This project was developed with Lazarus-0.9.31 and FPC-2.4.2
It should be possible to also build it with the stable release of Lazarus-0.9.30, it does not use any things that are specific to the very latest SVN release, at least not to my knowledge and not intentionally.
To build it from source open the project file linuxastrocam.lpi with Lazarus and from the menu select Run -> Build. This should give you the excutable binary.
I have tested it only on i386, the program makes a few hardcoded assumptions about how GTK2 stores raw bitmaps and this might lead to unexpected results on 64 bit machines or if you have a different endianness. Please leave me a message (or provide a patch if you can) if you encounter such portbility problems. Since I could not test it myself anyways I did not even try to write code for different architectures.
V4l2 will be accessed through libv4l1 (using the v4l1 potocol). This should work even if there is no v4l1 support in the kernel aymore, but I could not test this because I am still using a v4l1 camera and an old kernel. Eventually I might port it to V4l2 some day using the v4l2 component from the 5dpo project.
This program is only a dirty hack to make some things easier for me, don't expect me to add every feature you might suggest. The main reason why I uploaded this on github was to document for other Pascal programmers how to access v4l1 devices and how I managed to create FITS files.