Examples/DVBAdapter/ULEdec.cc

   1 // $Id$
   2 //
   3 // Copyright (C) 2006
   4 // Fraunhofer Institut fuer offene Kommunikationssysteme (FOKUS)
   5 // Kompetenzzentrum fuer Satelitenkommunikation (SatCom)
   6 //     Stefan Bund <stefan.bund@fokus.fraunhofer.de>
   7 //
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 2 of the License, or
  11 // (at your option) any later version.
  12 //
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the
  20 // Free Software Foundation, Inc.,
  21 // 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  22
  23 // Definition of non-inline non-template functions
  24
  25 #include "ULEdec.hh"
  26
  27 #include "Packets/PacketData.hh"
  28 #include "Utils/hexdump.hh"
  29 #include "Utils/membind.hh"
  30
  31 #define PID 271
  32 #define TS_SYNC 0x47
  33
  34 #define prefix_
  35 ///////////////////////////////cc.p////////////////////////////////////////
  36
  37
  38 ULEdec::ULEdec()
  39 {
  40     struct dmx_pes_filter_params pes_filter;
  41     memset(&pes_filter, 0, sizeof (struct dmx_pes_filter_params));
  42     pes_filter.pid = PID;
  43     pes_filter.input  = DMX_IN_FRONTEND;
  44     pes_filter.output = DMX_OUT_TS_TAP;
  45     pes_filter.pes_type = DMX_PES_OTHER;
  46     pes_filter.flags = DMX_IMMEDIATE_START;
  47     demuxHandle.protocol().setPESFilter( &pes_filter );
  48
  49     senf::Scheduler::instance().add(
  50         dvrHandle, senf::membind(&ULEdec::handleEvent, this));
  51
  52     this->receiver_state = Idle;
  53     this->priv_sndu_type_1 = false;
  54 }
  55
  56 void ULEdec::handleEvent(senf::FileHandle, senf::Scheduler::EventId event)
  57 {
  58     senf::TransportPacket ts_packet (
  59             senf::TransportPacket::create(188, senf::TransportPacket::noinit));
  60     dvrHandle.read( ts_packet.data() );
  61
  62     // Check TS error conditions: sync_byte, transport_error_indicator, scrambling_control.
  63     if ( (ts_packet->sync_byte() != TS_SYNC) ||
  64          (ts_packet->transport_error_indicator() == true) ||
  65          (ts_packet->transport_scrmbl_ctrl() != 0))
  66     {
  67         std::cerr << "invalid ts packet\n";
  68         // drop partly decoded SNDU, reset state, resync on PUSI.
  69         return;
  70     }
  71
  72     handleTSPacket(ts_packet);
  73 }
  74
  75 void ULEdec::handleTSPacket(senf::TransportPacket ts_packet)
  76 {
  77     senf::PacketData & payloadData (ts_packet.next().data());
  78     iterator payload_iter = payloadData.begin();
  79     iterator payload_end = payloadData.end();
  80
  81     std::cout << "New TS Packet:\n"
  82               << "----------------------------------------------------------------------------\n";
  83     senf::hexdump(payload_iter, payload_end, std::cout);
  84     std::cout << "----------------------------------------------------------------------------\n";
  85
  86     // Synchronize continuity counter
  87     this->priv_tscc = ts_packet->continuity_counter();
  88
  89     switch (ts_packet->pusi()) {
  90     case 0: {
  91         switch (this->receiver_state) {
  92         case Idle:
  93             return;
  94         case Reassembly:
  95             payload_iter = readContSNDUPacket( payload_iter, payload_end );
  96             if (isSDNUPacketComplete()) {
  97                 this->receiver_state = Idle;
  98                 try {
  99                     handleSNDUPacket();
 100                 } catch (ULEdecException const & ex) {
 101                     std::cerr << ex.what() << "\n";
 102                     return;
 103                 }
 104                 switch (std::distance( payload_iter, payload_end ))
 105                 case 0:
 106                 case 1:
 107                     return;
 108                 default:
 109                     if ( (*payload_iter++ << 8 | *payload_iter++) != ULE_END_INDICATOR )
 110                         std::cerr << "delimiting error 1\n";
 111             } else {
 112                 BOOST_ASSERT( std::distance( payload_iter, payload_end ) == 0 );
 113             }
 114         }
 115         break;
 116     }
 117     case 1: {
 118         // a PUSI value of 1 indicates the presence of a Payload Pointer.
 119         unsigned char payload_pointer = *payload_iter++;
 120         if (payload_pointer > 181) {
 121             std::cerr << "invalid payload_pointer\n";
 122             this->receiver_state = Idle;
 123             return;
 124         }
 125         switch (this->receiver_state) {
 126         case Idle:
 127             std::advance(payload_iter, payload_pointer);
 128             break;
 129         case Reassembly:
 130             // Reassembly Payload Pointer Checking
 131             if (snduPacketBytesLeft() != payload_pointer) {
 132                 // delimiting error
 133                 std::cerr << "delimiting error 2\n";
 134                 std::advance(payload_iter, payload_pointer);
 135             } else {
 136                 payload_iter = readContSNDUPacket( payload_iter, payload_end );
 137                 BOOST_ASSERT( isSDNUPacketComplete() );
 138                 try {
 139                     handleSNDUPacket();
 140                 } catch (ULEdecException const & ex) {
 141                     std::cerr << ex.what() << "\n";
 142                     this->receiver_state = Idle;
 143                     return;
 144                 }
 145             }
 146         }
 147         this->receiver_state = Idle;
 148         try {
 149             do {
 150                 payload_iter = readNewSNDUPacket( payload_iter, payload_end );
 151                 if (! isSDNUPacketComplete()) {
 152                     BOOST_ASSERT( std::distance( payload_iter, payload_end ) == 0 );
 153                     this->receiver_state = Reassembly;
 154                     break;
 155                 }
 156                 handleSNDUPacket();
 157             } while (std::distance(payload_iter, payload_end) < 2 );
 158         }
 159         catch (ULEdecException const & ex) {
 160             std::cerr << ex.what() << "\n";
 161             return;
 162         }
 163     }
 164
 165     } // end pusi-switch
 166 }
 167
 168
 169 ULEdec::iterator ULEdec::readContSNDUPacket(iterator i, iterator const i_end)
 170 {
 171     if (priv_sndu_type_1) {
 172         this->snduPacket->type() |= *i++;
 173     }
 174     return readRawSNDUPacketData(i, i_end);
 175 }
 176
 177
 178 ULEdec::iterator ULEdec::readNewSNDUPacket(iterator i, iterator const i_end)
 179 {
 180     bool dbit = false;
 181     senf::Packet::size_type sndu_length = *i++ << 8 | *i++;
 182     if (sndu_length & 0x8000) {
 183         sndu_length &= 0x7FFF;
 184         dbit = true;
 185     }
 186     if (sndu_length < 5 || sndu_length == 0xffff) {
 187         throw ULEdecException("SNDU length error");
 188      }
 189     this->snduPacket = senf::SNDUPacket::create(sndu_length+4);
 190     this->snduPacket->d_bit() = dbit;
 191     this->snduPacket->length() = sndu_length;
 192     this->snduPacketData_iter = boost::next(this->snduPacket.data().begin(), 2);
 193     this->priv_sndu_type_1 = false;
 194
 195     switch (std::distance(i, i_end)) {
 196     case 1:
 197         this->priv_sndu_type_1 = true;
 198         this->snduPacket->type() = *i++ << 8;
 199         this->snduPacketData_iter++;
 200     case 0:
 201         break;
 202
 203     default:
 204         this->snduPacket->type() = *i++ << 8 | *i++;
 205         std::advance(this->snduPacketData_iter, 2);
 206         i = readRawSNDUPacketData(i, i_end);
 207     }
 208
 209     return i;
 210 }
 211
 212
 213 ULEdec::iterator ULEdec::readRawSNDUPacketData(iterator i, iterator i_end)
 214 {
 215     unsigned char how_much = std::min(
 216             snduPacketBytesLeft(), std::distance(i, i_end) );
 217     copy_n(i, how_much, this->snduPacketData_iter);
 218     std::advance(i, how_much);
 219     std::advance(this->snduPacketData_iter, how_much);
 220     return i;
 221 }
 222
 223
 224 void ULEdec::handleSNDUPacket()
 225 {
 226     this->snduPacket.dump(std::cout);
 227     std::cout << "----------------------------------------------------------------------------\n\n";
 228     if (this->snduPacket->crc() != this->snduPacket->calcCrc()) {
 229         throw ULEdecException("CRC Error");
 230     }
 231 //    senf::Packet nextPacket = this->snduPacket.next();
 232 //    senf::hexdump(
 233 //            nextPacket.data().begin(),
 234 //            nextPacket.data().end(),
 235 //            std::cout);
 236
 237 }
 238
 239
 240 inline bool ULEdec::isSDNUPacketComplete()
 241 {
 242     return this->snduPacketData_iter == this->snduPacket.data().end();
 243 }
 244
 245 inline ULEdec::iterator::difference_type ULEdec::snduPacketBytesLeft()
 246 {
 247     return std::distance( this->snduPacketData_iter, this->snduPacket.data().end() );
 248 }
 249
 250
 251 int main(int argc, char const * argv[])
 252 {
 253     try {
 254         ULEdec decoder;
 255         senf::Scheduler::instance().process();
 256     }
 257     catch (std::exception const & ex) {
 258         std::cerr << senf::prettyName(typeid(ex)) << ": " << ex.what() << "\n";
 259     }
 260     return 0;
 261 }
 262
 263
 264 ///////////////////////////////cc.e////////////////////////////////////////
 265 #undef prefix_
 266
 267
 268 // Local Variables:
 269 // mode: c++
 270 // fill-column: 100
 271 // c-file-style: "senf"
 272 // indent-tabs-mode: nil
 273 // ispell-local-dictionary: "american"
 274 // compile-command: "scons -u test"
 275 // comment-column: 40
 276 // End: