Created
January 23, 2025 20:47
-
-
Save ckuethe/8655bd0c6a9e5f754b0e88aa986d93b5 to your computer and use it in GitHub Desktop.
A tool for trimming IQ recordings produced by GQRX and other SDR tools
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#!/usr/bin/env python3 | |
# -*- coding: utf-8 -*- | |
# | |
# SPDX-License-Identifier: GPL-3.0 | |
# GNU Radio Python Flow Graph | |
# Author: Chris Kuethe <[email protected]> | |
# GNU Radio version: 3.10.1.1 | |
import signal | |
import sys | |
from argparse import ArgumentParser, Namespace | |
from gnuradio import blocks, eng_notation, gr | |
from gnuradio.eng_arg import eng_float, intx | |
from pmt import PMT_NIL | |
def get_args() -> Namespace: | |
ap = ArgumentParser(description="Trim a cfile recording, such as that produced by gqrx or the file sink block") | |
def _time(s) -> int: | |
x = [int(i, 10) for i in s.split(":")] | |
if len(x) != 3: | |
raise ValueError | |
return int(x[0] * 3600 + x[1] * 60 + x[2]) | |
ap.add_argument("-i", "--input", type=str, metavar="FILE", required=True) | |
ap.add_argument( | |
"-t", | |
"--duration", | |
type=_time, | |
metavar="H:MM:SS", | |
help="Duration to copy", | |
required=True, | |
) | |
ap.add_argument( | |
"-r", | |
"--samp-rate", | |
type=float, | |
required=True, | |
metavar="HZ", | |
help="Sample rate of the file", | |
) | |
ap.add_argument( | |
"-s", | |
"--skip", | |
type=_time, | |
default="0:00:00", | |
metavar="H:MM:SS", | |
help="Duration to seek before copying", | |
) | |
ap.add_argument( | |
"-o", | |
"--output", | |
type=str, | |
metavar="FILE", | |
help="Output filename. Default: <input>.edit.cfile", | |
) | |
rv = ap.parse_args() | |
if not rv.output: | |
rv.output = rv.input + ".edit.cfile" | |
return rv | |
class IqTrimmer(gr.top_block): | |
def __init__(self, args: Namespace): | |
gr.top_block.__init__(self, "IQ Trimmer", catch_exceptions=True) | |
################################################## | |
# Variables | |
################################################## | |
skip_items = int(args.skip * args.samp_rate) | |
proc_items = int(args.duration * args.samp_rate) | |
################################################## | |
# Blocks | |
################################################## | |
self.blocks_skiphead = blocks.skiphead(gr.sizeof_gr_complex * 1, skip_items) | |
self.blocks_head = blocks.head(gr.sizeof_gr_complex * 1, proc_items) | |
self.blocks_file_source = blocks.file_source(gr.sizeof_gr_complex * 1, args.input, False, 0, 0) | |
self.blocks_file_source.set_begin_tag(PMT_NIL) | |
self.blocks_file_sink = blocks.file_sink(gr.sizeof_gr_complex * 1, args.output, False) | |
self.blocks_file_sink.set_unbuffered(False) | |
################################################## | |
# Connections | |
################################################## | |
# file_source : read file | |
# head : read through until the desired end time | |
# skiphead: skip any junk at the beginning | |
# file_sink: and write the result to disk | |
self.connect((self.blocks_file_source, 0), (self.blocks_head, 0)) | |
self.connect((self.blocks_head, 0), (self.blocks_skiphead, 0)) | |
self.connect((self.blocks_skiphead, 0), (self.blocks_file_sink, 0)) | |
def main(): | |
args = get_args() | |
print(args) | |
iqt = IqTrimmer(args) | |
def sig_handler(sig=None, frame=None): | |
iqt.stop() | |
iqt.wait() | |
sys.exit(0) | |
signal.signal(signal.SIGINT, sig_handler) | |
signal.signal(signal.SIGTERM, sig_handler) | |
iqt.start() | |
iqt.wait() | |
if __name__ == "__main__": | |
main() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment