vector.c

spiht的压缩解压缩c编写的

#include "spiht.h"
#include "spihtdecode.h"

QccVector QccVectorAlloc(int vector_dimension)
{
  QccVector vector;

  if (vector_dimension <= 0)
    return(NULL);

  if ((vector = (QccVector)calloc(vector_dimension, sizeof(double))) == NULL)
    QccErrorAddMessage("(QccVectorAlloc): Error allocating memory");

  return(vector);
}

void QccVectorFree(QccVector vector)
{
  if (vector != NULL)
    free(vector);
}

int QccVectorZero(QccVector vector, int vector_dimension)
{
  int component;

  if ((vector == NULL) || (vector_dimension <= 0))
    return(0);
  for (component = 0; component < vector_dimension; component++)
    vector[component] = 0;

  return(0);
}

int QccVectorAdd(QccVector vector1, const QccVector vector2,
                 int vector_dimension)
{
  int component;

  if ((vector1 == NULL) || (vector2 == NULL) || (vector_dimension <= 0))
    return(0);
  for (component = 0; component < vector_dimension; component++)
    vector1[component] += vector2[component];

  return(0);
}

int QccVectorCopy(QccVector vector1, const QccVector vector2,
                  int vector_dimension)
{
  int component;

  if ((vector1 == NULL) || (vector2 == NULL) || (vector_dimension <= 0))
    return(0);

  for (component = 0; component < vector_dimension; component++)
    vector1[component] = vector2[component];

  return(0);
}

int QccVectorSubsample(const QccVector input_signal,
                       int input_length,
                       QccVector output_signal,
                       int output_length,
                       int sampling_flag)
{
  int index;

  if (input_signal == NULL)
    return(0);
  if (output_signal == NULL)
    return(0);

  switch (sampling_flag)
    {
    case QCCVECTOR_EVEN:
      for (index = 0;
           (index < output_length) && ((index * 2) < input_length);
           index++)
        output_signal[index] = input_signal[index * 2];
      break;
    case QCCVECTOR_ODD:
      for (index = 0;
           (index < output_length) && ((index * 2 + 1) < input_length);
           index++)
        output_signal[index] = input_signal[index * 2 + 1];
      break;
    default:
      QccErrorAddMessage("(QccVectorSubsample): Undefined sampling (%d)",
                         sampling_flag);
      return(1);
    }

  return(0);
}

int QccVectorUpsample(const QccVector input_signal,
                      int input_length,
                      QccVector output_signal,
                      int output_length,
                      int sampling_flag)
{
  int index;

  if (input_signal == NULL)
    return(0);
  if (output_signal == NULL)
    return(0);

  QccVectorZero(output_signal, output_length);

  switch (sampling_flag)
    {
    case QCCVECTOR_EVEN:
      for (index = 0;
           (index < input_length) && ((index * 2) < output_length);
           index++)
        output_signal[index * 2] = input_signal[index];
      break;
    case QCCVECTOR_ODD:
      for (index = 0;
           (index < input_length) && ((index * 2 + 1) < output_length);
           index++)
        output_signal[index * 2 + 1] = input_signal[index];
      break;
    default:
      QccErrorAddMessage("(QccVectorUpsample): Undefined sampling (%d)",
                         sampling_flag);
      return(1);
    }

  return(0);
}