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 <string>
  26 #include <iostream>
  27 #include <iomanip>
  28 #include <algorithm>
  29 #include <sys/ioctl.h>
  30 #include <linux/sockios.h>
  31 #include <linux/dvb/dmx.h>
  32
  33 #include "Scheduler/Scheduler.hh"
  34 #include "Packets/DefaultBundle/EthernetPacket.hh"
  35 #include "Packets/MPEGDVBBundle/TransportPacket.hh"
  36 #include "Packets/MPEGDVBBundle/SNDUPacket.hh"
  37 #include "Utils/membind.hh"
  38 #include "Utils/hexdump.hh"
  39 #include "Socket/Protocols/DVB/DVBDemuxHandles.hh"
  40 #include "Packets/ParseInt.hh"
  41 #include "Packets/Packet.hh"
  42 #include "Packets/PacketData.hh"
  43 #include "Packets/ParseInt.hh"
  44
  45 #include "ULEdec.hh"
  46
  47 #define PID 271
  48 #define TS_SYNC 0x47
  49
  50 #define prefix_
  51 ///////////////////////////////cc.p////////////////////////////////////////
  52
  53
  54 ULEdec::ULEdec()
  55 {
  56     struct dmx_pes_filter_params pes_filter;
  57     memset(&pes_filter, 0, sizeof (struct dmx_pes_filter_params));
  58     pes_filter.pid = PID;
  59     pes_filter.input  = DMX_IN_FRONTEND;
  60     pes_filter.output = DMX_OUT_TS_TAP;
  61     pes_filter.pes_type = DMX_PES_OTHER;
  62     pes_filter.flags = DMX_IMMEDIATE_START;
  63     demuxHandle.protocol().setPESFilter( &pes_filter );
  64
  65     senf::Scheduler::instance().add(
  66         dvrHandle, senf::membind(&ULEdec::handleEvent, this));
  67
  68     this->receiver_state = Idle;
  69     this->priv_sndu_type_1 = false;
  70 }
  71
  72 void ULEdec::handleEvent(senf::FileHandle, senf::Scheduler::EventId event)
  73 {
  74     senf::TransportPacket ts_packet (
  75             senf::TransportPacket::create(188, senf::TransportPacket::noinit));
  76     dvrHandle.read( ts_packet.data() );
  77
  78     // Check TS error conditions: sync_byte, transport_error_indicator, scrambling_control.
  79     if ( (ts_packet->sync_byte() != TS_SYNC) ||
  80          (ts_packet->transport_error_indicator() == true) ||
  81          (ts_packet->transport_scrmbl_ctrl() != 0))
  82     {
  83         std::cerr << "invalid ts packet\n";
  84         // drop partly decoded SNDU, reset state, resync on PUSI.
  85         return;
  86     }
  87
  88     handleTSPacket(ts_packet);
  89 }
  90
  91 void ULEdec::handleTSPacket(senf::TransportPacket ts_packet)
  92 {
  93     senf::PacketData & payloadData (ts_packet.next().data());
  94     iterator payload_start = payloadData.begin();
  95     iterator payload_end = payloadData.end();
  96
  97     senf::hexdump(payload_start, payload_end, std::cout);
  98
  99     // Synchronize continuity counter
 100     this->priv_tscc = ts_packet->continuity_counter();
 101
 102     switch (ts_packet->pusi()) {
 103     case 0: {
 104         switch (this->receiver_state) {
 105         case Idle:
 106             return;
 107         case Reassembly:
 108             payload_start = readContSNDUPacket( payload_start, payload_end );
 109             if (isSDNUPacketComplete()) {
 110                 handleSNDUPacket();
 111                 this->receiver_state = Idle;
 112                 switch (std::distance( payload_start, payload_end ))
 113                 case 0:
 114                 case 1:
 115                     return;
 116                 default:
 117                     if ( (*payload_start++ | *payload_start++) != ULE_END_INDICATOR )
 118                         std::cerr << "delimiting error\n";
 119             } else {
 120                 BOOST_ASSERT( std::distance( payload_start, payload_end ) == 0 );
 121             }
 122         }
 123         break;
 124     }
 125     case 1: {
 126         // a PUSI value of 1 indicates the presence of a Payload Pointer.
 127         unsigned char payload_pointer = *payload_start++;
 128         if (payload_pointer > 181) {
 129             std::cerr << "invalid payload_pointer\n";
 130             return;
 131         }
 132         switch (this->receiver_state) {
 133         case Idle:
 134             payload_start += payload_pointer;
 135             readNewSNDUPacket( payload_start, payload_end );
 136             break;
 137         case Reassembly:
 138             // Reassembly Payload Pointer Checking
 139             unsigned char sndu_bytes_left = snduPacketBytesLeft();
 140             if (sndu_bytes_left != payload_pointer) {
 141                 // delimiting error
 142                 std::cerr << "delimiting error\n";
 143                 payload_start += payload_pointer;
 144             } else {
 145                 readContSNDUPacket( payload_start, payload_end );
 146                 BOOST_ASSERT( isSDNUPacketComplete() );
 147             }
 148             readNewSNDUPacket( payload_start, payload_end );
 149         }
 150     }
 151     } // end pusi-switch
 152
 153 }
 154
 155
 156 ULEdec::iterator ULEdec::readContSNDUPacket(iterator i_start, iterator i_end)
 157 {
 158     if (priv_sndu_type_1) {
 159         this->snduPacket->type() |= *i_start++;
 160     }
 161     i_start = readRawSNDUPacketData(i_start, i_end);
 162
 163     return i_start;
 164 }
 165
 166
 167 ULEdec::iterator ULEdec::readNewSNDUPacket(iterator i_start, iterator i_end)
 168 {
 169     bool dbit = false;
 170     senf::Packet::size_type sndu_length;
 171     sndu_length = *i_start++ << 8 | *i_start++;
 172     if (sndu_length & 0x8000) {
 173         sndu_length &= 0x7FFF;
 174         dbit = true;
 175     }
 176     this->snduPacket = senf::SNDUPacket::create(sndu_length+4);
 177     this->snduPacket->d_bit() = dbit;
 178     this->snduPacket->length() = sndu_length;
 179     this->snduPacketData_iter = this->snduPacket.data().begin() + 2;
 180     this->priv_sndu_type_1 = false;
 181
 182     switch (std::distance(i_start, i_end)) {
 183     case 1:
 184         this->priv_sndu_type_1 = true;
 185         this->snduPacket->type() = *i_start++;
 186         this->snduPacketData_iter++;
 187     case 0:
 188         break;
 189
 190     default:
 191         this->snduPacket->type() = *i_start++ | *i_start++;
 192         this->snduPacketData_iter += 2;
 193         i_start = readRawSNDUPacketData(i_start, i_end);
 194     }
 195
 196     return i_start;
 197 }
 198
 199
 200 ULEdec::iterator ULEdec::readRawSNDUPacketData(iterator i_start, iterator i_end)
 201 {
 202     unsigned char how_much = std::min(
 203             snduPacketBytesLeft(), std::distance( i_start, i_end ) );
 204     copy_n(i_start, how_much, this->snduPacketData_iter);
 205     i_start += how_much;
 206     this->snduPacketData_iter += how_much;
 207     return i_start;
 208 }
 209
 210
 211 void ULEdec::handleSNDUPacket()
 212 {
 213     this->snduPacket.dump(std::cout);
 214 }
 215
 216
 217 inline bool ULEdec::isSDNUPacketComplete()
 218 {
 219     return this->snduPacketData_iter == this->snduPacket.data().end();
 220 }
 221
 222 inline ULEdec::iterator::difference_type ULEdec::snduPacketBytesLeft()
 223 {
 224     return std::distance( this->snduPacketData_iter, this->snduPacket.data().end() );
 225 }
 226
 227
 228 int main(int argc, char const * argv[])
 229 {
 230     try {
 231         ULEdec decoder;
 232         senf::Scheduler::instance().process();
 233     }
 234     catch (std::exception const & ex) {
 235         std::cerr << senf::prettyName(typeid(ex)) << ": " << ex.what() << "\n";
 236     }
 237     return 0;
 238 }
 239
 240
 241 ///////////////////////////////cc.e////////////////////////////////////////
 242 #undef prefix_
 243
 244 \f
 245 // Local Variables:
 246 // mode: c++
 247 // fill-column: 100
 248 // c-file-style: "senf"
 249 // indent-tabs-mode: nil
 250 // ispell-local-dictionary: "american"
 251 // compile-command: "scons -u test"
 252 // comment-column: 40
 253 // End: