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guglhupf

guglhupf is an extensible, distributed camera feed processing platform powered by Raspberry Pis and a comprehensive stack of open source tools, libraries, and frameworks. It has been developed targetting the use case of dashcams but can also be customized to serve other camera-based scenarios such as home security.
The platform consists of one controller acting as a central hub and multiple agents, each serving a camera video feed.

Controller

The controller hosts the main components of the platform:

• the guglhupf Python backend based on FastApi
• the zuckerguss frontend based on React
• the nginx reverse proxy to serve as entry point
• the nfs-managed storage for video recordings and gps location sharing
• the gps-sync command and cronjob to continously update location data from gpsd
• the guglhupf-sync command and cronjob to upload recordings to Google Drive using drive

Controller Setup Guides

Setting up nginx as reverse proxy

1. Install nginx using dietpi-software.

2. Create a guglhupf.conf nginx config file.

   sudo nano /etc/nginx/conf.d/guglhupf.conf`

   The content of guglhupf.conf can be found in the resources folder.

3. Disable the default nginx config.

   sudo unlink /etc/nginx/sites-enabled/default

4. Restart the nginx service.

   sudo systemctl restart nginx.service

Agents

The Camera Agents use the Video4Linux V4L2 API to process the video feed from the Raspberry Pi Camera Module.

Agent Setup Guides

Preparing a Raspberry Pi as Camera Agent

These steps have been verified using a Raspberry Pi 3 Model B+ but should be the same on newer models like the Raspberry Pi 4 Model B. This tutorial is based on DietPi, but the steps should be similar on Raspberry Pi OS and other Raspberry Pi OS-based systems. Your Raspberry Pi should have the Camera Module connected.

1. Follow the DietPi instructions to download the latest DietPi release and flash it to an SD card with balenaEtcher.

   Stop after step "2. Flash the DietPi image" since we will prepare a headless install and need to change some files before the first boot.

2. Reinsert/mount the SD card (typically called boot) once more after balenaEtcher is finished.

3. Open boot/dietpi.txt in your favorite editor/IDE and update the settings for a headless boot.

   An example dietpi.txt can be found in the resources folder.
   Some of your settings might differ (e.g., regional settings)

   Overview of changed values:

   -AUTO_SETUP_ACCEPT_LICENSE=0
   +AUTO_SETUP_ACCEPT_LICENSE=1
   
   -AUTO_SETUP_LOCALE=C.UTF-8
   +AUTO_SETUP_LOCALE=en_US.UTF-8
   
   -AUTO_SETUP_KEYBOARD_LAYOUT=gb
   +AUTO_SETUP_KEYBOARD_LAYOUT=us
   
   -AUTO_SETUP_TIMEZONE=Europe/London
   +AUTO_SETUP_TIMEZONE=America/Los_Angeles
   
   -AUTO_SETUP_NET_WIFI_ENABLED=0
   +AUTO_SETUP_NET_WIFI_ENABLED=1
   
   -AUTO_SETUP_NET_WIFI_COUNTRY_CODE=GB
   +AUTO_SETUP_NET_WIFI_COUNTRY_CODE=US
   
   -AUTO_SETUP_NET_HOSTNAME=DietPi
   +AUTO_SETUP_NET_HOSTNAME=<custom hostname>
   
   -AUTO_SETUP_HEADLESS=0
   +AUTO_SETUP_HEADLESS=1
   
   -AUTO_SETUP_AUTOSTART_TARGET_INDEX=0
   +AUTO_SETUP_AUTOSTART_TARGET_INDEX=7
   
   -AUTO_SETUP_AUTOMATED=0
   +AUTO_SETUP_AUTOMATED=1
   
   -AUTO_SETUP_GLOBAL_PASSWORD=dietpi
   +AUTO_SETUP_GLOBAL_PASSWORD=<custom password>
   
   -#AUTO_SETUP_INSTALL_SOFTWARE_ID=23
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=0   #OpenSSH Client
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=7   #FFmpeg
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=16  #Build-Essentials
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=17  #Git
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=103 #DietPi-RAMlog
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=104 #Dropbear
   +AUTO_SETUP_INSTALL_SOFTWARE_ID=110 #NFS Client
   
   -SURVEY_OPTED_IN=-1
   +SURVEY_OPTED_IN=0
   
   -CONFIG_BOOT_WAIT_FOR_NETWORK=1
   +CONFIG_BOOT_WAIT_FOR_NETWORK=2

   Next, update boot/dietpi-wifi.txt by setting aWIFI_SSID[0] to your WiFi SSID and aWIFI_KEY[0] to your WiFi password.

4. Unmount the SD card, insert it into the Raspberry Pi, and power it on.

   It might take a moment to fully boot up and allow an SSH session since it will install all listed software on the first boot.

5. Check your WiFi router for connected devices to retrieve the IP of the Raspberry Pi.

6. Open an SSH session to the Raspberry Pi: ssh root@<rpi-ip>

   All upcoming steps are executed on the Raspberry Pi.
   You can also use ssh-copy-id to install your public SSH key as an authorized key on the Raspberry Pi to avoid typing your password for new SSH sessions.

   ssh-copy-id root@<rpi-ip>
   ssh-copy-id dietpi@<rpi-ip>

7. Run dietpi-config to enable the camera and adjust the GPU memory.

   Under 1 : Display Options, turn on 8 : RPi Camera and adjust the 2 : GPU/RAM Memory Split, e.g. to 256 : General Gaming.

8. Mount the NFS directory of the guglhupf controller to using dietpi-drive_manager.

   Select Add network drive, then NFS, enter the guglhupf controller IP, and give it a unique folder name (e.g., recordings).

9. Follow the other steps below to set up...

   • the open-source bcm2835-v4l2 camera driver
   • the camera utils v4l-utils for controlling rotation and resolution
   • a loopback device using v4l2loopback to mirror dev/video0 for multi-client access
   • a mirror from dev/video0 to dev/video1 using FFmpeg
   • a live video stream with webrtc-streamer
   • a recording service with FFmpeg

Set up bcm2835-v4l2 camera driver

1. Add bcm2835-v4l2 to /etc/modules-load.d/ (kernel modules to load at boot time).

   sudo nano /etc/modules-load.d/bcm2835-v4l2.conf:

   bcm2835-v4l2
   

2. Reboot and check that /dev/video0 exists.

Install v4l-utils and set up camera automatically with v4l2-ctl

1. Install v4l-utils for debugging & control commands.

   sudo apt install -y v4l-utils

   Example command "rotatation of camera":

   v4l2-ctl --set-ctrl=rotate=90

   Example command "list video devices":

   v4l2-ctl --list-devices

   Example command "list video device details":

   v4l2-ctl --device=/dev/video0 --all

2. Add v4l2-ctl command to system boot via udev subsystem.

   sudo nano /etc/udev/rules.d/99-local-webcam.rules:

   SUBSYSTEM=="video4linux", PROGRAM="/usr/bin/v4l2-ctl --set-fmt-video=width=640,height=480 --set-ctrl=rotate=90"
   

   Adjust the settings according to your needs (e.g., camera mounting rotation).

3. Reboot and check updated settings with v4l2-ctl --device=/dev/video0 --all.

Install and set up v4l2loopback for dev/video1 loopback device

1. Install v4l2loopback.

   sudo apt install -y linux-headers v4l2loopback-dkms v4l2loopback-utils

2. Add v4l2loopback to /etc/modules-load.d/ (kernel modules to load at boot time).

   sudo nano /etc/modules-load.d/v4l2loopback.conf:

   v4l2loopback
   

3. Set parameters for v4l2loopback by creating a config file:

   Parameters for v4l2loopback

   sudo nano /etc/modprobe.d/v4l2loopback.conf:

   options v4l2loopback devices=1
   options v4l2loopback card_label="front"
   

   Adjust the label to your preference. For guglhupf, there are two Raspberry Pis acting as Camera Agents with the camera labels front and back.

4. Reboot and check that /dev/video1 exists.

Set up FFmpeg to mirror /dev/video0 to /dev/video1

Based on this StackOverflow answer.

1. Add video devices to systemd via udev subsystem.

   sudo nano /lib/udev/rules.d/99-systemd.rules, before LABEL="systemd_end":

   # Systemd events for video devices
   KERNEL=="video0", SYMLINK="video0", TAG+="systemd"
   KERNEL=="video1", SYMLINK="video1", TAG+="systemd"
   

2. Reboot to activate new udev rules.

3. Register video-mirror service with systemd.

   sudo nano /lib/systemd/system/video-mirror.service:

   [Unit]
   Description=Mirror /dev/video0 to /dev/video1 with FFmpeg
   BindsTo=dev-video0.device dev-video1.device
   After=dev-video0.device dev-video1.device
   
   [Service]
   Type=simple
   ExecStart=ffmpeg -f v4l2 -i /dev/video0 -codec copy -f v4l2 /dev/video1
   Restart=always
   RestartSec=1
   StartLimitInterval=0
   
   [Install]
   WantedBy=multi-user.target

4. Enable and start video-mirror service in systemd.

   sudo systemctl daemon-reload
   sudo systemctl enable video-mirror.service
   sudo systemctl start video-mirror.service

Install and set up WebRTC-streamer for live stream of camera feed

1. Retrieve the latest armv7l-Release.

   cd /tmp
   wget https://github.com/mpromonet/webrtc-streamer/releases/download/v0.6.3/webrtc-streamer-v0.6.3-Linux-armv7l-Release.tar.gz
   tar -zxf webrtc-streamer-v0.6.3-Linux-armv7l-Release.tar.gz

2. Move webrtc-streamer binary.

   cd /tmp/webrtc-streamer-v0.6.3-Linux-armv7l-Release
   sudo mv ./webrtc-streamer /usr/local/bin/webrtc-streamer

3. Verify availability of webrtc-streamer command.

   webrtc-streamer --help

4. Register webrtc-streamer service with systemd.

   sudo nano /lib/systemd/system/webrtc-streamer.service:

   [Unit]
   Description=WebRTC-streamer
   After=video-mirror.service
   
   [Service]
   Type=simple
   ExecStart=webrtc-streamer
   Restart=always
   RestartSec=1
   StartLimitInterval=0
   
   [Install]
   WantedBy=multi-user.target

5. Enable and start webrtc-streamer service in systemd.

   sudo systemctl daemon-reload
   sudo systemctl enable webrtc-streamer.service
   sudo systemctl start webrtc-streamer.service

6. Validate WebRTC stream using a simple HTML page

Set up FFmpeg to record camera feed in segments to file

1. Add monospaced SourceCodePro font.

   cd /tmp
   wget https://fonts.google.com/download?family=Source%20Code%20Pro -O SourceCodePro.zip
   unzip SourceCodePro.zip -d /tmp/SourceCodePro
   sudo mv /tmp/SourceCodePro /usr/share/fonts/truetype/

2. Add new video-recording command (bash script wrapping ffmpeg with parameters).

   sudo nano /usr/local/bin/video-recording:

   #!/bin/bash
   
   ffmpeg \
   -f v4l2 \
   -video_size 640x480 \
   -i /dev/video1 \
   -map 0 \
   -segment_time 300 \
   -g 30 \
   -sc_threshold 0 \
   -force_key_frames "expr:gte(t,n_forced*300)" \
   -f segment \
   -reset_timestamps 1 \
   -strftime 1 \
   -vf "[in]\
   drawtext=\
   fontfile=/usr/share/fonts/truetype/SourceCodePro/SourceCodePro-Regular.ttf: \
   textfile=/mnt/recordings/gps.txt: \
   reload=1: \
   x=10: \
   y=h-text_h-10: \
   fontsize=15: \
   fontcolor=black: \
   box=1: \
   boxcolor=white@0.5: \
   boxborderw=5,\
   drawtext=\
   fontfile=/usr/share/fonts/truetype/SourceCodePro/SourceCodePro-Regular.ttf: \
   text='%{localtime}': \
   x=w-text_w-10: \
   y=h-text_h-10: \
   fontsize=15: \
   fontcolor=black: \
   box=1: \
   boxcolor=white@0.5: \
   boxborderw=5
   [out]" \
   -c:v h264_omx \
   -pix_fmt yuv420p \
   /mnt/recordings/guglhupf/video_front_%Y-%m-%d_%H-%M-%S.mp4

   A lot is going on here, and you might have to adjust a couple of settings (e.g., the filename template string).
   FFmpeg reads from /dev/video1 in a fixed resolution of 640x480. It writes segments of the video feed to disk. Each segment is 5min (300sec), with keyframes enforced at the same time mark to allow a smooth cutover. It uses two drawtext filters: one to add GPS coordinates from a file (gps.txt) to the lower-left corner and one to add timestamps to the lower-right corner of every frame. It uses the hardware-accelerated h264_omx codec and writes the output files to the configured NFS folder /mnt/recordings with timestamps in the file name.

3. Give execution rights to the new video-recording command:

   sudo chmod +x /usr/local/bin/video-recording

4. Test video-recording command:

   video-recording

5. Register video-recording service with systemd.

   sudo nano /lib/systemd/system/video-recording.service:

   [Unit]
   Description=Video Recording with FFmpeg
   After=video-mirror.service
   
   [Service]
   Type=simple
   ExecStart=video-recording
   Restart=always
   RestartSec=1
   StartLimitInterval=0
   
   [Install]
   WantedBy=multi-user.target

6. Enable and start video-recording service in systemd.

   sudo systemctl daemon-reload
   sudo systemctl enable video-recording.service
   sudo systemctl start video-recording.service

7. Use htop to verify that video-recording is running. You can also check the configured output folder, which should contain .mp4 files now.