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gstreamer/gst-libs/gst/mpegts/gstmpegtssection.c
Sebastian Dröge 57bb47f3f7 mpegtssection: Fix off-by-one in PMT parsing
2016-11-28 20:05:02 +02:00

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/*
* gstmpegtssection.c -
* Copyright (C) 2013 Edward Hervey
* Copyright (C) 2011, Hewlett-Packard Development Company, L.P.
* Copyright (C) 2007 Alessandro Decina
* 2010 Edward Hervey
* Author: Youness Alaoui <youness.alaoui@collabora.co.uk>, Collabora Ltd.
* Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>, Collabora Ltd.
* Author: Edward Hervey <bilboed@bilboed.com>, Collabora Ltd.
*
* Authors:
* Alessandro Decina <alessandro@nnva.org>
* Zaheer Abbas Merali <zaheerabbas at merali dot org>
* Edward Hervey <edward@collabora.com>
*
* 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 <string.h>
#include <stdlib.h>
#include "mpegts.h"
#include "gstmpegts-private.h"
/**
* SECTION:gstmpegts
* @title: Mpeg-ts helper library
* @short_description: Mpeg-ts helper library for plugins and applications
* @include: gst/mpegts/mpegts.h
*/
/**
* SECTION:gstmpegtssection
* @title: Base MPEG-TS sections
* @short_description: Sections for ITU H.222.0 | ISO/IEC 13818-1
* @include: gst/mpegts/mpegts.h
*
* For more details, refer to the ITU H.222.0 or ISO/IEC 13818-1 specifications
* and other specifications mentioned in the documentation.
*/
/*
* TODO
*
* * Check minimum size for section parsing in the various
* gst_mpegts_section_get_<tabld>() methods
*
* * Implement parsing code for
* * BAT
* * CAT
* * TSDT
*/
GST_DEBUG_CATEGORY (gst_mpegts_debug);
static GQuark QUARK_PAT;
static GQuark QUARK_CAT;
static GQuark QUARK_BAT;
static GQuark QUARK_PMT;
static GQuark QUARK_NIT;
static GQuark QUARK_SDT;
static GQuark QUARK_EIT;
static GQuark QUARK_TDT;
static GQuark QUARK_TOT;
static GQuark QUARK_SECTION;
static GType _gst_mpegts_section_type = 0;
#define MPEG_TYPE_TS_SECTION (_gst_mpegts_section_type)
GST_DEFINE_MINI_OBJECT_TYPE (GstMpegtsSection, gst_mpegts_section);
static const guint32 crc_tab[256] = {
0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};
/* _calc_crc32 relicensed to LGPL from fluendo ts demuxer */
guint32
_calc_crc32 (const guint8 * data, guint datalen)
{
gint i;
guint32 crc = 0xffffffff;
for (i = 0; i < datalen; i++) {
crc = (crc << 8) ^ crc_tab[((crc >> 24) ^ *data++) & 0xff];
}
return crc;
}
gpointer
__common_section_checks (GstMpegtsSection * section, guint min_size,
GstMpegtsParseFunc parsefunc, GDestroyNotify destroynotify)
{
gpointer res;
/* Check section is big enough */
if (section->section_length < min_size) {
GST_WARNING
("PID:0x%04x table_id:0x%02x, section too small (Got %d, need at least %d)",
section->pid, section->table_id, section->section_length, min_size);
return NULL;
}
/* If section has a CRC, check it */
if (!section->short_section
&& (_calc_crc32 (section->data, section->section_length) != 0)) {
GST_WARNING ("PID:0x%04x table_id:0x%02x, Bad CRC on section", section->pid,
section->table_id);
return NULL;
}
/* Finally parse and set the destroy notify */
res = parsefunc (section);
if (res == NULL)
GST_WARNING ("PID:0x%04x table_id:0x%02x, Failed to parse section",
section->pid, section->table_id);
else
section->destroy_parsed = destroynotify;
return res;
}
/*
* GENERIC MPEG-TS SECTION
*/
static void
_gst_mpegts_section_free (GstMpegtsSection * section)
{
GST_DEBUG ("Freeing section type %d", section->section_type);
if (section->cached_parsed && section->destroy_parsed)
section->destroy_parsed (section->cached_parsed);
g_free (section->data);
g_slice_free (GstMpegtsSection, section);
}
static GstMpegtsSection *
_gst_mpegts_section_copy (GstMpegtsSection * section)
{
GstMpegtsSection *copy;
copy = g_slice_new0 (GstMpegtsSection);
gst_mini_object_init (GST_MINI_OBJECT_CAST (copy), 0, MPEG_TYPE_TS_SECTION,
(GstMiniObjectCopyFunction) _gst_mpegts_section_copy, NULL,
(GstMiniObjectFreeFunction) _gst_mpegts_section_free);
copy->section_type = section->section_type;
copy->pid = section->pid;
copy->table_id = section->table_id;
copy->subtable_extension = section->subtable_extension;
copy->version_number = section->version_number;
copy->current_next_indicator = section->current_next_indicator;
copy->section_number = section->section_number;
copy->last_section_number = section->last_section_number;
copy->crc = section->crc;
copy->data = g_memdup (section->data, section->section_length);
copy->section_length = section->section_length;
/* Note: We do not copy the cached parsed item, it will be
* reconstructed on that copy */
copy->cached_parsed = NULL;
copy->offset = section->offset;
copy->short_section = section->short_section;
return copy;
}
/**
* gst_mpegts_section_get_data:
* @section: a #GstMpegtsSection
*
* Gets the original unparsed section data.
*
* Returns: (transfer full): The original unparsed section data.
*/
GBytes *
gst_mpegts_section_get_data (GstMpegtsSection * section)
{
return g_bytes_new (section->data, section->section_length);
}
/**
* gst_message_parse_mpegts_section:
* @message: a #GstMessage
*
* Returns the #GstMpegtsSection contained in a message.
*
* Returns: (transfer full): the contained #GstMpegtsSection, or %NULL.
*/
GstMpegtsSection *
gst_message_parse_mpegts_section (GstMessage * message)
{
const GstStructure *st;
GstMpegtsSection *section;
if (message->type != GST_MESSAGE_ELEMENT)
return NULL;
st = gst_message_get_structure (message);
/* FIXME : Add checks against know section names */
if (!gst_structure_id_get (st, QUARK_SECTION, GST_TYPE_MPEGTS_SECTION,
&section, NULL))
return NULL;
return section;
}
static GstStructure *
_mpegts_section_get_structure (GstMpegtsSection * section)
{
GstStructure *st;
GQuark quark;
switch (section->section_type) {
case GST_MPEGTS_SECTION_PAT:
quark = QUARK_PAT;
break;
case GST_MPEGTS_SECTION_PMT:
quark = QUARK_PMT;
break;
case GST_MPEGTS_SECTION_CAT:
quark = QUARK_CAT;
break;
case GST_MPEGTS_SECTION_EIT:
quark = QUARK_EIT;
break;
case GST_MPEGTS_SECTION_BAT:
quark = QUARK_BAT;
break;
case GST_MPEGTS_SECTION_NIT:
quark = QUARK_NIT;
break;
case GST_MPEGTS_SECTION_SDT:
quark = QUARK_SDT;
break;
case GST_MPEGTS_SECTION_TDT:
quark = QUARK_TDT;
break;
case GST_MPEGTS_SECTION_TOT:
quark = QUARK_TOT;
break;
default:
GST_DEBUG ("Creating structure for unknown GstMpegtsSection");
quark = QUARK_SECTION;
break;
}
st = gst_structure_new_id (quark, QUARK_SECTION, MPEG_TYPE_TS_SECTION,
section, NULL);
return st;
}
/**
* gst_message_new_mpegts_section:
* @parent: (transfer none): The creator of the message
* @section: (transfer none): The #GstMpegtsSection to put in a message
*
* Creates a new #GstMessage for a @GstMpegtsSection.
*
* Returns: (transfer full): The new #GstMessage to be posted, or %NULL if the
* section is not valid.
*/
GstMessage *
gst_message_new_mpegts_section (GstObject * parent, GstMpegtsSection * section)
{
GstMessage *msg;
GstStructure *st;
st = _mpegts_section_get_structure (section);
msg = gst_message_new_element (parent, st);
return msg;
}
static GstEvent *
_mpegts_section_get_event (GstMpegtsSection * section)
{
GstStructure *structure;
GstEvent *event;
structure = _mpegts_section_get_structure (section);
event = gst_event_new_custom (GST_EVENT_CUSTOM_DOWNSTREAM, structure);
return event;
}
/**
* gst_event_parse_mpegts_section:
* @event: (transfer none): #GstEvent containing a #GstMpegtsSection
*
* Extracts the #GstMpegtsSection contained in the @event #GstEvent
*
* Returns: (transfer full): The extracted #GstMpegtsSection
*/
GstMpegtsSection *
gst_event_parse_mpegts_section (GstEvent * event)
{
const GstStructure *structure;
GstMpegtsSection *section;
structure = gst_event_get_structure (event);
if (!gst_structure_id_get (structure, QUARK_SECTION, MPEG_TYPE_TS_SECTION,
&section, NULL))
return NULL;
return section;
}
/**
* gst_mpegts_section_send_event:
* @element: (transfer none): The #GstElement to send to section event to
* @section: (transfer none): The #GstMpegtsSection to put in the event
*
* Creates a custom #GstEvent with a @GstMpegtsSection.
* The #GstEvent is sent to the @element #GstElement.
*
* Returns: %TRUE if the event is sent
*/
gboolean
gst_mpegts_section_send_event (GstMpegtsSection * section, GstElement * element)
{
GstEvent *event;
g_return_val_if_fail (section != NULL, FALSE);
g_return_val_if_fail (element != NULL, FALSE);
event = _mpegts_section_get_event (section);
if (!gst_element_send_event (element, event)) {
gst_event_unref (event);
return FALSE;
}
return TRUE;
}
static GstMpegtsPatProgram *
_mpegts_pat_program_copy (GstMpegtsPatProgram * orig)
{
return g_slice_dup (GstMpegtsPatProgram, orig);
}
static void
_mpegts_pat_program_free (GstMpegtsPatProgram * orig)
{
g_slice_free (GstMpegtsPatProgram, orig);
}
G_DEFINE_BOXED_TYPE (GstMpegtsPatProgram, gst_mpegts_pat_program,
(GBoxedCopyFunc) _mpegts_pat_program_copy,
(GFreeFunc) _mpegts_pat_program_free);
/* Program Association Table */
static gpointer
_parse_pat (GstMpegtsSection * section)
{
GPtrArray *pat;
guint16 i, nb_programs;
GstMpegtsPatProgram *program;
guint8 *data, *end;
/* Skip already parsed data */
data = section->data + 8;
/* stop at the CRC */
end = section->data + section->section_length;
/* Initialize program list */
nb_programs = (end - 4 - data) / 4;
pat =
g_ptr_array_new_full (nb_programs,
(GDestroyNotify) _mpegts_pat_program_free);
GST_LOG ("nb_programs %u", nb_programs);
for (i = 0; i < nb_programs; i++) {
program = g_slice_new0 (GstMpegtsPatProgram);
program->program_number = GST_READ_UINT16_BE (data);
data += 2;
program->network_or_program_map_PID = GST_READ_UINT16_BE (data) & 0x1FFF;
data += 2;
g_ptr_array_index (pat, i) = program;
}
pat->len = nb_programs;
if (data != end - 4) {
GST_ERROR ("at the end of PAT data != end - 4");
g_ptr_array_unref (pat);
return NULL;
}
return (gpointer) pat;
}
/**
* gst_mpegts_section_get_pat:
* @section: a #GstMpegtsSection of type %GST_MPEGTS_SECTION_PAT
*
* Parses a Program Association Table (ITU H.222.0, ISO/IEC 13818-1).
*
* Returns the array of #GstMpegtsPatProgram contained in the section.
*
* Note: The PAT "transport_id" field corresponds to the "subtable_extension"
* field of the provided @section.
*
* Returns: (transfer container) (element-type GstMpegtsPatProgram): The
* #GstMpegtsPatProgram contained in the section, or %NULL if an error
* happened. Release with #g_ptr_array_unref when done.
*/
GPtrArray *
gst_mpegts_section_get_pat (GstMpegtsSection * section)
{
g_return_val_if_fail (section->section_type == GST_MPEGTS_SECTION_PAT, NULL);
g_return_val_if_fail (section->cached_parsed || section->data, NULL);
if (!section->cached_parsed)
section->cached_parsed =
__common_section_checks (section, 12, _parse_pat,
(GDestroyNotify) g_ptr_array_unref);
if (section->cached_parsed)
return g_ptr_array_ref ((GPtrArray *) section->cached_parsed);
return NULL;
}
/**
* gst_mpegts_pat_new:
*
* Allocates a new #GPtrArray for #GstMpegtsPatProgram
*
* Returns: (transfer full) (element-type GstMpegtsPatProgram): A newly allocated #GPtrArray
*/
GPtrArray *
gst_mpegts_pat_new (void)
{
GPtrArray *pat;
pat = g_ptr_array_new_with_free_func (
(GDestroyNotify) _mpegts_pat_program_free);
return pat;
}
/**
* gst_mpegts_pat_program_new:
*
* Allocates a new #GstMpegtsPatProgram.
*
* Returns: (transfer full): A newly allocated #GstMpegtsPatProgram
*/
GstMpegtsPatProgram *
gst_mpegts_pat_program_new (void)
{
GstMpegtsPatProgram *program;
program = g_slice_new0 (GstMpegtsPatProgram);
return program;
}
static gboolean
_packetize_pat (GstMpegtsSection * section)
{
GPtrArray *programs;
guint8 *data;
gsize length;
guint i;
programs = gst_mpegts_section_get_pat (section);
if (programs == NULL)
return FALSE;
/* 8 byte common section fields
4 byte CRC */
length = 12;
/* 2 byte program number
2 byte program/network PID */
length += programs->len * 4;
_packetize_common_section (section, length);
data = section->data + 8;
for (i = 0; i < programs->len; i++) {
GstMpegtsPatProgram *program;
program = g_ptr_array_index (programs, i);
/* program_number - 16 bit uimsbf */
GST_WRITE_UINT16_BE (data, program->program_number);
data += 2;
/* reserved - 3 bit
program/network_PID - 13 uimsbf */
GST_WRITE_UINT16_BE (data, program->network_or_program_map_PID | 0xE000);
data += 2;
}
g_ptr_array_unref (programs);
return TRUE;
}
/**
* gst_mpegts_section_from_pat:
* @programs: (transfer full) (element-type GstMpegtsPatProgram): an array of #GstMpegtsPatProgram
* @ts_id: Transport stream ID of the PAT
*
* Creates a PAT #GstMpegtsSection from the @programs array of #GstMpegtsPatPrograms
*
* Returns: (transfer full): a #GstMpegtsSection
*/
GstMpegtsSection *
gst_mpegts_section_from_pat (GPtrArray * programs, guint16 ts_id)
{
GstMpegtsSection *section;
section = _gst_mpegts_section_init (0x00,
GST_MTS_TABLE_ID_PROGRAM_ASSOCIATION);
section->subtable_extension = ts_id;
section->cached_parsed = (gpointer) programs;
section->packetizer = _packetize_pat;
section->destroy_parsed = (GDestroyNotify) g_ptr_array_unref;
return section;
}
/* Program Map Table */
static GstMpegtsPMTStream *
_gst_mpegts_pmt_stream_copy (GstMpegtsPMTStream * pmt)
{
GstMpegtsPMTStream *copy;
copy = g_slice_dup (GstMpegtsPMTStream, pmt);
copy->descriptors = g_ptr_array_ref (pmt->descriptors);
return copy;
}
static void
_gst_mpegts_pmt_stream_free (GstMpegtsPMTStream * pmt)
{
if (pmt->descriptors)
g_ptr_array_unref (pmt->descriptors);
g_slice_free (GstMpegtsPMTStream, pmt);
}
G_DEFINE_BOXED_TYPE (GstMpegtsPMTStream, gst_mpegts_pmt_stream,
(GBoxedCopyFunc) _gst_mpegts_pmt_stream_copy,
(GFreeFunc) _gst_mpegts_pmt_stream_free);
static GstMpegtsPMT *
_gst_mpegts_pmt_copy (GstMpegtsPMT * pmt)
{
GstMpegtsPMT *copy;
copy = g_slice_dup (GstMpegtsPMT, pmt);
if (pmt->descriptors)
copy->descriptors = g_ptr_array_ref (pmt->descriptors);
copy->streams = g_ptr_array_ref (pmt->streams);
return copy;
}
static void
_gst_mpegts_pmt_free (GstMpegtsPMT * pmt)
{
if (pmt->descriptors)
g_ptr_array_unref (pmt->descriptors);
if (pmt->streams)
g_ptr_array_unref (pmt->streams);
g_slice_free (GstMpegtsPMT, pmt);
}
G_DEFINE_BOXED_TYPE (GstMpegtsPMT, gst_mpegts_pmt,
(GBoxedCopyFunc) _gst_mpegts_pmt_copy, (GFreeFunc) _gst_mpegts_pmt_free);
static gpointer
_parse_pmt (GstMpegtsSection * section)
{
GstMpegtsPMT *pmt = NULL;
guint i = 0, allocated_streams = 8;
guint8 *data, *end;
guint program_info_length;
guint stream_info_length;
pmt = g_slice_new0 (GstMpegtsPMT);
data = section->data;
end = data + section->section_length;
GST_DEBUG ("Parsing %d Program Map Table", section->subtable_extension);
/* Assign program number from subtable extension,
and skip already parsed data */
pmt->program_number = section->subtable_extension;
data += 8;
pmt->pcr_pid = GST_READ_UINT16_BE (data) & 0x1FFF;
data += 2;
program_info_length = GST_READ_UINT16_BE (data) & 0x0FFF;
data += 2;
/* check that the buffer is large enough to contain at least
* program_info_length bytes + CRC */
if (program_info_length && (data + program_info_length + 4 > end)) {
GST_WARNING ("PID %d invalid program info length %d left %d",
section->pid, program_info_length, (gint) (end - data));
goto error;
}
pmt->descriptors = gst_mpegts_parse_descriptors (data, program_info_length);
if (pmt->descriptors == NULL)
goto error;
data += program_info_length;
pmt->streams =
g_ptr_array_new_full (allocated_streams,
(GDestroyNotify) _gst_mpegts_pmt_stream_free);
/* parse entries, cycle until there's space for another entry (at least 5
* bytes) plus the CRC */
while (data <= end - 4 - 5) {
GstMpegtsPMTStream *stream = g_slice_new0 (GstMpegtsPMTStream);
g_ptr_array_add (pmt->streams, stream);
stream->stream_type = *data++;
GST_DEBUG ("[%d] Stream type 0x%02x found", i, stream->stream_type);
stream->pid = GST_READ_UINT16_BE (data) & 0x1FFF;
data += 2;
stream_info_length = GST_READ_UINT16_BE (data) & 0x0FFF;
data += 2;
if (data + stream_info_length + 4 > end) {
GST_WARNING ("PID %d invalid stream info length %d left %d", section->pid,
stream_info_length, (gint) (end - data));
goto error;
}
stream->descriptors =
gst_mpegts_parse_descriptors (data, stream_info_length);
if (stream->descriptors == NULL)
goto error;
data += stream_info_length;
i += 1;
}
/* Section length was longer than the actual content of the PMT */
if (data < end - 4)
goto error;
/* Ensure we did not read after the end of our array */
g_assert (data == end - 4);
return (gpointer) pmt;
error:
if (pmt)
_gst_mpegts_pmt_free (pmt);
return NULL;
}
/**
* gst_mpegts_section_get_pmt:
* @section: a #GstMpegtsSection of type %GST_MPEGTS_SECTION_PMT
*
* Returns the #GstMpegtsPMT contained in the @section.
*
* Returns: The #GstMpegtsPMT contained in the section, or %NULL if an error
* happened.
*/
const GstMpegtsPMT *
gst_mpegts_section_get_pmt (GstMpegtsSection * section)
{
g_return_val_if_fail (section->section_type == GST_MPEGTS_SECTION_PMT, NULL);
g_return_val_if_fail (section->cached_parsed || section->data, NULL);
if (!section->cached_parsed)
section->cached_parsed =
__common_section_checks (section, 16, _parse_pmt,
(GDestroyNotify) _gst_mpegts_pmt_free);
return (const GstMpegtsPMT *) section->cached_parsed;
}
/**
* gst_mpegts_pmt_new:
*
* Allocates and initializes a new #GstMpegtsPMT.
*
* Returns: (transfer full): #GstMpegtsPMT
*/
GstMpegtsPMT *
gst_mpegts_pmt_new (void)
{
GstMpegtsPMT *pmt;
pmt = g_slice_new0 (GstMpegtsPMT);
pmt->descriptors = g_ptr_array_new_with_free_func ((GDestroyNotify)
gst_mpegts_descriptor_free);
pmt->streams = g_ptr_array_new_with_free_func ((GDestroyNotify)
_gst_mpegts_pmt_stream_free);
return pmt;
}
/**
* gst_mpegts_pmt_stream_new:
*
* Allocates and initializes a new #GstMpegtsPMTStream.
*
* Returns: (transfer full): #GstMpegtsPMTStream
*/
GstMpegtsPMTStream *
gst_mpegts_pmt_stream_new (void)
{
GstMpegtsPMTStream *stream;
stream = g_slice_new0 (GstMpegtsPMTStream);
stream->descriptors = g_ptr_array_new_with_free_func ((GDestroyNotify)
gst_mpegts_descriptor_free);
return stream;
}
static gboolean
_packetize_pmt (GstMpegtsSection * section)
{
const GstMpegtsPMT *pmt;
GstMpegtsPMTStream *stream;
GstMpegtsDescriptor *descriptor;
gsize length, pgm_info_length, stream_length;
guint8 *data;
guint i, j;
pmt = gst_mpegts_section_get_pmt (section);
if (pmt == NULL)
return FALSE;
/* 8 byte common section fields
2 byte PCR pid
2 byte program info length
4 byte CRC */
length = 16;
/* Find length of program info */
pgm_info_length = 0;
if (pmt->descriptors) {
for (i = 0; i < pmt->descriptors->len; i++) {
descriptor = g_ptr_array_index (pmt->descriptors, i);
pgm_info_length += descriptor->length + 2;
}
}
/* Find length of PMT streams */
stream_length = 0;
if (pmt->streams) {
for (i = 0; i < pmt->streams->len; i++) {
stream = g_ptr_array_index (pmt->streams, i);
/* 1 byte stream type
2 byte PID
2 byte ES info length */
stream_length += 5;
if (stream->descriptors) {
for (j = 0; j < stream->descriptors->len; j++) {
descriptor = g_ptr_array_index (stream->descriptors, j);
stream_length += descriptor->length + 2;
}
}
}
}
length += pgm_info_length + stream_length;
_packetize_common_section (section, length);
data = section->data + 8;
/* reserved - 3 bit
PCR_PID - 13 uimsbf */
GST_WRITE_UINT16_BE (data, pmt->pcr_pid | 0xE000);
data += 2;
/* reserved - 4 bit
program_info_length - 12 uimsbf */
GST_WRITE_UINT16_BE (data, pgm_info_length | 0xF000);
data += 2;
_packetize_descriptor_array (pmt->descriptors, &data);
if (pmt->streams) {
guint8 *pos;
for (i = 0; i < pmt->streams->len; i++) {
stream = g_ptr_array_index (pmt->streams, i);
/* stream_type - 8 bit uimsbf */
*data++ = stream->stream_type;
/* reserved - 3 bit
elementary_PID - 13 bit uimsbf */
GST_WRITE_UINT16_BE (data, stream->pid | 0xE000);
data += 2;
/* reserved - 4 bit
ES_info_length - 12 bit uimsbf */
pos = data;
data += 2;
_packetize_descriptor_array (stream->descriptors, &data);
/* Go back and update descriptor length */
GST_WRITE_UINT16_BE (pos, (data - pos - 2) | 0xF000);
}
}
return TRUE;
}
/**
* gst_mpegts_section_from_pmt:
* @pmt: (transfer full): a #GstMpegtsPMT to create a #GstMpegtsSection from
* @pid: The PID that the #GstMpegtsPMT belongs to
*
* Creates a #GstMpegtsSection from @pmt that is bound to @pid
*
* Returns: (transfer full): #GstMpegtsSection
*/
GstMpegtsSection *
gst_mpegts_section_from_pmt (GstMpegtsPMT * pmt, guint16 pid)
{
GstMpegtsSection *section;
g_return_val_if_fail (pmt != NULL, NULL);
section = _gst_mpegts_section_init (pid, GST_MTS_TABLE_ID_TS_PROGRAM_MAP);
section->subtable_extension = pmt->program_number;
section->cached_parsed = (gpointer) pmt;
section->packetizer = _packetize_pmt;
section->destroy_parsed = (GDestroyNotify) _gst_mpegts_pmt_free;
return section;
}
/* Conditional Access Table */
static gpointer
_parse_cat (GstMpegtsSection * section)
{
guint8 *data;
guint desc_len;
/* Skip parts already parsed */
data = section->data + 8;
/* descriptors */
desc_len = section->section_length - 4 - 8;
return (gpointer) gst_mpegts_parse_descriptors (data, desc_len);
}
/**
* gst_mpegts_section_get_cat:
* @section: a #GstMpegtsSection of type %GST_MPEGTS_SECTION_CAT
*
* Returns the array of #GstMpegtsDescriptor contained in the Conditional
* Access Table.
*
* Returns: (transfer container) (element-type GstMpegtsDescriptor): The
* #GstMpegtsDescriptor contained in the section, or %NULL if an error
* happened. Release with #g_array_unref when done.
*/
GPtrArray *
gst_mpegts_section_get_cat (GstMpegtsSection * section)
{
g_return_val_if_fail (section->section_type == GST_MPEGTS_SECTION_CAT, NULL);
g_return_val_if_fail (section->cached_parsed || section->data, NULL);
if (!section->cached_parsed)
section->cached_parsed =
__common_section_checks (section, 12, _parse_cat,
(GDestroyNotify) g_ptr_array_unref);
if (section->cached_parsed)
return g_ptr_array_ref ((GPtrArray *) section->cached_parsed);
return NULL;
}
/* Transport Stream Description Table (TSDT) */
/**
* gst_mpegts_section_get_tsdt:
* @section: a #GstMpegtsSection of type %GST_MPEGTS_SECTION_TSDT
*
* Returns the array of #GstMpegtsDescriptor contained in the section
*
* Returns: (transfer container) (element-type GstMpegtsDescriptor): The
* #GstMpegtsDescriptor contained in the section, or %NULL if an error
* happened. Release with #g_array_unref when done.
*/
GPtrArray *
gst_mpegts_section_get_tsdt (GstMpegtsSection * section)
{
g_return_val_if_fail (section->section_type == GST_MPEGTS_SECTION_TSDT, NULL);
g_return_val_if_fail (section->cached_parsed || section->data, NULL);
if (section->cached_parsed)
return g_ptr_array_ref ((GPtrArray *) section->cached_parsed);
/* FIXME : parse TSDT */
return NULL;
}
/**
* gst_mpegts_initialize:
*
* Initializes the MPEG-TS helper library. Must be called before any
* usage.
*/
void
gst_mpegts_initialize (void)
{
if (_gst_mpegts_section_type)
return;
GST_DEBUG_CATEGORY_INIT (gst_mpegts_debug, "mpegts", 0,
"MPEG-TS helper library");
/* FIXME : Temporary hack to initialize section gtype */
_gst_mpegts_section_type = gst_mpegts_section_get_type ();
QUARK_PAT = g_quark_from_string ("pat");
QUARK_CAT = g_quark_from_string ("cat");
QUARK_PMT = g_quark_from_string ("pmt");
QUARK_NIT = g_quark_from_string ("nit");
QUARK_BAT = g_quark_from_string ("bat");
QUARK_SDT = g_quark_from_string ("sdt");
QUARK_EIT = g_quark_from_string ("eit");
QUARK_TDT = g_quark_from_string ("tdt");
QUARK_TOT = g_quark_from_string ("tot");
QUARK_SECTION = g_quark_from_string ("section");
__initialize_descriptors ();
}
/* FIXME : Later on we might need to use more than just the table_id
* to figure out which type of section this is. */
static GstMpegtsSectionType
_identify_section (guint16 pid, guint8 table_id)
{
switch (table_id) {
case GST_MTS_TABLE_ID_PROGRAM_ASSOCIATION:
if (pid == 0x00)
return GST_MPEGTS_SECTION_PAT;
break;
case GST_MTS_TABLE_ID_CONDITIONAL_ACCESS:
if (pid == 0x01)
return GST_MPEGTS_SECTION_CAT;
break;
case GST_MTS_TABLE_ID_TS_PROGRAM_MAP:
return GST_MPEGTS_SECTION_PMT;
case GST_MTS_TABLE_ID_BOUQUET_ASSOCIATION:
if (pid == 0x0011)
return GST_MPEGTS_SECTION_BAT;
break;
case GST_MTS_TABLE_ID_NETWORK_INFORMATION_ACTUAL_NETWORK:
case GST_MTS_TABLE_ID_NETWORK_INFORMATION_OTHER_NETWORK:
if (pid == 0x0010)
return GST_MPEGTS_SECTION_NIT;
break;
case GST_MTS_TABLE_ID_SERVICE_DESCRIPTION_ACTUAL_TS:
case GST_MTS_TABLE_ID_SERVICE_DESCRIPTION_OTHER_TS:
if (pid == 0x0011)
return GST_MPEGTS_SECTION_SDT;
break;
case GST_MTS_TABLE_ID_TIME_DATE:
if (pid == 0x0014)
return GST_MPEGTS_SECTION_TDT;
break;
case GST_MTS_TABLE_ID_TIME_OFFSET:
if (pid == 0x0014)
return GST_MPEGTS_SECTION_TOT;
break;
case GST_MTS_TABLE_ID_ATSC_TERRESTRIAL_VIRTUAL_CHANNEL:
if (pid == 0x1ffb)
return GST_MPEGTS_SECTION_ATSC_TVCT;
break;
case GST_MTS_TABLE_ID_ATSC_CABLE_VIRTUAL_CHANNEL:
if (pid == 0x1ffb)
return GST_MPEGTS_SECTION_ATSC_CVCT;
break;
case GST_MTS_TABLE_ID_ATSC_MASTER_GUIDE:
if (pid == 0x1ffb)
return GST_MPEGTS_SECTION_ATSC_MGT;
break;
case GST_MTS_TABLE_ID_ATSC_EVENT_INFORMATION:
/* FIXME check pids reported on the MGT to confirm expectations */
return GST_MPEGTS_SECTION_ATSC_EIT;
case GST_MTS_TABLE_ID_ATSC_CHANNEL_OR_EVENT_EXTENDED_TEXT:
/* FIXME check pids reported on the MGT to confirm expectations */
return GST_MPEGTS_SECTION_ATSC_ETT;
/* FIXME : FILL */
case GST_MTS_TABLE_ID_ATSC_SYSTEM_TIME:
if (pid == 0x1ffb)
return GST_MPEGTS_SECTION_ATSC_STT;
break;
default:
/* Handle ranges */
if (table_id >= GST_MTS_TABLE_ID_EVENT_INFORMATION_ACTUAL_TS_PRESENT &&
table_id <= GST_MTS_TABLE_ID_EVENT_INFORMATION_OTHER_TS_SCHEDULE_N) {
if (pid == 0x0012)
return GST_MPEGTS_SECTION_EIT;
}
return GST_MPEGTS_SECTION_UNKNOWN;
}
return GST_MPEGTS_SECTION_UNKNOWN;
}
GstMpegtsSection *
_gst_mpegts_section_init (guint16 pid, guint8 table_id)
{
GstMpegtsSection *section;
section = g_slice_new0 (GstMpegtsSection);
gst_mini_object_init (GST_MINI_OBJECT_CAST (section), 0, MPEG_TYPE_TS_SECTION,
(GstMiniObjectCopyFunction) _gst_mpegts_section_copy, NULL,
(GstMiniObjectFreeFunction) _gst_mpegts_section_free);
section->pid = pid;
section->table_id = table_id;
section->current_next_indicator = TRUE;
section->section_type = _identify_section (pid, table_id);
return section;
}
void
_packetize_common_section (GstMpegtsSection * section, gsize length)
{
guint8 *data;
section->section_length = length;
data = section->data = g_malloc (length);
/* table_id - 8 bit uimsbf */
*data++ = section->table_id;
/* section_syntax_indicator - 1 bit
reserved - 3 bit
section_length - 12 bit uimsbf */
switch (section->section_type) {
case GST_MPEGTS_SECTION_PAT:
case GST_MPEGTS_SECTION_PMT:
case GST_MPEGTS_SECTION_CAT:
case GST_MPEGTS_SECTION_TSDT:
/* Tables from ISO/IEC 13818-1 has a '0' bit
* after the section_syntax_indicator */
GST_WRITE_UINT16_BE (data, (section->section_length - 3) | 0x3000);
break;
default:
GST_WRITE_UINT16_BE (data, (section->section_length - 3) | 0x7000);
}
/* short sections do not contain any further fields */
if (section->short_section)
return;
/* Set section_syntax_indicator bit since we do not have a short section */
*data |= 0x80;
data += 2;
/* subtable_extension - 16 bit uimsbf */
GST_WRITE_UINT16_BE (data, section->subtable_extension);
data += 2;
/* reserved - 2 bit
version_number - 5 bit uimsbf
current_next_indicator - 1 bit */
*data++ = 0xC0 |
((section->version_number & 0x1F) << 1) |
(section->current_next_indicator & 0x01);
/* section_number - 8 bit uimsbf */
*data++ = section->section_number;
/* last_section_number - 8 bit uimsbf */
*data++ = section->last_section_number;
}
/**
* gst_mpegts_section_new:
* @pid: the PID to which this section belongs
* @data: (transfer full): a pointer to the beginning of the section (i.e. the first byte
* should contain the table_id field).
* @data_size: size of the @data argument.
*
* Creates a new #GstMpegtsSection from the provided @data.
*
* Note: Ensuring @data is big enough to contain the full section is the
* responsibility of the caller. If it is not big enough, %NULL will be
* returned.
*
* Note: it is the responsibility of the caller to ensure @data does point
* to the beginning of the section.
*
* Returns: (transfer full): A new #GstMpegtsSection if the data was valid,
* else %NULL
*/
GstMpegtsSection *
gst_mpegts_section_new (guint16 pid, guint8 * data, gsize data_size)
{
GstMpegtsSection *res = NULL;
guint8 tmp;
guint8 table_id;
guint16 section_length = 0;
/* The smallest section ever is 3 bytes */
if (G_UNLIKELY (data_size < 3))
goto short_packet;
/* Check for length */
section_length = GST_READ_UINT16_BE (data + 1) & 0x0FFF;
if (G_UNLIKELY (data_size < section_length + 3))
goto short_packet;
GST_LOG ("data_size:%" G_GSIZE_FORMAT " section_length:%u",
data_size, section_length);
/* Table id is in first byte */
table_id = *data;
res = _gst_mpegts_section_init (pid, table_id);
res->data = data;
/* table_id (already parsed) : 8 bit */
data++;
/* section_syntax_indicator : 1 bit
* other_fields (reserved) : 3 bit*/
res->short_section = (*data & 0x80) == 0x00;
/* section_length (already parsed) : 12 bit */
res->section_length = section_length + 3;
if (!res->short_section) {
/* A long packet needs to be at least 11 bytes long
* _ 3 for the bytes above
* _ 5 for the bytes below
* _ 4 for the CRC */
if (G_UNLIKELY (data_size < 11))
goto bad_long_packet;
/* CRC is after section_length (-4 for the size of the CRC) */
res->crc = GST_READ_UINT32_BE (res->data + res->section_length - 4);
/* Skip to after section_length */
data += 2;
/* subtable extension : 16 bit */
res->subtable_extension = GST_READ_UINT16_BE (data);
data += 2;
/* reserved : 2 bit
* version_number : 5 bit
* current_next_indicator : 1 bit */
tmp = *data++;
res->version_number = tmp >> 1 & 0x1f;
res->current_next_indicator = tmp & 0x01;
/* section_number : 8 bit */
res->section_number = *data++;
/* last_section_number : 8 bit */
res->last_section_number = *data;
}
return res;
short_packet:
{
GST_WARNING
("PID 0x%04x section extends past provided data (got:%" G_GSIZE_FORMAT
", need:%d)", pid, data_size, section_length + 3);
g_free (data);
return NULL;
}
bad_long_packet:
{
GST_WARNING ("PID 0x%04x long section is too short (%" G_GSIZE_FORMAT
" bytes, need at least 11)", pid, data_size);
gst_mpegts_section_unref (res);
return NULL;
}
}
/**
* gst_mpegts_section_packetize:
* @section: (transfer none): the #GstMpegtsSection that holds the data
* @output_size: (out): #gsize to hold the size of the data
*
* If the data in @section has already been packetized, the data pointer is returned
* immediately. Otherwise, the data field is allocated and populated.
*
* Returns: (transfer none): pointer to section data, or %NULL on fail
*/
guint8 *
gst_mpegts_section_packetize (GstMpegtsSection * section, gsize * output_size)
{
guint8 *crc;
g_return_val_if_fail (section != NULL, NULL);
g_return_val_if_fail (output_size != NULL, NULL);
g_return_val_if_fail (section->packetizer != NULL, NULL);
/* Section data has already been packetized */
if (section->data) {
*output_size = section->section_length;
return section->data;
}
if (!section->packetizer (section))
return NULL;
if (!section->short_section) {
/* Update the CRC in the last 4 bytes of the section */
crc = section->data + section->section_length - 4;
GST_WRITE_UINT32_BE (crc, _calc_crc32 (section->data, crc - section->data));
}
*output_size = section->section_length;
return section->data;
}
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