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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
try:
from gnuradio import blocks
except ImportError:
import blocks_swig as blocks
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.
Args:
item_size: the number of bytes per sample
sample_rate: the rate of incoming samples
vec_rate: the rate of outgoing vectors (same units as sample_rate)
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 = blocks.stream_to_vector(item_size, vec_len)
self.one_in_n = blocks.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.
Args:
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.
Args:
vec_rate: the new rate
"""
self._vec_rate = vec_rate
self._update_decimator()
def set_decimation(self, decim):
"""
Set the decimation parameter directly.
Args:
decim: the new decimation
"""
self._decim = max(1, int(round(decim)))
self.one_in_n.set_n(self._decim)
def _update_decimator(self):
self.set_decimation(self._sample_rate/self._vec_len/self._vec_rate)
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
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