--- /dev/null
+#
+# 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
+
+class stream_to_vector_decimator(gr.hier_block2):
+ """
+ Convert the stream to a vector, decimate the vector stream to achieve the vector rate.
+ """
+
+ def __init__(self, item_size, sample_rate, vec_rate, vec_len):
+ """
+ Create the block chain.
+ @param item_size the number of bytes per sample
+ @param sample_rate the rate of incoming samples
+ @param vec_rate the rate of outgoing vectors (same units as sample_rate)
+ @param vec_len the length of the outgoing vectors in items
+ """
+ self._vec_rate = vec_rate
+ self._vec_len = vec_len
+ self._sample_rate = sample_rate
+
+ gr.hier_block2.__init__(self, "stream_to_vector_decimator",
+ gr.io_signature(1, 1, item_size), # Input signature
+ gr.io_signature(1, 1, item_size*vec_len)) # Output signature
+
+ s2v = gr.stream_to_vector(item_size, vec_len)
+ self.one_in_n = gr.keep_one_in_n(item_size*vec_len, 1)
+ self._update_decimator()
+ self.connect(self, s2v, self.one_in_n, self)
+
+ def set_sample_rate(self, sample_rate):
+ """
+ Set the new sampling rate and update the decimator.
+ @param sample_rate the new rate
+ """
+ self._sample_rate = sample_rate
+ self._update_decimator()
+
+ def set_vec_rate(self, vec_rate):
+ """
+ Set the new vector rate and update the decimator.
+ @param vec_rate the new rate
+ """
+ self._vec_rate = vec_rate
+ self._update_decimator()
+
+ def set_decimation(self, decim):
+ """
+ Set the decimation parameter directly.
+ @param decim the new decimation
+ """
+ self._decim = max(1, int(round(decim)))
+ self.one_in_n.set_n(self._decim)
+
+ def _update_decimator(self):
+ self._decim = max(1, int(round(self._sample_rate/self._vec_len/self._vec_rate)))
+ self.one_in_n.set_n(self._decim)
+
+ def decimation(self):
+ """
+ Returns the actual decimation.
+ """
+ return self._decim
+
+ def sample_rate(self):
+ """
+ Returns configured sample rate.
+ """
+ return self._sample_rate
+
+ def frame_rate(self):
+ """
+ Returns actual frame rate
+ """
+ return self._sample_rate/self._vec_len/self._decim