Merge pull request #14 from r9y9/synthesis-filters

Synthesis filters

docs/api.rst

@@ -1,8 +1,11 @@
-API
-===
+SPTK API
+========
 
 All functionality in ``pysptk.sptk`` is directly accesible from the top-level ``pysptk.*`` namespace.
 
 .. note:: Almost all of pysptk functions assume that the input array is **C-contiguous** and has ``float64`` element type.
 
 .. automodule:: pysptk.sptk
+
+
+.. automodule:: pysptk.conversion

docs/conf.py

@@ -42,6 +42,7 @@
 ]
 
 autosummary_generate = True
+numpydoc_show_class_members = False
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -217,25 +218,25 @@
 # -- Options for LaTeX output ---------------------------------------------
 
 latex_elements = {
-# The paper size ('letterpaper' or 'a4paper').
-#'papersize': 'letterpaper',
+    # The paper size ('letterpaper' or 'a4paper').
+    #'papersize': 'letterpaper',
 
-# The font size ('10pt', '11pt' or '12pt').
-#'pointsize': '10pt',
+    # The font size ('10pt', '11pt' or '12pt').
+    #'pointsize': '10pt',
 
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
+    # Additional stuff for the LaTeX preamble.
+    #'preamble': '',
 
-# Latex figure (float) alignment
-#'figure_align': 'htbp',
+    # Latex figure (float) alignment
+    #'figure_align': 'htbp',
 }
 
 # Grouping the document tree into LaTeX files. List of tuples
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-  (master_doc, 'pysptk.tex', u'pysptk Documentation',
-   u'Ryuichi YAMAMOTO', 'manual'),
+    (master_doc, 'pysptk.tex', u'pysptk Documentation',
+     u'Ryuichi YAMAMOTO', 'manual'),
 ]
 
 # The name of an image file (relative to this directory) to place at the top of
@@ -278,9 +279,9 @@
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-  (master_doc, 'pysptk', u'pysptk Documentation',
-   author, 'pysptk', 'One line description of project.',
-   'Miscellaneous'),
+    (master_doc, 'pysptk', u'pysptk Documentation',
+     author, 'pysptk', 'One line description of project.',
+     'Miscellaneous'),
 ]
 
 # Documents to append as an appendix to all manuals.

docs/index.rst

@@ -15,6 +15,7 @@ API documentation
     :maxdepth: 2
 
     api
+    synthesis
 
 
 

docs/synthesis.rst

@@ -0,0 +1,4 @@
+High-level interface for waveform synthesis
+===========================================
+
+.. automodule:: pysptk.synthesis

pysptk/__init__.py

@@ -15,8 +15,7 @@
 <https://github.com/r9y9/SPTK>`_)
 """
 
-from __future__ import print_function
-from __future__ import absolute_import
+from __future__ import division, print_function, absolute_import
 
 import pkg_resources
 
@@ -33,6 +32,11 @@ def assert_pade(pade):
         raise ValueError("4 or 5 pade approximation is supported")
 
 
+def assert_stage(stage):
+    if stage < 1:
+        raise ValueError("stage >= 1 (-1 <= gamma < 0)")
+
+
 def ispow2(num):
     return ((num & (num - 1)) == 0) and num != 0
 
@@ -43,3 +47,6 @@ def assert_fftlen(fftlen):
 
 
 from .sptk import *  # pylint: disable=wildcard-import
+
+from . import synthesis
+from .conversion import mgc2b

pysptk/conversion.py

@@ -0,0 +1,60 @@
+# coding: utf-8
+
+"""
+Other conversions
+-----------------
+.. autosummary::
+    :toctree: generated/
+
+    mgc2b
+
+"""
+
+from __future__ import division, print_function, absolute_import
+
+import numpy as np
+
+from pysptk.sptk import mc2b, gnorm
+
+
+def mgc2b(mgc, alpha=0.35, gamma=0.0):
+    """Mel-generalized cepstrum to MGCLSA filter coefficients
+
+    Parameters
+    ----------
+    mgc : array, shape
+        Mel-generalized cepstrum
+
+    alpha : float
+        All-pass constant. Default is 0.35.
+
+    gamma : float
+        Parameter of generalized log function. Default is 0.0.
+
+    Returns
+    -------
+    b : array, shape(same as `mgc`)
+        MGLSA filter coefficients
+
+    See Also
+    --------
+    pysptk.sptk.mlsadf
+    pysptk.sptk.mglsadf
+    pysptk.sptk.mc2b
+    pysptk.sptk.b2mc
+    pysptk.sptk.mcep
+    pysptk.sptk.mgcep
+    pysptk.sptk.mgcep
+
+    """
+
+    b = mc2b(mgc, alpha)
+    if gamma == 0:
+        return b
+
+    b = gnorm(b, gamma)
+
+    b[0] = np.log(b[0])
+    b[1:] *= gamma
+
+    return b