CACAU - Camera Capture Annotate and Upload

This project provides a script to capture a picture from an IP webcam, annotate it with a timestamp and upload it to an FTP server. The script does also store a copy of each captured picture in subfolder capture, for the aim of a time lapse video.

In html/index.html you can find an example for html website that cyclically reloads the picture.

Camera

A chinese camera with the following "specification" is used:

"Manufacturer": "H264"
"Model": "XM530_R80X20-PQ_8M"
"FirmwareVersion": "V5.00.R02.00030695.10010.343106..ONVIF 2.41",

Capture

Snapshot

The above mentioned camera has a REST endpoint to capture a picture (sadly only in low resolution: 640x360). The following curl command executed on a linux command line, fetches the picture:

curl "http://<ip-of-cam>/webcapture.jpg?command=snap" -o snapshot.jpg

Audio-/Video-Stream

The camera provides a full HD audio-/video-stream at the following url (which can be played for example with vlc or ffplay):

rtsp://<ip-of-cam>:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp?real_stream

Note: With ffplay parameter -an audio playback can be disabled.

ffplay -an 'rtsp://192.168.178.52:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp?real_stream'

The stream can be used to capture a picture with 1920x1080. This is done with ffmpeg:

ffmpeg -f rtsp -rtsp_transport tcp -y -i "rtsp://<ip-of-cam>:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp?real_stream" -f image2 -vframes 1 -vsync 2 snapshot.jpg

Note: Using the following command, the current date is included in the filname of the captured picture:

ffmpeg -f rtsp -rtsp_transport tcp -y -i "rtsp://<ip-of-cam>:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp?real_stream" -f image2 -vframes 1 -vsync 2 "snapshot_$(date +%Y-%m-%d_%H-%M-%S).jpg"

Annotate

Annotation of the picture with current timestamp can be done directly at the time it is captured with ffmpeg, for example like this:

ffmpeg -f rtsp -rtsp_transport tcp -y -i "rtsp://<ip-of-cam>:554/user=admin_password=tlJwpbo6_channel=1_stream=0.sdp?real_stream" -f image2 -vframes 1 -vsync 2 -vf "drawtext=text='%{localtime\:%Y/%m/%d %H\\\\\:%M}':x=10:y=10:fontsize=24:fontcolor=white" "snapshot_hd.jpg"

Another solution is the usage of ImageMagick's convert:

convert snapshot.jpg -fill '#0008' -draw 'rectangle 0,0,250,40' -pointsize 30 -fill white -annotate +8+30 "$(date +%Y/%m/%d\ %H:%M)" snapshot_ts.jpg

Upload

The upload of the picture to an FTP server is done using curl:

curl --upload-file snapshot_ts.jpg ftp://<server-url>/<optional-subfolders>/<optional-filename> --user <ftp-user>:<ftp-password>

Time lapse video

In order to create - later on - a time lapse video from the captured pictures, they are moved to subfolder capture. Thereby a timestamp is added to the filename:

mv snapshot_ts.jpg "capture/snapshot_$(date +%Y-%m-%d_%H-%M-%S).jpg"

To create the video from the pictures in folder capture, ffmpeg is used:

ffmpeg -framerate 12 -pattern_type glob -i "snapshot_*.jpg" timelapse.mp4

Run script

One possibility to execute the script cyclically is as simple as the following snippet (see also run.sh):

#!/bin/bash
#Infinite loop, executed every 5 minutes. Hit CTRL+C to stop
for (( ; ; ))
do
   ./cacau.sh
   sleep 5m
done

Cronjob

Another option to execute the script cyclically is the use linux's cronjob. Therefore execute the following command to add a new job to the cron table:

crontab -e

For example add the following line to the table to execute the script every 5 minutes:

*/5 * * * * ~/cacau.sh

The following A more sophisticated example executes the script

from monday (1) to friday (5), from 17 to 23 o'clock, every 5 minutes.
and on saturday(6) .. sunday(0), from 13 to 23 o'clock, every 5

*/5 17-23 * * 1-5 ~/cacau.sh
*/5 13-23 * * 6,0 ~/cacau.sh

minlux / cacau