https://github.com/dernasherbrezon/sdr-server

High performant TCP server for rtl-sdr
https://github.com/dernasherbrezon/sdr-server

libvolk rtl-sdr

Last synced: about 1 year ago
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High performant TCP server for rtl-sdr

• Host: GitHub
• URL: https://github.com/dernasherbrezon/sdr-server
• Owner: dernasherbrezon
• License: gpl-2.0
• Created: 2021-01-07T20:13:17.000Z (over 5 years ago)
• Default Branch: main
• Last Pushed: 2025-01-28T08:31:25.000Z (over 1 year ago)
• Last Synced: 2025-03-28T17:08:15.719Z (about 1 year ago)
• Topics: libvolk, rtl-sdr
• Language: C
• Homepage:
• Size: 570 KB
• Stars: 196
• Watchers: 21
• Forks: 19
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

          
# About [![CMake](https://github.com/dernasherbrezon/sdr-server/actions/workflows/cmake.yml/badge.svg)](https://github.com/dernasherbrezon/sdr-server/actions/workflows/cmake.yml) [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=dernasherbrezon_sdr-server&metric=alert_status)](https://sonarcloud.io/dashboard?id=dernasherbrezon_sdr-server)

![design](/docs/dsp.jpg?raw=true)

## Key features

 * Share available RF bandwidth between several independent clients:

   * Total bandwidth can be 2016000 samples/sec at 436,600,000 hz

   * One client might request 48000 samples/sec at 436,700,000 hz

   * Another client might request 96000 samples/sec at 435,000,000 hz

 * Several clients can access the same band simultaneously

 * Output saved onto disk or streamed back via TCP socket

 * Output can be gzipped (by default = true)

 * Output will be decimated to the requested bandwidth

 * Clients can request overlapping RF spectrum

 * Rtl-sdr starts only after first client connects (i.e. saves solar power &etc). Stops only when the last client disconnects

 * MacOS and Linux (Debian Raspberrypi)

 

## Design

![design](/docs/threads.png?raw=true)

 * Each client has its own dsp thread

 * Each dsp thread executes [Frequency Xlating FIR Filter](http://blog.sdr.hu/grblocks/xlating-fir.html)

 * Only RTL-SDRs are supported

 

## API

 * Defined in the [api.h](https://github.com/dernasherbrezon/sdr-server/blob/main/src/api.h)

 * Clients can connect and send request to initiate listening:

   * center_freq - this is required center frequency. For example, 436,700,000 hz

   * sampling_rate - required sampling rate. For example, 48000

   * band\_freq - first connected client can select the center of the band. All other clients should request center\_freq within the currently selected band

   * destination - "0" - save into file on local disk, "1" - stream back via TCP socket

 * To stop listening, clients can send SHUTDOWN request or disconnect

 

## Queue

![design](/docs/queue.png?raw=true)

The data between rtl-sdr worker and the dsp workers is passed via queue. This is bounded queue with pre-allocated memory blocks. It has the following features:

 * Thread-safe

 * If no free blocks (consumer is slow), then the last block will be overriden by the next one

 * there is a special detached block. It is used to minimize synchronization section. All potentially long operations on it are happening outside of synchronization section.

 * Consumer will block and wait until new data produced

 

## Configuration

Sample configuration can be found in tests:

[https://github.com/dernasherbrezon/sdr-server/blob/main/test/resources/configuration.config](https://github.com/dernasherbrezon/sdr-server/blob/main/test/resources/configuration.config)

## Performance

Is good. Some numbers in ```test/perf_xlating.c```

 

## Dependencies

sdr-server depends on several libraries:

 * [librtlsdr](https://github.com/dernasherbrezon/librtlsdr). Version >=0.5.4 is required.

 * [libairspy](https://github.com/airspy/airspyone_host/)

 * [libhackrf](https://github.com/greatscottgadgets/hackrf)

 * [libconfig](https://hyperrealm.github.io/libconfig/libconfig_manual.html)

 * libz. Should be installed in every operational system

 * libm. Same

 

All dependencies can be easily installed from [leosatdata APT repository](https://leosatdata.com/apt):

```

sudo apt-get install curl lsb-release

curl -fsSL https://leosatdata.com/r2cloud.gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/r2cloud.gpg

sudo bash -c "echo 'deb [signed-by=/usr/share/keyrings/r2cloud.gpg] http://apt.leosatdata.com $(lsb_release --codename --short) main' > /etc/apt/sources.list.d/r2cloud.list"

sudo apt-get update

sudo apt-get install librtlsdr-dev libconfig-dev

```

## Build

To build the project execute the following commands:

```

mkdir build

cd build

cmake ..

make

```

## Install

sdr-server can be installed from [leosatdata APT repository](https://leosatdata.com/apt):

```

sudo apt-get install sdr-server

```