USB Webcam on the Raspberry Pi

I wanted to use a USB webcam to mount on the robot, and drive it using the RPi. Turns out it is pretty simple to not only drive a USB webcam, but to also stream a MJPEG video feed over a port. After plugging the webcam in, we can check to see if the device is detected:

I run Arch on my RPi, which means installing things is super easy. Someone wrote up some software to do this streaming called mjpg-streamer.

$ sudo pacman -S mjpg-streamer

Once this installs the software is relatively simple to run. The options are defined as follows:

-d - USB Webcam (or video device)
-r - Resolution
-f - Frame Rate
-p - Port Number
-w -Web directory

An example of running the software:

$ mjpg_streamer -i "/usr/lib/input_uvc.so -d /dev/video0  -r 640x480 -f 28" -o "/usr/lib/output_http.so -p 8090 -w /var/www/mjpg_streamer"

This will send the stream over port 8090. Which can be accessed via URL through the following link (where alarmpi is the IP of the raspberry pi).

http://alarmpi:8090/?action=stream

This works with browsers which can read mjpg streams. If you happen have a web-controlled servo and some tape, you can embed the stream in the website and have a rotatable webcam.