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/*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
* License for the specific language governing rights and limitations
* under the License.
*
* The Original Code is Fluendo MPEG Demuxer plugin.
*
* The Initial Developer of the Original Code is Fluendo, S.L.
* Portions created by Fluendo, S.L. are Copyright (C) 2005
* Fluendo, S.L. All Rights Reserved.
*
* Contributor(s): Wim Taymans <wim@fluendo.com>
*
* Alternatively, the contents of this file may be used under the terms of
* the GNU Lesser General Public License Version 2 or later (the "LGPL"),
* in which case the provisions of the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of the MPL or the LGPL.
*/
#include <string.h>
#include <gst/gst.h>
#include "gstmpegdesc.h"
GST_DEBUG_CATEGORY (gstmpegtsdesc_debug);
#define GST_CAT_DEFAULT (gstmpegtsdesc_debug)
void
gst_mpeg_descriptor_free (GstMPEGDescriptor * desc)
{
g_return_if_fail (desc != NULL);
g_free (desc);
}
static guint
gst_mpeg_descriptor_parse_1 (guint8 * data, guint size)
{
guint8 tag;
guint8 length;
/* need at least 2 bytes for tag and length */
if (size < 2)
return 0;
tag = *data++;
length = *data++;
size -= 2;
GST_DEBUG ("tag: 0x%02x, length: %d", tag, length);
if (length > size)
return 0;
return length + 2;;
}
GstMPEGDescriptor *
gst_mpeg_descriptor_parse (guint8 * data, guint size)
{
guint8 *current;
guint consumed, total, n_desc;
GstMPEGDescriptor *result;
g_return_val_if_fail (data != NULL, NULL);
current = data;
total = 0;
n_desc = 0;
do {
consumed = gst_mpeg_descriptor_parse_1 (current, size);
if (consumed > 0) {
current += consumed;
total += consumed;
size -= consumed;
n_desc++;
}
}
while (consumed > 0);
GST_DEBUG ("parsed %d descriptors", n_desc);
if (total == 0)
return NULL;
result = g_malloc (sizeof (GstMPEGDescriptor) + total);
result->n_desc = n_desc;
result->data_length = total;
result->data = ((guint8 *) result) + sizeof (GstMPEGDescriptor);
memcpy (result->data, data, total);
return result;
}
guint
gst_mpeg_descriptor_n_desc (GstMPEGDescriptor * desc)
{
g_return_val_if_fail (desc != NULL, 0);
return desc->n_desc;
}
guint8 *
gst_mpeg_descriptor_find (GstMPEGDescriptor * desc, gint tag)
{
guint8 length;
guint8 *current;
guint size;
g_return_val_if_fail (desc != NULL, NULL);
current = desc->data;
length = desc->data_length;
while (length > 0) {
if (DESC_TAG (current) == tag)
return current;
size = DESC_LENGTH (current) + 2;
current += size;
length -= size;
}
return NULL;
}
/* array needs freeing afterwards */
GArray *
gst_mpeg_descriptor_find_all (GstMPEGDescriptor * desc, gint tag)
{
GArray *all;
guint8 length;
guint8 *current;
guint size;
g_return_val_if_fail (desc != NULL, NULL);
all = g_array_new (TRUE, TRUE, sizeof (guint8 *));
current = desc->data;
length = desc->data_length;
while (length > 0) {
if (DESC_TAG (current) == tag)
g_array_append_val (all, current);
size = DESC_LENGTH (current) + 2;
current += size;
length -= size;
}
GST_DEBUG ("found tag 0x%02x %d times", tag, all->len);
return all;
}
guint8 *
gst_mpeg_descriptor_nth (GstMPEGDescriptor * desc, guint i)
{
guint8 length;
guint8 *current;
guint size;
g_return_val_if_fail (desc != NULL, NULL);
if (i > desc->n_desc)
return NULL;
current = desc->data;
length = desc->data_length;
while (length > 0) {
if (i == 0)
return current;
size = DESC_LENGTH (current) + 2;
current += size;
length -= size;
i--;
}
return NULL;
}
void
gst_mpegtsdesc_init_debug ()
{
GST_DEBUG_CATEGORY_INIT (gstmpegtsdesc_debug, "mpegtsdesc", 0,
"MPEG transport stream parser (descriptor)");
}
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