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