/* * gstmpegtsdescriptor.c - * Copyright (C) 2013 Edward Hervey * * Authors: * Edward Hervey * * 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. */ #include #include #include "mpegts.h" #include "gstmpegts-private.h" /** * SECTION:gstmpegtsdescriptor * @title: Base MPEG-TS descriptors * @short_description: Descriptors for ITU H.222.0 | ISO/IEC 13818-1 * @include: gst/mpegts/mpegts.h * * These are the base descriptor types and methods. * * For more details, refer to the ITU H.222.0 or ISO/IEC 13818-1 specifications * and other specifications mentionned in the documentation. */ /* FIXME : Move this to proper file once we have a C file for ATSC/ISDB descriptors */ /** * SECTION:gst-atsc-descriptor * @title: ATSC variants of MPEG-TS descriptors * @short_description: Descriptors for the various ATSC specifications * @include: gst/mpegts/mpegts.h * */ /** * SECTION:gst-isdb-descriptor * @title: ISDB variants of MPEG-TS descriptors * @short_description: Descriptors for the various ISDB specifications * @include: gst/mpegts/mpegts.h * */ /* * TODO * * * Add common validation code for data presence and minimum/maximum expected * size. * * Add parsing methods for the following descriptors that were previously * handled in mpegtsbase: * * GST_MTS_DESC_DVB_DATA_BROADCAST_ID * * GST_MTS_DESC_DVB_CAROUSEL_IDENTIFIER * * GST_MTS_DESC_DVB_FREQUENCY_LIST */ #define MAX_KNOWN_ICONV 25 /* First column is the original encoding, * second column is the target encoding */ static GIConv __iconvs[MAX_KNOWN_ICONV][MAX_KNOWN_ICONV]; /* All these conversions will be to UTF8 */ typedef enum { _ICONV_UNKNOWN = -1, _ICONV_ISO8859_1, _ICONV_ISO8859_2, _ICONV_ISO8859_3, _ICONV_ISO8859_4, _ICONV_ISO8859_5, _ICONV_ISO8859_6, _ICONV_ISO8859_7, _ICONV_ISO8859_8, _ICONV_ISO8859_9, _ICONV_ISO8859_10, _ICONV_ISO8859_11, _ICONV_ISO8859_12, _ICONV_ISO8859_13, _ICONV_ISO8859_14, _ICONV_ISO8859_15, _ICONV_UCS_2BE, _ICONV_EUC_KR, _ICONV_GB2312, _ICONV_UTF_16BE, _ICONV_ISO10646_UTF8, _ICONV_ISO6937, _ICONV_UTF8, /* Insert more here if needed */ _ICONV_MAX } LocalIconvCode; static const gchar *iconvtablename[] = { "iso-8859-1", "iso-8859-2", "iso-8859-3", "iso-8859-4", "iso-8859-5", "iso-8859-6", "iso-8859-7", "iso-8859-8", "iso-8859-9", "iso-8859-10", "iso-8859-11", "iso-8859-12", "iso-8859-13", "iso-8859-14", "iso-8859-15", "UCS-2BE", "EUC-KR", "GB2312", "UTF-16BE", "ISO-10646/UTF8", "iso6937", "utf-8" /* Insert more here if needed */ }; void __initialize_descriptors (void) { guint i, j; /* Initialize converters */ /* FIXME : How/when should we close them ??? */ for (i = 0; i < MAX_KNOWN_ICONV; i++) { for (j = 0; j < MAX_KNOWN_ICONV; j++) __iconvs[i][j] = ((GIConv) - 1); } } /* * @text: The text you want to get the encoding from * @start_text: Location where the beginning of the actual text is stored * @is_multibyte: Location where information whether it's a multibyte encoding * or not is stored * @returns: GIconv for conversion or NULL */ static LocalIconvCode get_encoding (const gchar * text, guint * start_text, gboolean * is_multibyte) { LocalIconvCode encoding; guint8 firstbyte; *is_multibyte = FALSE; *start_text = 0; firstbyte = (guint8) text[0]; /* A wrong value */ g_return_val_if_fail (firstbyte != 0x00, _ICONV_UNKNOWN); if (firstbyte <= 0x0B) { /* 0x01 => iso 8859-5 */ encoding = firstbyte + _ICONV_ISO8859_4; *start_text = 1; goto beach; } /* ETSI EN 300 468, "Selection of character table" */ switch (firstbyte) { case 0x0C: case 0x0D: case 0x0E: case 0x0F: /* RESERVED */ encoding = _ICONV_UNKNOWN; break; case 0x10: { guint16 table; table = GST_READ_UINT16_BE (text + 1); if (table < 17) encoding = _ICONV_UNKNOWN + table; else encoding = _ICONV_UNKNOWN;; *start_text = 3; break; } case 0x11: encoding = _ICONV_UCS_2BE; *start_text = 1; *is_multibyte = TRUE; break; case 0x12: /* EUC-KR implements KSX1001 */ encoding = _ICONV_EUC_KR; *start_text = 1; *is_multibyte = TRUE; break; case 0x13: encoding = _ICONV_GB2312; *start_text = 1; break; case 0x14: encoding = _ICONV_UTF_16BE; *start_text = 1; *is_multibyte = TRUE; break; case 0x15: /* TODO : Where does this come from ?? */ encoding = _ICONV_ISO10646_UTF8; *start_text = 1; break; case 0x16: case 0x17: case 0x18: case 0x19: case 0x1A: case 0x1B: case 0x1C: case 0x1D: case 0x1E: case 0x1F: /* RESERVED */ encoding = _ICONV_UNKNOWN; break; default: encoding = _ICONV_ISO6937; break; } beach: GST_DEBUG ("Found encoding %d, first byte is 0x%02x, start_text: %u, is_multibyte: %d", encoding, firstbyte, *start_text, *is_multibyte); return encoding; } static GIConv _get_iconv (LocalIconvCode from, LocalIconvCode to) { if (__iconvs[from][to] == (GIConv) - 1) __iconvs[from][to] = g_iconv_open (iconvtablename[to], iconvtablename[from]); return __iconvs[from][to]; } static void _encode_control_codes (gchar * text, gsize length, gboolean is_multibyte) { gsize pos = 0; while (pos < length) { if (is_multibyte) { guint16 code = GST_READ_UINT16_BE (text + pos); if (code == 0x000A) { text[pos] = 0xE0; text[pos + 1] = 0x8A; } pos += 2; } else { guint8 code = text[pos]; if (code == 0x0A) text[pos] = 0x8A; pos++; } } } /** * dvb_text_from_utf8: * @text: The text to convert. This should be in UTF-8 format * @out_size: (out): the byte length of the new text * * Converts UTF-8 strings to text characters compliant with EN 300 468. * The converted text can be used directly in DVB #GstMpegTsDescriptor * * The function will try different character maps until the string is * completely converted. * * The function tries the default ISO 6937 character map first. * * If no character map that contains all characters could be found, the * string is converted to ISO 6937 with unknown characters set to `?`. * * Returns: (transfer full): byte array of size @out_size */ guint8 * dvb_text_from_utf8 (const gchar * text, gsize * out_size) { GError *error = NULL; gchar *out_text; guint8 *out_buffer; guint encoding; GIConv giconv = (GIConv) - 1; /* We test character maps one-by-one. Start with the default */ encoding = _ICONV_ISO6937; giconv = _get_iconv (_ICONV_UTF8, encoding); out_text = g_convert_with_iconv (text, -1, giconv, NULL, out_size, &error); if (out_text) { GST_DEBUG ("Using default ISO6937 encoding"); goto out; } g_clear_error (&error); for (encoding = _ICONV_ISO8859_1; encoding <= _ICONV_ISO10646_UTF8; encoding++) { giconv = _get_iconv (_ICONV_UTF8, encoding); if (giconv == (GIConv) - 1) continue; out_text = g_convert_with_iconv (text, -1, giconv, NULL, out_size, &error); if (out_text) { GST_DEBUG ("Found suitable character map - %s", iconvtablename[encoding]); goto out; } g_clear_error (&error); } out_text = g_convert_with_fallback (text, -1, iconvtablename[_ICONV_ISO6937], iconvtablename[_ICONV_UTF8], "?", NULL, out_size, &error); out: if (error) { GST_WARNING ("Could not convert from utf-8: %s", error->message); g_error_free (error); if (out_text) g_free (out_text); return NULL; } switch (encoding) { case _ICONV_ISO6937: /* Default encoding contains no selection bytes. */ _encode_control_codes (out_text, *out_size, FALSE); return (guint8 *) out_text; case _ICONV_ISO8859_1: case _ICONV_ISO8859_2: case _ICONV_ISO8859_3: case _ICONV_ISO8859_4: /* These character sets requires 3 selection bytes */ _encode_control_codes (out_text, *out_size, FALSE); out_buffer = g_malloc (*out_size + 3); out_buffer[0] = 0x10; out_buffer[1] = 0x00; out_buffer[2] = encoding - _ICONV_ISO8859_1 + 1; memcpy (out_buffer + 3, out_text, *out_size); *out_size += 3; g_free (out_text); return out_buffer; case _ICONV_ISO8859_5: case _ICONV_ISO8859_6: case _ICONV_ISO8859_7: case _ICONV_ISO8859_8: case _ICONV_ISO8859_9: case _ICONV_ISO8859_10: case _ICONV_ISO8859_11: case _ICONV_ISO8859_12: case _ICONV_ISO8859_13: case _ICONV_ISO8859_14: case _ICONV_ISO8859_15: /* These character sets requires 1 selection byte */ _encode_control_codes (out_text, *out_size, FALSE); out_buffer = g_malloc (*out_size + 1); out_buffer[0] = encoding - _ICONV_ISO8859_5 + 1; memcpy (out_buffer + 1, out_text, *out_size); *out_size += 1; g_free (out_text); return out_buffer; case _ICONV_UCS_2BE: case _ICONV_EUC_KR: case _ICONV_UTF_16BE: /* These character sets requires 1 selection byte */ _encode_control_codes (out_text, *out_size, TRUE); out_buffer = g_malloc (*out_size + 1); out_buffer[0] = encoding - _ICONV_UCS_2BE + 0x11; memcpy (out_buffer + 1, out_text, *out_size); *out_size += 1; g_free (out_text); return out_buffer; case _ICONV_GB2312: case _ICONV_ISO10646_UTF8: /* These character sets requires 1 selection byte */ _encode_control_codes (out_text, *out_size, FALSE); out_buffer = g_malloc (*out_size + 1); out_buffer[0] = encoding - _ICONV_UCS_2BE + 0x11; memcpy (out_buffer + 1, out_text, *out_size); *out_size += 1; g_free (out_text); return out_buffer; default: g_free (out_text); return NULL; } } /* * @text: The text to convert. It may include pango markup ( and ) * @length: The length of the string -1 if it's nul-terminated * @start: Where to start converting in the text * @encoding: The encoding of text * @is_multibyte: Whether the encoding is a multibyte encoding * @error: The location to store the error, or NULL to ignore errors * @returns: UTF-8 encoded string * * Convert text to UTF-8. */ static gchar * convert_to_utf8 (const gchar * text, gint length, guint start, GIConv giconv, gboolean is_multibyte, GError ** error) { gchar *new_text; gchar *tmp, *pos; gint i; text += start; pos = tmp = g_malloc (length * 2); if (is_multibyte) { if (length == -1) { while (*text != '\0') { guint16 code = GST_READ_UINT16_BE (text); switch (code) { case 0xE086: /* emphasis on */ case 0xE087: /* emphasis off */ /* skip it */ break; case 0xE08A:{ pos[0] = 0x00; /* 0x00 0x0A is a new line */ pos[1] = 0x0A; pos += 2; break; } default: pos[0] = text[0]; pos[1] = text[1]; pos += 2; break; } text += 2; } } else { for (i = 0; i < length; i += 2) { guint16 code = GST_READ_UINT16_BE (text); switch (code) { case 0xE086: /* emphasis on */ case 0xE087: /* emphasis off */ /* skip it */ break; case 0xE08A:{ pos[0] = 0x00; /* 0x00 0x0A is a new line */ pos[1] = 0x0A; pos += 2; break; } default: pos[0] = text[0]; pos[1] = text[1]; pos += 2; break; } text += 2; } } } else { if (length == -1) { while (*text != '\0') { guint8 code = (guint8) (*text); switch (code) { case 0x86: /* emphasis on */ case 0x87: /* emphasis off */ /* skip it */ break; case 0x8A: *pos = '\n'; pos += 1; break; default: *pos = *text; pos += 1; break; } text++; } } else { for (i = 0; i < length; i++) { guint8 code = (guint8) (*text); switch (code) { case 0x86: /* emphasis on */ case 0x87: /* emphasis off */ /* skip it */ break; case 0x8A: *pos = '\n'; pos += 1; break; default: *pos = *text; pos += 1; break; } text++; } } } if (pos > tmp) { gsize bread = 0; new_text = g_convert_with_iconv (tmp, pos - tmp, giconv, &bread, NULL, error); GST_DEBUG ("Converted to : %s", new_text); } else { new_text = g_strdup (""); } g_free (tmp); return new_text; } gchar * get_encoding_and_convert (const gchar * text, guint length) { GError *error = NULL; gchar *converted_str; guint start_text = 0; gboolean is_multibyte; LocalIconvCode encoding; GIConv giconv = (GIConv) - 1; g_return_val_if_fail (text != NULL, NULL); if (text == NULL || length == 0) return g_strdup (""); encoding = get_encoding (text, &start_text, &is_multibyte); if (encoding > _ICONV_UNKNOWN && encoding < _ICONV_MAX) { GST_DEBUG ("Encoding %s", iconvtablename[encoding]); giconv = _get_iconv (encoding, _ICONV_UTF8); } else { GST_FIXME ("Could not detect encoding. Returning NULL string"); converted_str = NULL; goto beach; } converted_str = convert_to_utf8 (text, length - start_text, start_text, giconv, is_multibyte, &error); if (error != NULL) { GST_WARNING ("Could not convert string: %s", error->message); if (converted_str) g_free (converted_str); g_error_free (error); error = NULL; if (encoding >= _ICONV_ISO8859_2 && encoding <= _ICONV_ISO8859_15) { /* Sometimes using the standard 8859-1 set fixes issues */ GST_DEBUG ("Encoding %s", iconvtablename[_ICONV_ISO8859_1]); giconv = _get_iconv (_ICONV_ISO8859_1, _ICONV_UTF8); GST_INFO ("Trying encoding ISO 8859-1"); converted_str = convert_to_utf8 (text, length, 1, giconv, FALSE, &error); if (error != NULL) { GST_WARNING ("Could not convert string while assuming encoding ISO 8859-1: %s", error->message); g_error_free (error); goto failed; } } else if (encoding == _ICONV_ISO6937) { /* The first part of ISO 6937 is identical to ISO 8859-9, but * they differ in the second part. Some channels don't * provide the first byte that indicates ISO 8859-9 encoding. * If decoding from ISO 6937 failed, we try ISO 8859-9 here. */ giconv = _get_iconv (_ICONV_ISO8859_9, _ICONV_UTF8); GST_INFO ("Trying encoding ISO 8859-9"); converted_str = convert_to_utf8 (text, length, 0, giconv, FALSE, &error); if (error != NULL) { GST_WARNING ("Could not convert string while assuming encoding ISO 8859-9: %s", error->message); g_error_free (error); goto failed; } } else goto failed; } beach: return converted_str; failed: { text += start_text; return g_strndup (text, length - start_text); } } void _packetize_descriptor_array (GPtrArray * array, guint8 ** out_data) { guint i; guint8 header_size; GstMpegTsDescriptor *descriptor; g_return_if_fail (out_data != NULL); g_return_if_fail (*out_data != NULL); if (array == NULL) return; for (i = 0; i < array->len; i++) { descriptor = g_ptr_array_index (array, i); if (descriptor->tag == GST_MTS_DESC_DVB_EXTENSION) header_size = 3; else header_size = 2; memcpy (*out_data, descriptor->data, descriptor->length + header_size); *out_data += descriptor->length + header_size; } } GstMpegTsDescriptor * _new_descriptor (guint8 tag, guint8 length) { GstMpegTsDescriptor *descriptor; guint8 *data; descriptor = g_slice_new (GstMpegTsDescriptor); descriptor->tag = tag; descriptor->tag_extension = 0; descriptor->length = length; descriptor->data = g_malloc (length + 2); data = descriptor->data; *data++ = descriptor->tag; *data = descriptor->length; return descriptor; } GstMpegTsDescriptor * _new_descriptor_with_extension (guint8 tag, guint8 tag_extension, guint8 length) { GstMpegTsDescriptor *descriptor; guint8 *data; descriptor = g_slice_new (GstMpegTsDescriptor); descriptor->tag = tag; descriptor->tag_extension = tag_extension; descriptor->length = length; descriptor->data = g_malloc (length + 3); data = descriptor->data; *data++ = descriptor->tag; *data++ = descriptor->tag_extension; *data = descriptor->length; return descriptor; } static GstMpegTsDescriptor * _copy_descriptor (GstMpegTsDescriptor * desc) { GstMpegTsDescriptor *copy; copy = g_slice_dup (GstMpegTsDescriptor, desc); copy->data = g_memdup (desc->data, desc->length + 2); return copy; } void _free_descriptor (GstMpegTsDescriptor * desc) { g_free ((gpointer) desc->data); g_slice_free (GstMpegTsDescriptor, desc); } G_DEFINE_BOXED_TYPE (GstMpegTsDescriptor, gst_mpegts_descriptor, (GBoxedCopyFunc) _copy_descriptor, (GBoxedFreeFunc) _free_descriptor); /** * gst_mpegts_parse_descriptors: * @buffer: (transfer none): descriptors to parse * @buf_len: Size of @buffer * * Parses the descriptors present in @buffer and returns them as an * array. * * Note: The data provided in @buffer will not be copied. * * Returns: (transfer full) (element-type GstMpegTsDescriptor): an * array of the parsed descriptors or %NULL if there was an error. * Release with #g_array_unref when done with it. */ GPtrArray * gst_mpegts_parse_descriptors (guint8 * buffer, gsize buf_len) { GPtrArray *res; guint8 length; guint8 *data; guint i, nb_desc = 0; /* fast-path */ if (buf_len == 0) return g_ptr_array_new (); data = buffer; GST_MEMDUMP ("Full descriptor array", buffer, buf_len); while (data - buffer < buf_len) { data++; /* skip tag */ length = *data++; if (data - buffer > buf_len) { GST_WARNING ("invalid descriptor length %d now at %d max %" G_GSIZE_FORMAT, length, (gint) (data - buffer), buf_len); return NULL; } data += length; nb_desc++; } GST_DEBUG ("Saw %d descriptors, read %" G_GSIZE_FORMAT " bytes", nb_desc, data - buffer); if (data - buffer != buf_len) { GST_WARNING ("descriptors size %d expected %" G_GSIZE_FORMAT, (gint) (data - buffer), buf_len); return NULL; } res = g_ptr_array_new_full (nb_desc + 1, (GDestroyNotify) _free_descriptor); data = buffer; for (i = 0; i < nb_desc; i++) { GstMpegTsDescriptor *desc = g_slice_new0 (GstMpegTsDescriptor); desc->data = data; desc->tag = *data++; desc->length = *data++; /* Copy the data now that we known the size */ desc->data = g_memdup (desc->data, desc->length + 2); GST_LOG ("descriptor 0x%02x length:%d", desc->tag, desc->length); GST_MEMDUMP ("descriptor", desc->data + 2, desc->length); /* extended descriptors */ if (G_UNLIKELY (desc->tag == 0x7f)) desc->tag_extension = *data; data += desc->length; /* Set the descriptor in the array */ g_ptr_array_index (res, i) = desc; } res->len = nb_desc; return res; } /** * gst_mpegts_find_descriptor: * @descriptors: (element-type GstMpegTsDescriptor) (transfer none): an array * of #GstMpegTsDescriptor * @tag: the tag to look for * * Finds the first descriptor of type @tag in the array. * * Note: To look for descriptors that can be present more than once in an * array of descriptors, iterate the #GArray manually. * * Returns: (transfer none): the first descriptor matchin @tag, else %NULL. */ const GstMpegTsDescriptor * gst_mpegts_find_descriptor (GPtrArray * descriptors, guint8 tag) { guint i, nb_desc; g_return_val_if_fail (descriptors != NULL, NULL); nb_desc = descriptors->len; for (i = 0; i < nb_desc; i++) { GstMpegTsDescriptor *desc = g_ptr_array_index (descriptors, i); if (desc->tag == tag) return (const GstMpegTsDescriptor *) desc; } return NULL; } /* GST_MTS_DESC_REGISTRATION (0x05) */ /** * gst_mpegts_descriptor_from_registration: * @format_identifier: (transfer none): a 4 character format identifier string * @additional_info: (transfer none) (allow-none): pointer to optional additional info * @additional_info_length: length of the optional @additional_info * * Creates a %GST_MTS_DESC_REGISTRATION #GstMpegTsDescriptor * * Return: #GstMpegTsDescriptor, %NULL on failure */ GstMpegTsDescriptor * gst_mpegts_descriptor_from_registration (const gchar * format_identifier, guint8 * additional_info, gsize additional_info_length) { GstMpegTsDescriptor *descriptor; g_return_val_if_fail (format_identifier != NULL, NULL); descriptor = _new_descriptor (GST_MTS_DESC_REGISTRATION, 4 + additional_info_length); memcpy (descriptor->data + 2, format_identifier, 4); if (additional_info && (additional_info_length > 0)) memcpy (descriptor->data + 6, additional_info, additional_info_length); return descriptor; } /* GST_MTS_DESC_ISO_639_LANGUAGE (0x0A) */ /** * gst_mpegts_descriptor_parse_iso_639_language: * @descriptor: a %GST_MTS_DESC_ISO_639_LANGUAGE #GstMpegTsDescriptor * @res: (out) (transfer none): the #GstMpegTsISO639LanguageDescriptor to fill * * Extracts the iso 639-2 language information from @descriptor. * * Note: Use #gst_tag_get_language_code if you want to get the the * ISO 639-1 language code from the returned ISO 639-2 one. * * Returns: %TRUE if parsing succeeded, else %FALSE. */ gboolean gst_mpegts_descriptor_parse_iso_639_language (const GstMpegTsDescriptor * descriptor, GstMpegTsISO639LanguageDescriptor * res) { guint i; guint8 *data; g_return_val_if_fail (descriptor != NULL && res != NULL, FALSE); /* This descriptor can be empty, no size check needed */ __common_desc_checks (descriptor, GST_MTS_DESC_ISO_639_LANGUAGE, 0, FALSE); data = (guint8 *) descriptor->data + 2; /* Each language is 3 + 1 bytes */ res->nb_language = descriptor->length / 4; for (i = 0; i < res->nb_language; i++) { memcpy (res->language[i], data, 3); res->audio_type[i] = data[3]; data += 4; } return TRUE; } /** * gst_mpegts_descriptor_parse_iso_639_language_idx: * @descriptor: a %GST_MTS_DESC_ISO_639_LANGUAGE #GstMpegTsDescriptor * @idx: Table id of the language to parse * @lang: (out) (transfer none): 4-byte gchar array to hold the language code * @audio_type: (out) (transfer none) (allow-none): the #GstMpegTsIso639AudioType to set * * Extracts the iso 639-2 language information from specific table id in @descriptor. * * Note: Use #gst_tag_get_language_code if you want to get the the * ISO 639-1 language code from the returned ISO 639-2 one. * * Returns: %TRUE if parsing succeeded, else %FALSE. */ gboolean gst_mpegts_descriptor_parse_iso_639_language_idx (const GstMpegTsDescriptor * descriptor, guint idx, gchar (*lang)[4], GstMpegTsIso639AudioType * audio_type) { guint8 *data; g_return_val_if_fail (descriptor != NULL && lang != NULL, FALSE); /* This descriptor can be empty, no size check needed */ __common_desc_checks (descriptor, GST_MTS_DESC_ISO_639_LANGUAGE, 0, FALSE); if (descriptor->length / 4 <= idx) return FALSE; data = (guint8 *) descriptor->data + 2 + idx * 4; memcpy (lang, data, 3); (*lang)[3] = 0; data += 3; if (audio_type) *audio_type = *data; return TRUE; } /** * gst_mpegts_descriptor_parse_iso_639_language_nb: * @descriptor: a %GST_MTS_DESC_ISO_639_LANGUAGE #GstMpegTsDescriptor * * Returns: The number of languages in @descriptor */ guint gst_mpegts_descriptor_parse_iso_639_language_nb (const GstMpegTsDescriptor * descriptor) { g_return_val_if_fail (descriptor != NULL, 0); /* This descriptor can be empty, no size check needed */ __common_desc_checks (descriptor, GST_MTS_DESC_ISO_639_LANGUAGE, 0, FALSE); return descriptor->length / 4; } /** * gst_mpegts_descriptor_parse_logical_channel: * @descriptor: a %GST_MTS_DESC_DTG_LOGICAL_CHANNEL #GstMpegTsDescriptor * @res: (out) (transfer none): the #GstMpegTsLogicalChannelDescriptor to fill * * Extracts the logical channels from @descriptor. * * Returns: %TRUE if parsing succeeded, else %FALSE. */ gboolean gst_mpegts_descriptor_parse_logical_channel (const GstMpegTsDescriptor * descriptor, GstMpegTsLogicalChannelDescriptor * res) { guint i; guint8 *data; g_return_val_if_fail (descriptor != NULL && res != NULL, FALSE); /* This descriptor loop can be empty, no size check required */ __common_desc_checks (descriptor, GST_MTS_DESC_DTG_LOGICAL_CHANNEL, 0, FALSE); data = (guint8 *) descriptor->data + 2; res->nb_channels = descriptor->length / 4; for (i = 0; i < res->nb_channels; i++) { res->channels[i].service_id = GST_READ_UINT16_BE (data); data += 2; res->channels[i].visible_service = *data >> 7; res->channels[i].logical_channel_number = GST_READ_UINT16_BE (data) & 0x03ff; data += 2; } return TRUE; } /** * gst_mpegts_descriptor_from_custom: * @tag: descriptor tag * @data: (transfer none): descriptor data (after tag and length field) * @length: length of @data * * Creates a #GstMpegTsDescriptor with custom @tag and @data * * Returns: #GstMpegTsDescriptor */ GstMpegTsDescriptor * gst_mpegts_descriptor_from_custom (guint8 tag, const guint8 * data, gsize length) { GstMpegTsDescriptor *descriptor; descriptor = _new_descriptor (tag, length); if (data && (length > 0)) memcpy (descriptor->data + 2, data, length); return descriptor; }