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-rw-r--r--lib/libdvben50221/en50221_app_teletext.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/lib/libdvben50221/en50221_app_teletext.c b/lib/libdvben50221/en50221_app_teletext.c
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+++ b/lib/libdvben50221/en50221_app_teletext.c
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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;
+}