git.sesse.net Git - nageru/blob - nageru/input_mapping.cpp

   1 #include "input_mapping.h"
   2
   3 #include <assert.h>
   4 #include <map>
   5 #include <set>
   6 #include <string>
   7 #include <utility>
   8 #include <vector>
   9
  10 #include "audio_mixer.h"
  11 #include "state.pb.h"
  12 #include "shared/text_proto.h"
  13
  14 using namespace std;
  15 using namespace google::protobuf;
  16
  17 bool save_input_mapping_to_file(const map<DeviceSpec, DeviceInfo> &devices, const InputMapping &input_mapping, const string &filename)
  18 {
  19         InputMappingProto mapping_proto;
  20         {
  21                 map<DeviceSpec, unsigned> used_devices;
  22                 for (const InputMapping::Bus &bus : input_mapping.buses) {
  23                         if (!used_devices.count(bus.device)) {
  24                                 used_devices.emplace(bus.device, used_devices.size());
  25                                 global_audio_mixer->serialize_device(bus.device, mapping_proto.add_device());
  26                         }
  27
  28                         BusProto *bus_proto = mapping_proto.add_bus();
  29                         bus_proto->set_name(bus.name);
  30                         bus_proto->set_device_index(used_devices[bus.device]);
  31                         bus_proto->set_source_channel_left(bus.source_channel[0]);
  32                         bus_proto->set_source_channel_right(bus.source_channel[1]);
  33                 }
  34         }
  35
  36         return save_proto_to_file(mapping_proto, filename);
  37 }
  38
  39 bool load_input_mapping_from_file(const map<DeviceSpec, DeviceInfo> &devices, const string &filename, InputMapping *new_mapping)
  40 {
  41         InputMappingProto mapping_proto;
  42         if (!load_proto_from_file(filename, &mapping_proto)) {
  43                 return false;
  44         }
  45
  46         // Map devices in the proto to our current ones:
  47
  48         // Get a list of all active devices.
  49         set<DeviceSpec> remaining_devices;
  50         for (const auto &device_spec_and_info : devices) {
  51                 remaining_devices.insert(device_spec_and_info.first);
  52         }
  53
  54         // Now look at every device in the serialized protobuf and try to map
  55         // it to one device we haven't taken yet. This isn't a full maximal matching,
  56         // but it's good enough for our uses.
  57         vector<DeviceSpec> device_mapping;
  58         for (unsigned device_index = 0; device_index < unsigned(mapping_proto.device_size()); ++device_index) {
  59                 const DeviceSpecProto &device_proto = mapping_proto.device(device_index);
  60                 switch (device_proto.type()) {
  61                 case DeviceSpecProto::SILENCE:
  62                         device_mapping.push_back(DeviceSpec{InputSourceType::SILENCE, 0});
  63                         break;
  64                 case DeviceSpecProto::CAPTURE_CARD: {
  65                         // First see if there's a card that matches on both index and name.
  66                         DeviceSpec spec;
  67                         spec.type = InputSourceType::CAPTURE_CARD;
  68                         spec.index = unsigned(device_proto.index());
  69                         assert(devices.count(spec));
  70
  71                         const DeviceInfo &dev = devices.find(spec)->second;
  72                         if (remaining_devices.count(spec) &&
  73                             dev.display_name == device_proto.display_name()) {
  74                                 device_mapping.push_back(spec);
  75                                 remaining_devices.erase(spec);
  76                                 goto found_capture_card;
  77                         }
  78
  79                         // Scan and see if there's a match on name alone.
  80                         for (const DeviceSpec &spec : remaining_devices) {
  81                                 if (spec.type == InputSourceType::CAPTURE_CARD &&
  82                                     dev.display_name == device_proto.display_name()) {
  83                                         device_mapping.push_back(spec);
  84                                         remaining_devices.erase(spec);
  85                                         goto found_capture_card;
  86                                 }
  87                         }
  88
  89                         // OK, see if at least the index is free.
  90                         if (remaining_devices.count(spec)) {
  91                                 device_mapping.push_back(spec);
  92                                 remaining_devices.erase(spec);
  93                                 goto found_capture_card;
  94                         }
  95
  96                         // Give up.
  97                         device_mapping.push_back(DeviceSpec{InputSourceType::SILENCE, 0});
  98 found_capture_card:
  99                         break;
 100                 }
 101                 case DeviceSpecProto::ALSA_INPUT: {
 102                         // For ALSA, we don't really care about index, but we can use address
 103                         // in its place.
 104
 105                         // First see if there's a card that matches on name, num_channels and address.
 106                         for (const DeviceSpec &spec : remaining_devices) {
 107                                 assert(devices.count(spec));
 108                                 const DeviceInfo &dev = devices.find(spec)->second;
 109                                 if (spec.type == InputSourceType::ALSA_INPUT &&
 110                                     dev.alsa_name == device_proto.alsa_name() &&
 111                                     dev.alsa_info == device_proto.alsa_info() &&
 112                                     int(dev.num_channels) == device_proto.num_channels() &&
 113                                     dev.alsa_address == device_proto.address()) {
 114                                         device_mapping.push_back(spec);
 115                                         remaining_devices.erase(spec);
 116                                         goto found_alsa_input;
 117                                 }
 118                         }
 119
 120                         // Looser check: Ignore the address.
 121                         for (const DeviceSpec &spec : remaining_devices) {
 122                                 assert(devices.count(spec));
 123                                 const DeviceInfo &dev = devices.find(spec)->second;
 124                                 if (spec.type == InputSourceType::ALSA_INPUT &&
 125                                     dev.alsa_name == device_proto.alsa_name() &&
 126                                     dev.alsa_info == device_proto.alsa_info() &&
 127                                     int(dev.num_channels) == device_proto.num_channels()) {
 128                                         device_mapping.push_back(spec);
 129                                         remaining_devices.erase(spec);
 130                                         goto found_alsa_input;
 131                                 }
 132                         }
 133
 134                         // OK, so we couldn't map this to a device, but perhaps one is added
 135                         // at some point in the future through hotplug. Create a dead card
 136                         // matching this one; right now, it will give only silence,
 137                         // but it could be replaced with something later.
 138                         //
 139                         // NOTE: There's a potential race condition here, if the card
 140                         // gets inserted while we're doing the device remapping
 141                         // (or perhaps more realistically, while we're reading the
 142                         // input mapping from disk).
 143                         DeviceSpec dead_card_spec;
 144                         dead_card_spec = global_audio_mixer->create_dead_card(
 145                                 device_proto.alsa_name(), device_proto.alsa_info(), device_proto.num_channels());
 146                         device_mapping.push_back(dead_card_spec);
 147
 148 found_alsa_input:
 149                         break;
 150                 }
 151                 default:
 152                         assert(false);
 153                 }
 154         }
 155
 156         for (const BusProto &bus_proto : mapping_proto.bus()) {
 157                 if (bus_proto.device_index() < 0 || unsigned(bus_proto.device_index()) >= device_mapping.size()) {
 158                         return false;
 159                 }
 160                 InputMapping::Bus bus;
 161                 bus.name = bus_proto.name();
 162                 bus.device = device_mapping[bus_proto.device_index()];
 163                 bus.source_channel[0] = bus_proto.source_channel_left();
 164                 bus.source_channel[1] = bus_proto.source_channel_right();
 165                 new_mapping->buses.push_back(bus);
 166         }
 167
 168         return true;
 169 }