PySDR displays spectral waterfall, a visualization of signal's frequency spectrum over time. It is developed for SDR-related applications, but can be fed any equidistantly-sampled complex-valued signal for which it makes sense.
A live waterfall is launched by pysdr-waterfall. It connects to the JACK audio system and takes its input from there, or, if the flag -r is passed, it expects its input on the standard input in the form of an endless stream of 32-bit interleaved floats.
$ pysdr-waterfall -h
usage: pysdr-waterfall [-h] [-b BINS] [-H HEIGHT] [-o OVERLAP] [-j NAME]
[-r RATE] [-d ARGS] [-p FILENAME]
Plot live spectral waterfall of a quadrature signal.
optional arguments:
-h, --help show this help message and exit
-b BINS, --bins BINS number of FFT bins (default: 4096)
-H HEIGHT, --height HEIGHT
minimal height of the waterfall in seconds
(default corresponds to 1024 windows)
-o OVERLAP, --overlap OVERLAP
overlap between consecutive windows as a
proportion of the number of bins (default: 0.75)
-j NAME, --jack NAME feed signal from JACK and use the given client
name (by default, with name 'pysdr')
-r RATE, --raw RATE feed signal from the standard input, expects 2
channel interleaved floats with the given sample-
rate
-d ARGS, --detector ARGS
attach the given detector script, expects to be
given the script filename followed by arguments
for the script, all joined by spaces and passed on
the command-line as one quoted argument
-p FILENAME, --persfn FILENAME
a file in which to preserve the visualization
parameters that come from interactive
manipulation, i.e. the visible area of the
waterfall and the selected magnitude range (save
triggered by pressing 'p')
$ sox -d -e floating-point -b 32 -r 48000 -t raw --buffer 1024 - | ./pysdr-waterfall -r 48000
$ arecord -f FLOAT_LE -c 2 -r 44100 --buffer-size 1024 | pysdr-waterfall -r 44100
There's also pysdr-reciewer, which displays spectral waterfall of short recordings. The recordings are expected to be either WAV files, or FITS files in the format produced by Radio Observer. The number of frequency bins reflects the aspect ratio of the waterfall, and so is interactive.
$ pysdr-recviewer path/to/recording
$ sudo apt-get install python3-numpy python3-opengl python3-dev libjack-jackd2-dev python3-pil
The package has a binary component which has to be built on the target machine. (It is not needed for pysdr-waterfall at the moment.)
For usage without installation, do an in-place build first.
$ python setup.py build_ext --inplace
$ python setup.py install
PySDR is developed to be used, among others, with the RMDS designs by the MLAB project.
Everything in this repository is GNU GPL v3 licensed.