SDRPP, The SDR software with immediate mode GUI

This project is based on SDR++ code originaly written by Alexandre Rouma. This is modified version of code and explicitly marked as changed, so their problems will not be attributed erroneously to authors of original SDR++ code.

The project in this repository is maintained by qrp73. The code is provided "as is" under GPL-3.0 license and with no warranty.

Your feedback and bug reports are welcome. Feel free to report issues and discuss technical details and functionality.

Have good day and 73

Features

• added SDL2 OpenGL ES backend (enabled by default) which supports Linux KMS DRM and Wayland rendering, it can run without desktop. Tested on Raspberry Pi Zero 2W.
• fixed waterfall zoom
• SNR meter replaced with level meter + peak meter + level and SNR text indication in dB
• unity gain for FFT and window functions
• added Blackman-Harris-7, Blackman-Harris-4, Hamming and Hann window functions
• added 1M FFT
• fixed AM,FM,WFM,SSB,DSB bandwidth
• fixed units misspelling
• improved squelch to reduce false triggering
• rtl_sdr_source: fixed sample conversion
• hpsdr_source: added new module for HPSDR protocol enabled devices
• file_source: code replaced with a new multi-format support (supported: FLOAT 32/64 bit and PCM 8/16/24/32 bit)
• audio_source: added support for mono source, fixed error logging
• recorder: fixed default filename pattern
• recorder: added 24-bit PCM support
• recorder: added FLAC container support (8/16/24/32 bit mono/stereo, see libflac for supported sample rates)
• recorder: added MP3 container support (VBR)
• frequency_manager: fixed jittery label position
• some minor fixes

SDL2 Wayland mode

Using the Wayland driver allows for smoother graphics with less CPU load. This is especially useful for low-power computers. For example, it provides smoother graphics with reduced CPU usage when running on Raspberry Pi OS Bookworm with the Wayland Labwc or Wayland Wayfire compositor.

By default, SDL2 uses the X11 driver if X11 or XWayland is available on the system. To run the application with the Wayland driver, you need to set the environment variable SDL_VIDEODRIVER=wayland. For example, run the following in the terminal:

SDL_VIDEODRIVER=wayland sdrpp

This will launch the application using the Wayland driver, which provides about a 20% performance boost compared to the X11 driver.

Additionally, note that SDL2 blocks the Wayland screensaver (idle). To allow the screensaver to function while the application is running, you should set the environment variable SDL_VIDEO_ALLOW_SCREENSAVER=1 for the application.

You can create the following bash script sdrpp-wayland to run the application with Wayland driver:

#!/usr/bin/env bash

SDL_VIDEODRIVER=wayland SDL_VIDEO_ALLOW_SCREENSAVER=1 sdrpp

and place it into /usr/local/bin with execute permission.

You can check if the SDL2 backend is being used by running the application in the terminal and looking for the line SDL_GetCurrentVideoDriver(): in the log. This line shows the driver that is actually being used. For example:

$ SDL_VIDEODRIVER=wayland sdrpp
[15/03/2025 09:29:32.000] [INFO] SDR++ v1.1.0
[15/03/2025 09:29:32.000] [INFO] Loading config
[15/03/2025 09:29:32.000] [WARN] ConfigManager locked, waiting...
[15/03/2025 09:29:32.000] [INFO] SDL_GetCurrentVideoDriver(): wayland
[15/03/2025 09:29:32.000] [INFO] OpenGL: OpenGL ES 3.1 Mesa 24.2.8-1~bpo12+rpt1
[15/03/2025 09:29:32.000] [INFO] GLSL:   OpenGL ES GLSL ES 3.10
[15/03/2025 09:29:32.000] [INFO] GL_SAMPLES: 0
[15/03/2025 09:29:32.000] [INFO] Loading icons

SDL2 KMSDRM mode

If you are running the application on a system without a graphical desktop (X11, Wayland), SDL2 will automatically select the KMSDRM driver. However, if you are running the application from a virtual terminal with a background-running graphical manager, it may prevent SDL2 from correctly detecting the driver.

In this case, you can force SDL2 to use the KMSDRM driver by specifying it explicitly with environment variable for application:

SDL_VIDEODRIVER=kmsdrm sdrpp

You can exit the application in KMSDRM mode using the Alt+F4 key combination.

Hardware

The only hardware that I have is RTLSDRv3 and custom FPGA DSP chains for different hardware which are using my custom or HPSDR protocol. So, this project is targeted primary on RTLSDRv3 and HPSDR protocol devices. But feel free to report issues with other hardware.

Source code

You can download the latest code version from this repository: https://github.com/qrp73/SDRPP

Build & Install

You can install SDRPP with manual build.

Build and install on Debian

Install pre-requisites:

sudo apt update
sudo apt install -y \
   git wget p7zip-full build-essential cmake cmake-curses-gui libtool xxd autoconf \
   libfftw3-dev libglfw3-dev libglew-dev libvolk2-dev libsoapysdr-dev libairspyhf-dev libairspy-dev \
   libiio-dev libad9361-dev librtaudio-dev libhackrf-dev librtlsdr-dev libbladerf-dev liblimesuite-dev \
   libcodec2-dev libzstd-dev portaudio19-dev libsdl2-dev libflac-dev libmp3lame-dev

If libvolk2-dev is not available, use libvolk1-dev.

Build and install:

git clone https://github.com/qrp73/SDRPP
cd SDRPP
mkdir -p build && cd build
cmake ..
make -j4
sudo make install

Build with SDL2 backend to use in KMS DRM mode (don't requires graphics desktop to run):

git clone https://github.com/qrp73/SDRPP
cd SDRPP
mkdir -p build && cd build
cmake -DOPT_BACKEND_GLFW=OFF -DOPT_BACKEND_SDL2=ON ..
make -j4
sudo make install

Run:

sdrpp

When running with SDL2 backend you can exit to command line with Alt+F4.

Uninstall on Debian

cd SDRPP/build
sudo make uninstall
make clean

sudo rm /usr/bin/sdrpp
sudo rm -r /usr/lib/sdrpp
sudo rm -r /usr/share/sdrpp
sudo rm -r /home/<USERNAME>/.config/sdrpp

Build and install on Arch

Install pre-requisites:

sudo pacman -Syu
sudo pacman -Sy \
    git wget base-devel cmake core/libtool core/autoconf \
    fftw extra/glfw-x11 extra/glew libvolk extra/soapysdr extra/airspy \
    extra/libiio extra/libad9361 extra/rtaudio extra/hackrf extra/rx_tools extra/bladerf extra/limesuite \
    extra/codec2 core/zstd extra/portaudio rtl-sdr
yay airspyhf-git

Build and install:

git clone https://github.com/qrp73/SDRPP
cd SDRPP
mkdir -p build
cd build
cmake ..
make -j4
sudo make install

Modules

Name	Stage	Dependencies	Option	Built by default	Built in Release	Enabled in SDR++ by default
airspy_source	Working	libairspy	OPT_BUILD_AIRSPY_SOURCE	✅	✅	✅
airspyhf_source	Working	libairspyhf	OPT_BUILD_AIRSPYHF_SOURCE	✅	✅	✅
bladerf_source	Working	libbladeRF	OPT_BUILD_BLADERF_SOURCE	⛔	✅ (not Debian Buster)	✅
file_source	Working	-	OPT_BUILD_FILE_SOURCE	✅	✅	✅
hackrf_source	Working	libhackrf	OPT_BUILD_HACKRF_SOURCE	✅	✅	✅
hpsdr_source	Beta	-	OPT_BUILD_HPSDR_SOURCE	✅	✅	✅
hermes_source	Beta	-	OPT_BUILD_HERMES_SOURCE	✅	✅	✅
limesdr_source	Working	liblimesuite	OPT_BUILD_LIMESDR_SOURCE	⛔	✅	✅
perseus_source	Beta	libperseus-sdr	OPT_BUILD_PERSEUS_SOURCE	⛔	⛔	⛔
plutosdr_source	Working	libiio, libad9361	OPT_BUILD_PLUTOSDR_SOURCE	✅	✅	✅
rfspace_source	Working	-	OPT_BUILD_RFSPACE_SOURCE	✅	✅	✅
rtl_sdr_source	Working	librtlsdr	OPT_BUILD_RTL_SDR_SOURCE	✅	✅	✅
rtl_tcp_source	Working	-	OPT_BUILD_RTL_TCP_SOURCE	✅	✅	✅
sdrplay_source	Working	SDRplay API	OPT_BUILD_SDRPLAY_SOURCE	⛔	✅	✅
sdrpp_server_source	Working	-	OPT_BUILD_SDRPP_SERVER_SOURCE	✅	✅	✅
soapy_source	Working	soapysdr	OPT_BUILD_SOAPY_SOURCE	✅	✅	✅
spectran_source	Unfinished	RTSA Suite	OPT_BUILD_SPECTRAN_SOURCE	⛔	⛔	⛔
spectran_http_source	Unfinished	-	OPT_BUILD_SPECTRAN_HTTP_SOURCE	✅	✅	⛔
spyserver_source	Working	-	OPT_BUILD_SPYSERVER_SOURCE	✅	✅	✅
usrp_source	Beta	libuhd	OPT_BUILD_USRP_SOURCE	⛔	⛔	⛔

Sinks

Name	Stage	Dependencies	Option	Built by default	Built in Release	Enabled in SDR++ by default
android_audio_sink	Working	-	OPT_BUILD_ANDROID_AUDIO_SINK	⛔	✅	✅ (Android only)
audio_sink	Working	rtaudio	OPT_BUILD_AUDIO_SINK	✅	✅	✅
network_sink	Working	-	OPT_BUILD_NETWORK_SINK	✅	✅	✅
new_portaudio_sink	Beta	portaudio	OPT_BUILD_NEW_PORTAUDIO_SINK	⛔	✅	⛔
portaudio_sink	Beta	portaudio	OPT_BUILD_PORTAUDIO_SINK	⛔	✅	⛔

Decoders

Name	Stage	Dependencies	Option	Built by default	Built in Release	Enabled in SDR++ by default
atv_decoder	Unfinished	-	OPT_BUILD_ATV_DECODER	⛔	⛔	⛔
dmr_decoder	Unfinished	-	OPT_BUILD_DMR_DECODER	⛔	⛔	⛔
falcon9_decoder	Unfinished	ffplay	OPT_BUILD_FALCON9_DECODER	⛔	⛔	⛔
kgsstv_decoder	Unfinished	-	OPT_BUILD_KGSSTV_DECODER	⛔	⛔	⛔
m17_decoder	Beta	-	OPT_BUILD_M17_DECODER	⛔	✅	⛔
meteor_demodulator	Working	-	OPT_BUILD_METEOR_DEMODULATOR	✅	✅	⛔
radio	Working	-	OPT_BUILD_RADIO	✅	✅	✅
weather_sat_decoder	Unfinished	-	OPT_BUILD_WEATHER_SAT_DECODER	⛔	⛔	⛔

Misc

Name	Stage	Dependencies	Option	Built by default	Built in Release	Enabled in SDR++ by default
frequency_manager	Working	-	OPT_BUILD_FREQUENCY_MANAGER	✅	✅	✅
recorder	Working	-	OPT_BUILD_RECORDER	✅	✅	✅
rigctl_client	Unfinished	-	OPT_BUILD_RIGCTL_CLIENT	✅	✅	⛔
rigctl_server	Working	-	OPT_BUILD_RIGCTL_SERVER	✅	✅	✅
scanner	Beta	-	OPT_BUILD_SCANNER	✅	✅	⛔
scheduler	Unfinished	-	OPT_BUILD_SCHEDULER	⛔	⛔	⛔

This software contains code writen by the following contributors

• qrp73
• Ryzerth
• Aang23
• Alexsey Shestacov
• Aosync
• Benjamin Kyd
• Benjamin Vernoux
• Cropinghigh
• Fred F4EED
• Howard0su
• John Donkersley
• Joshua Kimsey
• Manawyrm
• Martin Hauke
• Marvin Sinister
• Maxime Biette
• Paulo Matias
• Raov
• Cam K.
• Shuyuan Liu
• Syne Ardwin (WI9SYN)
• Szymon Zakrent
• Youssef Touil
• Zimm

Libraries used

• Dear ImGui (ocornut)
• json (nlohmann)
• rtaudio
• Portable File Dialogs
• SoapySDR (PothosWare)