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Diffstat (limited to '')
| -rw-r--r-- | lib/libdvben50221/en50221_app_teletext.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/lib/libdvben50221/en50221_app_teletext.c b/lib/libdvben50221/en50221_app_teletext.c new file mode 100644 index 0000000..b839407 --- /dev/null +++ b/lib/libdvben50221/en50221_app_teletext.c @@ -0,0 +1,141 @@ +/* + 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; +} |