nrsc5

This program receives NRSC-5 digital radio stations using an RTL-SDR dongle. It offers a command-line interface as well as an API upon which other applications can be built. Before using it, you'll first need to compile the program using the build instructions below.

Building on Ubuntu, Debian or Raspbian

$ sudo apt install git build-essential cmake autoconf libtool libao-dev libfftw3-dev librtlsdr-dev
$ git clone https://github.com/theori-io/nrsc5.git
$ cd nrsc5
$ mkdir build
$ cd build
$ cmake [options] ..
$ make
$ sudo make install
$ sudo ldconfig

Available build options:

-DUSE_NEON=ON            Use NEON instructions. [ARM, default=OFF]
-DUSE_SSE=ON             Use SSSE3 instructions. [x86, default=OFF]
-DUSE_FAAD2=ON           AAC decoding with FAAD2. [default=ON]
-DLIBRARY_DEBUG_LEVEL=1  Debug logging level for libnrsc5. [default=5]
-DBUILD_DOC=ON           Generate html API documentation [default=OFF]

You can test the program using the included sample capture:

$ xz -d < ../support/sample.xz | src/nrsc5 -r - 0

Building on Fedora

Follow the Ubuntu instructions above, but replace the first command with the following:

$ sudo dnf install make patch cmake autoconf libtool libao-devel fftw-devel rtl-sdr-devel libusb-devel

Building on macOS using Homebrew

$ curl https://raw.githubusercontent.com/theori-io/nrsc5/master/nrsc5.rb > /tmp/nrsc5.rb
$ brew install --HEAD -s /tmp/nrsc5.rb

Building for Windows

To build the program for Windows, you can either use MSYS2 on Windows, or else use a cross-compiler on an Ubuntu, Debian or macOS machine. Scripts are provided to help with both cases.

Building on Windows with MSYS2

Install MSYS2. Open a terminal using the "MSYS2 MinGW 32-bit" shortcut. (Or use the 64-bit shortcut if you prefer a 64-bit build.)

$ pacman -Syu

If this is the first time running pacman, you will be told to close the terminal window. After doing so, reopen using the same shortcut as before.

$ pacman -Su
$ pacman -S git
$ git clone https://github.com/theori-io/nrsc5.git
$ nrsc5/support/msys2-build

You can test your installation using the included sample file:

$ cd ~/nrsc5/support
$ xz -d sample.xz
$ nrsc5.exe -r sample 0

If the sample file does not work, make sure you followed all of the instructions. If it still doesn't work, file an issue with the error message. Please put "[Windows]" in the title of the issue.

Once everything is built, you can run nrsc5 independently of MSYS2. Copy the following files from your MSYS2/mingw32 directory (e.g. C:\msys64\mingw32\bin):

• libnrsc5.dll
• nrsc5.exe

Cross-compiling for Windows from Ubuntu / Debian

$ sudo apt install mingw-w64
$ support/win-cross-compile 32

Replace 32 with 64 if you want a 64-bit build. Once the build is complete, copy *.dll and nrsc5.exe from the build-win32/bin (or build-win64/bin) folder to your Windows machine.

Cross-compiling for Windows from macOS

$ brew install mingw-w64
$ support/win-cross-compile 32

Replace 32 with 64 if you want a 64-bit build. Once the build is complete, copy *.dll and nrsc5.exe from the build-win32/bin (or build-win64/bin) folder to your Windows machine.

Usage

Command-line options:

frequency                       center frequency in MHz or Hz
                                  (do not provide frequency when reading from file)
program                         audio program to decode
                                  (0, 1, 2, or 3)
-g gain                         gain
                                  (example: 49.6)
                                  (automatic gain selection if not specified)
-d device-index                 rtl-sdr device
-p ppm-error                    rtl-sdr ppm error
-H rtltcp-host                  rtl_tcp host with optional port
                                  (example: localhost:1234)
-r iq-input                     read IQ samples from input file
-w iq-output                    write IQ samples to output file
-o audio-output                 write audio to output file
-t audio-type                   type of audio output (wav or raw)
                                  (default is wav. used in conjunction with -o)
-q                              disable log output
-l log-level                    set log level
                                  (1 = DEBUG, 2 = INFO, 3 = WARN)
-v                              print the version number and exit
--am                            receive AM signals
                                  (default is FM)
-T                              enable bias-T
-D direct-sampling-mode         enable direct sampling
                                  (1 = I-ADC input, 2 = Q-ADC input)
--dump-aas-files dir-name       dump AAS files
                                  (WARNING: insecure)
--dump-hdc file-name            dump HDC packets

Examples:

Tune to 107.1 MHz and play audio program 0:

$ nrsc5 107.1 0

Tune to 107.1 MHz and play audio program 0. Manually set gain to 49.0 dB and save raw IQ samples to a file:

$ nrsc5 -g 49.0 -w samples1071 107.1 0

Read raw IQ samples from a file and play back audio program 0:

$ nrsc5 -r samples1071 0

Tune to 90.5 MHz and convert audio program 0 to WAV format for playback in an external media player:

$ nrsc5 -o - 90.5 0 | mplayer -

Keyboard commands:

To switch between audio programs at runtime, press 0 through 7.

To quit, press Q.

RTL-SDR drivers on Windows

If you get errors trying to access your RTL-SDR device, then you may need to use Zadig to change the USB driver. Once you download and run Zadig, select your RTL-SDR device, ensure the driver is set to WinUSB, and then click "Replace Driver". If your device is not listed, enable "Options" -> "List All Devices".