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/* GStreamer
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
*
* 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.
*/
/*#define DEBUG_ENABLED */
#include <gst/gst.h>
#include <string.h> /* memcmp */
static GstCaps* mp3_type_find(GstBuffer *buf, gpointer private);
static GstTypeDefinition mp3type_definitions[] = {
{ "mp3types_audio/x-mp3", "audio/x-mp3", ".mp3 .mp2 .mp1 .mpga", mp3_type_find },
{ NULL, NULL, NULL, NULL },
};
static GstCaps*
mp3_type_find(GstBuffer *buf, gpointer private)
{
guint8 *data;
gint size;
gulong head;
GstCaps *caps;
data = GST_BUFFER_DATA (buf);
size = GST_BUFFER_SIZE (buf);
GST_DEBUG (0,"mp3typefind: typefind");
/* gracefully ripped from libid3 */
if (size >= 3 &&
data[0] == 'T' && data[1] == 'A' && data[2] == 'G') {
/* ID V1 tags */
data += 128;
GST_DEBUG (0, "mp3typefind: detected ID3 Tag V1");
}
else {
if (size >= 10 &&
(data[0] == 'I' && data[1] == 'D' && data[2] == '3') &&
data[3] < 0xff && data[4] < 0xff &&
data[6] < 0x80 && data[7] < 0x80 && data[8] < 0x80 && data[9] < 0x80)
{
guint32 skip = 0;
skip = (skip << 7) | (data[6] & 0x7f);
skip = (skip << 7) | (data[7] & 0x7f);
skip = (skip << 7) | (data[8] & 0x7f);
skip = (skip << 7) | (data[9] & 0x7f);
if (data[0] == 'I') {
/* ID3V2 */
/* footer present? */
if (data[5] & 0x10)
skip += 10;
skip += 10;
}
GST_DEBUG (0, "mp3typefind: detected ID3 Tag V2 with %u bytes", skip);
/* we currently accept a valid ID3 tag as an mp3 as some ID3 tags have invalid
* offsets so the next check might fail */
goto done;
}
}
/* now with the right postion, do typefinding */
head = GULONG_FROM_BE(*((gulong *)data));
if ((head & 0xffe00000) != 0xffe00000)
return NULL;
if (!((head >> 17) & 3))
return NULL;
if (((head >> 12) & 0xf) == 0xf)
return NULL;
if (!((head >> 12) & 0xf))
return NULL;
if (((head >> 10) & 0x3) == 0x3)
return NULL;
done:
caps = gst_caps_new ("mp3_type_find", "audio/x-mp3", NULL);
return caps;
}
static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
gint i=0;
while (mp3type_definitions[i].name) {
GstTypeFactory *type;
type = gst_type_factory_new (&mp3type_definitions[i]);
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (type));
i++;
}
/* gst_info("gsttypes: loaded %d mp3 types\n",i); */
return TRUE;
}
GstPluginDesc plugin_desc = {
GST_VERSION_MAJOR,
GST_VERSION_MINOR,
"mp3types",
plugin_init
};
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