Tool for audio recording with SDR, tested to work with Gqrx: http://gqrx.dk
SDRecord is able to reduce network traffic, disk space needed for records and record for X specified minutes and/or for X specified MBs of data.
SDRecord drops UDP packets coming from Gqrx that do not contain any data ( data payload is 0 ) and sends in output ( on stdout or to a file and/or to a remote host ) only packets containing info.
Usage and Options
usage: java SDRecord [options] -d <arg> Remote UDP port, to use with -r option -f <arg> Output file where to save the recording -h Print help and exit -l <arg> Bind to a specific local IP address, DEFAULT: 0.0.0.0 (all) -m <arg> Minutes to record, DEFAULT: no limit -p <arg> Local UDP port to use, DEFAULT: 7355 -r <arg> Remote IP address where to send data -s <arg> MBs of data to record, DEFAULT: no limit -v Print SDRecord version and exit
NOTE: When is not specified an output file or a remote host, data is written on stdout.
Windows users alert!
This tool makes use of ANSI escape characters for text color and cursor position, Microsoft Windows OSs are not compliant with this standard.
For these users I suggest to use others terminal emulators, like Cygwin.
Putting all together
Clone the repository using git or download it manually.
Unzip the repository and compile the java code (requires JDK to be installed) ignoring warning messages:
Launch Gqrx enabling stream audio over UDP (default port 7355) setting squelch to eliminate noise.
In a terminal window, execute SDRecord (requires JRE to be installed):
andrea@Workstation:~/Downloads/SDRecord-master$java SDRecord [options]
Audio spec from Gqrx
The streamed audio has the following specifications:
Channels: 1 (left)
Sample rate: 48 kHz
Sample format: 16 bit signed, little endian (S16LE)
Recording in a file with no limit:
andrea@Workstation:~/Downloads/SDRecord-master$ java SDRecord -f audiofile INFO: Listening /0.0.0.0 on port 7355 345.9 KB transferred Press Ctrl+c to terminate
Recording in a file for a max of 10 MB:
andrea@Workstation:~/Downloads/SDRecord-master$ java SDRecord -s 10 -f audiofile INFO: Listening /0.0.0.0 on port 7355 345.9 KB / 10.00 MB transferred Press Ctrl+c to terminate
Recording for 30 minutes and sending max 50 MB of data to a remote host:
andrea@Workstation:~/Downloads/SDRecord-master$ java SDRecord -m 30 -s 50 -r 192.168.1.105 -d 7356 INFO: Listening /0.0.0.0 on port 7355 1782 seconds remaining 345.9 KB / 50.00 MB transferred Press Ctrl+c to terminate
License and Donations
Coded by Andrea Dari and licensed under GNU GPL v2.0