps_get(&au_caps))
static void
au_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  if (data) {
    if (memcmp (data, ".snd", 4) == 0 || memcmp (data, "dns.", 4) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, AU_CAPS);
    }
  }
}


/*** video/x-nuv ***/

/* NOTE: we cannot replace this function with TYPE_FIND_REGISTER_START_WITH,
 * as it is only possible to register one typefind factory per 'name'
 * (which is in this case the caps), and the first one would be replaced by
 * the second one. */
static GstStaticCaps nuv_caps = GST_STATIC_CAPS ("video/x-nuv");

#define NUV_CAPS (gst_static_caps_get(&nuv_caps))
static void
nuv_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 11);

  if (data) {
    if (memcmp (data, "MythTVVideo", 11) == 0
        || memcmp (data, "NuppelVideo", 11) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, NUV_CAPS);
    }
  }
}

/*** audio/x-paris ***/
/* NOTE: do not replace this function with two TYPE_FIND_REGISTER_START_WITH */
static GstStaticCaps paris_caps = GST_STATIC_CAPS ("audio/x-paris");

#define PARIS_CAPS (gst_static_caps_get(&paris_caps))
static void
paris_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 4);

  if (data) {
    if (memcmp (data, " paf", 4) == 0 || memcmp (data, "fap ", 4) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, PARIS_CAPS);
    }
  }
}

/*** audio/x-sbc ***/
static GstStaticCaps sbc_caps = GST_STATIC_CAPS ("audio/x-sbc");
#define SBC_CAPS (gst_static_caps_get(&sbc_caps))

static gsize
sbc_check_header (const guint8 * data, gsize len, guint * rate,
    guint * channels)
{
  static const guint16 sbc_rates[4] = { 16000, 32000, 44100, 48000 };
  static const guint8 sbc_blocks[4] = { 4, 8, 12, 16 };
  guint n_blocks, ch_mode, n_subbands, bitpool;

  if (data[0] != 0x9C || len < 4)
    return 0;

  n_blocks = sbc_blocks[(data[1] >> 4) & 0x03];
  ch_mode = (data[1] >> 2) & 0x03;
  n_subbands = (data[1] & 0x01) ? 8 : 4;
  bitpool = data[2];
  if (bitpool < 2)
    return 0;

  *rate = sbc_rates[(data[1] >> 6) & 0x03];
  *channels = (ch_mode == 0) ? 1 : 2;

  if (ch_mode == 0)
    return 4 + (n_subbands * 1) / 2 + (n_blocks * 1 * bitpool) / 8;
  else if (ch_mode == 1)
    return 4 + (n_subbands * 2) / 2 + (n_blocks * 2 * bitpool) / 8;
  else if (ch_mode == 2)
    return 4 + (n_subbands * 2) / 2 + (n_blocks * bitpool) / 8;
  else if (ch_mode == 3)
    return 4 + (n_subbands * 2) / 2 + (n_subbands + n_blocks * bitpool) / 8;

  return 0;
}

static void
sbc_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data;
  gsize frame_len;
  guint i, rate, channels, offset = 0;

  for (i = 0; i < 10; ++i) {
    data = gst_type_find_peek (tf, offset, 8);
    if (data == NULL)
      return;

    frame_len = sbc_check_header (data, 8, &rate, &channels);
    if (frame_len == 0)
      return;

    offset += frame_len;
  }
  gst_type_find_suggest_simple (tf, GST_TYPE_FIND_POSSIBLE, "audio/x-sbc",
      "rate", G_TYPE_INT, rate, "channels", G_TYPE_INT, channels,
      "parsed", G_TYPE_BOOLEAN, FALSE, NULL);
}

/*** audio/iLBC-sh ***/
/* NOTE: do not replace this function with two TYPE_FIND_REGISTER_START_WITH */
static GstStaticCaps ilbc_caps = GST_STATIC_CAPS ("audio/iLBC-sh");

#define ILBC_CAPS (gst_static_caps_get(&ilbc_caps))
static void
ilbc_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 8);

  if (data) {
    if (memcmp (data, "#!iLBC30", 8) == 0 || memcmp (data, "#!iLBC20", 8) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, ILBC_CAPS);
    }
  }
}

/*** application/x-ms-dos-executable ***/

static GstStaticCaps msdos_caps =
GST_STATIC_CAPS ("application/x-ms-dos-executable");
#define MSDOS_CAPS (gst_static_caps_get(&msdos_caps))
/* see http://www.madchat.org/vxdevl/papers/winsys/pefile/pefile.htm */
static void
msdos_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 64);

  if (data && data[0] == 'M' && data[1] == 'Z' &&
      GST_READ_UINT16_LE (data + 8) == 4) {
    guint32 pe_offset = GST_READ_UINT32_LE (data + 60);

    data = gst_type_find_peek (tf, pe_offset, 2);
    if (data && data[0] == 'P' && data[1] == 'E') {
      gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, MSDOS_CAPS);
    }
  }
}

/*** application/x-mmsh ***/

static GstStaticCaps mmsh_caps = GST_STATIC_CAPS ("application/x-mmsh");

#define MMSH_CAPS gst_static_caps_get(&mmsh_caps)

/* This is to recognise mssh-over-http */
static void
mmsh_type_find (GstTypeFind * tf, gpointer unused)
{
  static const guint8 asf_marker[16] = { 0x30, 0x26, 0xb2, 0x75, 0x8e, 0x66,
    0xcf, 0x11, 0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 0xce, 0x6c
  };

  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 2 + 2 + 4 + 2 + 2 + 16);
  if (data && data[0] == 0x24 && data[1] == 0x48 &&
      GST_READ_UINT16_LE (data + 2) > 2 + 2 + 4 + 2 + 2 + 16 &&
      memcmp (data + 2 + 2 + 4 + 2 + 2, asf_marker, 16) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_LIKELY, MMSH_CAPS);
  }
}

/*** video/x-dirac ***/

/* NOTE: we cannot replace this function with TYPE_FIND_REGISTER_START_WITH,
 * as it is only possible to register one typefind factory per 'name'
 * (which is in this case the caps), and the first one would be replaced by
 * the second one. */
static GstStaticCaps dirac_caps = GST_STATIC_CAPS ("video/x-dirac");

#define DIRAC_CAPS (gst_static_caps_get(&dirac_caps))
static void
dirac_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 8);

  if (data) {
    if (memcmp (data, "BBCD", 4) == 0 || memcmp (data, "KW-DIRAC", 8) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, DIRAC_CAPS);
    }
  }
}

/*** audio/x-tap-tap ***/

/* NOTE: we cannot replace this function with TYPE_FIND_REGISTER_START_WITH,
 * as it is only possible to register one typefind factory per 'name'
 * (which is in this case the caps), and the first one would be replaced by
 * the second one. */
static GstStaticCaps tap_caps = GST_STATIC_CAPS ("audio/x-tap-tap");

#define TAP_CAPS (gst_static_caps_get(&tap_caps))
static void
tap_type_find (GstTypeFind * tf, gpointer unused)
{
  const guint8 *data = gst_type_find_peek (tf, 0, 16);

  if (data) {
    if (memcmp (data, "C64-TAPE-RAW", 12) == 0
        || memcmp (data, "C16-TAPE-RAW", 12) == 0) {
      gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, TAP_CAPS);
    }
  }
}

/*** video/vivo ***/

static GstStaticCaps vivo_caps = GST_STATIC_CAPS ("video/vivo");

#define VIVO_CAPS gst_static_caps_get(&vivo_caps)

static void
vivo_type_find (GstTypeFind * tf, gpointer unused)
{
  static const guint8 vivo_marker[] = { 'V', 'e', 'r', 's', 'i', 'o', 'n',
    ':', 'V', 'i', 'v', 'o', '/'
  };
  const guint8 *data;
  guint hdr_len, pos;

  data = gst_type_find_peek (tf, 0, 1024);
  if (data == NULL || data[0] != 0x00)
    return;

  if ((data[1] & 0x80)) {
    if ((data[2] & 0x80))
      return;
    hdr_len = ((guint) (data[1] & 0x7f)) << 7;
    hdr_len += data[2];
    if (hdr_len > 2048)
      return;
    pos = 3;
  } else {
    hdr_len = data[1];
    pos = 2;
  }

  /* 1008 = 1022 - strlen ("Version:Vivo/") - 1 */
  while (pos < 1008 && data[pos] == '\r' && data[pos + 1] == '\n')
    pos += 2;

  if (memcmp (data + pos, vivo_marker, sizeof (vivo_marker)) == 0) {
    gst_type_find_suggest (tf, GST_TYPE_FIND_MAXIMUM, VIVO_CAPS);
  }
}

/*** XDG MIME typefinder (to avoid false positives mostly) ***/

#ifdef USE_GIO
static void
xdgmime_typefind (GstTypeFind * find, gpointer user_data)
{
  gchar *mimetype;
  gsize length = 16384;
  guint64 tf_length;
  const guint8 *data;
  gchar *tmp;

  if ((tf_length = gst_type_find_get_length (find)) > 0)
    length = MIN (length, tf_length);

  if ((data = gst_type_find_peek (find, 0, length)) == NULL)
    return;

  tmp = g_content_type_guess (NULL, data, length, NULL);
  if (tmp == NULL || g_content_type_is_unknown (tmp)) {
    g_free (tmp);
    return;
  }

  mimetype = g_content_type_get_mime_type (tmp);
  g_free (tmp);

  if (mimetype == NULL)
    return;

  GST_DEBUG ("Got mimetype '%s'", mimetype);

  /* Ignore audio/video types:
   *  - our own typefinders in -base are likely to be better at this
   *    (and if they're not, we really want to fix them, that's why we don't
   *    report xdg-detected audio/video types at all, not even with a low
   *    probability)
   *  - we want to detect GStreamer media types and not MIME types
   *  - the purpose of this xdg mime finder is mainly to prevent false
   *    positives of non-media formats, not to typefind audio/video formats */
  if (g_str_has_prefix (mimetype, "audio/") ||
      g_str_has_prefix (mimetype, "video/")) {
    GST_LOG ("Ignoring audio/video mime type");
    g_free (mimetype);
    return;
  }

  /* Again, we mainly want the xdg typefinding to prevent false-positives on
   * non-media formats, so suggest the type with a probability that trumps
   * uncertain results of our typefinders, but not more than that. */
  GST_LOG ("Suggesting '%s' with probability POSSIBLE", mimetype);
  gst_type_find_suggest_simple (find, GST_TYPE_FIND_POSSIBLE, mimetype, NULL);
  g_free (mimetype);
}
#endif /* USE_GIO */

/*** Windows icon typefinder (to avoid false positives mostly) ***/

static void
windows_icon_typefind (GstTypeFind * find, gpointer user_data)
{
  const guint8 *data;
  gint64 datalen;
  guint16 type, nimages;
  gint32 size, offset;

  datalen = gst_type_find_get_length (find);
  if (datalen < 22)
    return;
  if ((data = gst_type_find_peek (find, 0, 6)) == NULL)
    return;

  /* header - simple and not enough to rely on it alone */
  if (GST_READ_UINT16_LE (data) != 0)
    return;
  type = GST_READ_UINT16_LE (data + 2);
  if (type != 1 && type != 2)
    return;
  nimages = GST_READ_UINT16_LE (data + 4);
  if (nimages == 0)             /* we can assume we can't have an empty image file ? */
    return;

  /* first image */
  if (data[6 + 3] != 0)
    return;
  if (type == 1) {
    guint16 planes = GST_READ_UINT16_LE (data + 6 + 4);
    if (planes > 1)
      return;
  }
  size = GST_READ_UINT32_LE (data + 6 + 8);
  offset = GST_READ_UINT32_LE (data + 6 + 12);
  if (offset < 0 || size <= 0 || size >= datalen || offset >= datalen
      || size + offset > datalen)
    return;

  gst_type_find_suggest_simple (find, GST_TYPE_FIND_NEARLY_CERTAIN,
      "image/x-icon", NULL);
}

/*** WAP WBMP typefinder ***/

static void
wbmp_typefind (GstTypeFind * find, gpointer user_data)
{
  const guint8 *data;
  gint64 datalen;
  guint w, h, size;

  /* http://en.wikipedia.org/wiki/Wireless_Application_Protocol_Bitmap_Format */
  datalen = gst_type_find_get_length (find);
  if (datalen == 0)
    return;

  data = gst_type_find_peek (find, 0, 5);
  if (data == NULL)
    return;

  /* want 0x00 0x00 at start */
  if (*data++ != 0 || *data++ != 0)
    return;

  /* min header size */
  size = 4;

  /* let's assume max width/height is 65536 */
  w = *data++;
  if ((w & 0x80)) {
    w = (w << 8) | *data++;
    if ((w & 0x80))
      return;
    ++size;
    data = gst_type_find_peek (find, 4, 2);
    if (data == NULL)
      return;
  }
  h = *data++;
  if ((h & 0x80)) {
    h = (h << 8) | *data++;
    if ((h & 0x80))
      return;
    ++size;
  }

  if (w == 0 || h == 0)
    return;

  /* now add bitmap size */
  size += h * (GST_ROUND_UP_8 (w) / 8);

  if (datalen == size) {
    gst_type_find_suggest_simple (find, GST_TYPE_FIND_POSSIBLE - 10,
        "image/vnd.wap.wbmp", NULL);
  }
}

/*** DEGAS Atari images (also to avoid false positives, see #625129) ***/
static void
degas_type_find (GstTypeFind * tf, gpointer private)
{
  /* No magic, but it should have a fixed size and a few invalid values */
  /* http://www.fileformat.info/format/atari/spec/6ecf9f6eb5be494284a47feb8a214687/view.htm */
  gint64 len;
  const guint8 *data;
  guint16 resolution;
  int n;

  len = gst_type_find_get_length (tf);
  if (len < 34)                 /* smallest header of the lot */
    return;
  data = gst_type_find_peek (tf, 0, 4);
  if (G_UNLIKELY (data == NULL))
    return;
  resolution = GST_READ_UINT16_BE (data);
  if (len == 32034) {
    /* could be DEGAS */
    if (resolution <= 2)
      gst_type_find_suggest_simple (tf, GST_TYPE_FIND_POSSIBLE + 5,
          "image/x-degas", NULL);
  } else if (len == 32066) {
    /* could be DEGAS Elite */
    if (resolution <= 2) {
      data = gst_type_find_peek (tf, len - 16, 8);
      if (G_UNLIKELY (data == NULL))
        return;
      for (n = 0; n < 4; n++) {
        if (GST_READ_UINT16_BE (data + n * 2) > 2)
          return;
      }
      gst_type_find_suggest_simple (tf, GST_TYPE_FIND_POSSIBLE + 5,
          "image/x-degas", NULL);
    }
  } else if (len >= 66 && len < 32066) {
    /* could be compressed DEGAS Elite, but it's compressed and so we can't rely on size,
       it does have 4 16 bytes values near the end that are 0-2 though. */
    if ((resolution & 0x8000) && (resolution & 0x7fff) <= 2) {
      data = gst_type_find_peek (tf, len - 16, 8);
      if (G_UNLIKELY (data == NULL))
        return;
      for (n = 0; n < 4; n++) {
        if (GST_READ_UINT16_BE (data + n * 2) > 2)
          return;
      }
      gst_type_find_suggest_simple (tf, GST_TYPE_FIND_POSSIBLE + 5,
          "image/x-degas", NULL);
    }
  }
}

/*** y4m ***/

static void
y4m_typefind (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 10);
  if (data != NULL && memcmp (data, "YUV4MPEG2 ", 10) == 0) {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_LIKELY,
        "application/x-yuv4mpeg", "y4mversion", G_TYPE_INT, 2, NULL);
  }
}

/*** DVD ISO images (looks like H.264, see #674069) ***/
static void
dvdiso_type_find (GstTypeFind * tf, gpointer private)
{
  /* 0x8000 bytes of zeros, then "\001CD001" */
  gint64 len;
  const guint8 *data;

  len = gst_type_find_get_length (tf);
  if (len < 0x8006)
    return;
  data = gst_type_find_peek (tf, 0, 0x8006);
  if (G_UNLIKELY (data == NULL))
    return;
  for (len = 0; len < 0x8000; len++)
    if (data[len])
      return;
  /* Can the '1' be anything else ? My three samples all have '1'. */
  if (memcmp (data + 0x8000, "\001CD001", 6))
    return;

  /* May need more inspection, we may be able to demux some of them */
  gst_type_find_suggest_simple (tf, GST_TYPE_FIND_LIKELY,
      "application/octet-stream", NULL);
}

/* SSA/ASS subtitles
 *
 * http://en.wikipedia.org/wiki/SubStation_Alpha
 * http://matroska.org/technical/specs/subtitles/ssa.html
 */
static void
ssa_type_find (GstTypeFind * tf, gpointer private)
{
  const gchar *start, *end, *ver_str, *media_type = NULL;
  const guint8 *data;
  gchar *str, *script_type, *p = NULL;
  gint64 len;

  data = gst_type_find_peek (tf, 0, 32);

  if (data == NULL)
    return;

  /* FIXME: detect utf-16/32 BOM and convert before typefinding the rest */

  /* there might be a UTF-8 BOM at the beginning */
  if (memcmp (data, "[Script Info]", 13) != 0 &&
      memcmp (data + 3, "[Script Info]", 13) != 0) {
    return;
  }

  /* now check if we have SSA or ASS */
  len = gst_type_find_get_length (tf);
  if (len > 8192)
    len = 8192;

  data = gst_type_find_peek (tf, 0, len);
  if (data == NULL)
    return;

  /* skip BOM */
  start = (gchar *) memchr (data, '[', 5);
  g_assert (start);
  len -= (start - (gchar *) data);

  /* ignore anything non-UTF8 for now, in future we might at least allow
   * other UTF variants that are clearly prefixed with the appropriate BOM */
  if (!g_utf8_validate (start, len, &end) && (len - (end - start)) > 6) {
    GST_FIXME ("non-UTF8 SSA/ASS file");
    return;
  }

  /* something at start,  but not a UTF-8 BOM? */
  if (data[0] != '[' && (data[0] != 0xEF || data[1] != 0xBB || data[2] != 0xBF))
    return;

  /* ignore any partial UTF-8 characters at the end */
  len = end - start;

  /* create a NUL-terminated string so it's easier to process it safely */
  str = g_strndup (start, len - 1);
  script_type = strstr (str, "ScriptType:");
  if (script_type != NULL) {
    gdouble version;

    ver_str = script_type + 11;
    while (*ver_str == ' ' || *ver_str == 'v' || *ver_str == 'V')
      ++ver_str;
    version = g_ascii_strtod (ver_str, &p);
    if (version == 4.0 && p != NULL && *p == '+')
      media_type = "application/x-ass";
    else if (version >= 1.0 && version <= 4.0)
      media_type = "application/x-ssa";
  }

  if (media_type == NULL) {
    if (strstr (str, "[v4+ Styles]") || strstr (str, "[V4+ Styles]"))
      media_type = "application/x-ass";
    else if (strstr (str, "[v4 Styles]") || strstr (str, "[V4 Styles]"))
      media_type = "application/x-ssa";
  }

  if (media_type != NULL) {
    gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
        media_type, "parsed", G_TYPE_BOOLEAN, FALSE, NULL);
  } else {
    GST_WARNING ("could not detect SSA/ASS variant");
  }

  g_free (str);
}

/*** application/x-mcc ***/
static GstStaticCaps mcc_caps = GST_STATIC_CAPS ("application/x-mcc");

#define MCC_CAPS gst_static_caps_get(&mcc_caps)

static void
mcc_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 31);

  if (data == NULL)
    return;

  /* MCC files always start with this followed by the version */
  if (memcmp (data, "File Format=MacCaption_MCC V", 28) != 0 ||
      !g_ascii_isdigit (data[28]) || data[29] != '.' ||
      !g_ascii_isdigit (data[30])) {
    return;
  }

  gst_type_find_suggest_simple (tf, GST_TYPE_FIND_MAXIMUM,
      "application/x-mcc", "version", G_TYPE_INT, data[28] - '0', NULL);
}

/*** video/x-pva ***/

static GstStaticCaps pva_caps = GST_STATIC_CAPS ("video/x-pva");

#define PVA_CAPS gst_static_caps_get(&pva_caps)

static void
pva_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 5);

  if (data == NULL)
    return;

  if (data[0] == 'A' && data[1] == 'V' && data[2] < 3 && data[4] == 0x55)
    gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, PVA_CAPS);
}

/*** audio/audible ***/

/* derived from pyaudibletags
 * http://code.google.com/p/pyaudibletags/source/browse/trunk/pyaudibletags.py
 */
static GstStaticCaps aa_caps = GST_STATIC_CAPS ("audio/x-audible");

#define AA_CAPS gst_static_caps_get(&aa_caps)

static void
aa_type_find (GstTypeFind * tf, gpointer private)
{
  const guint8 *data;

  data = gst_type_find_peek (tf, 0, 12);
  if (data == NULL)
    return;

  if (GST_READ_UINT32_BE (data + 4) == 0x57907536) {
    guint64 media_len;

    media_len = gst_type_find_get_length (tf);
    if (media_len > 0 && GST_READ_UINT32_BE (data) == media_len)
      gst_type_find_suggest (tf, GST_TYPE_FIND_NEARLY_CERTAIN, AA_CAPS);
    else
      gst_type_find_suggest (tf, GST_TYPE_FIND_POSSIBLE, AA_CAPS);
  }
}

/*** generic typefind for streams that have some data at a specific position***/
typedef struct
{
  const guint8 *data;
  guint size;
  guint probability;
  GstCaps *caps;
}
GstTypeFindData;

static void
start_with_type_find (GstTypeFind * tf, gpointer private)
{
  GstTypeFindData *start_with = (GstTypeFindData *) private;
  const guint8 *data;

  GST_LOG ("trying to find mime type %s with the first %u bytes of data",
      gst_structure_get_name (gst_caps_get_structure (start_with->caps, 0)),
      start_with->size);
  data = gst_type_find_peek (tf, 0, start_with->size);
  if (data && memcmp (data, start_with->data, start_with->size) == 0) {
    gst_type_find_suggest (tf, start_with->probability, start_with->caps);
  }
}

static void
sw_data_destroy (GstTypeFindData * sw_data)
{
  if (G_LIKELY (sw_data->caps != NULL))
    gst_caps_unref (sw_data->caps);
  g_slice_free (GstTypeFindData, sw_data);
}

#define TYPE_FIND_REGISTER_START_WITH(plugin,name,rank,ext,_data,_size,_probability)\
G_BEGIN_DECLS{                                                          \
  GstTypeFindData *sw_data = g_slice_new (GstTypeFindData);             \
  sw_data->data = (const guint8 *)_data;                                \
  sw_data->size = _size;                                                \
  sw_data->probability = _probability;                                  \
  sw_data->caps = gst_caps_new_empty_simple (name);                     \
  if (!gst_type_find_register (plugin, name, rank, start_with_type_find,\
                     ext, sw_data->caps, sw_data,                       \
                     (GDestroyNotify) (sw_data_destroy))) {             \
    sw_data_destroy (sw_data);                                          \
  }                                                                     \
}G_END_DECLS

/*** same for riff types ***/

static void
riff_type_find (GstTypeFind * tf, gpointer private)
{
  GstTypeFindData *riff_data = (GstTypeFindData *) private;
  const guint8 *data = gst_type_find_peek (tf, 0, 12);

  if (data && (memcmp (data, "RIFF", 4) == 0 || memcmp (data, "AVF0", 4) == 0)) {
    data += 8;
    if (memcmp (data, riff_data->data, 4) == 0)
      gst_type_find_suggest (tf, riff_data->probability, riff_data->caps);
  }
}

#define TYPE_FIND_REGISTER_RIFF(plugin,name,rank,ext,_data)             \
G_BEGIN_DECLS{                                                          \
  GstTypeFindData *sw_data = g_slice_new (GstTypeFindData);             \
  sw_data->data = (gpointer)_data;                                      \
  sw_data->size = 4;                                                    \
  sw_data->probability = GST_TYPE_FIND_MAXIMUM;                         \
  sw_data->caps = gst_caps_new_empty_simple (name);                     \
  if (!gst_type_find_register (plugin, name, rank, riff_type_find,      \
                      ext, sw_data->caps, sw_data,                      \
                      (GDestroyNotify) (sw_data_destroy))) {            \
    sw_data_destroy (sw_data);                                          \
  }                                                                     \
}G_END_DECLS


/*** plugin initialization ***/

#define TYPE_FIND_REGISTER(plugin,name,rank,func,ext,caps,priv,notify) \
G_BEGIN_DECLS{\
  if (!gst_type_find_register (plugin, name, rank, func, ext, caps, priv, notify))\
    return FALSE; \
}G_END_DECLS


static gboolean
plugin_init (GstPlugin * plugin)
{
  /* can't initialize this via a struct as caps can't be statically initialized */

  GST_DEBUG_CATEGORY_INIT (type_find_debug, "typefindfunctions",
      GST_DEBUG_FG_GREEN | GST_DEBUG_BG_RED, "generic type find functions");

  /* note: asx/wax/wmx are XML files, asf doesn't handle them */
  /* must use strings, macros don't accept initializers */
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-ms-asf", GST_RANK_SECONDARY,
      "asf,wm,wma,wmv",
      "\060\046\262\165\216\146\317\021\246\331\000\252\000\142\316\154", 16,
      GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/x-musepack", GST_RANK_PRIMARY,
      musepack_type_find, "mpc,mpp,mp+", MUSEPACK_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-au", GST_RANK_MARGINAL,
      au_type_find, "au,snd", AU_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_RIFF (plugin, "video/x-msvideo", GST_RANK_PRIMARY,
      "avi", "AVI ");
  TYPE_FIND_REGISTER_RIFF (plugin, "audio/qcelp", GST_RANK_PRIMARY,
      "qcp", "QLCM");
  TYPE_FIND_REGISTER_RIFF (plugin, "video/x-cdxa", GST_RANK_PRIMARY,
      "dat", "CDXA");
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-vcd", GST_RANK_PRIMARY,
      "dat", "\000\377\377\377\377\377\377\377\377\377\377\000", 12,
      GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-imelody", GST_RANK_PRIMARY,
      "imy,ime,imelody", "BEGIN:IMELODY", 13, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-scc", GST_RANK_PRIMARY,
      "scc", "Scenarist_SCC V1.0", 18, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "application/x-mcc", GST_RANK_PRIMARY,
      mcc_type_find, "mcc", MCC_CAPS, NULL, NULL);

#if 0
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-smoke", GST_RANK_PRIMARY,
      NULL, "\x80smoke\x00\x01\x00", 6, GST_TYPE_FIND_MAXIMUM);
#endif
  TYPE_FIND_REGISTER (plugin, "audio/midi", GST_RANK_PRIMARY, mid_type_find,
      "mid,midi", MID_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_RIFF (plugin, "audio/riff-midi", GST_RANK_PRIMARY,
      "mid,midi", "RMID");
  TYPE_FIND_REGISTER (plugin, "audio/mobile-xmf", GST_RANK_PRIMARY,
      mxmf_type_find, "mxmf", MXMF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-fli", GST_RANK_MARGINAL, flx_type_find,
      "flc,fli", FLX_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-id3v2", GST_RANK_PRIMARY + 103,
      id3v2_type_find, "mp3,mp2,mp1,mpga,ogg,flac,tta", ID3_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-id3v1", GST_RANK_PRIMARY + 101,
      id3v1_type_find, "mp3,mp2,mp1,mpga,ogg,flac,tta", ID3_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-apetag", GST_RANK_PRIMARY + 102,
      apetag_type_find, "mp3,ape,mpc,wv", APETAG_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-ttafile", GST_RANK_PRIMARY,
      tta_type_find, "tta", TTA_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-mod", GST_RANK_SECONDARY, mod_type_find,
      "669,amf,ams,dbm,digi,dmf,dsm,gdm,far,imf,it,j2b,mdl,med,mod,mt2,mtm,"
      "okt,psm,ptm,sam,s3m,stm,stx,ult,umx,xm", MOD_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/mpeg", GST_RANK_PRIMARY, mp3_type_find,
      "mp3,mp2,mp1,mpga", MP3_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-ac3", GST_RANK_PRIMARY, ac3_type_find,
      "ac3,eac3", AC3_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-dts", GST_RANK_SECONDARY, dts_type_find,
      "dts", DTS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-gsm", GST_RANK_PRIMARY, NULL, "gsm",
      GSM_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/mpeg-sys", GST_RANK_PRIMARY,
      mpeg_sys_type_find, "mpe,mpeg,mpg", MPEG_SYS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/mpegts", GST_RANK_PRIMARY,
      mpeg_ts_type_find, "ts,mts", MPEGTS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/ogg", GST_RANK_PRIMARY,
      ogganx_type_find, "ogg,oga,ogv,ogm,ogx,spx,anx,axa,axv", OGG_CAPS,
      NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/mpeg-elementary", GST_RANK_MARGINAL,
      mpeg_video_stream_type_find, "mpv,mpeg,mpg", MPEG_VIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/mpeg4", GST_RANK_PRIMARY,
      mpeg4_video_type_find, "m4v", MPEG_VIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-h263", GST_RANK_SECONDARY,
      h263_video_type_find, "h263,263", H263_VIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-h264", GST_RANK_PRIMARY,
      h264_video_type_find, "h264,x264,264", H264_VIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-h265", GST_RANK_PRIMARY,
      h265_video_type_find, "h265,x265,265", H265_VIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-nuv", GST_RANK_SECONDARY, nuv_type_find,
      "nuv", NUV_CAPS, NULL, NULL);

  /* ISO formats */
  TYPE_FIND_REGISTER (plugin, "audio/x-m4a", GST_RANK_PRIMARY, m4a_type_find,
      "m4a", M4A_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-3gp", GST_RANK_PRIMARY,
      q3gp_type_find, "3gp", Q3GP_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/quicktime", GST_RANK_PRIMARY,
      qt_type_find, "mov,mp4", QT_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/x-quicktime", GST_RANK_SECONDARY,
      qtif_type_find, "qif,qtif,qti", QTIF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/jp2", GST_RANK_PRIMARY,
      jp2_type_find, "jp2", JP2_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/x-jpc", GST_RANK_PRIMARY,
      jpc_type_find, "jpc,j2k", JPC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/mj2", GST_RANK_PRIMARY,
      jp2_type_find, "mj2", MJ2_CAPS, NULL, NULL);

  TYPE_FIND_REGISTER (plugin, "text/html", GST_RANK_SECONDARY, html_type_find,
      "htm,html", HTML_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/vnd.rn-realmedia",
      GST_RANK_SECONDARY, "ra,ram,rm,rmvb", ".RMF", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-pn-realaudio",
      GST_RANK_SECONDARY, "ra,ram,rm,rmvb", ".ra\375", 4,
      GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "application/x-shockwave-flash",
      GST_RANK_SECONDARY, swf_type_find, "swf,swfl", SWF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/xges",
      GST_RANK_PRIMARY, xges_type_find, "xges", XGES_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/dash+xml",
      GST_RANK_PRIMARY, dash_mpd_type_find, "mpd,MPD", DASH_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/vnd.ms-sstr+xml",
      GST_RANK_PRIMARY, mss_manifest_type_find, NULL, MSS_MANIFEST_CAPS, NULL,
      NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-flv", GST_RANK_SECONDARY,
      "flv", "FLV", 3, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "text/plain", GST_RANK_MARGINAL, utf8_type_find,
      "txt", UTF8_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "text/utf-16", GST_RANK_MARGINAL, utf16_type_find,
      "txt", UTF16_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "text/utf-32", GST_RANK_MARGINAL, utf32_type_find,
      "txt", UTF32_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "text/uri-list", GST_RANK_MARGINAL, uri_type_find,
      "ram", URI_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/itc", GST_RANK_SECONDARY,
      itc_type_find, "itc", ITC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-hls", GST_RANK_MARGINAL,
      hls_type_find, "m3u8", HLS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/sdp", GST_RANK_SECONDARY,
      sdp_type_find, "sdp", SDP_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/smil", GST_RANK_SECONDARY,
      smil_type_find, "smil", SMIL_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/ttml+xml", GST_RANK_SECONDARY,
      ttml_xml_type_find, "ttml+xml", TTML_XML_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/xml", GST_RANK_MARGINAL,
      xml_type_find, "xml", GENERIC_XML_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_RIFF (plugin, "audio/x-wav", GST_RANK_PRIMARY, "wav",
      "WAVE");
  TYPE_FIND_REGISTER (plugin, "audio/x-aiff", GST_RANK_SECONDARY,
      aiff_type_find, "aiff,aif,aifc", AIFF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-svx", GST_RANK_SECONDARY, svx_type_find,
      "iff,svx", SVX_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-paris", GST_RANK_SECONDARY,
      paris_type_find, "paf", PARIS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-nist", GST_RANK_SECONDARY,
      "nist", "NIST", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-voc", GST_RANK_SECONDARY,
      "voc", "Creative", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/x-sds", GST_RANK_SECONDARY, sds_type_find,
      "sds", SDS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-ircam", GST_RANK_SECONDARY,
      ircam_type_find, "sf", IRCAM_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-w64", GST_RANK_SECONDARY,
      "w64", "riff", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-rf64", GST_RANK_PRIMARY,
      "rf64", "RF64", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/x-shorten", GST_RANK_SECONDARY,
      shn_type_find, "shn", SHN_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ape", GST_RANK_SECONDARY,
      ape_type_find, "ape", APE_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/jpeg", GST_RANK_PRIMARY + 15,
      jpeg_type_find, "jpg,jpe,jpeg", JPEG_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/gif", GST_RANK_PRIMARY, "gif",
      "GIF8", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/png", GST_RANK_PRIMARY + 14,
      "png", "\211PNG\015\012\032\012", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "image/bmp", GST_RANK_PRIMARY, bmp_type_find,
      "bmp", BMP_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/tiff", GST_RANK_PRIMARY, tiff_type_find,
      "tif,tiff", TIFF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_RIFF (plugin, "image/webp", GST_RANK_PRIMARY,
      "webp", "WEBP");
  TYPE_FIND_REGISTER (plugin, "image/x-exr", GST_RANK_PRIMARY, exr_type_find,
      "exr", EXR_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/x-portable-pixmap", GST_RANK_SECONDARY,
      pnm_type_find, "pnm,ppm,pgm,pbm", PNM_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-matroska", GST_RANK_PRIMARY,
      matroska_type_find, "mkv,mka,mk3d,webm", MATROSKA_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/mxf", GST_RANK_PRIMARY,
      mxf_type_find, "mxf", MXF_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-mve", GST_RANK_SECONDARY,
      "mve", "Interplay MVE File\032\000\032\000\000\001\063\021", 26,
      GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "video/x-dv", GST_RANK_SECONDARY, dv_type_find,
      "dv,dif", DV_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-amr-nb-sh", GST_RANK_PRIMARY,
      "amr", "#!AMR", 5, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-amr-wb-sh", GST_RANK_PRIMARY,
      "amr", "#!AMR-WB", 7, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/iLBC-sh", GST_RANK_PRIMARY, ilbc_type_find,
      "ilbc", ILBC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-sbc", GST_RANK_MARGINAL, sbc_type_find,
      "sbc", SBC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-sid", GST_RANK_MARGINAL,
      "sid", "PSID", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/x-xcf", GST_RANK_SECONDARY,
      "xcf", "gimp xcf", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-mng", GST_RANK_SECONDARY,
      "mng", "\212MNG\015\012\032\012", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/x-jng", GST_RANK_SECONDARY,
      "jng", "\213JNG\015\012\032\012", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/x-xpixmap", GST_RANK_SECONDARY,
      "xpm", "/* XPM */", 9, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/x-sun-raster",
      GST_RANK_SECONDARY, "ras", "\131\246\152\225", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-bzip",
      GST_RANK_SECONDARY, "bz2", "BZh", 3, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-gzip",
      GST_RANK_SECONDARY, "gz", "\037\213", 2, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/zip", GST_RANK_SECONDARY,
      "zip", "PK\003\004", 4, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-compress",
      GST_RANK_SECONDARY, "Z", "\037\235", 2, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER (plugin, "subtitle/x-kate", GST_RANK_MARGINAL,
      kate_type_find, NULL, NULL, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-subtitle-vtt", GST_RANK_MARGINAL,
      webvtt_type_find, "vtt", WEBVTT_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-flac", GST_RANK_PRIMARY, flac_type_find,
      "flac", FLAC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-vorbis", GST_RANK_PRIMARY,
      vorbis_type_find, NULL, VORBIS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-theora", GST_RANK_PRIMARY,
      theora_type_find, NULL, THEORA_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ogm-video", GST_RANK_PRIMARY,
      ogmvideo_type_find, NULL, OGMVIDEO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ogm-audio", GST_RANK_PRIMARY,
      ogmaudio_type_find, NULL, OGMAUDIO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ogm-text", GST_RANK_PRIMARY,
      ogmtext_type_find, NULL, OGMTEXT_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-speex", GST_RANK_PRIMARY,
      speex_type_find, NULL, SPEEX_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-celt", GST_RANK_PRIMARY, celt_type_find,
      NULL, CELT_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ogg-skeleton", GST_RANK_PRIMARY,
      oggskel_type_find, NULL, OGG_SKELETON_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "text/x-cmml", GST_RANK_PRIMARY, cmml_type_find,
      NULL, CMML_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-executable",
      GST_RANK_MARGINAL, NULL, "\177ELF", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/aac", GST_RANK_SECONDARY, aac_type_find,
      "aac,adts,adif,loas", AAC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-spc", GST_RANK_SECONDARY,
      "spc", "SNES-SPC700 Sound File Data", 27, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "audio/x-wavpack", GST_RANK_SECONDARY,
      wavpack_type_find, "wv,wvp", WAVPACK_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "audio/x-wavpack-correction", GST_RANK_SECONDARY,
      wavpack_type_find, "wvc", WAVPACK_CORRECTION_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-caf", GST_RANK_SECONDARY,
      "caf", "caff\000\001", 6, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER (plugin, "application/postscript", GST_RANK_SECONDARY,
      postscript_type_find, "ps", POSTSCRIPT_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/svg+xml", GST_RANK_SECONDARY,
      svg_type_find, "svg", SVG_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/x-rar",
      GST_RANK_SECONDARY, "rar", "Rar!", 4, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER (plugin, "application/x-tar", GST_RANK_SECONDARY,
      tar_type_find, "tar", TAR_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ar", GST_RANK_SECONDARY,
      ar_type_find, "a", AR_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-ms-dos-executable",
      GST_RANK_SECONDARY, msdos_type_find, "dll,exe,ocx,sys,scr,msstyles,cpl",
      MSDOS_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/x-dirac", GST_RANK_PRIMARY,
      dirac_type_find, NULL, DIRAC_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "multipart/x-mixed-replace", GST_RANK_SECONDARY,
      multipart_type_find, NULL, MULTIPART_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-mmsh", GST_RANK_SECONDARY,
      mmsh_type_find, NULL, MMSH_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "video/vivo", GST_RANK_SECONDARY, vivo_type_find,
      "viv", VIVO_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-nsf", GST_RANK_SECONDARY,
      "nsf", "NESM\x1a", 5, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-gym", GST_RANK_SECONDARY,
      "gym", "GYMX", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-ay", GST_RANK_SECONDARY, "ay",
      "ZXAYEMUL", 8, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-gbs", GST_RANK_SECONDARY,
      "gbs", "GBS\x01", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-vgm", GST_RANK_SECONDARY,
      "vgm", "Vgm\x20", 4, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-sap", GST_RANK_SECONDARY,
      "sap", "SAP\x0d\x0a" "AUTHOR\x20", 12, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "video/x-ivf", GST_RANK_SECONDARY,
      "ivf", "DKIF", 4, GST_TYPE_FIND_NEARLY_CERTAIN);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-kss", GST_RANK_SECONDARY,
      "kss", "KSSX\0", 5, GST_TYPE_FIND_MAXIMUM);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/pdf", GST_RANK_SECONDARY,
      "pdf", "%PDF-", 5, GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/msword",
      GST_RANK_SECONDARY, "doc", "\320\317\021\340\241\261\032\341", 8,
      GST_TYPE_FIND_LIKELY);
  /* Mac OS X .DS_Store files tend to be taken for video/mpeg */
  TYPE_FIND_REGISTER_START_WITH (plugin, "application/octet-stream",
      GST_RANK_SECONDARY, "DS_Store", "\000\000\000\001Bud1", 8,
      GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER_START_WITH (plugin, "image/vnd.adobe.photoshop",
      GST_RANK_SECONDARY, "psd", "8BPS\000\001\000\000\000\000", 10,
      GST_TYPE_FIND_LIKELY);
  TYPE_FIND_REGISTER (plugin, "image/vnd.wap.wbmp", GST_RANK_MARGINAL,
      wbmp_typefind, NULL, NULL, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/x-yuv4mpeg", GST_RANK_SECONDARY,
      y4m_typefind, NULL, NULL, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "image/x-icon", GST_RANK_MARGINAL,
      windows_icon_typefind, NULL, NULL, NULL, NULL);

#ifdef USE_GIO
  TYPE_FIND_REGISTER (plugin, "xdgmime-base", GST_RANK_MARGINAL,
      xdgmime_typefind, NULL, NULL, NULL, NULL);
#endif

  TYPE_FIND_REGISTER (plugin, "image/x-degas", GST_RANK_MARGINAL,
      degas_type_find, NULL, NULL, NULL, NULL);
  TYPE_FIND_REGISTER (plugin, "application/octet-stream", GST_RANK_MARGINAL,
      dvdiso_type_find, NULL, NULL, NULL, NULL);

  TYPE_FIND_REGISTER (plugin, "application/x-ssa", GST_RANK_SECONDARY,
      ssa_type_find, "ssa,ass", NULL, NULL, NULL);

  TYPE_FIND_REGISTER (plugin, "video/x-pva", GST_RANK_SECONDARY,
      pva_type_find, "pva", PVA_CAPS, NULL, NULL);

  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-xi", GST_RANK_SECONDARY,
      "xi", "Extended Instrument: ", 21, GST_TYPE_FIND_MAXIMUM);

  TYPE_FIND_REGISTER (plugin, "audio/audible", GST_RANK_MARGINAL,
      aa_type_find, "aa,aax", AA_CAPS, NULL, NULL);

  TYPE_FIND_REGISTER (plugin, "audio/x-tap-tap", GST_RANK_PRIMARY,
      tap_type_find, "tap", TAP_CAPS, NULL, NULL);
  TYPE_FIND_REGISTER_START_WITH (plugin, "audio/x-tap-dmp",
      GST_RANK_SECONDARY, "dmp", "DC2N-TAP-RAW", 12, GST_TYPE_FIND_LIKELY);

  return TRUE;
}

GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
    GST_VERSION_MINOR,
    typefindfunctions,
    "default typefind functions",
    plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)