Method FindPlugin

src/effects/vamp/LoadVamp.cpp:251–325

// VampEffectsModule implementation

std::unique_ptr<Vamp::Plugin> VampEffectsModule::FindPlugin(const PluginPath & path,
                                      int & output,
                                      bool & hasParameters)
{
   PluginLoader::PluginKey key = path.BeforeFirst(wxT('/')).ToUTF8().data();

   std::unique_ptr<Plugin> vp{ PluginLoader::getInstance()->loadPlugin(key, 48000) }; // rate doesn't matter here
   if (!vp)
   {
      return nullptr;
   }

   // We limit the listed plugin outputs to those whose results can
   // readily be displayed in an Audacity label track.
   //
   // - Any output whose features have no values (time instants only),
   //   with or without duration, is fine
   //
   // - Any output whose features have more than one value, or an
   //   unknown or variable number of values, is right out
   //
   // - Any output whose features have exactly one value, with
   //   variable sample rate or with duration, should be OK --
   //   this implies a sparse feature, of which the time and/or
   //   duration are significant aspects worth displaying
   //
   // - An output whose features have exactly one value, with
   //   fixed sample rate and no duration, cannot be usefully
   //   displayed -- the value is the only significant piece of
   //   data there and we have no good value plot

   Plugin::OutputList outputs = vp->getOutputDescriptors();

   output = 0;

   hasParameters = !vp->getParameterDescriptors().empty();

   for (Plugin::OutputList::iterator j = outputs.begin(); j != outputs.end(); ++j)
   {
      if (j->sampleType == Plugin::OutputDescriptor::FixedSampleRate ||
            j->sampleType == Plugin::OutputDescriptor::OneSamplePerStep ||
            !j->hasFixedBinCount ||
            j->binCount > 1)
      {
         // All of these qualities disqualify (see notes above)

         ++output;
         continue;
      }

      wxString name = wxString::FromUTF8(vp->getName().c_str());

      if (outputs.size() > 1)
      {
         // This is not the plugin's only output.
         // Use "plugin name: output name" as the effect name,
         // unless the output name is the same as the plugin name
         wxString outputName = wxString::FromUTF8(j->name.c_str());