message: A couple of improvements to convert cmd, fail if format isn't explicit
diff: @@ -664,14 +664,14 @@ struct ConvertCommand : public Command
  if(infile.empty())
  {
  - std::cerr << "Need an input filename." << std::endl;
  + std::cerr << "Need an input filename (-f)." << std::endl << std::endl;
  std::cerr << parser.usage() << std::endl;
  return 1;
  }
  if(outfile.empty())
  {
  - std::cerr << "Need an output filename." << std::endl;
  + std::cerr << "Need an output filename (-o)." << std::endl << std::endl;
  std::cerr << parser.usage() << std::endl;
  return 1;
  }
  @@ -695,6 +695,13 @@ struct ConvertCommand : public Command
  }
  }
  + if(infmt.empty())
  + {
  + std::cerr << "Couldn't guess input format from filename." << std::endl << std::endl;
  + std::cerr << parser.usage() << std::endl;
  + return 1;
  + }
  +
  if(outfmt.empty())
  {
  // try to guess the format by looking for the extension in the filename
  @@ -711,6 +718,13 @@ struct ConvertCommand : public Command
  }
  }
  + if(outfmt.empty())
  + {
  + std::cerr << "Couldn't guess output format from filename." << std::endl << std::endl;
  + std::cerr << parser.usage() << std::endl;
  + return 1;
  + }
  +
  ICaptureFile *file = RENDERDOC_OpenCaptureFile();
  ReplayStatus st = file->OpenFile(infile.c_str(), infmt.c_str());
  