https://github.com/cesiumcz/webcam-snapshot

Shell script-based routine that takes unique snapshots from live JPEG images published on the Web.
https://github.com/cesiumcz/webcam-snapshot

timelapse webcam-capture

Last synced: about 2 months ago
JSON representation

Shell script-based routine that takes unique snapshots from live JPEG images published on the Web.

• Host: GitHub
• URL: https://github.com/cesiumcz/webcam-snapshot
• Owner: cesiumcz
• License: bsd-3-clause
• Created: 2024-02-10T22:02:33.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2024-02-10T22:56:28.000Z (over 1 year ago)
• Last Synced: 2025-03-02T20:28:25.624Z (7 months ago)
• Topics: timelapse, webcam-capture
• Language: Shell
• Homepage:
• Size: 1.95 KB
• Stars: 0
• Watchers: 0
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# cesium webcam snapshot

Shell script-based routine that takes unique snapshots from live JPEG images published on the Web.

## Prerequisities

- Shell - `bash` or Korn shell `ksh` (OpenBSD's default shell)

- `curl`

## Installation

### System user

	useradd -c "Webcam routine" -b /var/webcam/ -d /var/webcam-snapshot/ -s /sbin/nologin _webcam

	install -d -m 770 -o root -g _webcam /var/webcam-snapshot/

### Clone & file copy

	cd /tmp/

	git clone https://github.com/cesiumcz/webcam-snapshot.git

Determine correct version `bash`/`ksh`:

	mv snap.(bash|ksh) snap.sh

Install the script and set correct permissions

	install -d -m 755 -o root -g _webcam /usr/local/webcam-snapshot/

	install -m 754 -o root -g _webcam snap.sh /usr/local/webcam-snapshot/

	rm -rf /tmp/webcam-snapshot/

### Configuration

#### Camera list

	vim /usr/local/webcam-snapshot/cameras.txt

For each webcam, insert a line according to the following syntax:

	cam_name jpg_uri

- *cam_name* = unique string camera name. Use short and simple names.

- *jpg_uri* = URI to JPEG image

A line starting with `#` is ignored.

Example contents of `cameras.txt`

	pec https://www.chmi.cz/files/portal/docs/meteo/kam/pecpodsnezkou.jpg

	jizerka https://www.chmi.cz/files/portal/docs/meteo/kam/jizerka.jpg

Set proper permissions (`cameras.txt` is likely to contain credentials)

	chown -R root:_webcam /usr/local/webcam-snapshot/

	chmod 660 /usr/local/webcam-snapshot/cameras.txt

### Cron

Invoke the script every minute between 6 to 18 hours:

	crontab -e -u _webcam

	* 6-18 * * * /usr/local/webcam-snapshot/snap.sh

## Testing

	su -l _webcam /usr/local/webcam-snapshot/snap.sh

Or alternative using `doas` command:

	doas -u _webcam /usr/local/webcam-snapshot/snap.sh

## Modus operandi

**`snap.sh`** does the following sequentially for each webcam:

- downloads current image into temporary location, if succeeds:

- checks if the new image differs from the last downloaded, if so:

- moves the second oldest image into final location

### Directory structure

	/tmp/webcam-snapshot/

	|-- cam1

	|   `-- 202401201023.jpg

	`-- cam2

	    `-- 202401201023.jpg

	/var/webcam-snapshot/

	|-- cam1

	|   |-- 202401201020.jpg

	|   `-- 202401201010.jpg

	`-- cam2

	    |-- 202401201020.jpg

	    `-- 202401201010.jpg

## Author

[Matyáš Vohralík](https://mv.cesium.cz), 2024

## License

[BSD 3-Clause](LICENSE)