RTL_SDR to CFILE Conversion Utility

A utility to convert the raw output of the Osmocom rtl_sdr program to the .cfile format used by SDR programs like GQRX and GNU Radio.

Goal:

To explore data types and interactions, while learning the processes involved in writting a command line utility. Also to create a lighter weight utility to perform the conversion process normally required when handling raw data given by the Osmocom rtl-sdr program when used in conjuntion with inexpensive SDR tuners using the RTL2832U chip. Normally conversion is performed using GNU Radio signal processing blocks, which is where I obtained the algorithm used in this utility. While very robust and effective, there's quite a bit of overhead that limits working with the data on smaller systems (such as the Raspberry Pi).

What it does:

Takes the raw output of the Osmocom rtl_sdr program, which is unsigned 8 bit interleaved I/Q samples (0 - 255), and converts them to a normalized (between -1.0 and +1.0), interleaved, 32 bit floating point format that's useful with programs like GNU Radio and GQRX.

Building:

g++ -o rtl_sdr_converter rtl_sdr_converter.cpp

Usage:

./rtl_sdr_converter <input_file> <output_file>

ToDo List:

1. Modify the command line utility to use POSIX flags and switches, as well as the ability to handle piped input/output (for useage with fifo named pipes, for example).
2. Expand error handling to be more robust and verbose.

Author:

Tegan Lamoureux, [email protected]