deinvert is a scrambler-descrambler for voice inversion scrambling. It supports simple inversion as well as split-band inversion.
By default, deinvert requires liquid-dsp and libsndfile.
But it can be compiled without liquid-dsp using the configure
--without-liquid; filtering will be disabled and the result will not
sound as good. It can also be compiled
without libsndfile using the configure option
support will be disabled, only raw input/output will work.
./autogen.sh ./configure [--without-liquid] [--without-sndfile] make
Descrambling a WAV file scrambled with setting 4:
./src/deinvert -i input.wav -o output.wav -p 4
Descrambling split-band inversion with a bandwidth of 3500 Hz, split at 1200 Hz:
./src/deinvert -i input.wav -o output.wav -f 3500 -s 1200
Descrambling a live FM channel at 27 Megahertz from an RTL-SDR, setting 4:
rtl_fm -M fm -f 27.0M -s 12k -g 50 -l 70 | ./src/deinvert -r 12000 -p 4
Note that since scrambling and descrambling are the same operation this tool also works as a scrambler.
If no input and output file is given, deinvert reads raw 16-bit PCM via stdin and outputs in the same format via stdout. The inversion carrier defaults to 2632 Hz.
./src/deinvert [OPTIONS] -f, --frequency FREQ Frequency of the inversion carrier, in Hertz. -h, --help Display this usage help. -i, --input-file FILE Use an audio file as input. All formats supported by libsndfile should work. -o, --output-file FILE Write output to a WAV file instead of stdout. An existing file will be overwritten. -p, --preset NUM Scrambler frequency preset (1-8), referring to the set of common carrier frequencies used by e.g. the Selectone ST-20B scrambler. -q, --quality NUM Filter quality, from 0 (worst quality, low CPU usage) to 3 (best quality, higher CPU usage). The default is 2. -r, --samplerate RATE Sampling rate of raw input audio, in Hertz. -s, --split-frequency Split point for split-band inversion, in Hertz. -v, --version Display version string.
Inversion carrier presets
Can't find liquid-dsp on macOS
If you've installed liquid-dsp yet
configure can't find it, it's possible that
XCode command line tools aren't installed. Run this command to fix it:
Can't find liquid-dsp on Linux
Try running this in the terminal:
deinvert is released under the MIT license, which means it is copyrighted to Oona Räisänen OH2EIQ yet you're free to use it provided that the copyright information is not removed. See LICENSE.