mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-30 12:10:37 +00:00
161 lines
3.1 KiB
C
161 lines
3.1 KiB
C
/*
|
|
* 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>
|
|
* Jan Schmidt <thaytan@noraisin.net>
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
#include <gst/gst.h>
|
|
|
|
#include "gstmpegdesc.h"
|
|
|
|
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)
|
|
{
|
|
#ifndef GST_DISABLE_GST_DEBUG
|
|
guint8 tag;
|
|
#endif
|
|
guint8 length;
|
|
|
|
/* need at least 2 bytes for tag and length */
|
|
if (size < 2)
|
|
return 0;
|
|
|
|
#ifndef GST_DISABLE_GST_DEBUG
|
|
tag = *data;
|
|
#endif
|
|
data += 1;
|
|
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)
|
|
{
|
|
gint 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;
|
|
}
|
|
|
|
guint8 *
|
|
gst_mpeg_descriptor_nth (GstMPEGDescriptor * desc, guint i)
|
|
{
|
|
gint 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;
|
|
}
|