hello-websocket
Webcam over websocket in Python using OpenCV and Tornado.
How it works
A recorder process continuously reads images from a webcam. Upon every capture, it writes the image to a Redis key-value store.
A separate server process (running Tornado) handles websocket requests sent by a client (web browser). Upon receiving a request, it retrieves the latest image from the Redis database and sends it to the client over the established websocket connection.
The client web page is dead simple:
It sends an initial request on a websocket.
When image data arrives, it assigns it to src attribute of the
<img> tag, then simply sends the next request. That's it!
Installation
The code uses Python in a virtualenv. Since OpenCV is not officially in the Python Package Index, we manually copy the system OpenCV library into the virtualenv.
First, install OpenCV for Python system-wide:
apt-get install python-opencv
Also install Redis server:
apt-get install redis-server
Build the virtual environment with all needed modules:
make
Usage
Two separate programs need to be running: 1) the recorder which captures and writes to Redis database, and 2) the server which reads the current image from the database and serves to requesting WebSocket clients.
Run the recorder:
make recorder
Now (in a different shell) run the server:
make server
Go to http://localhost:9000 to view the webcam.