gstreamer/gst/realmedia/rmutils.c
Wim Taymans 3784de031d rmutils: fix byteswapping
fix the byteswapping code that was wrong because of the side effects of the
READ/WRITE macros.

Fixes #599676
2009-10-27 12:33:24 +01:00

142 lines
3.5 KiB
C

/* GStreamer RealMedia utility functions
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "rmutils.h"
gchar *
gst_rm_utils_read_string8 (const guint8 * data, guint datalen,
guint * p_total_len)
{
gint length;
if (p_total_len)
*p_total_len = 0;
if (datalen < 1)
return NULL;
length = GST_READ_UINT8 (data);
if (datalen < (1 + length))
return NULL;
if (p_total_len)
*p_total_len = 1 + length;
return g_strndup ((gchar *) data + 1, length);
}
gchar *
gst_rm_utils_read_string16 (const guint8 * data, guint datalen,
guint * p_total_len)
{
gint length;
if (p_total_len)
*p_total_len = 0;
if (datalen < 2)
return NULL;
length = GST_READ_UINT16_BE (data);
if (datalen < (2 + length))
return NULL;
if (p_total_len)
*p_total_len = 2 + length;
return g_strndup ((gchar *) data + 2, length);
}
GstTagList *
gst_rm_utils_read_tags (const guint8 * data, guint datalen,
GstRmUtilsStringReadFunc read_string_func)
{
const gchar *gst_tags[] = { GST_TAG_TITLE, GST_TAG_ARTIST,
GST_TAG_COPYRIGHT, GST_TAG_COMMENT
};
GstTagList *tags;
guint i;
g_assert (read_string_func != NULL);
GST_DEBUG ("File Content : (CONT) len = %d", datalen);
tags = gst_tag_list_new ();
for (i = 0; i < G_N_ELEMENTS (gst_tags); ++i) {
gchar *str = NULL;
guint total_length = 0;
str = read_string_func (data, datalen, &total_length);
data += total_length;
datalen -= total_length;
if (str != NULL && !g_utf8_validate (str, -1, NULL)) {
const gchar *encoding;
gchar *tmp;
encoding = g_getenv ("GST_TAG_ENCODING");
if (encoding == NULL || *encoding == '\0') {
if (g_get_charset (&encoding))
encoding = "ISO-8859-15";
}
GST_DEBUG ("converting tag from %s to UTF-8", encoding);
tmp = g_convert_with_fallback (str, -1, "UTF-8", encoding, "*",
NULL, NULL, NULL);
g_free (str);
str = tmp;
}
GST_DEBUG ("%s = %s", gst_tags[i], GST_STR_NULL (str));
if (str != NULL && *str != '\0') {
gst_tag_list_add (tags, GST_TAG_MERGE_APPEND, gst_tags[i], str, NULL);
}
g_free (str);
}
if (gst_structure_n_fields ((GstStructure *) tags) > 0)
return tags;
gst_tag_list_free (tags);
return NULL;
}
GstBuffer *
gst_rm_utils_descramble_dnet_buffer (GstBuffer * buf)
{
guint8 *data, *end, tmp;
buf = gst_buffer_make_writable (buf);
/* dnet = byte-order swapped AC3 */
data = GST_BUFFER_DATA (buf);
end = GST_BUFFER_DATA (buf) + GST_BUFFER_SIZE (buf);
while ((data + 1) < end) {
/* byte-swap */
tmp = data[0];
data[0] = data[1];
data[1] = tmp;
data += sizeof (guint16);
}
return buf;
}