diff options
Diffstat (limited to 'device.c')
| -rw-r--r-- | device.c | 25 |
1 files changed, 16 insertions, 9 deletions
@@ -4,7 +4,7 @@ * See the main source file 'vdr.c' for copyright information and * how to reach the author. * - * $Id: device.c 1.130 2006/05/27 11:14:42 kls Exp $ + * $Id: device.c 1.131 2006/06/15 09:59:40 kls Exp $ */ #include "device.h" @@ -281,19 +281,26 @@ cDevice *cDevice::GetDevice(int Index) cDevice *cDevice::GetDevice(const cChannel *Channel, int Priority, bool *NeedsDetachReceivers) { cDevice *d = NULL; - uint Impact = 0xFFFFFFFF; + uint Impact = 0xFFFFFFFF; // we're looking for a device with the least impact for (int i = 0; i < numDevices; i++) { bool ndr; if (device[i]->ProvidesChannel(Channel, Priority, &ndr)) { // this device is basicly able to do the job + // 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. uint imp = 0; - imp <<= 1; imp |= !device[i]->Receiving() || ndr; - imp <<= 1; imp |= device[i]->Receiving(); - imp <<= 1; imp |= device[i] == ActualDevice(); - imp <<= 1; imp |= device[i]->IsPrimaryDevice(); - imp <<= 1; imp |= device[i]->HasDecoder(); - imp <<= 8; imp |= min(max(device[i]->Priority() + MAXPRIORITY, 0), 0xFF); - imp <<= 8; imp |= min(max(device[i]->ProvidesCa(Channel), 0), 0xFF); + imp <<= 1; imp |= !device[i]->Receiving() || ndr; // use receiving devices if we don't need to detach existing receivers + imp <<= 1; imp |= device[i]->Receiving(); // avoid devices that are receiving + imp <<= 1; imp |= device[i] == ActualDevice(); // avoid the actual device (in case of Transfer Mode) + imp <<= 1; imp |= device[i]->IsPrimaryDevice(); // avoid the primary device + imp <<= 1; imp |= device[i]->HasDecoder(); // avoid full featured cards + imp <<= 8; imp |= min(max(device[i]->Priority() + MAXPRIORITY, 0), 0xFF); // use the device with the lowest priority (+MAXPRIORITY to assure that values -99..99 can be used) + imp <<= 8; imp |= min(max(device[i]->ProvidesCa(Channel), 0), 0xFF); // use the device that provides the lowest number of conditional access methods if (imp < Impact) { + // This device has less impact than any previous one, so we take it. Impact = imp; d = device[i]; if (NeedsDetachReceivers) |