add implementation for kaldi io (by ymz)

1 files changed, 346 insertions, 0 deletions

diff --git a/kaldi_io/src/kaldi/base/kaldi-math.h b/kaldi_io/src/kaldi/base/kaldi-math.h
new file mode 100644
index 0000000..4f60d00
--- /dev/null
+++ b/kaldi_io/src/kaldi/base/kaldi-math.h
@@ -0,0 +1,346 @@
+// base/kaldi-math.h
+
+// Copyright 2009-2011  Ondrej Glembek;  Microsoft Corporation;  Yanmin Qian;
+//                      Jan Silovsky;  Saarland University
+//
+// See ../../COPYING for clarification regarding multiple authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//  http://www.apache.org/licenses/LICENSE-2.0
+//
+// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
+// WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
+// MERCHANTABLITY OR NON-INFRINGEMENT.
+// See the Apache 2 License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef KALDI_BASE_KALDI_MATH_H_
+#define KALDI_BASE_KALDI_MATH_H_ 1
+
+#ifdef _MSC_VER
+#include <float.h>
+#endif
+
+#include <cmath>
+#include <limits>
+#include <vector>
+
+#include "base/kaldi-types.h"
+#include "base/kaldi-common.h"
+
+
+#ifndef DBL_EPSILON
+#define DBL_EPSILON 2.2204460492503131e-16
+#endif
+#ifndef FLT_EPSILON
+#define FLT_EPSILON 1.19209290e-7f
+#endif
+
+#ifndef M_PI
+#  define M_PI 3.1415926535897932384626433832795
+#endif
+
+#ifndef M_SQRT2
+#  define M_SQRT2 1.4142135623730950488016887
+#endif
+
+
+#ifndef M_2PI
+#  define M_2PI 6.283185307179586476925286766559005
+#endif
+
+#ifndef M_SQRT1_2
+# define M_SQRT1_2 0.7071067811865475244008443621048490
+#endif
+
+#ifndef M_LOG_2PI
+#define M_LOG_2PI 1.8378770664093454835606594728112
+#endif
+
+#ifndef M_LN2
+#define M_LN2 0.693147180559945309417232121458
+#endif
+
+#ifdef _MSC_VER
+#  define KALDI_ISNAN _isnan
+#  define KALDI_ISINF(x) (!_isnan(x) && _isnan(x-x))
+#  define KALDI_ISFINITE _finite
+#else
+#  define KALDI_ISNAN std::isnan
+#  define KALDI_ISINF std::isinf
+#  define KALDI_ISFINITE(x) std::isfinite(x)
+#endif
+#if !defined(KALDI_SQR)
+# define KALDI_SQR(x) ((x) * (x))
+#endif
+
+namespace kaldi {
+
+// -infinity
+const float kLogZeroFloat = -std::numeric_limits<float>::infinity();
+const double kLogZeroDouble = -std::numeric_limits<double>::infinity();
+const BaseFloat kLogZeroBaseFloat = -std::numeric_limits<BaseFloat>::infinity();
+
+// Returns a random integer between 0 and RAND_MAX, inclusive
+int Rand(struct RandomState* state=NULL);
+
+// State for thread-safe random number generator
+struct RandomState {
+  RandomState();
+  unsigned seed;
+};
+
+// Returns a random integer between min and max inclusive.
+int32 RandInt(int32 min, int32 max, struct RandomState* state=NULL);
+
+bool WithProb(BaseFloat prob, struct RandomState* state=NULL); // Returns true with probability "prob",
+// with 0 <= prob <= 1 [we check this].
+// Internally calls Rand().  This function is carefully implemented so
+// that it should work even if prob is very small.
+
+/// Returns a random number strictly between 0 and 1.
+inline float RandUniform(struct RandomState* state = NULL) {
+  return static_cast<float>((Rand(state) + 1.0) / (RAND_MAX+2.0));
+}
+
+inline float RandGauss(struct RandomState* state = NULL) {
+  return static_cast<float>(sqrtf (-2 * logf(RandUniform(state)))
+                            * cosf(2*M_PI*RandUniform(state)));
+}
+
+// Returns poisson-distributed random number.  Uses Knuth's algorithm.
+// Take care: this takes time proportinal
+// to lambda.  Faster algorithms exist but are more complex.
+int32 RandPoisson(float lambda, struct RandomState* state=NULL);
+
+// Returns a pair of gaussian random numbers. Uses Box-Muller transform
+void RandGauss2(float *a, float *b, RandomState *state = NULL);
+void RandGauss2(double *a, double *b, RandomState *state = NULL);
+
+// Also see Vector<float,double>::RandCategorical().
+
+// This is a randomized pruning mechanism that preserves expectations,
+// that we typically use to prune posteriors.
+template<class Float>
+inline Float RandPrune(Float post, BaseFloat prune_thresh, struct RandomState* state=NULL) {
+  KALDI_ASSERT(prune_thresh >= 0.0);
+  if (post == 0.0 || std::abs(post) >= prune_thresh)
+    return post;
+  return (post >= 0 ? 1.0 : -1.0) *
+      (RandUniform(state) <= fabs(post)/prune_thresh ? prune_thresh : 0.0);
+}
+
+static const double kMinLogDiffDouble = std::log(DBL_EPSILON);  // negative!
+static const float kMinLogDiffFloat = std::log(FLT_EPSILON);  // negative!
+
+inline double LogAdd(double x, double y) {
+  double diff;
+  if (x < y) {
+    diff = x - y;
+    x = y;
+  } else {
+    diff = y - x;
+  }
+  // diff is negative.  x is now the larger one.
+
+  if (diff >= kMinLogDiffDouble) {
+    double res;
+#ifdef _MSC_VER
+    res = x + log(1.0 + exp(diff));
+#else
+    res = x + log1p(exp(diff));
+#endif
+    return res;
+  } else {
+    return x;  // return the larger one.
+  }
+}
+
+
+inline float LogAdd(float x, float y) {
+  float diff;
+  if (x < y) {
+    diff = x - y;
+    x = y;
+  } else {
+    diff = y - x;
+  }
+  // diff is negative.  x is now the larger one.
+
+  if (diff >= kMinLogDiffFloat) {
+    float res;
+#ifdef _MSC_VER
+    res = x + logf(1.0 + expf(diff));
+#else
+    res = x + log1pf(expf(diff));
+#endif
+    return res;
+  } else {
+    return x;  // return the larger one.
+  }
+}
+
+
+// returns exp(x) - exp(y).
+inline double LogSub(double x, double y) {
+  if (y >= x) {  // Throws exception if y>=x.
+    if (y == x)
+      return kLogZeroDouble;
+    else
+      KALDI_ERR << "Cannot subtract a larger from a smaller number.";
+  }
+
+  double diff = y - x;  // Will be negative.
+  double res = x + log(1.0 - exp(diff));
+
+  // res might be NAN if diff ~0.0, and 1.0-exp(diff) == 0 to machine precision
+  if (KALDI_ISNAN(res))
+    return kLogZeroDouble;
+  return res;
+}
+
+
+// returns exp(x) - exp(y).
+inline float LogSub(float x, float y) {
+  if (y >= x) {  // Throws exception if y>=x.
+    if (y == x)
+      return kLogZeroDouble;
+    else
+      KALDI_ERR << "Cannot subtract a larger from a smaller number.";
+  }
+
+  float diff = y - x;  // Will be negative.
+  float res = x + logf(1.0 - expf(diff));
+
+  // res might be NAN if diff ~0.0, and 1.0-exp(diff) == 0 to machine precision
+  if (KALDI_ISNAN(res))
+    return kLogZeroFloat;
+  return res;
+}
+
+/// return abs(a - b) <= relative_tolerance * (abs(a)+abs(b)).
+static inline bool ApproxEqual(float a, float b,
+                               float relative_tolerance = 0.001) {
+  // a==b handles infinities.
+  if (a==b) return true;
+  float diff = std::abs(a-b);
+  if (diff == std::numeric_limits<float>::infinity()
+      || diff != diff) return false; // diff is +inf or nan.
+  return (diff <= relative_tolerance*(std::abs(a)+std::abs(b))); 
+}
+
+/// assert abs(a - b) <= relative_tolerance * (abs(a)+abs(b))
+static inline void AssertEqual(float a, float b,
+                               float relative_tolerance = 0.001) {
+  // a==b handles infinities.
+  KALDI_ASSERT(ApproxEqual(a, b, relative_tolerance));
+}
+
+
+// RoundUpToNearestPowerOfTwo does the obvious thing. It crashes if n <= 0.
+int32 RoundUpToNearestPowerOfTwo(int32 n);
+
+template<class I> I  Gcd(I m, I n) {
+  if (m == 0 || n == 0) {
+    if (m == 0 && n == 0) {  // gcd not defined, as all integers are divisors.
+      KALDI_ERR << "Undefined GCD since m = 0, n = 0.";
+    }
+    return (m == 0 ? (n > 0 ? n : -n) : ( m > 0 ? m : -m));
+    // return absolute value of whichever is nonzero
+  }
+  // could use compile-time assertion
+  // but involves messing with complex template stuff.
+  KALDI_ASSERT(std::numeric_limits<I>::is_integer);
+  while (1) {
+    m %= n;
+    if (m == 0) return (n > 0 ? n : -n);
+    n %= m;
+    if (n == 0) return (m > 0 ? m : -m);
+  }
+}
+
+/// Returns the least common multiple of two integers.  Will
+/// crash unless the inputs are positive.
+template<class I> I  Lcm(I m, I n) {
+  KALDI_ASSERT(m > 0 && n > 0);
+  I gcd = Gcd(m, n);
+  return gcd * (m/gcd) * (n/gcd);
+}
+
+
+template<class I> void Factorize(I m, std::vector<I> *factors) {
+  // Splits a number into its prime factors, in sorted order from
+  // least to greatest,  with duplication.  A very inefficient
+  // algorithm, which is mainly intended for use in the
+  // mixed-radix FFT computation (where we assume most factors
+  // are small).
+  KALDI_ASSERT(factors != NULL);
+  KALDI_ASSERT(m >= 1);  // Doesn't work for zero or negative numbers.
+  factors->clear();
+  I small_factors[10] = { 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 };
+
+  // First try small factors.
+  for (I i = 0; i < 10; i++) {
+    if (m == 1) return;  // We're done.
+    while (m % small_factors[i] == 0) {
+      m /= small_factors[i];
+      factors->push_back(small_factors[i]);
+    }
+  }
+  // Next try all odd numbers starting from 31.
+  for (I j = 31;; j += 2) {
+    if (m == 1) return;
+    while (m % j == 0) {
+      m /= j;
+      factors->push_back(j);
+    }
+  }
+}
+
+inline double Hypot(double x, double y) {  return hypot(x, y); }
+
+inline float Hypot(float x, float y) {  return hypotf(x, y); }
+
+#if !defined(_MSC_VER) || (_MSC_VER >= 1800)
+inline double Log1p(double x) {  return log1p(x); }
+
+inline float Log1p(float x) {  return log1pf(x); }
+#else
+inline double Log1p(double x) {
+    const double cutoff = 1.0e-08;
+    if (x < cutoff)
+        return x - 2 * x * x;
+    else 
+        return log(1.0 + x);
+}
+
+inline float Log1p(float x) {
+    const float cutoff = 1.0e-07;
+    if (x < cutoff)
+        return x - 2 * x * x;
+    else 
+        return log(1.0 + x);
+}
+#endif
+
+inline double Exp(double x) { return exp(x); }
+
+#ifndef KALDI_NO_EXPF
+inline float Exp(float x) { return expf(x); }
+#else
+inline float Exp(float x) { return exp(x); }
+#endif
+
+inline double Log(double x) { return log(x); }
+
+inline float Log(float x) { return logf(x); }
+
+
+}  // namespace kaldi
+
+
+#endif  // KALDI_BASE_KALDI_MATH_H_