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diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py b/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
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+#
+# Copyright 2008 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# GNU Radio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3, or (at your option)
+# any later version.
+#
+# GNU Radio is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNU Radio; see the file COPYING. If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+from gnuradio import gr, window
+from stream_to_vector_decimator import stream_to_vector_decimator
+import math
+
+class _logpwrfft_base(gr.hier_block2):
+ """
+ Create a log10(abs(fft)) stream chain, with real or complex input.
+ """
+
+ def __init__(self, sample_rate, fft_size, ref_scale, frame_rate, avg_alpha, average, win=None):
+ """
+ Create an log10(abs(fft)) stream chain.
+ Provide access to the setting the filter and sample rate.
+ @param sample_rate Incoming stream sample rate
+ @param fft_size Number of FFT bins
+ @param ref_scale Sets 0 dB value input amplitude
+ @param frame_rate Output frame rate
+ @param avg_alpha FFT averaging (over time) constant [0.0-1.0]
+ @param average Whether to average [True, False]
+ @param win the window taps generation function
+ """
+ gr.hier_block2.__init__(self, self._name,
+ gr.io_signature(1, 1, self._item_size), # Input signature
+ gr.io_signature(1, 1, gr.sizeof_float*fft_size)) # Output signature
+
+ self._sd = stream_to_vector_decimator(item_size=self._item_size,
+ sample_rate=sample_rate,
+ vec_rate=frame_rate,
+ vec_len=fft_size)
+
+ if win is None: win = window.blackmanharris
+ fft_window = win(fft_size)
+ fft = self._fft_block[0](fft_size, True, fft_window)
+ window_power = sum(map(lambda x: x*x, fft_window))
+
+ c2magsq = gr.complex_to_mag_squared(fft_size)
+ self._avg = gr.single_pole_iir_filter_ff(1.0, fft_size)
+ self._log = gr.nlog10_ff(10, fft_size,
+ -20*math.log10(fft_size) # Adjust for number of bins
+ -10*math.log10(window_power/fft_size) # Adjust for windowing loss
+ -20*math.log10(ref_scale/2)) # Adjust for reference scale
+ self.connect(self, self._sd, fft, c2magsq, self._avg, self._log, self)
+
+ self._average = average
+ self._avg_alpha = avg_alpha
+ self.set_avg_alpha(avg_alpha)
+ self.set_average(average)
+
+ def set_decimation(self, decim):
+ """
+ Set the decimation on stream decimator.
+ @param decim the new decimation
+ """
+ self._sd.set_decimation(decim)
+
+ def set_vec_rate(self, vec_rate):
+ """
+ Set the vector rate on stream decimator.
+ @param vec_rate the new vector rate
+ """
+ self._sd.set_vec_rate(vec_rate)
+
+ def set_sample_rate(self, sample_rate):
+ """
+ Set the new sampling rate
+ @param sample_rate the new rate
+ """
+ self._sd.set_sample_rate(sample_rate)
+
+ def set_average(self, average):
+ """
+ Set the averaging filter on/off.
+ @param average true to set averaging on
+ """
+ self._average = average
+ if self._average:
+ self._avg.set_taps(self._avg_alpha)
+ else:
+ self._avg.set_taps(1.0)
+
+ def set_avg_alpha(self, avg_alpha):
+ """
+ Set the average alpha and set the taps if average was on.
+ @param avg_alpha the new iir filter tap
+ """
+ self._avg_alpha = avg_alpha
+ self.set_average(self._average)
+
+ def sample_rate(self):
+ """
+ Return the current sample rate.
+ """
+ return self._sd.sample_rate()
+
+ def decimation(self):
+ """
+ Return the current decimation.
+ """
+ return self._sd.decimation()
+
+ def frame_rate(self):
+ """
+ Return the current frame rate.
+ """
+ return self._sd.frame_rate()
+
+ def average(self):
+ """
+ Return whether or not averaging is being performed.
+ """
+ return self._average
+
+ def avg_alpha(self):
+ """
+ Return averaging filter constant.
+ """
+ return self._avg_alpha
+
+class logpwrfft_f(_logpwrfft_base):
+ """
+ Create an fft block chain, with real input.
+ """
+ _name = "logpwrfft_f"
+ _item_size = gr.sizeof_float
+ _fft_block = (gr.fft_vfc, )
+
+class logpwrfft_c(_logpwrfft_base):
+ """
+ Create an fft block chain, with complex input.
+ """
+ _name = "logpwrfft_c"
+ _item_size = gr.sizeof_gr_complex
+ _fft_block = (gr.fft_vcc, )
+