lm_09.cc

这是一个从音频信号里提取特征参量的程序

// file: $isip/class/asr/LanguageModel/lm_09.cc
// version: $Id: lm_09.cc,v 1.6 2002/07/16 03:11:39 wang Exp $
//

// isip include files
//
#include "LanguageModel.h"
#include <Console.h>

// method: readJSGF
//
// arguments:
//      Sof& sof_a: (input) pointer pointing to the Sof file to be read
//      Vector<String>& nonspeech_symbol_list_a: (output) non-speech symbols
//      Vector<String>& sub_symbol_list_a: (output) symbol list
//      DiGraph<String>& graph_a: (output) graph converted from the file
//      String sub_graph_name_d: (output) grammar name for the graph
//
// return: a boolean value indicating status
//
boolean LanguageModel::readJSGF(Sof& sof_a,
				Vector<String>& nonspeech_symbol_list_a,
				Vector<String>& sub_symbol_list_a,
				DiGraph<String>& sub_graph_a,
				String& sub_graph_name_a) {

  // declare a JSGF parser
  //
  JSGFParser parser;

  // count the number of expression lines read into the parser
  //
  long expression_counter = 0;
  
  // a temporary string to hold each line of grammar in the following loop
  //
  String JSGF_line, grammar_str;
  sof_a.gets(JSGF_line, Sof::BUFFER_SIZE);
  
  // read all lines of the JSGF grammar file until
  // "};" indicating the end of the grammar is reached
  //
  while(!JSGF_line.eq(L"};", true)) {
  
    // read each line of the grammar file
    // and set the line as an expression in the JSGF parser
    //
    if(!JSGF_line.eq(L"", true)) {
      parser.setExpression(JSGF_line);
      expression_counter++;
      grammar_str.concat(JSGF_line);
      grammar_str.concat(L"\n");
    }

    // read next line
    //
    sof_a.gets(JSGF_line, Sof::BUFFER_SIZE);
  }

  // parse the JSGF grammar and convert it to a ISIP DiGraph in the parser
  //
  parser.parseJSGF(graph_start_d, graph_term_d);

  // check if this grammar is the definition for the non-speech symbols
  //
  if (isNonSpeechDefinition(grammar_str)) {
    nonspeech_symbol_list_a = parser.getSymbolList();
  }
  else {

    // pass symbol list of the current JSGF grammar
    //
    sub_symbol_list_a = parser.getSymbolList();

    // get the DiGraph from the parser
    //
    sub_graph_a = parser.getGraph();
    
    // get the grammar name from the parser
    //
    String graph_name = parser.getGrammarName();
    String sub_str;
    String delim(L". ;");
    long pos = 7;
    
    while(graph_name.tokenize(sub_str, pos, delim)) {
      sub_graph_name_a = sub_str;
    }
  } // else end
  
  // exit gracefully
  //
  return true;
}