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

   1 #include "input_mapping.h"
   2
   3 #include <assert.h>
   4 #include <fcntl.h>
   5 #include <google/protobuf/io/zero_copy_stream_impl.h>
   6 #include <google/protobuf/text_format.h>
   7 #include <stdio.h>
   8 #include <set>
   9 #include <utility>
  10
  11 #include "audio_mixer.h"
  12 #include "state.pb.h"
  13
  14 using namespace std;
  15 using namespace google::protobuf;
  16
  17 string spec_to_string(DeviceSpec device_spec)
  18 {
  19         char buf[256];
  20
  21         switch (device_spec.type) {
  22         case InputSourceType::SILENCE:
  23                 return "<silence>";
  24         case InputSourceType::CAPTURE_CARD:
  25                 snprintf(buf, sizeof(buf), "Capture card %u", device_spec.index);
  26                 return buf;
  27         case InputSourceType::ALSA_INPUT:
  28                 snprintf(buf, sizeof(buf), "ALSA input %u", device_spec.index);
  29                 return buf;
  30         default:
  31                 assert(false);
  32         }
  33 }
  34
  35 bool save_input_mapping_to_file(const map<DeviceSpec, DeviceInfo> &devices, const InputMapping &input_mapping, const string &filename)
  36 {
  37         InputMappingProto mapping_proto;
  38         {
  39                 map<DeviceSpec, unsigned> used_devices;
  40                 for (const InputMapping::Bus &bus : input_mapping.buses) {
  41                         if (!used_devices.count(bus.device)) {
  42                                 used_devices.emplace(bus.device, used_devices.size());
  43                                 global_audio_mixer->serialize_device(bus.device, mapping_proto.add_device());
  44                         }
  45
  46                         BusProto *bus_proto = mapping_proto.add_bus();
  47                         bus_proto->set_name(bus.name);
  48                         bus_proto->set_device_index(used_devices[bus.device]);
  49                         bus_proto->set_source_channel_left(bus.source_channel[0]);
  50                         bus_proto->set_source_channel_right(bus.source_channel[1]);
  51                 }
  52         }
  53
  54         // Save to disk. We use the text format because it's friendlier
  55         // for a user to look at and edit.
  56         int fd = open(filename.c_str(), O_WRONLY | O_TRUNC | O_CREAT, 0666);
  57         if (fd == -1) {
  58                 perror(filename.c_str());
  59                 return false;
  60         }
  61         io::FileOutputStream output(fd);  // Takes ownership of fd.
  62         if (!TextFormat::Print(mapping_proto, &output)) {
  63                 // TODO: Don't overwrite the old file (if any) on error.
  64                 output.Close();
  65                 return false;
  66         }
  67
  68         output.Close();
  69         return true;
  70 }
  71
  72 bool load_input_mapping_from_file(const map<DeviceSpec, DeviceInfo> &devices, const string &filename, InputMapping *new_mapping)
  73 {
  74         // Read and parse the protobuf from disk.
  75         int fd = open(filename.c_str(), O_RDONLY);
  76         if (fd == -1) {
  77                 perror(filename.c_str());
  78                 return false;
  79         }
  80         io::FileInputStream input(fd);  // Takes ownership of fd.
  81         InputMappingProto mapping_proto;
  82         if (!TextFormat::Parse(&input, &mapping_proto)) {
  83                 input.Close();
  84                 return false;
  85         }
  86         input.Close();
  87
  88         // Map devices in the proto to our current ones:
  89
  90         // Get a list of all active devices.
  91         set<DeviceSpec> remaining_devices;
  92         for (const auto &device_spec_and_info : devices) {
  93                 remaining_devices.insert(device_spec_and_info.first);
  94         }
  95
  96         // Now look at every device in the serialized protobuf and try to map
  97         // it to one device we haven't taken yet. This isn't a full maximal matching,
  98         // but it's good enough for our uses.
  99         vector<DeviceSpec> device_mapping;
 100         for (unsigned device_index = 0; device_index < unsigned(mapping_proto.device_size()); ++device_index) {
 101                 const DeviceSpecProto &device_proto = mapping_proto.device(device_index);
 102                 switch (device_proto.type()) {
 103                 case DeviceSpecProto::SILENCE:
 104                         device_mapping.push_back(DeviceSpec{InputSourceType::SILENCE, 0});
 105                         break;
 106                 case DeviceSpecProto::CAPTURE_CARD: {
 107                         // First see if there's a card that matches on both index and name.
 108                         DeviceSpec spec{InputSourceType::CAPTURE_CARD, unsigned(device_proto.index())};
 109                         assert(devices.count(spec));
 110                         const DeviceInfo &dev = devices.find(spec)->second;
 111                         if (remaining_devices.count(spec) &&
 112                             dev.display_name == device_proto.display_name()) {
 113                                 device_mapping.push_back(spec);
 114                                 remaining_devices.erase(spec);
 115                                 goto found_capture_card;
 116                         }
 117
 118                         // Scan and see if there's a match on name alone.
 119                         for (const DeviceSpec &spec : remaining_devices) {
 120                                 if (spec.type == InputSourceType::CAPTURE_CARD &&
 121                                     dev.display_name == device_proto.display_name()) {
 122                                         device_mapping.push_back(spec);
 123                                         remaining_devices.erase(spec);
 124                                         goto found_capture_card;
 125                                 }
 126                         }
 127
 128                         // OK, see if at least the index is free.
 129                         if (remaining_devices.count(spec)) {
 130                                 device_mapping.push_back(spec);
 131                                 remaining_devices.erase(spec);
 132                                 goto found_capture_card;
 133                         }
 134
 135                         // Give up.
 136                         device_mapping.push_back(DeviceSpec{InputSourceType::SILENCE, 0});
 137 found_capture_card:
 138                         break;
 139                 }
 140                 case DeviceSpecProto::ALSA_INPUT: {
 141                         // For ALSA, we don't really care about index, but we can use address
 142                         // in its place.
 143
 144                         // First see if there's a card that matches on name, num_channels and address.
 145                         for (const DeviceSpec &spec : remaining_devices) {
 146                                 assert(devices.count(spec));
 147                                 const DeviceInfo &dev = devices.find(spec)->second;
 148                                 if (spec.type == InputSourceType::ALSA_INPUT &&
 149                                     dev.alsa_name == device_proto.alsa_name() &&
 150                                     dev.alsa_info == device_proto.alsa_info() &&
 151                                     int(dev.num_channels) == device_proto.num_channels() &&
 152                                     dev.alsa_address == device_proto.address()) {
 153                                         device_mapping.push_back(spec);
 154                                         remaining_devices.erase(spec);
 155                                         goto found_alsa_input;
 156                                 }
 157                         }
 158
 159                         // Looser check: Ignore the address.
 160                         for (const DeviceSpec &spec : remaining_devices) {
 161                                 assert(devices.count(spec));
 162                                 const DeviceInfo &dev = devices.find(spec)->second;
 163                                 if (spec.type == InputSourceType::ALSA_INPUT &&
 164                                     dev.alsa_name == device_proto.alsa_name() &&
 165                                     dev.alsa_info == device_proto.alsa_info() &&
 166                                     int(dev.num_channels) == device_proto.num_channels()) {
 167                                         device_mapping.push_back(spec);
 168                                         remaining_devices.erase(spec);
 169                                         goto found_alsa_input;
 170                                 }
 171                         }
 172
 173                         // OK, so we couldn't map this to a device, but perhaps one is added
 174                         // at some point in the future through hotplug. Create a dead card
 175                         // matching this one; right now, it will give only silence,
 176                         // but it could be replaced with something later.
 177                         //
 178                         // NOTE: There's a potential race condition here, if the card
 179                         // gets inserted while we're doing the device remapping
 180                         // (or perhaps more realistically, while we're reading the
 181                         // input mapping from disk).
 182                         DeviceSpec dead_card_spec;
 183                         dead_card_spec = global_audio_mixer->create_dead_card(
 184                                 device_proto.alsa_name(), device_proto.alsa_info(), device_proto.num_channels());
 185                         device_mapping.push_back(dead_card_spec);
 186
 187 found_alsa_input:
 188                         break;
 189                 }
 190                 default:
 191                         assert(false);
 192                 }
 193         }
 194
 195         for (const BusProto &bus_proto : mapping_proto.bus()) {
 196                 if (bus_proto.device_index() < 0 || unsigned(bus_proto.device_index()) >= device_mapping.size()) {
 197                         return false;
 198                 }
 199                 InputMapping::Bus bus;
 200                 bus.name = bus_proto.name();
 201                 bus.device = device_mapping[bus_proto.device_index()];
 202                 bus.source_channel[0] = bus_proto.source_channel_left();
 203                 bus.source_channel[1] = bus_proto.source_channel_right();
 204                 new_mapping->buses.push_back(bus);
 205         }
 206
 207         return true;
 208 }