46 lines
1.4 KiB
Python
46 lines
1.4 KiB
Python
from owrx.source import SdrSource
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from pycsdr.modules import Buffer, FirDecimate, Shift
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from pycsdr.types import Format
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from csdr.chain import Chain
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class Resampler(SdrSource):
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def onPropertyChange(self, changes):
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self.logger.warning("Resampler is unable to handle property changes: {0}".format(changes))
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def __init__(self, props, sdr):
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sdrProps = sdr.getProps()
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shift = (sdrProps["center_freq"] - props["center_freq"]) / sdrProps["samp_rate"]
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decimation = int(float(sdrProps["samp_rate"]) / props["samp_rate"])
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if_samp_rate = sdrProps["samp_rate"] / decimation
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transition_bw = 0.15 * (if_samp_rate / float(sdrProps["samp_rate"]))
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props["samp_rate"] = if_samp_rate
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self.chain = Chain([
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Shift(shift),
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FirDecimate(decimation, transition_bw)
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])
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self.chain.setReader(sdr.getBuffer().getReader())
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super().__init__(None, props)
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def getBuffer(self):
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if self.buffer is None:
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self.buffer = Buffer(Format.COMPLEX_FLOAT)
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self.chain.setWriter(self.buffer)
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return self.buffer
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def stop(self):
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self.chain.stop()
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self.chain = None
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super().stop()
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def activateProfile(self, profile_id=None):
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self.logger.warning("Resampler does not support setting profiles")
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pass
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def validateProfiles(self):
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# resampler does not support profiles
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pass
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