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