Webcam Library and Tools

Introduction

The webcam-tools package contains the following two components:

libwebcam Webcam Library
uvcdynctrl Manage dynamic controls in uvcvideo

This README file contains information that is common to all of the above components. For component specific information please refer to the README files in the libwebcam/ and uvcdynctrl/ subdirectories.

Versions

Note that the latest versions of the Webcam Library, its API documentation, and the tools can always be found at the following address:

http://sourceforge.net/p/libwebcam

Dependencies

The Webcam Tools have the following external dependencies:

kernel headers (linux/videodev2.h and linux/uvcvideo.h)
LibXML 2 development files (usually from the libxml2-dev package)
gengetopt (optional)

gengetopt (optional):

The uvcdynctrl directory ships with the two files cmdline.[ch]. As long as those are present, gnugetopt is not required. If they are missing, the build process will try to create them with the help of gnugetopt.

V4L2 2.6.32 (optional):

To take advantage of the raw/string control support version 2.6.32 of V4L2 is required. To be more specific: V4L2_CTRL_TYPE_STRING needs to be supported. Whether this is the case is determined at build time and if string control support is not present in your version of V4L2 the corresponding feature in libwebcam is disabled. During the build process one of the following messages is displayed indicating the result of the test:

** Your V4L2 has V4L2_CTRL_TYPE_STRING support. Enabling raw control support. ** Your V4L2 does not have V4L2_CTRL_TYPE_STRING support. Compiling without raw control support.

Note that the uvcvideo version that comes with 2.6.32 does not yet support string controls. At the time of this writing support for it is being added to the UVC driver, so future versions should support it, therefore allowing V4L2 control values to be more than 4 bytes long.

Building

The build system is based on CMake. Because of the way CMake works, Makefiles do not ship with libwebcam, so you have to have CMake installed. Don't worry, though, you are likely to have much fewer illegible error messages than with the previous GNU Automake.

Once you have CMake installed you can build and install it by running the following commands in the webcam-tools top level source directory:

mkdir build cd build cmake .. make make install (as root)

You need at least CMake 2.6, so if you are running Ubuntu 8.04 you need to enable the hardy-backports repository in /etc/apt/sources.list and update the 'cmake' package.

CMake defaults to installing binaries and libraries to /usr/local. To use a different install prefix, you can add a command line parameter to 'cmake' like this:

cmake .. -DCMAKE_INSTALL_PREFIX=/usr

If you prefer to leave the prefix alone, you should make sure that /usr/local/bin is in your path and LD_LIBRARY_PATH contains the /usr/local/lib directory.

Questions and feedback

Please feel free to post your questions and comments at the sourceforge project page: