Adds blks2.logpwrfft_c,f blocks.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@8801 221aa14e-8319-0410-a670-987f0aec2ac5

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/Makefile.am b/gnuradio-core/src/python/gnuradio/blks2impl/Makefile.am
index 0a8df50cb7d6097a0b6ab748c0c00b3832c2c76a..66540c77a5fef0a774718382bd5ded1ddb348639 100644 (file)
--- a/gnuradio-core/src/python/gnuradio/blks2impl/Makefile.am
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/Makefile.am
@@ -38,6 +38,7 @@ grblkspython_PYTHON =         \
        fm_emph.py              \
        gmsk.py                 \
        cpm.py                  \
+       logpwrfft.py            \
        nbfm_rx.py              \
        nbfm_tx.py              \
        ofdm.py                 \

diff --git a/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py b/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
new file mode 100644 (file)
index 0000000..399e19d
--- /dev/null
+++ b/gnuradio-core/src/python/gnuradio/blks2impl/logpwrfft.py
@@ -0,0 +1,107 @@
+#
+# 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):
+       """!
+       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]
+       """
+       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)
+               
+       fft_window = window.blackmanharris(fft_size)
+       fft = self._fft_block[0](fft_size, True, fft_window)
+       window_power = sum(map(lambda x: x*x, fft_window))
+
+       c2mag = gr.complex_to_mag(fft_size)
+       self._avg = gr.single_pole_iir_filter_ff(1.0, fft_size)
+       self._log = gr.nlog10_ff(20, fft_size,
+                                -10*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, c2mag, self._avg, self._log, self)
+       self.set_average(average)
+       self.set_avg_alpha(avg_alpha)
+
+    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)
+
+
+class logpwrfft_f(_logpwrfft_base):
+       """!
+       Create an fft block chain, with real input.
+       """
+       _name = "fft_chain_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 = "fft_chain_c"
+       _item_size = gr.sizeof_gr_complex
+       _fft_block = (gr.fft_vcc, )
+