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/*
en50221 encoder An implementation for libdvb
an implementation for the en50221 transport layer
Copyright (C) 2004, 2005 Manu Abraham <abraham.manu@gmail.com>
Copyright (C) 2005 Julian Scheel (julian at jusst dot de)
Copyright (C) 2006 Andrew de Quincey (adq_dvb@lidskialf.net)
This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of
the License, or (at your option) any later version.
This program 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser 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
*/
#include <string.h>
#include <libdvbmisc/dvbmisc.h>
#include <pthread.h>
#include "en50221_app_teletext.h"
#include "en50221_app_tags.h"
#include "asn_1.h"
struct en50221_app_teletext {
struct en50221_app_send_functions *funcs;
en50221_app_teletext_callback callback;
void *callback_arg;
pthread_mutex_t lock;
};
static int en50221_app_teletext_parse_ebu(struct en50221_app_teletext *teletext,
uint8_t slot_id,
uint16_t session_number,
uint8_t * data,
uint32_t data_length);
struct en50221_app_teletext *
en50221_app_teletext_create(struct en50221_app_send_functions *funcs)
{
struct en50221_app_teletext *teletext = NULL;
// create structure and set it up
teletext = malloc(sizeof(struct en50221_app_teletext));
if (teletext == NULL) {
return NULL;
}
teletext->funcs = funcs;
teletext->callback = NULL;
pthread_mutex_init(&teletext->lock, NULL);
// done
return teletext;
}
void en50221_app_teletext_destroy(struct en50221_app_teletext *teletext)
{
pthread_mutex_destroy(&teletext->lock);
free(teletext);
}
void en50221_app_teletext_register_callback(struct en50221_app_teletext *teletext,
en50221_app_teletext_callback callback, void *arg)
{
pthread_mutex_lock(&teletext->lock);
teletext->callback = callback;
teletext->callback_arg = arg;
pthread_mutex_unlock(&teletext->lock);
}
int en50221_app_teletext_message(struct en50221_app_teletext *teletext,
uint8_t slot_id,
uint16_t session_number,
uint32_t resource_id,
uint8_t * data, uint32_t data_length)
{
(void) resource_id;
// get the tag
if (data_length < 3) {
print(LOG_LEVEL, ERROR, 1, "Received short data\n");
return -1;
}
uint32_t tag = (data[0] << 16) | (data[1] << 8) | data[2];
switch (tag) {
case TAG_TELETEXT_EBU:
return en50221_app_teletext_parse_ebu(teletext, slot_id,
session_number,
data + 3,
data_length - 3);
}
print(LOG_LEVEL, ERROR, 1, "Received unexpected tag %x\n", tag);
return -1;
}
static int en50221_app_teletext_parse_ebu(struct en50221_app_teletext *teletext,
uint8_t slot_id,
uint16_t session_number,
uint8_t *data,
uint32_t data_length)
{
// first of all, decode the length field
uint16_t asn_data_length;
int length_field_len;
if ((length_field_len = asn_1_decode(&asn_data_length, data, data_length)) < 0) {
print(LOG_LEVEL, ERROR, 1, "ASN.1 decode error\n");
return -1;
}
// check it
if (asn_data_length > (data_length - length_field_len)) {
print(LOG_LEVEL, ERROR, 1, "Received short data\n");
return -1;
}
uint8_t *teletext_data = data + length_field_len;
// tell the app
pthread_mutex_lock(&teletext->lock);
en50221_app_teletext_callback cb = teletext->callback;
void *cb_arg = teletext->callback_arg;
pthread_mutex_unlock(&teletext->lock);
if (cb) {
return cb(cb_arg, slot_id, session_number, teletext_data,
asn_data_length);
}
return 0;
}
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