inspectrum ng

inspectrum ng (next generation) is a fork of inspectrum for analysing captured signals from software-defined radio receivers.

Features

• Large (100GB+) file support with memory-mapped I/O
• Spectrogram with zoom/pan, zero-padding, Y zoom, averaging
• Plots of amplitude, frequency, phase and threshold with binary/hex/ASCII overlay
• Cursors with symbol rate detection (ASK/OOK), grid opacity, state preservation
• Tuner with editable centre frequency and bandwidth, crop-to-tuner, visibility toggle
• Session save/load (.isession) with full state including bookmarks
• Export: selected samples, tuner-filtered with resampling, spectrogram to PNG
• Drag & drop file loading
• SI unit display and input (k, M, G suffixes)
• FFTW wisdom with pre-warmed plans for fast startup
• Native platform UI style (Windows Vista / Fusion)

Build from source

Prerequisites

• cmake >= 3.5
• fftw 3.x
• liquid-dsp >= v1.3.0
• pkg-config
• Qt5 or Qt6

Linux (Ubuntu / Debian)

Install dependencies:

# Ubuntu 22.04 / 24.04 LTS, Debian 12 (Qt5)
sudo apt install cmake g++ pkg-config libfftw3-dev libliquid-dev libgl1-mesa-dev qtbase5-dev

# Ubuntu 24.04 LTS, Debian 12 (Qt6)
sudo apt install cmake g++ pkg-config libfftw3-dev libliquid-dev libgl1-mesa-dev qt6-base-dev

Build:

mkdir build && cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)

macOS (x86_64 / ARM64)

Install dependencies:

brew install cmake fftw liquid-dsp qt@6

Build:

mkdir build && cd build
cmake ../ -DCMAKE_BUILD_TYPE=Release -DCMAKE_PREFIX_PATH="$(brew --prefix qt@6)"
make -j$(sysctl -n hw.ncpu)

Windows (MinGW64 / MSYS2)

Install MSYS2 packages:

pacman -S mingw-w64-x86_64-toolchain mingw-w64-x86_64-cmake mingw-w64-x86_64-ninja \
          mingw-w64-x86_64-qt5-base mingw-w64-x86_64-fftw mingw-w64-x86_64-pkg-config

Build liquid-dsp from source (static), then:

mkdir build && cd build
cmake ../ -G Ninja -DCMAKE_BUILD_TYPE=Release -DFFTW_USE_STATIC=ON -DLIQUID_USE_STATIC=ON
ninja

Windows (Visual Studio 2022)

mkdir build && cd build
cmake ../ -G "Visual Studio 17 2022" -A x64
cmake --build . --config Release

Run

./inspectrum [filename]

Options:

-r, --rate <Hz>     Set sample rate
-f, --format <fmt>  Set file format (cfile, cs8, cu8, cs16, sigmf-meta, etc.)

Input formats

• *.wav - IQ WAV files (SDR++, HDSDR, etc.) - PCM 8/16/32-bit and IEEE float 32-bit, sample rate auto-detected
• *.sigmf-meta, *.sigmf-data - SigMF recordings
• *.cf32, *.fc32, *.cfile - Complex 32-bit floating point (GNU Radio, osmocom_fft)
• *.cf64, *.fc64 - Complex 64-bit floating point
• *.cs32, *.sc32, *.c32 - Complex 32-bit signed integer (SDRAngel)
• *.cs16, *.sc16, *.c16 - Complex 16-bit signed integer (BladeRF)
• *.cs8, *.sc8, *.c8 - Complex 8-bit signed integer (HackRF)
• *.cu8, *.uc8 - Complex 8-bit unsigned integer (RTL-SDR)
• *.f32 - Real 32-bit floating point
• *.f64 - Real 64-bit floating point
• *.s16 - Real 16-bit signed integer
• *.s8 - Real 8-bit signed integer
• *.u8 - Real 8-bit unsigned integer
• *.isession - inspectrum ng session file
• *.json - Bookmarks file

Unknown extensions default to *.cf32. 64-bit samples are truncated to 32-bit internally.

Session files

inspectrum ng saves/loads complete application state to .isession JSON files (version 0.5.0 format). Sessions include signal file path, spectrogram settings, tuner position, cursor state, bookmarks, derived plots, and window layout.

License

GPL v3 -- see original inspectrum for details.