core/ambdec.cpp

   1
   2 #include "config.h"
   3
   4 #include "ambdec.h"
   5
   6 #include <algorithm>
   7 #include <cctype>
   8 #include <cstdarg>
   9 #include <cstddef>
  10 #include <cstdio>
  11 #include <iterator>
  12 #include <sstream>
  13 #include <string>
  14
  15 #include "albit.h"
  16 #include "alfstream.h"
  17 #include "alspan.h"
  18 #include "opthelpers.h"
  19
  20
  21 namespace {
  22
  23 std::string read_word(std::istream &f)
  24 {
  25     std::string ret;
  26     f >> ret;
  27     return ret;
  28 }
  29
  30 bool is_at_end(const std::string &buffer, std::size_t endpos)
  31 {
  32     while(endpos < buffer.length() && std::isspace(buffer[endpos]))
  33         ++endpos;
  34     return !(endpos < buffer.length() && buffer[endpos] != '#');
  35 }
  36
  37
  38 enum class ReaderScope {
  39     Global,
  40     Speakers,
  41     LFMatrix,
  42     HFMatrix,
  43 };
  44
  45 #ifdef __USE_MINGW_ANSI_STDIO
  46 [[gnu::format(gnu_printf,2,3)]]
  47 #else
  48 [[gnu::format(printf,2,3)]]
  49 #endif
  50 al::optional<std::string> make_error(size_t linenum, const char *fmt, ...)
  51 {
  52     al::optional<std::string> ret;
  53     auto &str = ret.emplace();
  54
  55     str.resize(256);
  56     int printed{std::snprintf(const_cast<char*>(str.data()), str.length(), "Line %zu: ", linenum)};
  57     if(printed < 0) printed = 0;
  58     auto plen = std::min(static_cast<size_t>(printed), str.length());
  59
  60     std::va_list args, args2;
  61     va_start(args, fmt);
  62     va_copy(args2, args);
  63     const int msglen{std::vsnprintf(&str[plen], str.size()-plen, fmt, args)};
  64     if(msglen >= 0 && static_cast<size_t>(msglen) >= str.size()-plen) [[unlikely]]
  65     {
  66         str.resize(static_cast<size_t>(msglen) + plen + 1u);
  67         std::vsnprintf(&str[plen], str.size()-plen, fmt, args2);
  68     }
  69     va_end(args2);
  70     va_end(args);
  71
  72     return ret;
  73 }
  74
  75 } // namespace
  76
  77 AmbDecConf::~AmbDecConf() = default;
  78
  79
  80 al::optional<std::string> AmbDecConf::load(const char *fname) noexcept
  81 {
  82     al::ifstream f{fname};
  83     if(!f.is_open())
  84         return std::string("Failed to open file \"")+fname+"\"";
  85
  86     ReaderScope scope{ReaderScope::Global};
  87     size_t speaker_pos{0};
  88     size_t lfmatrix_pos{0};
  89     size_t hfmatrix_pos{0};
  90     size_t linenum{0};
  91
  92     std::string buffer;
  93     while(f.good() && std::getline(f, buffer))
  94     {
  95         ++linenum;
  96
  97         std::istringstream istr{buffer};
  98         std::string command{read_word(istr)};
  99         if(command.empty() || command[0] == '#')
 100             continue;
 101
 102         if(command == "/}")
 103         {
 104             if(scope == ReaderScope::Global)
 105                 return make_error(linenum, "Unexpected /} in global scope");
 106             scope = ReaderScope::Global;
 107             continue;
 108         }
 109
 110         if(scope == ReaderScope::Speakers)
 111         {
 112             if(command == "add_spkr")
 113             {
 114                 if(speaker_pos == NumSpeakers)
 115                     return make_error(linenum, "Too many speakers specified");
 116
 117                 AmbDecConf::SpeakerConf &spkr = Speakers[speaker_pos++];
 118                 istr >> spkr.Name;
 119                 istr >> spkr.Distance;
 120                 istr >> spkr.Azimuth;
 121                 istr >> spkr.Elevation;
 122                 istr >> spkr.Connection;
 123             }
 124             else
 125                 return make_error(linenum, "Unexpected speakers command: %s", command.c_str());
 126         }
 127         else if(scope == ReaderScope::LFMatrix || scope == ReaderScope::HFMatrix)
 128         {
 129             auto &gains = (scope == ReaderScope::LFMatrix) ? LFOrderGain : HFOrderGain;
 130             auto *matrix = (scope == ReaderScope::LFMatrix) ? LFMatrix : HFMatrix;
 131             auto &pos = (scope == ReaderScope::LFMatrix) ? lfmatrix_pos : hfmatrix_pos;
 132
 133             if(command == "order_gain")
 134             {
 135                 size_t toread{(ChanMask > Ambi3OrderMask) ? 5u : 4u};
 136                 std::size_t curgain{0u};
 137                 float value{};
 138                 while(toread)
 139                 {
 140                     --toread;
 141                     istr >> value;
 142                     if(curgain < al::size(gains))
 143                         gains[curgain++] = value;
 144                 }
 145             }
 146             else if(command == "add_row")
 147             {
 148                 if(pos == NumSpeakers)
 149                     return make_error(linenum, "Too many matrix rows specified");
 150
 151                 unsigned int mask{ChanMask};
 152
 153                 AmbDecConf::CoeffArray &mtxrow = matrix[pos++];
 154                 mtxrow.fill(0.0f);
 155
 156                 float value{};
 157                 while(mask)
 158                 {
 159                     auto idx = static_cast<unsigned>(al::countr_zero(mask));
 160                     mask &= ~(1u << idx);
 161
 162                     istr >> value;
 163                     if(idx < mtxrow.size())
 164                         mtxrow[idx] = value;
 165                 }
 166             }
 167             else
 168                 return make_error(linenum, "Unexpected matrix command: %s", command.c_str());
 169         }
 170         // Global scope commands
 171         else if(command == "/description")
 172         {
 173             while(istr.good() && std::isspace(istr.peek()))
 174                 istr.ignore();
 175             std::getline(istr, Description);
 176             while(!Description.empty() && std::isspace(Description.back()))
 177                 Description.pop_back();
 178         }
 179         else if(command == "/version")
 180         {
 181             if(Version)
 182                 return make_error(linenum, "Duplicate version definition");
 183             istr >> Version;
 184             if(Version != 3)
 185                 return make_error(linenum, "Unsupported version: %d", Version);
 186         }
 187         else if(command == "/dec/chan_mask")
 188         {
 189             if(ChanMask)
 190                 return make_error(linenum, "Duplicate chan_mask definition");
 191             istr >> std::hex >> ChanMask >> std::dec;
 192
 193             if(!ChanMask || ChanMask > Ambi4OrderMask)
 194                 return make_error(linenum, "Invalid chan_mask: 0x%x", ChanMask);
 195             if(ChanMask > Ambi3OrderMask && CoeffScale == AmbDecScale::FuMa)
 196                 return make_error(linenum, "FuMa not compatible with over third-order");
 197         }
 198         else if(command == "/dec/freq_bands")
 199         {
 200             if(FreqBands)
 201                 return make_error(linenum, "Duplicate freq_bands");
 202             istr >> FreqBands;
 203             if(FreqBands != 1 && FreqBands != 2)
 204                 return make_error(linenum, "Invalid freq_bands: %u", FreqBands);
 205         }
 206         else if(command == "/dec/speakers")
 207         {
 208             if(NumSpeakers)
 209                 return make_error(linenum, "Duplicate speakers");
 210             istr >> NumSpeakers;
 211             if(!NumSpeakers)
 212                 return make_error(linenum, "Invalid speakers: %zu", NumSpeakers);
 213             Speakers = std::make_unique<SpeakerConf[]>(NumSpeakers);
 214         }
 215         else if(command == "/dec/coeff_scale")
 216         {
 217             if(CoeffScale != AmbDecScale::Unset)
 218                 return make_error(linenum, "Duplicate coeff_scale");
 219
 220             std::string scale{read_word(istr)};
 221             if(scale == "n3d") CoeffScale = AmbDecScale::N3D;
 222             else if(scale == "sn3d") CoeffScale = AmbDecScale::SN3D;
 223             else if(scale == "fuma") CoeffScale = AmbDecScale::FuMa;
 224             else
 225                 return make_error(linenum, "Unexpected coeff_scale: %s", scale.c_str());
 226
 227             if(ChanMask > Ambi3OrderMask && CoeffScale == AmbDecScale::FuMa)
 228                 return make_error(linenum, "FuMa not compatible with over third-order");
 229         }
 230         else if(command == "/opt/xover_freq")
 231         {
 232             istr >> XOverFreq;
 233         }
 234         else if(command == "/opt/xover_ratio")
 235         {
 236             istr >> XOverRatio;
 237         }
 238         else if(command == "/opt/input_scale" || command == "/opt/nfeff_comp"
 239             || command == "/opt/delay_comp" || command == "/opt/level_comp")
 240         {
 241             /* Unused */
 242             read_word(istr);
 243         }
 244         else if(command == "/speakers/{")
 245         {
 246             if(!NumSpeakers)
 247                 return make_error(linenum, "Speakers defined without a count");
 248             scope = ReaderScope::Speakers;
 249         }
 250         else if(command == "/lfmatrix/{" || command == "/hfmatrix/{" || command == "/matrix/{")
 251         {
 252             if(!NumSpeakers)
 253                 return make_error(linenum, "Matrix defined without a speaker count");
 254             if(!ChanMask)
 255                 return make_error(linenum, "Matrix defined without a channel mask");
 256
 257             if(!Matrix)
 258             {
 259                 Matrix = std::make_unique<CoeffArray[]>(NumSpeakers * FreqBands);
 260                 LFMatrix = Matrix.get();
 261                 HFMatrix = LFMatrix + NumSpeakers*(FreqBands-1);
 262             }
 263
 264             if(FreqBands == 1)
 265             {
 266                 if(command != "/matrix/{")
 267                     return make_error(linenum, "Unexpected \"%s\" for a single-band decoder",
 268                         command.c_str());
 269                 scope = ReaderScope::HFMatrix;
 270             }
 271             else
 272             {
 273                 if(command == "/lfmatrix/{")
 274                     scope = ReaderScope::LFMatrix;
 275                 else if(command == "/hfmatrix/{")
 276                     scope = ReaderScope::HFMatrix;
 277                 else
 278                     return make_error(linenum, "Unexpected \"%s\" for a dual-band decoder",
 279                         command.c_str());
 280             }
 281         }
 282         else if(command == "/end")
 283         {
 284             const auto endpos = static_cast<std::size_t>(istr.tellg());
 285             if(!is_at_end(buffer, endpos))
 286                 return make_error(linenum, "Extra junk on end: %s", buffer.substr(endpos).c_str());
 287
 288             if(speaker_pos < NumSpeakers || hfmatrix_pos < NumSpeakers
 289                 || (FreqBands == 2 && lfmatrix_pos < NumSpeakers))
 290                 return make_error(linenum, "Incomplete decoder definition");
 291             if(CoeffScale == AmbDecScale::Unset)
 292                 return make_error(linenum, "No coefficient scaling defined");
 293
 294             return al::nullopt;
 295         }
 296         else
 297             return make_error(linenum, "Unexpected command: %s", command.c_str());
 298
 299         istr.clear();
 300         const auto endpos = static_cast<std::size_t>(istr.tellg());
 301         if(!is_at_end(buffer, endpos))
 302             return make_error(linenum, "Extra junk on line: %s", buffer.substr(endpos).c_str());
 303         buffer.clear();
 304     }
 305     return make_error(linenum, "Unexpected end of file");
 306 }