Tagged: tcp

New Audio Streaming TCP Server Plugin for SDR#

Over on his site rtl-sdr.ru, Vasilli has been back at work creating new plugins for SDR#. The latest plugin is a TCP server that takes the demodulated mono audio stream from SDR# and sends it over TCP (note that the site is in Russian but the Google translate button on the right can be used). This can be used to easily stream audio over the internet or a network, or even locally on the same PC to another program. If enough programs support TCP audio streams, then the plugin could potentially replace the need for software like Virtual Audio Cable or VBCable by allowing another method for piping the audio from SDR# into a decoding program.

Installing the plugin is the same as usual. Just extract the SDRSharp.TcpServer.dll file to the SDRSharp folder, open plugins.xml with a text editor and paste in the 'magic line' specified in MagicLine.txt.

To test the server you can connect to it with VLC media player. Some special commands need to be specified to VLC in order for it to understand the audio format. To enter them go to Media->Open Network Stream and make sure 'Show more options' is checked. Enter the network URL as 'TCP://' (without quotes), and enter the Edit Options field as ':demux=rawaud :rawaud-channels=1 :rawaud-samplerate=48000 :rawaud-fourcc=s16l' (without quotes). Ensure the first colon in the line is copied over properly. Then enable the TCP server in the SDR# plugin, and click Play in VLC. Ensure the SDR# is muted, and the volume in VLC turned up. Audio should now begin streaming through TCP.

Hopefully in the future we can see some audio compression algorithms and more decoding software supporting TCP audio connections.

Vasilli has also updated many of his other plugins too, including creating a DSD_TCP plugin which allows you to transmit the digital audio directly to DSD+ via a TCP connection.

The plugin streaming via TCP to VLC
The plugin streaming via TCP to VLC

TCP Enabled version of librtlsdr

Recently RTL-SDR.com reader Fabien wrote in to let us know that he has created a new version of the librtlsdr RTL-SDR drivers which have built in TCP support.

Fabien built a remote SDR using a BeagleBone Black mini embedded computer and put it outside for better reception and to be closer to the antenna. When trying to remotely access the dongle he discovered some problems. He writes:

I then access the dongle over TCP from an indoor PC. One issue is that some existing tools such as rtl_fm, rtlizer or rtlsdr_waterfall lacks TCP/IP connectivity.

To solve this problem, I added TCP support to the rtlsdr library. When a tool communicates with the now physically distant dongle, this new implementation transparently forwards the data using TCP instead of USB. It allows one to use existing tools without modifying them. Also, it allows a developer to use the same librtlsdr, no matter whether the dongle is local or distant.

The implementation is located here: https://github.com/texane/librtlsdr
branch: rpc

To use it, one must compile and install the library. Then, a server (called rtl_rpcd) must be run on the remote location (in my case, the beagle bone black at address RTLSDR_RPC_SERV_ADDR= \ rtl_rpcd

Then, the existing tool (for instance rtlizer) can be run using:

Outdoor RTL-SDR Receiver Running on a BeagleBone Black
Outdoor RTL-SDR Receiver Running on a BeagleBone Black
Outdoor RTL-SDR Receiver Running on a BeagleBone Black
Outdoor RTL-SDR Receiver Running on a BeagleBone Black