SignalPath

SignalPath is a beautiful and swift spectrum viewing app. It makes easy to look through hours worth of data finding interesting signal peaks in long recordings (computing spectrums is backed by SIMD and GPU (Metal)). In addition SignalPath allows recording audio data through microphone and supports FIFO channels for importing complex signal data from any source.

Features

Control how spectrums are represented

Use FFT settings popover to change FFT lengths, window functions, data types, sample rates, center frequencies and frequency offsets.

Fast Fourier Transform lengths from 256 to 8192.

Window functions:

  • Blackman,
  • Hamming,
  • Hann,
  • rectangular.

signalpath fft settings

Record audio data

In addition to viewing recorded spectrums SignalPath supports recording audio data from a connected microphone.
Have fun discovering what is going on around you.

signalpath input

Compress and decompress data

Scale data by merging multiple spectrums into one or duplicate spectrums onto several lines enabling fine-grained look on the data.
Note: When merging multiple spectrums into one maximum spectrum points from the set are presented.

signalpath heat map

Automatic data type selection

Using a file name format _.iq SignalPath is able to automatically choose IQ data type when first time opening a file.
Example: “audiorecording_i16.iq”
​
Supported data format descriptions in file names:

  • f32
  • i8, int8
  • u8, uint8
  • i16, int16
  • u16, uint16
  • i32, int32
  • u32, uint32

Note: IQ data type selection is persistent and needs to be done only once.

FIFO channels for importing data

SignalPath supports FIFO channels for importing data from any source.
Create FIFO recording by using File->New FIFO Recording menu item.
File path to the channel can be conveniently copied using Edit->Copy FIFO Path menu item.
Easiest way of testing it out is by using Terminal command:
macOS 10.13: echo "$(cat /path/to/existing/file/containing/data)" > /path/to/fifo/channel
​macOS 10.12: cat /path/to/existing/file/containing/data > /path/to/fifo/channel

signalpath fifo

Give it a try

Try SignalPath out with this example file.
Download Example