MythTV: dvbtables.cpp Source File

00001 // -*- Mode: c++ -*-
00002 // Copyright (c) 2005, Daniel Thor Kristjansson
00003 
00004 #include <cmath>
00005 
00006 #include "dvbtables.h"
00007 #include "dvbdescriptors.h"
00008 #include "qstring.h"
00009 
00010 void NetworkInformationTable::Parse(void) const
00011 {
00012     _tsc_ptr = pesdata() + 10 + NetworkDescriptorsLength();
00013 
00014     _ptrs.clear();
00015     _ptrs.push_back(_tsc_ptr + 2);
00016     for (uint i=0; _ptrs[i] + 6 <= _ptrs[0] + TransportStreamDataLength(); i++)
00017         _ptrs.push_back(_ptrs[i] + 6 + TransportDescriptorsLength(i));
00018 }
00019 
00020 QString NetworkInformationTable::toString(void) const
00021 {
00022     QString str = QString("NIT: NetID(%1) tranports(%2)\n")
00023         .arg(NetworkID()).arg(TransportStreamCount());
00024 
00025     if (0 != NetworkDescriptorsLength())
00026     {
00027         str.append(QString("Network descriptors length: %1\n")
00028                    .arg(NetworkDescriptorsLength()));
00029         vector<const unsigned char*> desc = 
00030             MPEGDescriptor::Parse(NetworkDescriptors(),
00031                                   NetworkDescriptorsLength());
00032         for (uint i = 0; i < desc.size(); i++)
00033             str.append(QString("  %1\n")
00034                        .arg(MPEGDescriptor(desc[i]).toString()));
00035     }
00036 
00037     for (uint i = 0; i < TransportStreamCount(); i++)
00038     {
00039         str.append(QString("  Transport #%1 TSID(0x%1) ")
00040                    .arg(i, 2, 10).arg(TSID(i), 0, 16));
00041         str.append(QString("original_network_id(0x%2) desc_len(%3)\n")
00042                    .arg(OriginalNetworkID(i), 0, 16)
00043                    .arg(TransportDescriptorsLength(i)));
00044 
00045         if (0 != TransportDescriptorsLength(i))
00046         {
00047             str.append(QString("  Transport descriptors length: %1\n")
00048                        .arg(TransportDescriptorsLength(i)));
00049             vector<const unsigned char*> desc = 
00050                 MPEGDescriptor::Parse(TransportDescriptors(i),
00051                                       TransportDescriptorsLength(i));
00052             for (uint i = 0; i < desc.size(); i++)
00053                 str.append(QString("    %1\n")
00054                            .arg(MPEGDescriptor(desc[i]).toString()));
00055         }
00056     }
00057     return str;
00058 }
00059 
00060 QString NetworkInformationTable::NetworkName() const
00061 {
00062     if (_cached_network_name == QString::null)
00063     {
00064         desc_list_t parsed =
00065             MPEGDescriptor::Parse(NetworkDescriptors(),
00066                                   NetworkDescriptorsLength());
00067 
00068         const unsigned char *desc =
00069             MPEGDescriptor::Find(parsed, DescriptorID::network_name);
00070 
00071         if (desc)
00072             _cached_network_name = NetworkNameDescriptor(desc).Name();
00073         else 
00074             _cached_network_name = QString("Net ID 0x%1")
00075                 .arg(NetworkID(), 0, 16);
00076     }
00077     return _cached_network_name;
00078 }
00079 
00080 
00081 void ServiceDescriptionTable::Parse(void) const
00082 {
00083     _ptrs.clear();
00084     _ptrs.push_back(pesdata() + 11);
00085     uint i = 0;
00086     while ((_ptrs[i] + 5) < (pesdata() + Length()))
00087     {
00088         _ptrs.push_back(_ptrs[i] + 5 + ServiceDescriptorsLength(i));
00089         i++;
00090     }
00091 }
00092 
00093 QString ServiceDescriptionTable::toString(void) const
00094 {
00095     QString str =
00096         QString("SDT: TSID(0x%1) original_network_id(0x%2) services(%3)\n")
00097         .arg(OriginalNetworkID(), 0, 16).arg(TSID(), 0, 16)
00098         .arg(ServiceCount());
00099     
00100     for (uint i = 0; i < ServiceCount(); i++)
00101     {
00102         str.append(QString("  Service #%1 SID(0x%2) ")
00103                    .arg(i, 2, 10).arg(ServiceID(i), 0, 16));
00104         str.append(QString("eit_schd(%1) eit_pf(%2) encrypted(%3)\n")
00105                    .arg(HasEITSchedule(i) ? "t" : "f")
00106                    .arg(HasEITPresentFollowing(i) ? "t" : "f")
00107                    .arg(IsEncrypted(i) ? "t" : "f"));
00108 
00109         if (0 != ServiceDescriptorsLength(i))
00110         {
00111             str.append(QString("  Service descriptors length: %1\n")
00112                        .arg(ServiceDescriptorsLength(i)));
00113             vector<const unsigned char*> desc = 
00114                 MPEGDescriptor::Parse(ServiceDescriptors(i),
00115                                       ServiceDescriptorsLength(i));
00116             for (uint i = 0; i < desc.size(); i++)
00117                 str.append(QString("    %1\n")
00118                            .arg(MPEGDescriptor(desc[i]).toString()));
00119         }
00120     }
00121     return str;
00122 }
00123 
00124 ServiceDescriptor *ServiceDescriptionTable::GetServiceDescriptor(uint i) const
00125 {
00126     desc_list_t parsed =
00127         MPEGDescriptor::Parse(ServiceDescriptors(i),
00128                               ServiceDescriptorsLength(i));
00129 
00130     const unsigned char *desc =
00131         MPEGDescriptor::Find(parsed, DescriptorID::service);
00132 
00133     if (desc)
00134         return new ServiceDescriptor(desc);
00135 
00136     return NULL;
00137 }
00138 
00139 bool ServiceDescriptionTable::Mutate(void)
00140 {
00141     if (VerifyCRC())
00142     {
00143         SetTableID((TableID() == TableID::SDTo) ? TableID::SDT : TableID::SDTo);
00144         SetCRC(CalcCRC());
00145         return true;
00146     }
00147     else
00148         return false;
00149 }
00150 
00151 void DVBEventInformationTable::Parse(void) const
00152 {
00153     _ptrs.clear();
00154     _ptrs.push_back(psipdata() + 6);
00155     uint i = 0;
00156     while ((_ptrs[i] + 12) < (pesdata() + Length()))
00157     {
00158         _ptrs.push_back(_ptrs[i] + 12 + DescriptorsLength(i));
00159         i++;
00160     }
00161 }
00162 
00163 bool DVBEventInformationTable::IsEIT(uint table_id)
00164 {
00165     bool is_eit = false;
00166 
00167     // Standard Now/Next Event Information Tables for this transport
00168     is_eit |= TableID::PF_EIT  == table_id;
00169     // Standard Now/Next Event Information Tables for other transport
00170     is_eit |= TableID::PF_EITo == table_id;
00171     // Standard Future Event Information Tables for this transport
00172     is_eit |= (TableID::SC_EITbeg  <= table_id &&
00173                TableID::SC_EITend  >= table_id);
00174     // Standard Future Event Information Tables for other transports
00175     is_eit |= (TableID::SC_EITbego <= table_id &&
00176                TableID::SC_EITendo >= table_id);
00177     // Dish Network Long Term Future Event Information for all transports
00178     is_eit |= (TableID::DN_EITbego <= table_id &&
00179                TableID::DN_EITendo >= table_id);
00180 
00181     return is_eit;
00182 }
00183 
00187 QDateTime dvbdate2qt(const unsigned char *buf)
00188 {
00189     uint mjd = (buf[0] << 8) | buf[1];
00190     if (mjd >= 40587)
00191     {
00192         QDateTime result;
00193         // Modified Julian date as number of days since 17th November 1858.
00194         // 1st Jan 1970 was date 40587.
00195         uint secsSince1970 = (mjd - 40587)   * 86400;
00196         secsSince1970 += byteBCD2int(buf[2]) * 3600;
00197         secsSince1970 += byteBCD2int(buf[3]) * 60;
00198         secsSince1970 += byteBCD2int(buf[4]);
00199         result.setTime_t(secsSince1970, Qt::UTC);
00200         return result;
00201     }
00202 
00203     // Original function taken from dvbdate.c in linuxtv-apps code
00204     // Use the routine specified in ETSI EN 300 468 V1.4.1,
00205     // "Specification for Service Information in Digital Video Broadcasting"
00206     // to convert from Modified Julian Date to Year, Month, Day.
00207 
00208     const float tmpA = 1.0 / 365.25;
00209     const float tmpB = 1.0 / 30.6001;
00210 
00211     float mjdf = mjd;
00212     int year  = (int) truncf((mjdf - 15078.2f) * tmpA);
00213     int month = (int) truncf(
00214         (mjdf - 14956.1f - truncf(year * 365.25f)) * tmpB);
00215     int day   = (int) truncf(
00216         (mjdf - 14956.0f - truncf(year * 365.25f) - truncf(month * 30.6001f)));
00217     int i     = (month == 14 || month == 15) ? 1 : 0;
00218 
00219     QDate date(1900 + year + i, month - 1 - i * 12, day);
00220     QTime time(byteBCD2int(buf[2]), byteBCD2int(buf[3]),
00221                byteBCD2int(buf[4]));
00222 
00223     return QDateTime(date, time);
00224 }
00225 
00229 time_t dvbdate2unix(const unsigned char *buf)
00230 {
00231     // Modified Julian date as number of days since 17th November 1858.
00232     // The unix epoch, 1st Jan 1970, was day 40587.
00233     uint mjd = (buf[0] << 8) | buf[1];
00234     if (mjd < 40587)
00235         return 0; // we don't handle pre-unix dates..
00236 
00237     uint secsSince1970 = (mjd - 40587)   * 86400;
00238     secsSince1970 += byteBCD2int(buf[2]) * 3600;
00239     secsSince1970 += byteBCD2int(buf[3]) * 60;
00240     secsSince1970 += byteBCD2int(buf[4]);
00241     return secsSince1970;
00242 }
00243 
00247 uint32_t dvbdate2key(const unsigned char *buf)
00248 {
00249     uint dt = (((uint)buf[0]) << 24) | (((uint)buf[1]) << 16); // 16 bits
00250     uint tm = ((byteBCD2int(buf[2]) * 3600) +
00251                (byteBCD2int(buf[3]) * 60) +
00252                (byteBCD2int(buf[4]))); // 17 bits
00253     return (dt | (tm>>1)) ^ ((tm & 1)<<31);
00254 }