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https://github.com/sergei-mironov/nixos-raspi-camera

RaspberryPi camera server in NixOS
https://github.com/sergei-mironov/nixos-raspi-camera

libcamera nix nixos raspberry-pi rpi-camera rtsp-server

Last synced: 18 days ago
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RaspberryPi camera server in NixOS

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README 

        
A [NixOS](https://nixos.org) module to stream video from the Raspberry Pi 4 Model B. The project is

in a draft state and will probably remain there permanently. Only one particular set of hardware is

supported; see the [Hardware](#hardware) section. A number of problems have been revealed in the

course of development. For some of them, workarounds were found and are described in the

[Problems](#problems) section. Have fun!



Contents

--------



* [Hardware](#hardware)

* [Software](#software)

* [Setting up](#setting-up)

* [Usage notes](#usage-notes)

    * [Detecting the camera](#detecting-the-camera)

    * [Making a snapshot](#making-a-snapshot)

    * [Video streaming with rpicam-apps RTSP mode (works)](#video-streaming-with-rpicam-apps-rtsp-mode-works)

    * [Video streaming using the rpicam-apps TCP mode (works)](#video-streaming-using-the-rpicam-apps-tcp-mode-works)

    * [Video streaming via the Gstreamer module shipped with libcamera (does not work)](#video-streaming-via-the-gstreamer-module-shipped-with-libcamera-does-not-work)

* [Problems](#problems)

    * [Where to find device tree overlay sources for the camera?](#where-to-find-device-tree-overlay-sources-for-the-camera)

    * [Meson buildsystem does not detect boost on NixOS](#meson-buildsystem-does-not-detect-boost-on-nixos)

    * [libcamera Gstreamer plugin reports timeout](#libcamera-gstreamer-plugin-reports-timeout)



Hardware

--------



* [Raspberry Pi 4 model B](https://www.raspberrypi.com/products/raspberry-pi-4-model-b/)

* [Arducam camera sensor ov5647](https://docs.arducam.com/Raspberry-Pi-Camera/Native-camera/5MP-OV5647/)





  




Software

--------



In this setup, the Raspberry Pi board runs [NixOS](https://nixos.org), initially obtained by

cross-compiling the [installation image](https://github.com/sergei-mironov/nixos-raspi-installer).

This image is later replaced by natively switching the system to its own configuration, which is not

published for security reasons. In this repository, we declare a few components related to the

camera service and its dependencies. The entry points of this repository are:



* [raspi-camera.nix](nix/raspi-camera.nix) - NixOS module setting up a simple camera broadcasting

  service.

* [libpisp.nix](nix/libpisp.nix) | [libcamera-raspi.nix](nix/libcamera-raspi.nix) |

  [pricam-apps.nix](nix/rpicam-apps.nix) - Nix build expressions for main dependencies



Setting up

----------



Here is how to add the rapi-camera dependency to a third-party Nix system configuration.



Consider a typical `flake.nix`. We add `raspi-camera` flake input [1], optionally link its nixpkgs

[2] to what other inputs use. Next we add the corresponding output argument [3] and finally include

the main module to your system's configuration [4].



``` nix

{

  inputs = rec {



    raspi-camera = { # [1]

      url = "github:sergei-mironov/nixos-raspi-camera";

      inputs.nixpkgs.follows = "nixpkgs"; # [2]

    };



    ...

  };

  outputs = { self, ... , raspi-camera } : { # [3]

    nixosConfigurations = {

      raspi = nixpkgs.lib.nixosSystem rec {

        system = "aarch64-linux";

        modules = [

          ...

          raspi-camera.nixosModules.raspi-camera # [4]

          ...

        ];

      };

    };

  }

}

```



Usage notes

-----------



### Detecting the camera



``` sh

$ cam -l

[0:01:07.881818018] [957]  INFO Camera camera_manager.cpp:316 libcamera v0.3.1

[0:01:07.988647665] [962]  INFO RPI vc4.cpp:447 Registered camera /base/soc/i2c0mux/i2c@1/ov5647@36 to Unicam device /dev/media4 and ISP device /dev/media0

Available cameras:

1: 'ov5647' (/base/soc/i2c0mux/i2c@1/ov5647@36)

```



### Making a snapshot



TODO



### Video streaming with rpicam-apps RTSP mode (works)



This is the preferred way which we encoded into the systemd streaming service.



Raspberry Pi:



```shell

rpicam-vid --width 320 --height 240 -t 0 --inline -o -  | cvlc stream:///dev/stdin --sout '#rtp{sdp=rtsp://:8554/stream1}' :demux=h264

```



Client:



``` shell

ffplay rtsp://10.0.0.80:8554/stream1 -vf "setpts=N/30" -fflags nobuffer -flags low_delay -framedrop

```



### Video streaming using the rpicam-apps TCP mode (works)



https://www.raspberrypi.com/documentation/computers/camera_software.html#tcp



Raspberry PI:



``` shell

$ rpicam-vid -t 0 --inline --listen -o tcp://0.0.0.0:5000

```



Client:



``` shell

$ vlc tcp/h264://10.0.0.80:5000

```



Downsides:



* Only one connection at a time

* Server crashes on disconnect



### Video streaming via the Gstreamer module shipped with libcamera (does not work)



* https://github.com/raspberrypi/libcamera?tab=readme-ov-file#using-gstreamer-plugin

* Same here https://www.raspberrypi.com/documentation/computers/camera_software.html#libcamerasrc-gstreamer-element



Raspi:



```sh

export LIBCAMERA_LOG_LEVELS=*:DEBUG



export GST_PLUGIN_SYSTEM_PATH_1_0=/nix/store/wlrmb5096gyi5xswy79kn6lpaj2b8p19-gstreamer-1.24.3/lib/gstreamer-1.0/



sudo gst-launch-1.0 libcamerasrc ! \

     video/x-raw,colorimetry=bt709,format=NV12,width=1280,height=720,framerate=30/1 ! \

     queue ! jpegenc ! multipartmux ! \

     tcpserversink host=0.0.0.0 port=5000

```



Client:



TODO



Problems

--------



### Where to find device tree overlay sources for the camera?



In contrast to [NixOS best

practices](https://wiki.nixos.org/wiki/NixOS_on_ARM/Raspberry_Pi#Device_trees), this repo includes a

[binary device tree overlay](https://github.com/raspberrypi/firmware/blob/master/boot/overlays/ov5647.dtbo)

from the Raspberry Pi firmware repo. Where can one find the sources of this overlay?



### Meson buildsystem does not detect boost on NixOS



A workaround in [raspi-camera.nix](./nix/raspi-camera.nix)



``` nix

env = {

  BOOST_INCLUDEDIR = "${lib.getDev boost}/include";

  BOOST_LIBRARYDIR = "${lib.getLib boost}/lib";

  # Also required in addition to the above fix.

  NIX_CFLAGS_COMPILE = "-I${lib.getDev boost}/include -L${lib.getDev boost}/lib";

};

```



Related reports:



* [Meson no longer able to pick up Boost](https://github.com/NixOS/nixpkgs/issues/86131#issuecomment-620155616)



### libcamera Gstreamer plugin reports timeout



Libcamera docs describe a

[neat way to run the streaming using Gstreamer](https://github.com/raspberrypi/libcamera?tab=readme-ov-file#using-gstreamer-plugin)

alone.



Sadly, we see the TIMEOUT failures, similar to what is described [in this raspi forum

thread](https://forums.raspberrypi.com/viewtopic.php?t=323609). Unfortunately, removing `arm64bit=1`

from the `/boot/config.txt` is not an option because NixOS only supports 64bit.



The workaround was to [switch](#video-streaming-using-the-rpicam-apps-tcp-mode-works) to

[rpicam-apps](https://github.com/raspberrypi/rpicam-apps).