ssrch_09.cc

这是一个从音频信号里提取特征参量的程序

// file: $isip/class/search/StackSearch/ssrch_09.cc
// version: $Id: ssrch_09.cc,v 1.3 2002/08/02 02:07:17 jelinek Exp $
//

// isip include files
//
#include "StackSearch.h"

// method: initializeLinearDecoder
//
// arguments: none
//
// return: logical error status
//
// initialize the lists, etc. needed to begin searching
//
boolean StackSearch::initializeLinearDecoder() {

  // make sure that we have at least one level defined
  //
  if (getNumLevels() < 1) {
    return Error::handle(name(), 
			 L"initializeLinearDecoder - read models first",
			 StackSearch::ERR_LEVELS_NOT_LOADED,
			 __FILE__, __LINE__);
  }
  
  // set the current frame
  //
  current_frame_d = 0; 

  // clear the valid_hyps_d list
  //
  clearTraceStorage();
  
  // clear the trace lists of all the search nodes
  //
  clearSearchNodesTraceLists();

  // generate all initial right context traces
  //
  generateInitialTraces();
  
  // exit gracefully
  //
  return true;
}

// method: generateInitialTraces
//
// arguments: none
//
// return: logical error status
//
// generate one trace for each right context at the top level
//
boolean StackSearch::generateInitialTraces() {

  // get the position of the central item in the context
  //
  long central_pos = search_levels_d(0).getRightContext() + 1;

  // get the total context length
  //
  long total_context_length = search_levels_d(0).getLeftContext()
                                                          + central_pos;
  
  // initialize the left context
  //
  Context left_context(total_context_length, central_pos);
  for (long i = 0; i < central_pos; i++) {
    left_context.assignAndAdvance(
                   (ulong)search_levels_d(0).getSubGraph(0).getStart()
		   );
  }

  // output the debugging information
  //
  if (debug_level_d >= Integral::ALL) {
    left_context.print();
  }
  
  // generate all possible right contexts by extending left context to
  // the depth of the right context
  //
  DoubleLinkedList<Context> right_context_list(DstrBase::USER);
  generateRightContexts(right_context_list, left_context,
			search_levels_d(0).getRightContext());
  
  // generate trace for each of above generated right contexts
  //
  for (boolean more_items = right_context_list.gotoFirst();
       more_items; more_items = right_context_list.gotoNext()) {
    
    // seed the top trace list with the start node of the search graph
    //
    Trace* tmp_trace = new Trace();
    tmp_trace ->setFrame((ulong)current_frame_d);
    tmp_trace->setBackPointer((Trace*)NULL);
    tmp_trace->getHistory()->push(right_context_list.getCurr());
    
    // add the start trace to the list
    //
    trace_lists_d(0).insertLast(tmp_trace);
    
    // output the debugging information
    //
    if (debug_level_d >= Integral::ALL) {
      String out;
      out.concat(L"initial trace: ");
      out.concat(tmp_trace);
      Console::put(out);
      printNewPath(tmp_trace, (Trace*)NULL);
    }
  }
    
  // clear the list of generated right contexts, since it is not needed
  //
  right_context_list.setAllocationMode(DstrBase::SYSTEM);
  right_context_list.clear();

  // exit gracefully
  //
  return true;
}

// method: initSizes
//
// arguments:
//  long total_num_frames: (input) total number of frames to decode
//
// return: logical error status
//
// set the features, initialize stacks and maximal stack scores
//
boolean StackSearch::initSizes(long total_num_frames_a) {

  if (total_num_frames_a > MAX_NUM_FRAMES) {
    return Error::handle(name(), L"initSizes - too long file to decode",
			 Error::ARG, __FILE__, __LINE__);
  }

  // allocate and initialize maximal scores for each stack
  //
  for (long i = 0; i <= total_num_frames_a; i++) {
    max_stack_scores_d(i) = Trace::INACTIVE_SCORE;
  }

  // check whether the search levels are loaded
  //
  if (getNumLevels() < 1) {
    return Error::handle(name(), 
			 L"setFeatures - read models first",
			 StackSearch::ERR_LEVELS_NOT_LOADED,
			 __FILE__, __LINE__);
  }
  
  // check whether the statistical models are loaded
  //
  long stat_models_dim =
    search_levels_d(DEF_NUM_LEVELS - 1).getStatisticalModels().length();
  if (stat_models_dim == 0) {
    return Error::handle(name(),
			 L"setFeatures - read models first",
			 StackSearch::ERR_LEVELS_NOT_LOADED,
			 __FILE__, __LINE__);
  }
  stat_model_scores_d.setDimensions(MAX_NUM_FRAMES, stat_models_dim);
  
  // initialize maximal trace scores at each frame for all levels and
  // statistical model scores for each frame and each statistical
  // model
  //
  for (long i = 0; i < total_num_frames_a; i++) {
    for (long j = 0; j < getNumLevels(); j++) {
      max_frame_scores_d.setValue(i, j, Trace::INACTIVE_SCORE);
    }
    for (long j = 0; j < stat_models_dim; j++) {
      stat_model_scores_d.setValue(i, j, Trace::INACTIVE_SCORE);
    }
  }
  
  // exit gracefully
  //
  return true;
}