Examples/DVBAdapter/ULEdec.cc

   1 // $Id$
   2 //
   3 // Copyright (C) 2007
   4 // Fraunhofer Institute for Open Communication Systems (FOKUS)
   5 // Competence Center NETwork research (NET), St. Augustin, GERMANY
   6 //     Thorsten Horstmann <tho@berlios.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 <cassert>
  28 #include <linux/dvb/dmx.h>
  29 #include <boost/format.hpp>
  30 #include <senf/Packets.hh>
  31 #include <senf/Utils/hexdump.hh>
  32 #include <senf/Utils/membind.hh>
  33
  34 #define PID 271
  35 #define TRANSPORT_PACKET_SIZE 188
  36 // max. payload_pointer = ts packet payload size ( = ts packet size - ts header - payload_pointer)
  37 //                          - 2 bytes min. sndu header
  38 #define MAX_PAYLOAD_POINTER ( TRANSPORT_PACKET_SIZE - 4 - 1 - 2 )
  39
  40 #define prefix_
  41 //-/////////////////////////////////////////////////////////////////////////////////////////////////
  42
  43
  44 ULEdec::ULEdec(unsigned short adapter, unsigned short device)
  45     : demuxHandle( adapter, device ),  dvrHandle( adapter, device )
  46 {
  47     struct dmx_pes_filter_params pes_filter;
  48     memset(&pes_filter, 0, sizeof (struct dmx_pes_filter_params));
  49     pes_filter.pid = PID;
  50     pes_filter.input  = DMX_IN_FRONTEND;
  51     pes_filter.output = DMX_OUT_TS_TAP;
  52     pes_filter.pes_type = DMX_PES_OTHER;
  53     pes_filter.flags = DMX_IMMEDIATE_START;
  54     demuxHandle.protocol().setPESFilter( &pes_filter );
  55
  56     senf::Scheduler::instance().add(
  57         dvrHandle, senf::membind(&ULEdec::handleEvent, this));
  58
  59     this->receiver_state = Idle;
  60     this->priv_sndu_type_1 = false;
  61 }
  62
  63 void ULEdec::handleEvent(senf::Scheduler::EventId event)
  64 {
  65     senf::TransportPacket ts_packet (
  66             senf::TransportPacket::create(188, senf::noinit));
  67     dvrHandle.read( ts_packet.data() );
  68
  69     // Check TS error conditions: sync_byte, transport_error_indicator, scrambling_control.
  70     if ( (ts_packet->sync_byte() != senf::TransportPacketType::SYNC_BYTE) ||
  71          (ts_packet->transport_error_indicator() == true) ||
  72          (ts_packet->transport_scrmbl_ctrl() != 0))
  73     {
  74         std::cerr << "invalid ts packet\n";
  75         // drop partly decoded SNDU, reset state, resync on PUSI.
  76         return;
  77     }
  78
  79     handleTSPacket(ts_packet);
  80 }
  81
  82 void ULEdec::handleTSPacket(senf::TransportPacket ts_packet)
  83 {
  84     senf::PacketData & payloadData (ts_packet.next().data());
  85     iterator payload_iter = payloadData.begin();
  86     iterator payload_end = payloadData.end();
  87
  88     std::cout << "New TS Packet:\n"
  89               << "----------------------------------------------------------------------------\n";
  90     senf::hexdump(payload_iter, payload_end, std::cout);
  91     std::cout << "----------------------------------------------------------------------------\n";
  92
  93     // Synchronize continuity counter
  94     this->priv_tscc = ts_packet->continuity_counter();
  95
  96     switch (ts_packet->pusi()) {
  97     case 0: {
  98         switch (this->receiver_state) {
  99         case Idle:
 100             return;
 101         case Reassembly:
 102             payload_iter = readContSNDUPacket( payload_iter, payload_end );
 103             if (isSDNUPacketComplete()) {
 104                 this->receiver_state = Idle;
 105                 try {
 106                     handleSNDUPacket();
 107                 } catch (ULEdecException const & ex) {
 108                     std::cerr << ex.what() << "\n";
 109                     return;
 110                 }
 111                 switch (std::distance( payload_iter, payload_end ))
 112                 case 0:
 113                 case 1:
 114                     return;
 115                 default:
 116                     if ( (*payload_iter++ << 8 | *payload_iter++) != ULE_END_INDICATOR )
 117                         std::cerr << "delimiting error\n";
 118             } else {
 119                 assert( std::distance( payload_iter, payload_end ) == 0 );
 120             }
 121         }
 122         break;
 123     }
 124     case 1: {
 125         // a PUSI value of 1 indicates the presence of a Payload Pointer.
 126         unsigned char payload_pointer = *payload_iter++;
 127         if (payload_pointer > MAX_PAYLOAD_POINTER) {
 128             std::cerr << str( boost::format(
 129                     "invalid payload_pointer (%d)\n") % unsigned(payload_pointer) ) ;
 130             this->receiver_state = Idle;
 131             return;
 132         }
 133         switch (this->receiver_state) {
 134         case Idle:
 135             std::advance(payload_iter, payload_pointer);
 136             break;
 137         case Reassembly:
 138             // Reassembly Payload Pointer Checking
 139             if (snduPacketBytesLeft() != payload_pointer) {
 140                 // delimiting error
 141                 std::cerr << str( boost::format(
 142                         "delimiting error: bytes left in SNDU packet != payload_pointer ("
 143                         "(%d != %d)\n") % snduPacketBytesLeft() % payload_pointer );
 144                 std::advance(payload_iter, payload_pointer);
 145             } else {
 146                 payload_iter = readContSNDUPacket( payload_iter, payload_end );
 147                 assert( isSDNUPacketComplete() );
 148                 try {
 149                     handleSNDUPacket();
 150                 } catch (ULEdecException const & ex) {
 151                     std::cerr << ex.what() << "\n";
 152                     this->receiver_state = Idle;
 153                     return;
 154                 }
 155             }
 156         }
 157         this->receiver_state = Idle;
 158         try {
 159             do {
 160                 payload_iter = readNewSNDUPacket( payload_iter, payload_end );
 161                 if (! isSDNUPacketComplete()) {
 162                     assert( std::distance( payload_iter, payload_end ) == 0 );
 163                     this->receiver_state = Reassembly;
 164                     break;
 165                 }
 166                 handleSNDUPacket();
 167             } while (std::distance(payload_iter, payload_end) < 2 );
 168         }
 169         catch (ULEdecException const & ex) {
 170             std::cerr << ex.what() << "\n";
 171             return;
 172         }
 173     }
 174
 175     } // end pusi-switch
 176 }
 177
 178
 179 ULEdec::iterator ULEdec::readContSNDUPacket(iterator i, iterator const i_end)
 180 {
 181     if (priv_sndu_type_1) {
 182         this->snduPacket->type() |= *i++;
 183     }
 184     return readRawSNDUPacketData(i, i_end);
 185 }
 186
 187
 188 ULEdec::iterator ULEdec::readNewSNDUPacket(iterator i, iterator const i_end)
 189 {
 190     bool dbit = false;
 191     senf::Packet::size_type sndu_length = *i++ << 8 | *i++;
 192     if (sndu_length & 0x8000) {
 193         sndu_length &= 0x7FFF;
 194         dbit = true;
 195     }
 196     if (sndu_length < 5 || sndu_length == 0xffff) {
 197         throw ULEdecException( str( boost::format(
 198                 "SNDU length error. length=%d") % sndu_length) );
 199      }
 200     this->snduPacket = senf::SNDUPacket::create(sndu_length+4);
 201
 202     if (dbit)
 203         this->snduPacket->withoutDestination();
 204     // else not needed since default on newly created packet is withDestination()
 205
 206     this->snduPacket->length() = sndu_length;
 207     this->snduPacketData_iter = boost::next(this->snduPacket.data().begin(), 2);
 208     this->priv_sndu_type_1 = false;
 209
 210     switch (std::distance(i, i_end)) {
 211     case 1:
 212         this->priv_sndu_type_1 = true;
 213         this->snduPacket->type() = *i++ << 8;
 214         this->snduPacketData_iter++;
 215     case 0:
 216         break;
 217
 218     default:
 219         this->snduPacket->type() = *i++ << 8 | *i++;
 220         std::advance(this->snduPacketData_iter, 2);
 221         i = readRawSNDUPacketData(i, i_end);
 222     }
 223
 224     return i;
 225 }
 226
 227
 228 ULEdec::iterator ULEdec::readRawSNDUPacketData(iterator i, iterator i_end)
 229 {
 230     unsigned char how_much = std::min(
 231             snduPacketBytesLeft(), std::distance(i, i_end) );
 232     copy_n(i, how_much, this->snduPacketData_iter);
 233     std::advance(i, how_much);
 234     std::advance(this->snduPacketData_iter, how_much);
 235     return i;
 236 }
 237
 238
 239 void ULEdec::handleSNDUPacket()
 240 {
 241     this->snduPacket.dump(std::cout);
 242     std::cout << "----------------------------------------------------------------------------\n\n";
 243     if (this->snduPacket->crc() != this->snduPacket->calcCrc()) {
 244         throw ULEdecException( str( boost::format(
 245                 "CRC Error. received crc:%d calculated crc:%d")
 246                     % this->snduPacket->crc() % this->snduPacket->calcCrc() ) );
 247     }
 248 //    senf::Packet nextPacket = this->snduPacket.next();
 249 //    senf::hexdump(
 250 //            nextPacket.data().begin(),
 251 //            nextPacket.data().end(),
 252 //            std::cout);
 253
 254 }
 255
 256
 257 inline bool ULEdec::isSDNUPacketComplete()
 258 {
 259     return this->snduPacketData_iter == this->snduPacket.data().end();
 260 }
 261
 262 inline ULEdec::iterator::difference_type ULEdec::snduPacketBytesLeft()
 263 {
 264     return std::distance( this->snduPacketData_iter, this->snduPacket.data().end() );
 265 }
 266
 267
 268 int main(int argc, char const * argv[])
 269 {
 270     try {
 271         ULEdec decoder;
 272         senf::Scheduler::instance().process();
 273     }
 274     catch (std::exception const & ex) {
 275         std::cerr << senf::prettyName(typeid(ex)) << ": " << ex.what() << "\n";
 276     }
 277     return 0;
 278 }
 279
 280
 281 //-/////////////////////////////////////////////////////////////////////////////////////////////////
 282 #undef prefix_
 283
 284 \f
 285 // Local Variables:
 286 // mode: c++
 287 // fill-column: 100
 288 // c-file-style: "senf"
 289 // indent-tabs-mode: nil
 290 // ispell-local-dictionary: "american"
 291 // compile-command: "scons -U"
 292 // comment-column: 40
 293 // End: