Webcams: Difference between revisions
(how the webcam works (adapted from a syscom email in April)) |
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== Operation == |
== Operation == |
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We use [http://www.lavrsen.dk/twiki/bin/view/Motion/WebHome Motion] to serve this webcam feed. It uses video4linux to read from the webcam, and pushes frames to the client (who maintains an HTTP connection). Frames are pushed when a certain amount of motion has detected, or a set maximum amount of time has passed since the last frame. One of these runs on each of our webcam hosts ([[Machine_List#maltodextrin|maltodextrin]] and [[Machine_List#bit-shifter|bit-shifter]], though the latter isn't working most of the time). Motion includes a builtin tiny HTTP server (running on port 8081 in our case) which serves a sequence of JPEG images to the browser. An ordinary <img> tag is embedded in the web page, and browsers will update the image when they receive a new one over the HTTP connection. |
We use [http://www.lavrsen.dk/twiki/bin/view/Motion/WebHome Motion] to serve this webcam feed. It uses video4linux to read from the webcam, and pushes frames to the client (who maintains an HTTP connection). Frames are pushed when a certain amount of motion has detected, or a set maximum amount of time has passed since the last frame. One of these runs on each of our webcam hosts ([[Machine_List#maltodextrin|maltodextrin]] and [[Machine_List#bit-shifter|bit-shifter]], though the latter isn't working most of the time). Motion includes a builtin tiny HTTP server (running on port 8081 in our case) which serves a sequence of JPEG images to the browser. An ordinary <tt><img></tt> tag is embedded in the web page, and browsers will update the image when they receive a new one over the HTTP connection. |
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The Motion documentation is fairly self-explanatory, but here are the options we use for the webcam server part: |
The Motion documentation is fairly self-explanatory, but here are the options we use for the webcam server part: |
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Revision as of 15:48, 22 May 2010
A live webcam feed of the office is available online.
Operation
We use Motion to serve this webcam feed. It uses video4linux to read from the webcam, and pushes frames to the client (who maintains an HTTP connection). Frames are pushed when a certain amount of motion has detected, or a set maximum amount of time has passed since the last frame. One of these runs on each of our webcam hosts (maltodextrin and bit-shifter, though the latter isn't working most of the time). Motion includes a builtin tiny HTTP server (running on port 8081 in our case) which serves a sequence of JPEG images to the browser. An ordinary <img> tag is embedded in the web page, and browsers will update the image when they receive a new one over the HTTP connection.
The Motion documentation is fairly self-explanatory, but here are the options we use for the webcam server part:
webcam_port 8081 webcam_quality 30 webcam_motion on webcam_maxrate 5 webcam_localhost off webcam_limit 1000
Hardware
Logitech QuickCam Messenger
- USB IDs: 046d:08da
- Kernel module: gspca (gspca-source)
- Max resolution: 640x480
Logitech QuickCam Zoom
- USB IDs: 046d:08b3
- Kernel module: pwc
- Max resolution: 640x480
Logitech QuickCam Web
- USB IDs: 046d:0850
- Kernel module: quickcam (qc-usb-source package)
- Max resolution: 480x360
Logitech QuickCam Chat
- USB IDs: 046d:092c
- Kernel module: gspca (gspca-source)
- Max resolution: 480x360