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.

$ 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_COLOR=ON       Colorize log output. [default=OFF]
-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]

You can test the program using the included sample capture:

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

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

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

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.

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

$ 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.

$ 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.

   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
   -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 WAV file
   -q                              disable log output
   -l log-level                    set log level
                                     (1 = DEBUG, 2 = INFO, 3 = WARN)
   -v                              print the version number and exit
   --dump-aas-files dir-name       dump AAS files
                                     (WARNING: insecure)
   --dump-hdc file-name            dump HDC packets

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 -

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".