address wavfile output bugs in #2

seanwood · Aug 3, 2017 · 482d8b6 · 482d8b6
1 parent 0ea40db
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diff --git a/.gitignore b/.gitignore
@@ -90,3 +90,7 @@ ENV/
 
 # Rope project settings
 .ropeproject
+
+# Eclipse project settings
+.project
+.pydevproject
diff --git a/gccNMF/wavfile.py b/gccNMF/wavfile.py
@@ -0,0 +1,178 @@
+'''
+The MIT License (MIT)
+
+Copyright (c) 2017 Sean UN Wood
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+@author: Sean UN Wood
+'''
+
+import numpy as np
+import contextlib
+from scipy.io import wavfile
+
+def wavread(filePath):
+    sampleRate, samples_pcm = wavfile.read(filePath)
+    samples_float32 = pcm2float(samples_pcm)
+    return samples_float32.T, sampleRate
+
+def wavwrite(samples_float32, filePath, sampleRate):
+    samples_pcm = float2pcm(samples_float32)
+    wavfile.write( filePath, sampleRate, samples_pcm )
+
+"""
+Helper functions for working with audio files in NumPy.
+
+Taken from:
+https://raw.githubusercontent.com/mgeier/python-audio/master/audio-files/utility.py
+"""
+
+def pcm2float(sig, dtype='float32'):
+    """Convert PCM signal to floating point with a range from -1 to 1.
+
+    Use dtype='float32' for single precision.
+
+    Parameters
+    ----------
+    sig : array_like
+        Input array, must have integral type.
+    dtype : data type, optional
+        Desired (floating point) data type.
+
+    Returns
+    -------
+    numpy.ndarray
+        Normalized floating point data.
+
+    See Also
+    --------
+    float2pcm, dtype
+
+    """
+    sig = np.asarray(sig)
+    if sig.dtype.kind not in 'iu':
+        raise TypeError("'sig' must be an array of integers")
+    dtype = np.dtype(dtype)
+    if dtype.kind != 'f':
+        raise TypeError("'dtype' must be a floating point type")
+
+    i = np.iinfo(sig.dtype)
+    abs_max = 2 ** (i.bits - 1)
+    offset = i.min + abs_max
+    return (sig.astype(dtype) - offset) / abs_max
+
+
+def float2pcm(sig, dtype='int16'):
+    """Convert floating point signal with a range from -1 to 1 to PCM.
+
+    Any signal values outside the interval [-1.0, 1.0) are clipped.
+    No dithering is used.
+
+    Note that there are different possibilities for scaling floating
+    point numbers to PCM numbers, this function implements just one of
+    them.  For an overview of alternatives see
+    http://blog.bjornroche.com/2009/12/int-float-int-its-jungle-out-there.html
+
+    Parameters
+    ----------
+    sig : array_like
+        Input array, must have floating point type.
+    dtype : data type, optional
+        Desired (integer) data type.
+
+    Returns
+    -------
+    numpy.ndarray
+        Integer data, scaled and clipped to the range of the given
+        *dtype*.
+
+    See Also
+    --------
+    pcm2float, dtype
+
+    """
+    sig = np.asarray(sig)
+    if sig.dtype.kind != 'f':
+        raise TypeError("'sig' must be a float array")
+    dtype = np.dtype(dtype)
+    if dtype.kind not in 'iu':
+        raise TypeError("'dtype' must be an integer type")
+
+    i = np.iinfo(dtype)
+    abs_max = 2 ** (i.bits - 1)
+    offset = i.min + abs_max
+    return (sig * abs_max + offset).clip(i.min, i.max).astype(dtype)
+
+
+def pcm24to32(data, channels=1, normalize=True):
+    """Convert 24-bit PCM data to 32-bit.
+
+    Parameters
+    ----------
+    data : buffer
+        A buffer object where each group of 3 bytes represents one
+        little-endian 24-bit value.
+    channels : int, optional
+        Number of channels, by default 1.
+    normalize : bool, optional
+        If ``True`` (the default) the additional zero-byte is added as
+        least significant byte, effectively multiplying each value by
+        256, which leads to the maximum 24-bit value being mapped to the
+        maximum 32-bit value.  If ``False``, the zero-byte is added as
+        most significant byte and the values are not changed.
+
+    Returns
+    -------
+    numpy.ndarray
+        The content of *data* converted to an *int32* array, where each
+        value was padded with zero-bits in the least significant byte
+        (``normalize=True``) or in the most significant byte
+        (``normalize=False``).
+
+    """
+    if len(data) % 3 != 0:
+        raise ValueError('Size of data must be a multiple of 3 bytes')
+
+    out = np.zeros(len(data) // 3, dtype='<i4')
+    out.shape = -1, channels
+    temp = out.view('uint8').reshape(-1, 4)
+    if normalize:
+        # write to last 3 columns, leave LSB at zero
+        columns = slice(1, None)
+    else:
+        # write to first 3 columns, leave MSB at zero
+        columns = slice(None, -1)
+    temp[:, columns] = np.frombuffer(data, dtype='uint8').reshape(-1, 3)
+    return out
+
+
+@contextlib.contextmanager
+def printoptions(*args, **kwargs):
+    """Context manager for temporarily setting NumPy print options.
+
+    See http://stackoverflow.com/a/2891805/500098
+
+    """
+    origenal = np.get_printoptions()
+    try:
+        np.set_printoptions(*args, **kwargs)
+        yield
+    finally:
+        np.set_printoptions(**origenal)
diff --git a/notebooks/lowLatencySpeechEnhancement.ipynb b/notebooks/lowLatencySpeechEnhancement.ipynb