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Quickstart

$ ./configure
$ make

Optional (you can try camsource without installing it): # make install

Take a look at the included sample config file (camsource.conf.example). It should be somewhat usable for experimental uses (although the hardware section <camdev> may need tweaking), but you should change it to suit your needs if you plan to use camsource. Put the config file in a place where camsource can find it (such as .camsource in your home dir, or /usr/local/etc/camsource.conf). The start camsource:

$ camsource

Or, if you didn't install it:

$ src/camsource

If camsource starts up without errors, it will go into background automatically. Note that any errors from the grabbing thread show up after the logfile has been started, so you should check the logfile for any errors (by default .camsource.log in your home dir). If everything worked right and camsource shows up in your process list (multiple time as it's multithreaded), feel free to try it out. With the default config, point your browser to <http://localhost:9192/> to see a 320x240 snapshot. The "/large" path gives you an unresized snapshot. If the images appear mirrored, edit your config and disable the "flip" module (it's enabled by default to mirror all images).

With the default config, you have multiple options for getting an animated webcam display:

http://host:9192/
http://host:9192/large
Using a javascript html page, you can continually reload these images to get an animation. The "camserv" software includes such a javascript snippet (javascript.txt), see <http://cserv.sourceforge.net/>.

http://host:9192/multipart
http://host:9192/multipart-large
These urls produce a multipart jpeg stream at a given fps. Netscape and mozilla can display and animate those without plugin (even though you may need to embed the url as image into a html page). This jpeg stream is compatible to what "camserv" produces (see above for url). To support multipart jpegs on other browsers such as ie, a java applet is required. Cambozola does an excellent job at this. See <http://www.charliemouse.com/code/cambozola/index.html>.

http://host:8888/
http://host:8889/
These are pseudo-urls and not accessible through a browser. They produce an output compatible to "webcam_server," and the java applet included with webcam_server can be use to access these urls and animate the images. Note that even though webcam_server allows you to get a snapshot image when you point a browser at its url, the camsource module doesn't do this; point your browser at one of the other urls above instead. You can find webcam_server and the java applet at <http://donn.dyndns.org/portalofnnod/webcam_server.html>.

http://host:9192/largequal
This is the unresized grabbed frame with a high jpeg compression quality (80). It is about twice the size of the default "/large" image. Use for your personal viewing pleasure or something.

Details (What is Camsource anyway?)

Camsource opens a video4linux device, grabs frames from it and does various things with those frames. What it does with them depends solely on the config file, which is in xml format.

Camsource uses plugins (also called modules) to provide functionality. The plugin configuration happens through the xml config file. The core camsource program, as well as the plugins, are heavily multithreaded, to make sure different plugins don't interfere with each other, and with the grabbing process.

Currently included plugins are:

wc_serv
Produces output compatible with webcam_server. You can use its java applet to view the images.

http
Generic http module, designed to answer requests by web browsers. It lets you define several virtual paths, each with distinct properties. Currently it is able to produce a single still image, as well as an animage multipart jpeg stream at a given framerate, usable on netscape/mozilla browsers or using a java applet such as Cambozola. Note that the paths you define can also include a query string such as "/image.jpg?large"; the requested url will always be matched exactly to the letter.

filewrite
Periodically saves a snapshot image to a local jpeg file. 'Nuff said.

ftpup
Works similar to the filewrite module, only that it uploads the snapshot to an ftp server instead of writing it out locally.

jpeg_comp
This plugin doesn't do anything by itself, but provides jpeg compression functionality for various other modules. It will be auto-loaded as dependency, but you can give a default jpeg compression quality level for this module in the config file.

flip (filter)
Lets you flip an image horizontally or vertically before doing anything else with it. Useful for cameras which produce mirrored images (such as my creative webcam 5).

resize (filter)
Lets you scale an image to a specific size. Actually it doesn't "scale" much, it just does nearest-neighbor matching (read: bad quality). The filter lets you specify the target image size as a fixed width/height value pair, or as a percentage of the original image.

text (filter)
This filter can add a text overlay containing a timestamp to an image. It has some special functionality with regards to the config file, which allow it to have a global config, and then override certain options in the per-module filter definition. See the example config file for details.
The text to display can be set in the config file, or it can be read on demand from a file or from a command's stdout (pipe).

rgbbgr (filter)
Swaps the red and blue information. Activate it in case your camera produces images with this reversed.

rotate (filter)
This filter can rotate the image left or right by 90 degrees (or in other words, by 90 or 270 degrees). Rotating by 180 degrees is not supported, as the same result can be achieved by "flip"ping the image both horizontally and vertically. Keep in mind that after rotating, the image's width and height values will be swapped, so when you intend to use the rotate filter frequently together with the resize module, you should probably specify the final image size as a percentage (scale) instead of a fixed height/width pair.

bw (filter)
Converts a color image into artistic grayscale / black & white.

The config file should be pretty self explanatory. Every possible feature is present in the default config. Filters can be applied globally (that is, to every grabbed frame), or on a per-module basis. Note that the module is responsible for calling the filters, this doesn't happen automatically. In the case of the http module, filters can be applied to every frame handled by the http module, as well as on a per-vpath basis.

Camsource looks in several places for its config file. First it looks for it as ".camsource" in your home dir, then checks for a camsource.conf file in /etc, /usr/local/etc and in the local dir. It also looks for a "camsource" file in /etc/defaults and /usr/local/etc/defaults. You can also specify a custom config file to use on the command line.

The command line switch "-c" has been created to dump the video4linux video capability information to console, then exit. Use this if you're unsure about which frame sizes your camera supports. Optionally you can specify another device file to open and query (defaults to /dev/video0).

Links

Homepage: http://camsource.sf.net/

$Id: README,v 1.14 2002/10/02 16:43:09 dfx Exp $