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cDevice *cDevice::GetDeviceForTransponder(const cChannel *Channel, int Priority)
{
  cDevice *Device = NULL;
  for (int i = 0; i < cDevice::NumDevices(); i++) {
      if (cDevice *d = cDevice::GetDevice(i)) {
         if (d->IsTunedToTransponder(Channel))
            return d; // if any device is tuned to the transponder, we're done                                                                                                                                                                                                                                               
         if (d->ProvidesTransponder(Channel)) {
            if (d->MaySwitchTransponder(Channel))
               Device = d; // this device may switch to the transponder without disturbing any receiver or live view                                                                                                                                                                                                         
            else if (!d->Occupied() && d->MaySwitchTransponder(Channel)) { // MaySwitchTransponder() implicitly calls Occupied()                                                                                                                                                                                             
               if (d->Priority() < Priority && (!Device || d->Priority() < Device->Priority()))
                  Device = d; // use this one only if no other with less impact can be found                                                                                                                                                                                                                                 
               }
            }
         }
      }
  return Device;
}

cDevice *cDevice::GetDevice(const cChannel *Channel, int Priority, bool LiveView, bool Query)
{
  // Collect the current priorities of all CAM slots that can decrypt the channel:
  int NumCamSlots = CamSlots.Count();
  int SlotPriority[NumCamSlots];
  int NumUsableSlots = 0;
  if (Channel->Ca() >= CA_ENCRYPTED_MIN) {
     for (cCamSlot *CamSlot = CamSlots.First(); CamSlot; CamSlot = CamSlots.Next(CamSlot)) {
         SlotPriority[CamSlot->Index()] = MAXPRIORITY + 1; // assumes it can't be used
         if (CamSlot->ModuleStatus() == msReady) {
            if (CamSlot->ProvidesCa(Channel->Caids())) {
               if (!ChannelCamRelations.CamChecked(Channel->GetChannelID(), CamSlot->SlotNumber())) {
                  SlotPriority[CamSlot->Index()] = CamSlot->Priority();
                  NumUsableSlots++;
                  }
               }
            }
         }
     if (!NumUsableSlots)
        return NULL; // no CAM is able to decrypt this channel
     }


  bool NeedsDetachReceivers = false;
  cDevice *d = NULL;
  cCamSlot *s = NULL;


  uint32_t Impact = 0xFFFFFFFF; // we're looking for a device with the least impact
  for (int j = 0; j < NumCamSlots || !NumUsableSlots; j++) {
      if (NumUsableSlots && SlotPriority[j] > MAXPRIORITY)
         continue; // there is no CAM available in this slot
      for (int i = 0; i < numDevices; i++) {
          if (Channel->Ca() && Channel->Ca() <= CA_DVB_MAX && Channel->Ca() != device[i]->CardIndex() + 1)
             continue; // a specific card was requested, but not this one
          if (NumUsableSlots && !CamSlots.Get(j)->Assign(device[i], true))
             continue; // CAM slot can't be used with this device
          bool ndr;
          if (device[i]->ProvidesChannel(Channel, Priority, &ndr)) { // this device is basicly able to do the job
             if (NumUsableSlots && device[i]->CamSlot() && device[i]->CamSlot() != CamSlots.Get(j))
                ndr = true; // using a different CAM slot requires detaching receivers
             // Put together an integer number that reflects the "impact" using
             // this device would have on the overall system. Each condition is represented
             // by one bit in the number (or several bits, if the condition is actually
             // a numeric value). The sequence in which the conditions are listed corresponds
             // to their individual severity, where the one listed first will make the most
             // difference, because it results in the most significant bit of the result.
             uint32_t imp = 0;
             imp <<= 1; imp |= LiveView ? !device[i]->IsPrimaryDevice() || ndr : 0; // prefer the primary device for live viewing if we don't need to detach existing receivers
             imp <<= 1; imp |= !device[i]->Receiving() && (device[i] != cTransferControl::ReceiverDevice() || device[i]->IsPrimaryDevice()) || ndr; // use receiving devices if we don't need to detach existing receivers, but avoid primary device in local transfer mode
             imp <<= 1; imp |= device[i]->Receiving(); // avoid devices that are receiving
             imp <<= 4; imp |= GetClippedNumProvidedSystems(4, device[i]) - 1; // avoid cards which support multiple delivery systems
             imp <<= 1; imp |= device[i] == cTransferControl::ReceiverDevice(); // avoid the Transfer Mode receiver device
             imp <<= 8; imp |= device[i]->Priority() - IDLEPRIORITY; // use the device with the lowest priority (- IDLEPRIORITY to assure that values -100..99 can be used)
             imp <<= 8; imp |= (NumUsableSlots ? SlotPriority[j] : IDLEPRIORITY) - IDLEPRIORITY; // use the CAM slot with the lowest priority (- IDLEPRIORITY to assure that values -100..99 can be used)
             imp <<= 1; imp |= ndr; // avoid devices if we need to detach existing receivers
             imp <<= 1; imp |= NumUsableSlots ? 0 : device[i]->HasCi(); // avoid cards with Common Interface for FTA channels
             imp <<= 1; imp |= device[i]->AvoidRecording(); // avoid SD full featured cards
             imp <<= 1; imp |= NumUsableSlots ? !ChannelCamRelations.CamDecrypt(Channel->GetChannelID(), j + 1) : 0; // prefer CAMs that are known to decrypt this channel
             imp <<= 1; imp |= device[i]->IsPrimaryDevice(); // avoid the primary device
             if (imp < Impact) {
                // This device has less impact than any previous one, so we take it.
                Impact = imp;
                d = device[i];
                NeedsDetachReceivers = ndr;
                if (NumUsableSlots)
                   s = CamSlots.Get(j);
                }
             }
          }
      if (!NumUsableSlots)
         break; // no CAM necessary, so just one loop over the devices
      }
  if (d && !Query) {
     if (NeedsDetachReceivers)
        d->DetachAllReceivers();
     if (s) {
        if (s->Device() != d) {
           if (s->Device())
              s->Device()->DetachAllReceivers();
           if (d->CamSlot())
              d->CamSlot()->Assign(NULL);
           s->Assign(d);
           }
        }
     else if (d->CamSlot() && !d->CamSlot()->IsDecrypting())
        d->CamSlot()->Assign(NULL);
     }
  return d;
}